From feffb5f030b527922f9971043e7fc6c2de330374 Mon Sep 17 00:00:00 2001
From: Deukhoofd <Deukhoofd@gmail.com>
Date: Sat, 15 Apr 2023 14:34:42 +0200
Subject: [PATCH] Support for new error handling.

---
 Cargo.toml                                    |  2 +
 src/dynamic_data/flow/choice_queue.rs         | 90 ++++++++++---------
 src/dynamic_data/flow/target_resolver.rs      | 35 ++++----
 src/dynamic_data/flow/turn_runner.rs          | 52 +++++++----
 src/dynamic_data/libraries/damage_library.rs  | 34 ++++---
 src/dynamic_data/libraries/dynamic_library.rs | 15 ++--
 src/dynamic_data/libraries/script_resolver.rs | 11 +--
 src/dynamic_data/models/battle.rs             | 79 +++++++++-------
 src/dynamic_data/models/battle_random.rs      | 38 +++++---
 src/dynamic_data/models/battle_side.rs        |  9 +-
 src/dynamic_data/models/executing_move.rs     | 12 +--
 src/dynamic_data/models/pokemon.rs            | 30 ++++---
 src/dynamic_data/models/pokemon_builder.rs    |  7 +-
 .../script_handling/script_set.rs             |  7 +-
 .../script_handling/volatile_scripts_owner.rs |  9 +-
 src/ffi/dynamic_data/models/battle.rs         | 18 ++--
 src/ffi/dynamic_data/models/pokemon.rs        | 17 ++--
 src/ffi/mod.rs                                | 64 +++++++++++++
 src/ffi/static_data/growth_rate.rs            |  9 +-
 .../libraries/growth_rate_library.rs          |  5 +-
 .../static_data/libraries/library_settings.rs | 14 ++-
 src/lib.rs                                    | 42 +--------
 .../export_registry/dynamic_data/battle.rs    |  2 +-
 .../dynamic_data/battle_random.rs             |  6 +-
 .../dynamic_data/choice_queue.rs              |  2 +-
 .../export_registry/dynamic_data/pokemon.rs   |  2 +-
 src/script_implementations/wasm/mod.rs        |  3 +
 .../wasm/script_resolver.rs                   | 26 +++---
 src/static_data/growth_rates.rs               | 13 +--
 .../libraries/growth_rate_library.rs          | 11 +--
 src/static_data/libraries/library_settings.rs | 12 +--
 src/static_data/libraries/nature_library.rs   | 14 +++
 src/static_data/libraries/static_data.rs      |  2 +-
 tests/common/library_loader.rs                |  2 +-
 tests/common/test_case.rs                     |  2 +-
 tests/integration.rs                          | 44 ++++++++-
 36 files changed, 466 insertions(+), 274 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index d4e3d48..19f310b 100755
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -58,6 +58,8 @@ uuid = "1.2.2"
 paste = { version = "1.0.8" }
 arcstr = { version = "1.1.4", features = ["std"] }
 enum-display-derive = "0.1.1"
+anyhow = "1.0.69"
+anyhow_ext = "0.2.1"
 
 [dev-dependencies]
 csv = "1.1.6"
diff --git a/src/dynamic_data/flow/choice_queue.rs b/src/dynamic_data/flow/choice_queue.rs
index a15f749..90d1b4a 100755
--- a/src/dynamic_data/flow/choice_queue.rs
+++ b/src/dynamic_data/flow/choice_queue.rs
@@ -2,6 +2,8 @@ use crate::dynamic_data::choices::TurnChoice;
 use crate::dynamic_data::script_handling::ScriptSource;
 use crate::dynamic_data::Pokemon;
 use crate::{script_hook, ValueIdentifiable, ValueIdentifier};
+use anyhow::Result;
+use anyhow_ext::anyhow;
 use parking_lot::lock_api::MappedRwLockReadGuard;
 use parking_lot::{RawRwLock, RwLock, RwLockReadGuard};
 
@@ -48,12 +50,16 @@ impl ChoiceQueue {
     }
 
     /// This reads what the next choice to execute will be, without modifying state.
-    pub fn peek(&self) -> Option<MappedRwLockReadGuard<'_, RawRwLock, TurnChoice>> {
+    pub fn peek(&self) -> Result<Option<MappedRwLockReadGuard<'_, RawRwLock, TurnChoice>>> {
         let read_lock = self.queue.read();
         if self.current >= read_lock.len() {
-            None
+            Ok(None)
         } else {
-            Some(RwLockReadGuard::map(read_lock, |a| a[self.current].as_ref().unwrap()))
+            let v = RwLockReadGuard::try_map(read_lock, |a| a[self.current].as_ref());
+            match v {
+                Ok(v) => Ok(Some(v)),
+                Err(_) => Err(anyhow!("Could not map choice")),
+            }
         }
     }
 
@@ -81,7 +87,7 @@ impl ChoiceQueue {
     }
 
     /// This moves the choice of a specific Pokemon up to the next choice to be executed.
-    pub fn move_pokemon_choice_next(&self, pokemon: &Pokemon) -> bool {
+    pub fn move_pokemon_choice_next(&self, pokemon: &Pokemon) -> Result<bool> {
         let mut queue_lock = self.queue.write();
         let mut desired_index = None;
         // Find the index for the choice we want to move up.
@@ -93,26 +99,29 @@ impl ChoiceQueue {
                 }
             }
         }
-        // If we couldn't find a choice, we can't execute, return.
-        if desired_index.is_none() {
-            return false;
-        }
-        let desired_index = desired_index.unwrap();
-        // If the choice we want to move up is already the next choice, just return.
-        if desired_index == self.current {
-            return true;
-        }
+        let result = match desired_index {
+            Some(desired_index) => {
+                // If the choice we want to move up is already the next choice, just return.
+                if desired_index == self.current {
+                    return Ok(true);
+                }
 
-        // Take the choice we want to move forward out of it's place.
-        let choice = queue_lock[desired_index].take().unwrap();
-        // Iterate backwards from the spot before the choice we want to move up, push them all back
-        // by 1 spot.
-        for index in (self.current..desired_index).rev() {
-            queue_lock.swap(index, index + 1);
-        }
-        // Place the choice that needs to be next in the next to be executed position.
-        let _ = queue_lock[self.current].insert(choice);
-        true
+                // Take the choice we want to move forward out of it's place.
+                let choice = queue_lock[desired_index]
+                    .take()
+                    .ok_or(anyhow!("Choice was already taken"))?;
+                // Iterate backwards from the spot before the choice we want to move up, push them all back
+                // by 1 spot.
+                for index in (self.current..desired_index).rev() {
+                    queue_lock.swap(index, index + 1);
+                }
+                // Place the choice that needs to be next in the next to be executed position.
+                let _ = queue_lock[self.current].insert(choice);
+                true
+            }
+            None => false,
+        };
+        Ok(result)
     }
 
     /// Internal helper function to be easily able to iterate over the yet to be executed choices.
@@ -140,7 +149,7 @@ mod tests {
     fn create_empty_queue() {
         let queue = ChoiceQueue::new(Vec::new());
         assert!(!queue.has_next());
-        assert!(queue.peek().is_none());
+        assert!(queue.peek().unwrap().is_none());
     }
 
     #[test]
@@ -168,6 +177,7 @@ mod tests {
             0,
             &"test_nature".into(),
         )
+        .unwrap()
     }
 
     #[test]
@@ -176,8 +186,8 @@ mod tests {
 
         let queue = ChoiceQueue::new(vec![Some(TurnChoice::Pass(PassChoice::new(user)))]);
         assert!(queue.has_next());
-        assert!(queue.peek().is_some());
-        assert_eq!(7, queue.peek().unwrap().speed());
+        assert!(queue.peek().unwrap().is_some());
+        assert_eq!(7, queue.peek().unwrap().unwrap().speed());
     }
 
     #[test]
@@ -188,7 +198,7 @@ mod tests {
         assert!(queue.has_next());
         assert_eq!(7, queue.dequeue().unwrap().speed());
         assert!(!queue.has_next());
-        assert!(queue.peek().is_none());
+        assert!(queue.peek().unwrap().is_none());
     }
 
     #[test]
@@ -201,8 +211,8 @@ mod tests {
             Some(TurnChoice::Pass(PassChoice::new(user2))),
         ]);
         assert!(queue.has_next());
-        assert!(queue.peek().is_some());
-        assert_eq!(7, queue.peek().unwrap().speed());
+        assert!(queue.peek().unwrap().is_some());
+        assert_eq!(7, queue.peek().unwrap().unwrap().speed());
     }
 
     #[test]
@@ -247,12 +257,12 @@ mod tests {
         user2.change_level_by(60);
         assert_eq!(
             user1.value_identifier(),
-            queue.peek().unwrap().user().value_identifier()
+            queue.peek().unwrap().unwrap().user().value_identifier()
         );
         queue.resort();
         assert_eq!(
             user2.value_identifier(),
-            queue.peek().unwrap().user().value_identifier()
+            queue.peek().unwrap().unwrap().user().value_identifier()
         );
     }
 
@@ -267,9 +277,9 @@ mod tests {
         ]);
         assert_eq!(
             user1.value_identifier(),
-            queue.peek().unwrap().user().value_identifier()
+            queue.peek().unwrap().unwrap().user().value_identifier()
         );
-        assert!(queue.move_pokemon_choice_next(user2.as_ref()));
+        assert!(queue.move_pokemon_choice_next(user2.as_ref()).unwrap());
 
         assert_eq!(
             user2.value_identifier(),
@@ -294,13 +304,13 @@ mod tests {
             user2.value_identifier(),
             queue.dequeue().unwrap().user().value_identifier()
         );
-        assert!(!queue.move_pokemon_choice_next(user2.as_ref()));
+        assert!(!queue.move_pokemon_choice_next(user2.as_ref()).unwrap());
 
         assert_eq!(
             user1.value_identifier(),
             queue.dequeue().unwrap().user().value_identifier()
         );
-        assert!(queue.peek().is_none())
+        assert!(queue.peek().unwrap().is_none())
     }
 
     #[test]
@@ -314,12 +324,12 @@ mod tests {
         ]);
         assert_eq!(
             user1.value_identifier(),
-            queue.peek().unwrap().user().value_identifier()
+            queue.peek().unwrap().unwrap().user().value_identifier()
         );
-        assert!(queue.move_pokemon_choice_next(user1.as_ref()));
+        assert!(queue.move_pokemon_choice_next(user1.as_ref()).unwrap());
         assert_eq!(
             user1.value_identifier(),
-            queue.peek().unwrap().user().value_identifier()
+            queue.peek().unwrap().unwrap().user().value_identifier()
         );
     }
 
@@ -346,9 +356,9 @@ mod tests {
         ]);
         assert_eq!(
             users[0].value_identifier(),
-            queue.peek().unwrap().user().value_identifier()
+            queue.peek().unwrap().unwrap().user().value_identifier()
         );
-        assert!(queue.move_pokemon_choice_next(users[4].as_ref()));
+        assert!(queue.move_pokemon_choice_next(users[4].as_ref()).unwrap());
 
         assert_eq!(
             users[4].value_identifier(),
diff --git a/src/dynamic_data/flow/target_resolver.rs b/src/dynamic_data/flow/target_resolver.rs
index 0de5a50..a41688a 100755
--- a/src/dynamic_data/flow/target_resolver.rs
+++ b/src/dynamic_data/flow/target_resolver.rs
@@ -135,45 +135,48 @@ pub fn resolve_targets(side: u8, index: u8, target: MoveTarget, battle: &Battle)
 
 /// Checks whether a given side and index are valid for a given move target and user.
 pub fn is_valid_target(side: u8, index: u8, target: MoveTarget, user: &Pokemon) -> bool {
-    let user_side = user.get_battle_side_index();
-    let user_index = user.get_battle_index();
     // If the user is not on the field, nothing is a valid target
-    if user_side.is_none() || user_index.is_none() {
-        return false;
-    }
+    let user_side = match user.get_battle_side_index() {
+        Some(side) => side,
+        None => return false,
+    };
+    let user_index = match user.get_battle_index() {
+        Some(index) => index,
+        None => return false,
+    };
 
     match target {
         MoveTarget::Adjacent | MoveTarget::AllAdjacent => {
-            let diff = abs(index as i32 - user_index.unwrap() as i32);
+            let diff = abs(index as i32 - user_index as i32);
             if diff == 0 {
-                return user_side.unwrap() != side;
+                return user_side != side;
             }
             diff <= 1
         }
         MoveTarget::AdjacentAlly => {
-            if user_side.unwrap() != side {
+            if user_side != side {
                 false
             } else {
-                abs(index as i32 - user_index.unwrap() as i32) == 1
+                abs(index as i32 - user_index as i32) == 1
             }
         }
         MoveTarget::AdjacentAllySelf => {
-            if user_side.unwrap() != side {
+            if user_side != side {
                 false
             } else {
-                abs(index as i32 - user_index.unwrap() as i32) <= 1
+                abs(index as i32 - user_index as i32) <= 1
             }
         }
         MoveTarget::AdjacentOpponent | MoveTarget::AllAdjacentOpponent => {
-            if user_side.unwrap() == side {
+            if user_side == side {
                 false
             } else {
-                abs(index as i32 - user_index.unwrap() as i32) <= 1
+                abs(index as i32 - user_index as i32) <= 1
             }
         }
         MoveTarget::All | MoveTarget::Any | MoveTarget::RandomOpponent => true,
-        MoveTarget::AllAlly => user_side.unwrap() == side,
-        MoveTarget::AllOpponent => user_side.unwrap() != side,
-        MoveTarget::SelfUse => user_side.unwrap() == side && user_index.unwrap() == index,
+        MoveTarget::AllAlly => user_side == side,
+        MoveTarget::AllOpponent => user_side != side,
+        MoveTarget::SelfUse => user_side == side && user_index == index,
     }
 }
diff --git a/src/dynamic_data/flow/turn_runner.rs b/src/dynamic_data/flow/turn_runner.rs
index 1cef78e..882a7c3 100755
--- a/src/dynamic_data/flow/turn_runner.rs
+++ b/src/dynamic_data/flow/turn_runner.rs
@@ -1,3 +1,5 @@
+use anyhow::Result;
+use anyhow_ext::anyhow;
 use std::ops::Deref;
 use std::sync::Arc;
 
@@ -10,11 +12,21 @@ use crate::dynamic_data::DamageSource;
 use crate::dynamic_data::ExecutingMove;
 use crate::dynamic_data::Pokemon;
 use crate::static_data::MoveCategory;
-use crate::{run_scripts, script_hook, PkmnResult};
+use crate::{run_scripts, script_hook};
+
+/// Simple macro to get a read lock on the choice queue.
+macro_rules! read_choice_queue {
+    ($choice_queue:ident) => {
+        $choice_queue
+            .read()
+            .as_ref()
+            .ok_or(anyhow!("Could not get a lock on choice queue"))?
+    };
+}
 
 impl Battle {
     /// Execute the entire turn after the choices are all set.
-    pub(crate) fn run_turn(&self) -> PkmnResult<()> {
+    pub(crate) fn run_turn(&self) -> Result<()> {
         let choice_queue = self.current_turn_queue();
 
         // We are now at the very beginning of a turn. We have assigned speeds and priorities to all
@@ -24,15 +36,19 @@ impl Battle {
         // is primarily intended to be used to reset variables on a script (for example scripts that need
         // to check whether a pokemon was hit this turn. By resetting here, and setting a variable to true
         // they can then know this later on.)
-        for choice in choice_queue.read().as_ref().unwrap().get_queue().iter().flatten() {
+        for choice in read_choice_queue!(choice_queue).get_queue().iter().flatten() {
             script_hook!(on_before_turn, choice, choice);
         }
 
         // Now we can properly begin executing choices.
         // One by one dequeue the turns, and run them. If the battle has ended we do not want to
         // continue running however.
-        while choice_queue.read().as_ref().unwrap().has_next() && !self.has_ended() {
-            let choice = choice_queue.write().as_mut().unwrap().dequeue();
+        while read_choice_queue!(choice_queue).has_next() && !self.has_ended() {
+            let choice = choice_queue
+                .write()
+                .as_mut()
+                .ok_or(anyhow!("Failed to get a write lock on choice queue"))?
+                .dequeue();
             if let Some(choice) = choice {
                 self.execute_choice(&choice)?;
             }
@@ -64,7 +80,7 @@ impl Battle {
     }
 
     /// Executes a single choice.
-    fn execute_choice(&self, choice: &TurnChoice) -> PkmnResult<()> {
+    fn execute_choice(&self, choice: &TurnChoice) -> Result<()> {
         // A pass turn choice means the user does not intend to do anything. As such, return.
         if let TurnChoice::Pass(..) = choice {
             return Ok(());
@@ -93,7 +109,7 @@ impl Battle {
     }
 
     /// Executes a move choice.
-    fn execute_move_choice<'func>(&'func self, choice: &'func TurnChoice) -> PkmnResult<()> {
+    fn execute_move_choice<'func>(&'func self, choice: &'func TurnChoice) -> Result<()> {
         let move_choice = choice.get_move_turn_data();
         let used_move = move_choice.used_move();
         let move_data = {
@@ -101,7 +117,11 @@ impl Battle {
             let move_data = move_data_lock.move_data();
             let mut move_name = move_data.name().clone();
             script_hook!(change_move, choice, choice, &mut move_name);
-            self.library().static_data().moves().get(&move_name).unwrap()
+            self.library()
+                .static_data()
+                .moves()
+                .get(&move_name)
+                .ok_or(anyhow!("Move not found"))?
         };
         // FIXME: also change the script on the choice if changed;
         let target_type = move_data.target();
@@ -150,7 +170,7 @@ impl Battle {
     }
 
     /// Executes a move turn choice on a single target.
-    fn handle_move_for_target(&self, executing_move: &mut ExecutingMove, target: &Arc<Pokemon>) -> PkmnResult<()> {
+    fn handle_move_for_target(&self, executing_move: &mut ExecutingMove, target: &Arc<Pokemon>) -> Result<()> {
         {
             let mut fail = false;
             script_hook!(fail_incoming_move, target, executing_move, target, &mut fail);
@@ -228,7 +248,7 @@ impl Battle {
                 let is_critical =
                     self.library()
                         .damage_calculator()
-                        .is_critical(self, executing_move, target, hit_index);
+                        .is_critical(self, executing_move, target, hit_index)?;
                 hit_data.set_critical(is_critical);
             }
             let base_power = self.library().damage_calculator().get_base_power(
@@ -243,7 +263,7 @@ impl Battle {
                 target,
                 hit_index,
                 executing_move.get_hit_data(target, hit_index)?,
-            );
+            )?;
             hit_data.set_damage(damage);
 
             let mut accuracy = executing_move.use_move().accuracy();
@@ -259,7 +279,9 @@ impl Battle {
                     &mut accuracy
                 );
             }
-            if accuracy < 100 && self.random().get_max(100) as u8 >= accuracy {
+
+            // TODO: Deal with accuracy/evasion stats.
+            if accuracy < 100 && self.random().get_max(100)? as u8 >= accuracy {
                 script_hook!(on_move_miss, target, executing_move, target);
                 self.event_hook().trigger(Event::Miss {
                     user: executing_move.user().deref(),
@@ -273,7 +295,7 @@ impl Battle {
                     if secondary_effect_chance == -1.0
                         || self
                             .random()
-                            .effect_chance(secondary_effect_chance, executing_move, target, hit_index)
+                            .effect_chance(secondary_effect_chance, executing_move, target, hit_index)?
                     {
                         script_hook!(on_secondary_effect, executing_move, executing_move, target, hit_index);
                         // TODO: on fail
@@ -287,7 +309,7 @@ impl Battle {
                     hit_data.set_damage(damage);
                 }
                 if damage > 0 {
-                    target.damage(damage, DamageSource::MoveDamage);
+                    target.damage(damage, DamageSource::MoveDamage)?;
                     if !target.is_fainted() {
                         script_hook!(on_incoming_hit, target, executing_move, target, hit_index);
                     } else {
@@ -313,7 +335,7 @@ impl Battle {
                                         executing_move,
                                         target,
                                         hit_index,
-                                    )
+                                    )?
                                 {
                                     script_hook!(
                                         on_secondary_effect,
diff --git a/src/dynamic_data/libraries/damage_library.rs b/src/dynamic_data/libraries/damage_library.rs
index 8bb2249..e9a21f0 100755
--- a/src/dynamic_data/libraries/damage_library.rs
+++ b/src/dynamic_data/libraries/damage_library.rs
@@ -1,3 +1,5 @@
+use anyhow::Result;
+use anyhow_ext::anyhow;
 use std::sync::Arc;
 
 use crate::dynamic_data::script_handling::ScriptSource;
@@ -16,7 +18,7 @@ pub trait DamageLibrary: std::fmt::Debug + ValueIdentifiable {
         target: &Arc<Pokemon>,
         hit_number: u8,
         hit_data: &HitData,
-    ) -> u32;
+    ) -> Result<u32>;
 
     /// Calculate the base power for a given hit on a Pokemon.
     fn get_base_power(
@@ -34,7 +36,7 @@ pub trait DamageLibrary: std::fmt::Debug + ValueIdentifiable {
         executing_move: &ExecutingMove,
         target: &Arc<Pokemon>,
         hit_number: u8,
-    ) -> bool;
+    ) -> Result<bool>;
 }
 
 /// The implementation of a Damage Library for generation 7.
@@ -174,9 +176,9 @@ impl DamageLibrary for Gen7DamageLibrary {
         target: &Arc<Pokemon>,
         hit_number: u8,
         hit_data: &HitData,
-    ) -> u32 {
+    ) -> Result<u32> {
         if executing_move.use_move().category() == MoveCategory::Status {
-            return 0;
+            return Ok(0);
         }
 
         let level_modifier = ((2.0 * executing_move.user().level() as f32) / 5.0).floor() + 2.0;
@@ -205,7 +207,13 @@ impl DamageLibrary for Gen7DamageLibrary {
         }
 
         if self.has_randomness {
-            let random_percentage = 85 + executing_move.user().get_battle().unwrap().random().get_between(0, 16);
+            let random_percentage = 85
+                + executing_move
+                    .user()
+                    .get_battle()
+                    .ok_or(anyhow!("Damage calculation was done for a Pokemon not in battle"))?
+                    .random()
+                    .get_between(0, 16)?;
             float_damage = (float_damage * (random_percentage as f32 / 100.0)).floor();
         }
 
@@ -247,7 +255,7 @@ impl DamageLibrary for Gen7DamageLibrary {
             hit_number,
             &mut damage
         );
-        damage
+        Ok(damage)
     }
 
     fn get_base_power(
@@ -279,10 +287,10 @@ impl DamageLibrary for Gen7DamageLibrary {
         executing_move: &ExecutingMove,
         target: &Arc<Pokemon>,
         hit_number: u8,
-    ) -> bool {
+    ) -> Result<bool> {
         // Status moves can't be critical.
         if executing_move.use_move().category() == MoveCategory::Status {
-            return false;
+            return Ok(false);
         }
         // Get the critical stage from scripts.
         let mut crit_stage = 0;
@@ -296,12 +304,12 @@ impl DamageLibrary for Gen7DamageLibrary {
         );
         // Crit stage is an unsigned byte, so we only care about values of 0 or higher.
         // For a critical stage of 3+ we always return true.
-        match crit_stage {
-            0 => battle.random().get_max(24) == 0,
-            1 => battle.random().get_max(8) == 0,
-            2 => battle.random().get_max(2) == 0,
+        Ok(match crit_stage {
+            0 => battle.random().get_max(24)? == 0,
+            1 => battle.random().get_max(8)? == 0,
+            2 => battle.random().get_max(2)? == 0,
             _ => true,
-        }
+        })
     }
 }
 
diff --git a/src/dynamic_data/libraries/dynamic_library.rs b/src/dynamic_data/libraries/dynamic_library.rs
index 063dea0..f26ba44 100755
--- a/src/dynamic_data/libraries/dynamic_library.rs
+++ b/src/dynamic_data/libraries/dynamic_library.rs
@@ -1,3 +1,4 @@
+use anyhow::Result;
 use std::fmt::Debug;
 use std::sync::Arc;
 
@@ -9,7 +10,7 @@ use crate::dynamic_data::{ItemScript, ScriptResolver};
 use crate::dynamic_data::{Script, ScriptOwnerData};
 use crate::static_data::Item;
 use crate::static_data::StaticData;
-use crate::{PkmnResult, StringKey, ValueIdentifiable, ValueIdentifier};
+use crate::{StringKey, ValueIdentifiable, ValueIdentifier};
 
 /// The dynamic library stores a static data library, as well as holding different libraries and
 /// calculators that might be customized between different generations and implementations.
@@ -32,11 +33,11 @@ pub trait DynamicLibrary: Debug + ValueIdentifiable {
         owner: ScriptOwnerData,
         _category: ScriptCategory,
         _key: &StringKey,
-    ) -> PkmnResult<Option<Arc<dyn Script>>>;
+    ) -> Result<Option<Arc<dyn Script>>>;
     /// Loads an item script with the given unique key. If no script can be created with this
     /// combinations, returns None. Note that ItemScripts are immutable, as their script should be
     /// shared between all different usages.
-    fn load_item_script(&self, _key: &Arc<dyn Item>) -> PkmnResult<Option<Arc<dyn ItemScript>>>;
+    fn load_item_script(&self, _key: &Arc<dyn Item>) -> Result<Option<Arc<dyn ItemScript>>>;
 }
 
 /// The dynamic library stores a static data library, as well as holding different libraries and
@@ -107,13 +108,13 @@ impl DynamicLibrary for DynamicLibraryImpl {
         owner: ScriptOwnerData,
         _category: ScriptCategory,
         _key: &StringKey,
-    ) -> PkmnResult<Option<Arc<dyn Script>>> {
+    ) -> Result<Option<Arc<dyn Script>>> {
         self.script_resolver.load_script(owner, _category, _key)
     }
     /// Loads an item script with the given unique key. If no script can be created with this
     /// combinations, returns None. Note that ItemScripts are immutable, as their script should be
     /// shared between all different usages.
-    fn load_item_script(&self, _key: &Arc<dyn Item>) -> PkmnResult<Option<Arc<dyn ItemScript>>> {
+    fn load_item_script(&self, _key: &Arc<dyn Item>) -> Result<Option<Arc<dyn ItemScript>>> {
         todo!()
     }
 }
@@ -145,8 +146,8 @@ pub mod test {
                 owner: ScriptOwnerData,
                 _category: ScriptCategory,
                 _key: &StringKey,
-            ) -> PkmnResult<Option<Arc<dyn Script>>>;
-            fn load_item_script(&self, _key: &Arc<dyn Item>) -> PkmnResult<Option<Arc<dyn ItemScript>>>;
+            ) -> Result<Option<Arc<dyn Script>>>;
+            fn load_item_script(&self, _key: &Arc<dyn Item>) -> Result<Option<Arc<dyn ItemScript>>>;
         }
         impl ValueIdentifiable for DynamicLibrary{
             fn value_identifier(&self) -> ValueIdentifier{
diff --git a/src/dynamic_data/libraries/script_resolver.rs b/src/dynamic_data/libraries/script_resolver.rs
index a815321..f833736 100755
--- a/src/dynamic_data/libraries/script_resolver.rs
+++ b/src/dynamic_data/libraries/script_resolver.rs
@@ -1,9 +1,10 @@
+use anyhow::Result;
 use std::fmt::Debug;
 use std::sync::Arc;
 
 use crate::dynamic_data::{ItemScript, Script, ScriptOwnerData};
 use crate::static_data::Item;
-use crate::{PkmnResult, StringKey, ValueIdentifiable, ValueIdentifier};
+use crate::{StringKey, ValueIdentifiable, ValueIdentifier};
 
 /// A script resolver deals with the resolving of scripts. These scripts are non-hardcoded
 /// implementations of different effects in Pokemon. This allows for things such as generational
@@ -16,12 +17,12 @@ pub trait ScriptResolver: Debug + ValueIdentifiable {
         owner: ScriptOwnerData,
         category: ScriptCategory,
         script_key: &StringKey,
-    ) -> PkmnResult<Option<Arc<dyn Script>>>;
+    ) -> Result<Option<Arc<dyn Script>>>;
 
     /// Loads an item script with the given unique key. If no script can be created with this
     /// combinations, returns None. Note that ItemScripts are immutable, as their script should be
     /// shared between all different usages.
-    fn load_item_script(&self, _key: &dyn Item) -> PkmnResult<Option<Arc<dyn ItemScript>>>;
+    fn load_item_script(&self, _key: &dyn Item) -> Result<Option<Arc<dyn ItemScript>>>;
 }
 
 use std::fmt::Display;
@@ -73,11 +74,11 @@ impl ScriptResolver for EmptyScriptResolver {
         _owner: ScriptOwnerData,
         _category: ScriptCategory,
         _script_key: &StringKey,
-    ) -> PkmnResult<Option<Arc<dyn Script>>> {
+    ) -> Result<Option<Arc<dyn Script>>> {
         Ok(None)
     }
 
-    fn load_item_script(&self, _key: &dyn Item) -> PkmnResult<Option<Arc<dyn ItemScript>>> {
+    fn load_item_script(&self, _key: &dyn Item) -> Result<Option<Arc<dyn ItemScript>>> {
         Ok(None)
     }
 }
diff --git a/src/dynamic_data/models/battle.rs b/src/dynamic_data/models/battle.rs
index 026a8f7..f346016 100755
--- a/src/dynamic_data/models/battle.rs
+++ b/src/dynamic_data/models/battle.rs
@@ -2,6 +2,8 @@ use std::ops::{Deref, DerefMut};
 use std::sync::atomic::{AtomicBool, AtomicU32, Ordering};
 use std::sync::Arc;
 
+use anyhow::Result;
+use anyhow_ext::anyhow;
 use atomig::Atomic;
 use parking_lot::RwLock;
 
@@ -18,7 +20,7 @@ use crate::dynamic_data::VolatileScriptsOwner;
 use crate::dynamic_data::{is_valid_target, ScriptWrapper};
 use crate::dynamic_data::{ChoiceQueue, ScriptContainer};
 use crate::dynamic_data::{ScriptCategory, ScriptSource, ScriptSourceData};
-use crate::{script_hook, PkmnResult, StringKey, ValueIdentifiable, ValueIdentifier};
+use crate::{script_hook, StringKey, ValueIdentifiable, ValueIdentifier};
 
 /// A pokemon battle, with any amount of sides and pokemon per side.
 #[derive(Debug)]
@@ -169,11 +171,9 @@ impl Battle {
     /// Get a Pokemon on the battlefield, on a specific side and an index on that side.
     pub fn get_pokemon(&self, side: u8, index: u8) -> Option<Arc<Pokemon>> {
         let side = self.sides.get(side as usize);
-        side?;
-        let pokemon_read_lock = side.unwrap().pokemon();
+        let pokemon_read_lock = side?.pokemon();
         let pokemon = pokemon_read_lock.get(index as usize);
-        pokemon?;
-        pokemon.unwrap().clone()
+        pokemon?.clone()
     }
 
     /// Returns whether a slot on the battlefield can still be filled. If no party is responsible
@@ -190,10 +190,10 @@ impl Battle {
 
     /// Validates whether the battle is still in a non-ended state. If the battle has ended, this
     /// properly sets who has won etc.
-    pub fn validate_battle_state(&self) {
+    pub fn validate_battle_state(&self) -> Result<()> {
         // If we've already ended, we dont need to run this.
         if self.has_ended() {
-            return;
+            return Ok(());
         }
         let mut surviving_side_exists = false;
         let mut winning_side = None;
@@ -205,13 +205,13 @@ impl Battle {
                     self.result.data_ptr().replace(BattleResult::Inconclusive);
                 }
                 self.has_ended.store(true, Ordering::SeqCst);
-                return;
+                return Ok(());
             }
             // If the side is not defeated
             if !side.is_defeated() {
                 // More than 1 surviving side. Battle is not ended
                 if surviving_side_exists {
-                    return;
+                    return Ok(());
                 }
                 surviving_side_exists = true;
                 winning_side = Some(side_index as u8);
@@ -228,12 +228,13 @@ impl Battle {
         else {
             let _w = self.result.write();
             unsafe {
-                self.result
-                    .data_ptr()
-                    .replace(BattleResult::Conclusive(winning_side.unwrap()));
+                self.result.data_ptr().replace(BattleResult::Conclusive(
+                    winning_side.ok_or(anyhow!("Winning side was not set"))?,
+                ));
             }
         }
         self.has_ended.store(true, Ordering::SeqCst);
+        Ok(())
     }
 
     /// Checks whether a choice is actually possible.
@@ -260,7 +261,7 @@ impl Battle {
     }
 
     /// Try and set the choice for the battle. If the choice is not valid, this returns false.
-    pub fn try_set_choice(&self, choice: TurnChoice) -> PkmnResult<bool> {
+    pub fn try_set_choice(&self, choice: TurnChoice) -> Result<bool> {
         if !self.can_use(&choice) {
             return Ok(false);
         }
@@ -268,17 +269,19 @@ impl Battle {
             return Ok(false);
         }
         let side = choice.user().get_battle_side_index();
-        if side.is_none() {
-            return Ok(false);
+        match side {
+            Some(side) => {
+                self.sides[side as usize].set_choice(choice);
+                self.check_choices_set_and_run()?;
+                Ok(true)
+            }
+            None => Ok(false),
         }
-        self.sides[side.unwrap() as usize].set_choice(choice);
-        self.check_choices_set_and_run()?;
-        Ok(true)
     }
 
     /// Checks to see whether all Pokemon on the field have set their choices. If so, we then run
     /// the turn.
-    fn check_choices_set_and_run(&self) -> PkmnResult<()> {
+    fn check_choices_set_and_run(&self) -> Result<()> {
         for side in &self.sides {
             if !side.all_choices_set() {
                 return Ok(());
@@ -292,10 +295,9 @@ impl Battle {
         for side in &self.sides {
             let mut side_choices = side.choices().write();
             for choice_opt in side_choices.deref_mut() {
-                if choice_opt.is_none() {
-                    panic!("Choice was none, but all choices were set? Logic error.");
-                }
-                let mut choice = choice_opt.as_mut().unwrap();
+                let mut choice = choice_opt
+                    .as_mut()
+                    .ok_or(anyhow!("Choice was none, but all choices were set? Logic error."))?;
                 let c = choice.deref();
                 if let TurnChoice::Move(data) = c {
                     let mut change_priority = data.priority();
@@ -312,7 +314,7 @@ impl Battle {
                 script_hook!(change_speed, c, c, &mut speed);
                 *choice.speed_mut() = speed;
 
-                choice.set_random_value(self.random.get() as u32);
+                choice.set_random_value(self.random.get()? as u32);
                 choices.push(choice_opt.take());
             }
             // Drop the lock guard, as we need to write into it in reset_choices.
@@ -331,32 +333,41 @@ impl Battle {
         self.event_hook.trigger(Event::EndTurn);
         let end_time = chrono::Utc::now();
         let time = end_time - start_time;
-        self.last_turn_time
-            .store(time.num_nanoseconds().unwrap() as u64, Ordering::SeqCst);
+        match time.num_nanoseconds() {
+            None => {}
+            Some(v) => {
+                self.last_turn_time.store(v as u64, Ordering::SeqCst);
+            }
+        }
         Ok(())
     }
 
     /// Sets the current weather for the battle. If None is passed, this clears the weather.
-    pub fn set_weather(&self, weather: Option<StringKey>) {
+    pub fn set_weather(&self, weather: Option<StringKey>) -> Result<()> {
         if let Some(weather) = weather {
             let script = self
                 .library()
-                .load_script(self.into(), ScriptCategory::Weather, &weather)
-                .unwrap()
-                .unwrap_or_else(|| panic!("Couldn't find weather script by name {}", weather));
+                .load_script(self.into(), ScriptCategory::Weather, &weather)?
+                .ok_or(anyhow!("Couldn't find weather script by name {}", weather))?;
             self.weather.set(script);
         } else {
             self.weather.clear();
         }
+        Ok(())
     }
 
     /// Gets the current weather of the battle. If no weather is present, this returns None.
-    pub fn weather_name(&self) -> Option<StringKey> {
+    pub fn weather_name(&self) -> Result<Option<StringKey>> {
         if let Some(script) = self.weather.get() {
             let lock = script.read();
-            Some(lock.as_ref().unwrap().name().clone())
+            Ok(Some(
+                lock.as_ref()
+                    .ok_or(anyhow!("Failed to get a lock on weather"))?
+                    .name()
+                    .clone(),
+            ))
         } else {
-            None
+            Ok(None)
         }
     }
 }
@@ -366,7 +377,7 @@ impl VolatileScriptsOwner for Battle {
         &self.volatile_scripts
     }
 
-    fn load_volatile_script(&self, key: &StringKey) -> PkmnResult<Option<Arc<dyn Script>>> {
+    fn load_volatile_script(&self, key: &StringKey) -> Result<Option<Arc<dyn Script>>> {
         self.library.load_script(self.into(), ScriptCategory::Battle, key)
     }
 }
diff --git a/src/dynamic_data/models/battle_random.rs b/src/dynamic_data/models/battle_random.rs
index 24c3690..fdf49f9 100755
--- a/src/dynamic_data/models/battle_random.rs
+++ b/src/dynamic_data/models/battle_random.rs
@@ -1,3 +1,5 @@
+use anyhow::Result;
+use anyhow_ext::anyhow;
 use std::fmt::{Debug, Formatter};
 use std::sync::{Arc, Mutex};
 
@@ -32,16 +34,25 @@ impl BattleRandom {
     }
 
     /// Get a random 32 bit integer. Can be any value between min int and max int.
-    pub fn get(&self) -> i32 {
-        return self.get_rng().lock().unwrap().get();
+    pub fn get(&self) -> Result<i32> {
+        match self.get_rng().lock() {
+            Ok(mut l) => Ok(l.get()),
+            Err(_) => Err(anyhow!("Failed to get a RNG lock")),
+        }
     }
     /// Get a random 32 bit integer between 0 and max.
-    pub fn get_max(&self, max: i32) -> i32 {
-        return self.get_rng().lock().unwrap().get_max(max);
+    pub fn get_max(&self, max: i32) -> Result<i32> {
+        match self.get_rng().lock() {
+            Ok(mut l) => Ok(l.get_max(max)),
+            Err(_) => Err(anyhow!("Failed to get a RNG lock")),
+        }
     }
     /// Get a random 32 bit integer between min and max.
-    pub fn get_between(&self, min: i32, max: i32) -> i32 {
-        return self.get_rng().lock().unwrap().get_between(min, max);
+    pub fn get_between(&self, min: i32, max: i32) -> Result<i32> {
+        match self.get_rng().lock() {
+            Ok(mut l) => Ok(l.get_between(min, max)),
+            Err(_) => Err(anyhow!("Failed to get a RNG lock")),
+        }
     }
 
     /// Gets whether or not a move triggers its secondary effect. This takes its chance, and
@@ -53,7 +64,7 @@ impl BattleRandom {
         executing_move: &ExecutingMove,
         target: &Arc<Pokemon>,
         hit_number: u8,
-    ) -> bool {
+    ) -> Result<bool> {
         script_hook!(
             change_effect_chance,
             executing_move,
@@ -72,12 +83,15 @@ impl BattleRandom {
         );
         if chance < 100.0 {
             if chance > 0.0 {
-                self.get_rng().lock().unwrap().get_float() < (chance / 100.0)
+                match self.get_rng().lock() {
+                    Ok(mut l) => Ok(l.get_float() < (chance / 100.0)),
+                    Err(_) => Err(anyhow!("Failed to get a RNG lock")),
+                }
             } else {
-                false
+                Ok(false)
             }
         } else {
-            true
+            Ok(true)
         }
     }
 }
@@ -92,6 +106,10 @@ impl Clone for BattleRandom {
     fn clone(&self) -> Self {
         Self {
             identifier: Default::default(),
+
+            // As cloning when we can't get a lock on the randomness is completely impossible, we
+            // should unwrap here.
+            #[allow(clippy::unwrap_used)]
             random: Mutex::new(self.random.lock().unwrap().clone()),
         }
     }
diff --git a/src/dynamic_data/models/battle_side.rs b/src/dynamic_data/models/battle_side.rs
index fb44b52..bd21b72 100755
--- a/src/dynamic_data/models/battle_side.rs
+++ b/src/dynamic_data/models/battle_side.rs
@@ -2,6 +2,7 @@ use std::ops::Deref;
 use std::sync::atomic::{AtomicBool, AtomicU8, Ordering};
 use std::sync::Arc;
 
+use anyhow::Result;
 use parking_lot::lock_api::RwLockReadGuard;
 use parking_lot::{RawRwLock, RwLock};
 
@@ -14,7 +15,7 @@ use crate::dynamic_data::script_handling::{ScriptSource, ScriptSourceData, Scrip
 use crate::dynamic_data::Script;
 use crate::dynamic_data::ScriptSet;
 use crate::dynamic_data::VolatileScriptsOwner;
-use crate::{script_hook, PkmnResult, StringKey, ValueIdentifiable, ValueIdentifier};
+use crate::{script_hook, StringKey, ValueIdentifiable, ValueIdentifier};
 
 /// A side on a battle.
 #[derive(Debug)]
@@ -248,9 +249,9 @@ impl BattleSide {
     }
 
     /// Gets a random Pokemon on the given side.
-    pub fn get_random_creature_index(&self) -> u8 {
+    pub fn get_random_creature_index(&self) -> Result<u8> {
         // TODO: Consider adding parameter to only get index for available creatures.
-        self.battle().random().get_max(self.pokemon_per_side as i32) as u8
+        Ok(self.battle().random().get_max(self.pokemon_per_side as i32)? as u8)
     }
 
     /// Swap two Pokemon on a single side around.
@@ -299,7 +300,7 @@ impl VolatileScriptsOwner for BattleSide {
         &self.volatile_scripts
     }
 
-    fn load_volatile_script(&self, key: &StringKey) -> PkmnResult<Option<Arc<dyn Script>>> {
+    fn load_volatile_script(&self, key: &StringKey) -> Result<Option<Arc<dyn Script>>> {
         self.battle()
             .library()
             .load_script(self.into(), crate::ScriptCategory::Side, key)
diff --git a/src/dynamic_data/models/executing_move.rs b/src/dynamic_data/models/executing_move.rs
index 0ab0056..aa0485b 100755
--- a/src/dynamic_data/models/executing_move.rs
+++ b/src/dynamic_data/models/executing_move.rs
@@ -2,6 +2,8 @@ use std::ops::Deref;
 use std::sync::atomic::{AtomicBool, AtomicU32, AtomicU8, Ordering};
 use std::sync::Arc;
 
+use anyhow::Result;
+use anyhow_ext::bail;
 use atomig::Atomic;
 use parking_lot::RwLock;
 
@@ -11,7 +13,7 @@ use crate::dynamic_data::script_handling::{ScriptSource, ScriptSourceData, Scrip
 use crate::dynamic_data::ScriptContainer;
 use crate::dynamic_data::TargetList;
 use crate::static_data::{MoveData, TypeIdentifier};
-use crate::{PkmnResult, PokemonError, ValueIdentifiable, ValueIdentifier};
+use crate::{ValueIdentifiable, ValueIdentifier};
 
 /// A hit data is the data for a single hit, on a single target.
 #[derive(Default, Debug)]
@@ -164,7 +166,7 @@ impl ExecutingMove {
     }
 
     /// Gets a hit data for a target, with a specific index.
-    pub fn get_hit_data(&self, for_target: &Pokemon, hit: u8) -> PkmnResult<&HitData> {
+    pub fn get_hit_data(&self, for_target: &Pokemon, hit: u8) -> Result<&HitData> {
         for (index, target) in self.targets.iter().enumerate() {
             if let Some(target) = target {
                 if std::ptr::eq(target.deref().deref(), for_target.deref().deref()) {
@@ -173,7 +175,7 @@ impl ExecutingMove {
                 }
             }
         }
-        Err(PokemonError::InvalidTargetRequested)
+        bail!("Invalid target requested");
     }
 
     /// Checks whether a Pokemon is a target for this move.
@@ -187,7 +189,7 @@ impl ExecutingMove {
     }
 
     /// Gets the index of the hits in this move where the hits for a specific target start.
-    pub(crate) fn get_index_of_target(&self, for_target: &Arc<Pokemon>) -> PkmnResult<usize> {
+    pub(crate) fn get_index_of_target(&self, for_target: &Arc<Pokemon>) -> Result<usize> {
         for (index, target) in self.targets.iter().enumerate() {
             if let Some(target) = target {
                 if std::ptr::eq(target.deref().deref(), for_target.deref().deref()) {
@@ -196,7 +198,7 @@ impl ExecutingMove {
                 }
             }
         }
-        Err(PokemonError::InvalidTargetRequested)
+        bail!("Invalid target requested");
     }
 
     /// Gets a hit based on its raw index.
diff --git a/src/dynamic_data/models/pokemon.rs b/src/dynamic_data/models/pokemon.rs
index 6d3f9e3..7de6298 100755
--- a/src/dynamic_data/models/pokemon.rs
+++ b/src/dynamic_data/models/pokemon.rs
@@ -22,7 +22,8 @@ use crate::static_data::TypeIdentifier;
 use crate::static_data::{Ability, Statistic};
 use crate::static_data::{ClampedStatisticSet, StatisticSet};
 use crate::utils::Random;
-use crate::{script_hook, PkmnResult, StringKey, ValueIdentifiable, ValueIdentifier};
+use crate::{script_hook, StringKey, ValueIdentifiable, ValueIdentifier};
+use anyhow::Result;
 
 /// An individual Pokemon as we know and love them.
 #[derive(Debug)]
@@ -129,12 +130,12 @@ impl Pokemon {
         gender: Gender,
         coloring: u8,
         nature: &StringKey,
-    ) -> Self {
+    ) -> Result<Self> {
         // Calculate experience from the level for the specified growth rate.
         let experience = library
             .static_data()
             .growth_rates()
-            .calculate_experience(species.growth_rate(), level);
+            .calculate_experience(species.growth_rate(), level)?;
         let weight = form.weight();
         let height = form.height();
         let nature = library
@@ -183,7 +184,7 @@ impl Pokemon {
         let health = pokemon.flat_stats().hp();
         pokemon.current_health = AtomicU32::new(health);
 
-        pokemon
+        Ok(pokemon)
     }
 
     /// The library data of the Pokemon.
@@ -617,12 +618,12 @@ impl Pokemon {
     }
 
     /// Damages the Pokemon by a certain amount of damage, from a damage source.
-    pub fn damage(&self, mut damage: u32, source: DamageSource) {
+    pub fn damage(&self, mut damage: u32, source: DamageSource) -> Result<()> {
         if damage > self.current_health() {
             damage = self.current_health();
         }
         if damage == 0 {
-            return;
+            return Ok(());
         }
         let new_health = self.current_health() - damage;
         if let Some(battle_data) = &self.battle_data.read().deref() {
@@ -641,12 +642,13 @@ impl Pokemon {
 
         self.current_health.store(new_health, Ordering::SeqCst);
         if self.is_fainted() && damage > 0 {
-            self.on_faint(source);
+            self.on_faint(source)?;
         }
+        Ok(())
     }
 
     /// Triggers when the Pokemon faints.
-    fn on_faint(&self, source: DamageSource) {
+    fn on_faint(&self, source: DamageSource) -> Result<()> {
         let r = self.battle_data.read();
         if let Some(battle_data) = r.deref() {
             if let Some(battle) = battle_data.battle() {
@@ -659,9 +661,10 @@ impl Pokemon {
                         .mark_slot_as_unfillable(battle_data.index());
                 }
 
-                battle.validate_battle_state();
+                battle.validate_battle_state()?;
             }
         }
+        Ok(())
     }
 
     /// Heals the Pokemon by a specific amount. Unless allow_revive is set to true, this will not
@@ -803,7 +806,7 @@ impl VolatileScriptsOwner for Pokemon {
         &self.volatile
     }
 
-    fn load_volatile_script(&self, key: &StringKey) -> PkmnResult<Option<Arc<dyn Script>>> {
+    fn load_volatile_script(&self, key: &StringKey) -> Result<Option<Arc<dyn Script>>> {
         self.library.load_script(self.into(), ScriptCategory::Pokemon, key)
     }
 }
@@ -866,7 +869,9 @@ pub mod test {
         static_lib.expect_species().return_const(Box::new(species_lib));
 
         let mut growth_rate_lib = MockGrowthRateLibrary::new();
-        growth_rate_lib.expect_calculate_experience().return_const(1000u32);
+        growth_rate_lib
+            .expect_calculate_experience()
+            .returning(|_, _| Ok(1000u32));
 
         let mut nature_lib = MockNatureLibrary::new();
         nature_lib.expect_get_nature().returning(|_| {
@@ -907,7 +912,8 @@ pub mod test {
             Gender::Male,
             0,
             &"test_nature".into(),
-        );
+        )
+        .unwrap();
         assert_eq!(pokemon.species().name(), &"test_species".into());
         assert_eq!(pokemon.form().name(), &"default".into());
     }
diff --git a/src/dynamic_data/models/pokemon_builder.rs b/src/dynamic_data/models/pokemon_builder.rs
index 645b855..4673f29 100755
--- a/src/dynamic_data/models/pokemon_builder.rs
+++ b/src/dynamic_data/models/pokemon_builder.rs
@@ -6,6 +6,7 @@ use crate::dynamic_data::models::pokemon::Pokemon;
 use crate::dynamic_data::DynamicLibrary;
 use crate::static_data::{AbilityIndex, Gender};
 use crate::{Random, StringKey};
+use anyhow::Result;
 
 /// This allows for the easy chain building of a Pokemon.
 pub struct PokemonBuilder {
@@ -39,7 +40,7 @@ impl PokemonBuilder {
     }
 
     /// Finally turn the builder into an actual Pokemon.
-    pub fn build(self) -> Pokemon {
+    pub fn build(self) -> Result<Pokemon> {
         let mut random = if let Some(seed) = self.random_seed {
             Random::new(seed)
         } else {
@@ -61,11 +62,11 @@ impl PokemonBuilder {
             Gender::Male,
             0,
             &"hardy".into(),
-        );
+        )?;
         for learned_move in self.learned_moves {
             p.learn_move(&learned_move, MoveLearnMethod::Unknown);
         }
 
-        p
+        Ok(p)
     }
 }
diff --git a/src/dynamic_data/script_handling/script_set.rs b/src/dynamic_data/script_handling/script_set.rs
index 02aab3d..6d3dbdb 100755
--- a/src/dynamic_data/script_handling/script_set.rs
+++ b/src/dynamic_data/script_handling/script_set.rs
@@ -1,11 +1,12 @@
 use std::ops::Deref;
 use std::sync::Arc;
 
+use anyhow::Result;
 use indexmap::IndexMap;
 use parking_lot::RwLock;
 
 use crate::dynamic_data::script_handling::script::{Script, ScriptContainer};
-use crate::{PkmnResult, StringKey};
+use crate::StringKey;
 
 /// A collection of unique scripts.
 #[derive(Debug, Default)]
@@ -36,9 +37,9 @@ impl ScriptSet {
 
     /// Adds a script with a name to the set. If the script with that name already exists in this
     /// set, this makes that script stack instead. The return value here is that script.
-    pub fn stack_or_add<F>(&self, key: &StringKey, instantiation: &F) -> PkmnResult<Option<ScriptContainer>>
+    pub fn stack_or_add<F>(&self, key: &StringKey, instantiation: &F) -> Result<Option<ScriptContainer>>
     where
-        F: Fn() -> PkmnResult<Option<Arc<dyn Script>>>,
+        F: Fn() -> Result<Option<Arc<dyn Script>>>,
     {
         if let Some(lock) = self.scripts.read().get(key) {
             if let Some(existing) = lock.get() {
diff --git a/src/dynamic_data/script_handling/volatile_scripts_owner.rs b/src/dynamic_data/script_handling/volatile_scripts_owner.rs
index fe620c9..ae71fe0 100755
--- a/src/dynamic_data/script_handling/volatile_scripts_owner.rs
+++ b/src/dynamic_data/script_handling/volatile_scripts_owner.rs
@@ -1,15 +1,16 @@
+use anyhow::Result;
 use std::sync::Arc;
 
 use crate::dynamic_data::script_handling::script::{Script, ScriptContainer};
 use crate::dynamic_data::script_handling::script_set::ScriptSet;
-use crate::{PkmnResult, StringKey};
+use crate::StringKey;
 
 /// This trait adds a bunch of helper functions to deal with volatile scripts on a struct.
 pub trait VolatileScriptsOwner {
     /// Return the [`ScriptSet`] that are our volatile scripts.
     fn volatile_scripts(&self) -> &Arc<ScriptSet>;
     /// Loads a volatile script by name.
-    fn load_volatile_script(&self, key: &StringKey) -> PkmnResult<Option<Arc<dyn Script>>>;
+    fn load_volatile_script(&self, key: &StringKey) -> Result<Option<Arc<dyn Script>>>;
 
     /// Check if a volatile script with given name exists.
     fn has_volatile_script(&self, key: &StringKey) -> bool {
@@ -22,13 +23,13 @@ pub trait VolatileScriptsOwner {
     }
 
     /// Adds a volatile script by name.
-    fn add_volatile_script(&self, key: &StringKey) -> PkmnResult<Option<ScriptContainer>> {
+    fn add_volatile_script(&self, key: &StringKey) -> Result<Option<ScriptContainer>> {
         self.volatile_scripts()
             .stack_or_add(key, &|| self.load_volatile_script(key))
     }
 
     /// Adds a volatile script by name.
-    fn add_volatile_script_with_script(&self, script: Arc<dyn Script>) -> PkmnResult<Option<ScriptContainer>> {
+    fn add_volatile_script_with_script(&self, script: Arc<dyn Script>) -> Result<Option<ScriptContainer>> {
         self.volatile_scripts()
             .stack_or_add(&script.name().clone(), &|| Ok(Some(script.clone())))
     }
diff --git a/src/ffi/dynamic_data/models/battle.rs b/src/ffi/dynamic_data/models/battle.rs
index 69423fd..f027bee 100644
--- a/src/ffi/dynamic_data/models/battle.rs
+++ b/src/ffi/dynamic_data/models/battle.rs
@@ -2,7 +2,7 @@ use crate::dynamic_data::{
     Battle, BattleParty, BattleRandom, BattleResult, BattleSide, DynamicLibrary, Pokemon, TurnChoice,
 };
 use crate::ffi::dynamic_data::models::native_event_hook::NativeEventHook;
-use crate::ffi::{ExternPointer, IdentifiablePointer, OwnedPtr};
+use crate::ffi::{ExternPointer, IdentifiablePointer, NativeResult, OwnedPtr};
 use std::ffi::{c_char, CStr, CString};
 use std::sync::Arc;
 
@@ -191,20 +191,20 @@ extern "C" fn battle_try_set_choice(ptr: ExternPointer<Arc<Battle>>, choice: Own
 
 /// Sets the current weather for the battle. If nullptr is passed, this clears the weather.
 #[no_mangle]
-extern "C" fn battle_set_weather(ptr: ExternPointer<Arc<Battle>>, weather: *const c_char) {
+extern "C" fn battle_set_weather(ptr: ExternPointer<Arc<Battle>>, weather: *const c_char) -> NativeResult<()> {
     if weather.is_null() {
-        ptr.as_ref().set_weather(None)
+        ptr.as_ref().set_weather(None).into()
     } else {
-        unsafe { ptr.as_ref().set_weather(Some(CStr::from_ptr(weather).into())) }
+        unsafe { ptr.as_ref().set_weather(Some(CStr::from_ptr(weather).into())).into() }
     }
 }
 
 /// Gets the current weather of the battle. If no weather is present, this returns nullptr.
 #[no_mangle]
-extern "C" fn battle_weather_name(ptr: ExternPointer<Arc<Battle>>) -> *mut c_char {
-    if let Some(w) = ptr.as_ref().weather_name() {
-        CString::new(w.str()).unwrap().into_raw()
-    } else {
-        std::ptr::null_mut()
+extern "C" fn battle_weather_name(ptr: ExternPointer<Arc<Battle>>) -> NativeResult<*mut c_char> {
+    match ptr.as_ref().weather_name() {
+        Ok(Some(w)) => CString::new(w.str()).unwrap().into_raw().into(),
+        Ok(None) => std::ptr::null_mut::<c_char>().into(),
+        Err(e) => NativeResult::err(e),
     }
 }
diff --git a/src/ffi/dynamic_data/models/pokemon.rs b/src/ffi/dynamic_data/models/pokemon.rs
index e005623..2571456 100644
--- a/src/ffi/dynamic_data/models/pokemon.rs
+++ b/src/ffi/dynamic_data/models/pokemon.rs
@@ -1,6 +1,6 @@
 use crate::defines::LevelInt;
 use crate::dynamic_data::{Battle, DamageSource, DynamicLibrary, LearnedMove, MoveLearnMethod, Pokemon};
-use crate::ffi::{ffi_arc_getter, ffi_vec_value_getters, ExternPointer, IdentifiablePointer, OwnedPtr};
+use crate::ffi::{ffi_arc_getter, ffi_vec_value_getters, ExternPointer, IdentifiablePointer, NativeResult, OwnedPtr};
 use crate::static_data::{
     Ability, AbilityIndex, Form, Gender, Item, Nature, Species, Statistic, StatisticSet, TypeIdentifier,
 };
@@ -21,9 +21,9 @@ extern "C" fn pokemon_new(
     gender: Gender,
     coloring: u8,
     nature: *const c_char,
-) -> IdentifiablePointer<Arc<Pokemon>> {
+) -> NativeResult<IdentifiablePointer<Arc<Pokemon>>> {
     let nature = unsafe { CStr::from_ptr(nature) }.into();
-    Arc::new(Pokemon::new(
+    let pokemon = Pokemon::new(
         library.as_ref().clone(),
         species.as_ref().clone(),
         form.as_ref(),
@@ -36,8 +36,11 @@ extern "C" fn pokemon_new(
         gender,
         coloring,
         &nature,
-    ))
-    .into()
+    );
+    match pokemon {
+        Ok(pokemon) => NativeResult::ok(Arc::new(pokemon).into()),
+        Err(err) => NativeResult::err(err),
+    }
 }
 
 /// Drops an Arc reference held by the FFI.
@@ -327,8 +330,8 @@ extern "C" fn pokemon_is_on_battlefield(ptr: ExternPointer<Arc<Pokemon>>) -> u8
 
 /// Damages the Pokemon by a certain amount of damage, from a damage source.
 #[no_mangle]
-extern "C" fn pokemon_damage(ptr: ExternPointer<Arc<Pokemon>>, damage: u32, source: DamageSource) {
-    ptr.as_ref().damage(damage, source)
+extern "C" fn pokemon_damage(ptr: ExternPointer<Arc<Pokemon>>, damage: u32, source: DamageSource) -> NativeResult<()> {
+    ptr.as_ref().damage(damage, source).into()
 }
 
 /// Heals the Pokemon by a specific amount. Unless allow_revive is set to true, this will not
diff --git a/src/ffi/mod.rs b/src/ffi/mod.rs
index 2668c6d..9b11953 100644
--- a/src/ffi/mod.rs
+++ b/src/ffi/mod.rs
@@ -93,6 +93,7 @@ pub(self) use ffi_arc_getter;
 pub(self) use ffi_arc_stringkey_getter;
 pub(self) use ffi_vec_stringkey_getters;
 pub(self) use ffi_vec_value_getters;
+use std::ffi::{c_char, CString};
 use std::mem::transmute;
 use std::sync::Arc;
 
@@ -131,6 +132,17 @@ pub(self) struct IdentifiablePointer<T> {
     pub id: usize,
 }
 
+impl<T> Clone for IdentifiablePointer<T> {
+    fn clone(&self) -> Self {
+        Self {
+            id: self.id,
+            ptr: self.ptr,
+        }
+    }
+}
+
+impl<T> Copy for IdentifiablePointer<T> {}
+
 impl<T> IdentifiablePointer<T> {
     /// Creates a new IdentifiablePointer.
     pub(self) fn new(ptr: *const T, id: ValueIdentifier) -> Self {
@@ -244,3 +256,55 @@ impl<T> IdentifiablePointer<T> {
         }
     }
 }
+
+/// Helper utility class to give either the data or an error to a FFI.
+#[repr(C)]
+union ResultUnion<T: Copy> {
+    /// If the result is ok, this contains the value.
+    ok: T,
+    /// If the result is an error, this contains the error message.
+    err: OwnedPtr<c_char>,
+}
+
+/// The result of a FFI call that can either be an error or a value.
+#[repr(C)]
+pub struct NativeResult<T: Copy> {
+    /// If the result is ok, this is 1, otherwise 0.
+    ok: u8,
+    /// The value or error.
+    value: ResultUnion<T>,
+}
+
+impl<T: Copy> NativeResult<T> {
+    /// Creates a new NativeResult with the given value.
+    pub fn ok(value: T) -> Self {
+        Self {
+            ok: 1,
+            value: ResultUnion { ok: value },
+        }
+    }
+    /// Creates a new NativeResult with the given error.
+    pub fn err(err: anyhow::Error) -> Self {
+        Self {
+            ok: 0,
+            value: ResultUnion {
+                err: CString::new(err.to_string()).unwrap().into_raw(),
+            },
+        }
+    }
+}
+
+impl<T: Copy> From<anyhow::Result<T>> for NativeResult<T> {
+    fn from(value: anyhow::Result<T>) -> Self {
+        match value {
+            Ok(v) => Self::ok(v),
+            Err(e) => Self::err(e),
+        }
+    }
+}
+
+impl<T: Copy> From<T> for NativeResult<T> {
+    fn from(value: T) -> Self {
+        Self::ok(value)
+    }
+}
diff --git a/src/ffi/static_data/growth_rate.rs b/src/ffi/static_data/growth_rate.rs
index 18bd282..6e45ce9 100644
--- a/src/ffi/static_data/growth_rate.rs
+++ b/src/ffi/static_data/growth_rate.rs
@@ -1,5 +1,5 @@
 use crate::defines::LevelInt;
-use crate::ffi::{ExternPointer, OwnedPtr};
+use crate::ffi::{ExternPointer, NativeResult, OwnedPtr};
 use crate::static_data::{GrowthRate, LookupGrowthRate};
 use std::ptr::drop_in_place;
 
@@ -25,6 +25,9 @@ extern "C" fn growth_rate_calculate_level(ptr: ExternPointer<Box<dyn GrowthRate>
 
 /// Calculate the experience something with this growth rate would have at a certain level.
 #[no_mangle]
-extern "C" fn growth_rate_calculate_experience(ptr: ExternPointer<Box<dyn GrowthRate>>, level: LevelInt) -> u32 {
-    ptr.as_ref().calculate_experience(level)
+extern "C" fn growth_rate_calculate_experience(
+    ptr: ExternPointer<Box<dyn GrowthRate>>,
+    level: LevelInt,
+) -> NativeResult<u32> {
+    ptr.as_ref().calculate_experience(level).into()
 }
diff --git a/src/ffi/static_data/libraries/growth_rate_library.rs b/src/ffi/static_data/libraries/growth_rate_library.rs
index ffd9774..155f948 100644
--- a/src/ffi/static_data/libraries/growth_rate_library.rs
+++ b/src/ffi/static_data/libraries/growth_rate_library.rs
@@ -1,5 +1,5 @@
 use crate::defines::LevelInt;
-use crate::ffi::{BorrowedPtr, ExternPointer, IdentifiablePointer, OwnedPtr};
+use crate::ffi::{BorrowedPtr, ExternPointer, IdentifiablePointer, NativeResult, OwnedPtr};
 use crate::static_data::{GrowthRate, GrowthRateLibrary, GrowthRateLibraryImpl};
 use std::ffi::{c_char, CStr};
 use std::ptr::drop_in_place;
@@ -34,9 +34,10 @@ unsafe extern "C" fn growth_rate_library_calculate_experience(
     ptr: ExternPointer<Box<dyn GrowthRateLibrary>>,
     growth_rate: BorrowedPtr<c_char>,
     level: LevelInt,
-) -> u32 {
+) -> NativeResult<u32> {
     ptr.as_ref()
         .calculate_experience(&CStr::from_ptr(growth_rate).into(), level)
+        .into()
 }
 
 /// Adds a new growth rate with a name and value.
diff --git a/src/ffi/static_data/libraries/library_settings.rs b/src/ffi/static_data/libraries/library_settings.rs
index bb2bf2e..ac2abad 100644
--- a/src/ffi/static_data/libraries/library_settings.rs
+++ b/src/ffi/static_data/libraries/library_settings.rs
@@ -1,5 +1,5 @@
 use crate::defines::LevelInt;
-use crate::ffi::{ExternPointer, IdentifiablePointer, OwnedPtr};
+use crate::ffi::{ExternPointer, IdentifiablePointer, NativeResult, OwnedPtr};
 use crate::static_data::{LibrarySettings, LibrarySettingsImpl};
 use std::ptr::drop_in_place;
 
@@ -12,9 +12,15 @@ use std::ptr::drop_in_place;
 extern "C" fn library_settings_new(
     max_level: LevelInt,
     shiny_rate: u32,
-) -> IdentifiablePointer<Box<dyn LibrarySettings>> {
-    let b: Box<dyn LibrarySettings> = Box::new(LibrarySettingsImpl::new(max_level, shiny_rate));
-    b.into()
+) -> NativeResult<IdentifiablePointer<Box<dyn LibrarySettings>>> {
+    match LibrarySettingsImpl::new(max_level, shiny_rate) {
+        Ok(settings) => {
+            let b: Box<dyn LibrarySettings> = Box::new(settings);
+            let p: IdentifiablePointer<Box<dyn LibrarySettings>> = b.into();
+            p.into()
+        }
+        Err(e) => NativeResult::err(e),
+    }
 }
 
 /// Drop a library settings object.
diff --git a/src/lib.rs b/src/lib.rs
index cffcea2..c557c73 100755
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
+// Linter modifications
 #![allow(clippy::too_many_arguments, clippy::needless_range_loop)]
 #![allow(clippy::not_unsafe_ptr_arg_deref)]
 #![allow(clippy::borrowed_box)]
@@ -5,9 +6,11 @@
 #![allow(ambiguous_glob_reexports)]
 #![deny(missing_docs)]
 #![deny(clippy::missing_docs_in_private_items)]
+// #![deny(clippy::unwrap_used)]
+// #![deny(clippy::expect_used)]
+// Features
 #![feature(test)]
 #![feature(const_option)]
-#![feature(is_some_and)]
 #![feature(new_uninit)]
 #![feature(get_mut_unchecked)]
 #![feature(strict_provenance)]
@@ -27,7 +30,6 @@ extern crate core;
 #[macro_use]
 extern crate enum_display_derive;
 
-use std::fmt::{Display, Formatter};
 #[doc(hidden)]
 pub use utils::*;
 
@@ -48,39 +50,3 @@ pub mod script_implementations;
 pub mod static_data;
 /// The utils module includes misc utils that are used within PkmnLib
 pub mod utils;
-
-/// The PokemonError enum holds all different error states that can be encountered in PkmnLib.
-#[derive(Debug, Clone)]
-pub enum PokemonError {
-    /// A script was requested, but we were unable to find it.
-    ScriptNotFound {
-        /// The category of the script we requested,
-        category: ScriptCategory,
-        /// The unique key of the requested script.
-        name: StringKey,
-    },
-    /// We requested data for a specific target, but that target does not exist on the battle field.
-    InvalidTargetRequested,
-
-    /// Misc errors. Use of this should be minimized, but it is useful for early development.
-    MiscError,
-}
-
-/// A simple result type.
-pub type PkmnResult<T> = Result<T, PokemonError>;
-
-impl Display for PokemonError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        match self {
-            PokemonError::ScriptNotFound { category, name } => {
-                write!(f, "No script found with category `{category}` and name `{name}`")
-            }
-            PokemonError::InvalidTargetRequested => {
-                write!(f, "Invalid target was requested")
-            }
-            PokemonError::MiscError => {
-                write!(f, "An unknown error occurred")
-            }
-        }
-    }
-}
diff --git a/src/script_implementations/wasm/export_registry/dynamic_data/battle.rs b/src/script_implementations/wasm/export_registry/dynamic_data/battle.rs
index 6268c28..3f923fc 100755
--- a/src/script_implementations/wasm/export_registry/dynamic_data/battle.rs
+++ b/src/script_implementations/wasm/export_registry/dynamic_data/battle.rs
@@ -59,7 +59,7 @@ register! {
         env: FunctionEnvMut<WebAssemblyEnv>,
         battle: ExternRef<Battle>,
     ) -> ExternRef<StringKey> {
-        let weather = battle.value_func(&env).unwrap().weather_name();
+        let weather = battle.value_func(&env).unwrap().weather_name().unwrap();
         if let Some(weather) = weather {
             ExternRef::func_new(&env, &weather)
         } else {
diff --git a/src/script_implementations/wasm/export_registry/dynamic_data/battle_random.rs b/src/script_implementations/wasm/export_registry/dynamic_data/battle_random.rs
index 308fa45..477c692 100755
--- a/src/script_implementations/wasm/export_registry/dynamic_data/battle_random.rs
+++ b/src/script_implementations/wasm/export_registry/dynamic_data/battle_random.rs
@@ -10,14 +10,14 @@ register! {
         env: FunctionEnvMut<WebAssemblyEnv>,
         battle_random: ExternRef<BattleRandom>,
     ) -> i32 {
-        battle_random.value_func(&env).unwrap().get()
+        battle_random.value_func(&env).unwrap().get().unwrap()
     }
     fn battle_random_get_max(
         env: FunctionEnvMut<WebAssemblyEnv>,
         battle_random: ExternRef<BattleRandom>,
         max: i32
     ) -> i32 {
-        battle_random.value_func(&env).unwrap().get_max(max)
+        battle_random.value_func(&env).unwrap().get_max(max).unwrap()
     }
     fn battle_random_get_between(
         env: FunctionEnvMut<WebAssemblyEnv>,
@@ -25,6 +25,6 @@ register! {
         min: i32,
         max: i32
     ) -> i32 {
-        battle_random.value_func(&env).unwrap().get_between(min, max)
+        battle_random.value_func(&env).unwrap().get_between(min, max).unwrap()
     }
 }
diff --git a/src/script_implementations/wasm/export_registry/dynamic_data/choice_queue.rs b/src/script_implementations/wasm/export_registry/dynamic_data/choice_queue.rs
index 4df32ef..55c5e6b 100755
--- a/src/script_implementations/wasm/export_registry/dynamic_data/choice_queue.rs
+++ b/src/script_implementations/wasm/export_registry/dynamic_data/choice_queue.rs
@@ -10,6 +10,6 @@ register! {
         battle_random: ExternRef<ChoiceQueue>,
         pokemon: ExternRef<Pokemon>
     ) -> u8 {
-        u8::from(battle_random.value_func(&env).unwrap().move_pokemon_choice_next(pokemon.value_func(&env).unwrap()))
+        u8::from(battle_random.value_func(&env).unwrap().move_pokemon_choice_next(pokemon.value_func(&env).unwrap()).unwrap())
     }
 }
diff --git a/src/script_implementations/wasm/export_registry/dynamic_data/pokemon.rs b/src/script_implementations/wasm/export_registry/dynamic_data/pokemon.rs
index 7c23e9c..b840f52 100755
--- a/src/script_implementations/wasm/export_registry/dynamic_data/pokemon.rs
+++ b/src/script_implementations/wasm/export_registry/dynamic_data/pokemon.rs
@@ -108,7 +108,7 @@ register! {
         source: u8
     ) {
         unsafe{
-            pokemon.value_func(&env).unwrap().damage(damage, transmute(source));
+            pokemon.value_func(&env).unwrap().damage(damage, transmute(source)).unwrap();
         }
     }
 
diff --git a/src/script_implementations/wasm/mod.rs b/src/script_implementations/wasm/mod.rs
index 424fd3a..051c163 100755
--- a/src/script_implementations/wasm/mod.rs
+++ b/src/script_implementations/wasm/mod.rs
@@ -1,3 +1,6 @@
+// allow these for now until we have a good result interface defined.
+#[allow(clippy::unwrap_used)]
+#[allow(clippy::expect_used)]
 /// The export registry module deals with registering all functions we require in WebAssembly.
 mod export_registry;
 /// A hacky extern ref implementation to ensure the client does not do things it is not allowed to do.
diff --git a/src/script_implementations/wasm/script_resolver.rs b/src/script_implementations/wasm/script_resolver.rs
index 01d2486..37bb11e 100755
--- a/src/script_implementations/wasm/script_resolver.rs
+++ b/src/script_implementations/wasm/script_resolver.rs
@@ -3,6 +3,8 @@ use std::fmt::{Debug, Formatter};
 use std::mem::{align_of, forget, size_of};
 use std::sync::{Arc, Weak};
 
+use anyhow::Result;
+use anyhow_ext::{anyhow, ensure};
 use hashbrown::{HashMap, HashSet};
 use parking_lot::lock_api::RwLockReadGuard;
 use parking_lot::{RawRwLock, RwLock};
@@ -19,7 +21,7 @@ use crate::script_implementations::wasm::script_function_cache::ScriptFunctionCa
 use crate::script_implementations::wasm::temp_wasm_allocator::{AllocatedObject, TempWasmAllocator};
 use crate::script_implementations::wasm::WebAssemblyScriptCapabilities;
 use crate::static_data::Item;
-use crate::{PkmnResult, ScriptCategory, StringKey, ValueIdentifiable, ValueIdentifier};
+use crate::{ScriptCategory, StringKey, ValueIdentifiable, ValueIdentifier};
 
 /// A WebAssembly script resolver implements the dynamic scripts functionality with WebAssembly.
 pub struct WebAssemblyScriptResolver {
@@ -175,21 +177,20 @@ impl ScriptResolver for WebAssemblyScriptResolver {
         owner: ScriptOwnerData,
         category: ScriptCategory,
         script_key: &StringKey,
-    ) -> PkmnResult<Option<Arc<dyn Script>>> {
+    ) -> Result<Option<Arc<dyn Script>>> {
         let script = self
             .load_script_fn
             .as_ref()
-            .unwrap()
+            .ok_or(anyhow!("Load script function was not found"))?
             .call(
                 &mut self.store_mut(),
                 category as u8,
                 ExternRef::new_with_resolver(self, script_key),
-            )
-            .unwrap();
+            )?;
         self.environment_data.setup_script(script, category, script_key, owner)
     }
 
-    fn load_item_script(&self, _key: &dyn Item) -> PkmnResult<Option<Arc<dyn ItemScript>>> {
+    fn load_item_script(&self, _key: &dyn Item) -> Result<Option<Arc<dyn ItemScript>>> {
         todo!()
     }
 }
@@ -354,7 +355,7 @@ impl WebAssemblyEnvironmentData {
             .unwrap()
             .call(
                 &mut self.store_mut(),
-                (size_of::<T>() * v.len()) as u32,
+                (std::mem::size_of_val(v)) as u32,
                 align_of::<T>() as u32,
             )
             .unwrap();
@@ -484,7 +485,7 @@ impl WebAssemblyEnvironmentData {
         category: ScriptCategory,
         script_key: &StringKey,
         owner: ScriptOwnerData,
-    ) -> PkmnResult<Option<Arc<dyn Script>>> {
+    ) -> Result<Option<Arc<dyn Script>>> {
         if script_ptr == 0 {
             return Ok(None);
         }
@@ -502,13 +503,12 @@ impl WebAssemblyEnvironmentData {
                     .read()
                     .get::<StringKey>(&"get_script_capabilities".into())
                 {
-                    let res = get_cap
-                        .call(&mut self.store_mut(), &[Value::I32(script_ptr as i32)])
-                        .unwrap();
+                    let res = get_cap.call(&mut self.store_mut(), &[Value::I32(script_ptr as i32)])?;
                     let ptr =
                         (self.memory() as *const WebAssemblyScriptCapabilities).offset(res[0].i32().unwrap() as isize);
-                    let length = res[1].i32().unwrap() as usize;
-                    for i in 0..length {
+                    let length = res[1].i32();
+                    ensure!(length.is_some(), "Script capabilities length was not a valid i32");
+                    for i in 0..length.unwrap() as usize {
                         capabilities.insert(*ptr.add(i));
                     }
                 }
diff --git a/src/static_data/growth_rates.rs b/src/static_data/growth_rates.rs
index 172afdf..dd035e5 100755
--- a/src/static_data/growth_rates.rs
+++ b/src/static_data/growth_rates.rs
@@ -1,11 +1,13 @@
 use crate::defines::LevelInt;
+use anyhow::Result;
+use anyhow_ext::ensure;
 
 /// A growth rate defines how much experience is required per level.
 pub trait GrowthRate {
     /// Calculate the level something with this growth rate would have at a certain experience.
     fn calculate_level(&self, experience: u32) -> LevelInt;
     /// Calculate the experience something with this growth rate would have at a certain level.
-    fn calculate_experience(&self, level: LevelInt) -> u32;
+    fn calculate_experience(&self, level: LevelInt) -> Result<u32>;
 }
 
 /// An implementation of the growth rate that uses a lookup table for experience.
@@ -32,11 +34,12 @@ impl GrowthRate for LookupGrowthRate {
         self.experience.len() as LevelInt
     }
 
-    fn calculate_experience(&self, level: LevelInt) -> u32 {
+    fn calculate_experience(&self, level: LevelInt) -> Result<u32> {
+        ensure!(level > 0, "Level must be greater than 0, but was {}", level);
         if level >= self.experience.len() as LevelInt {
-            *self.experience.last().unwrap()
+            Ok(*self.experience.last().unwrap())
         } else {
-            self.experience[(level - 1) as usize]
+            Ok(self.experience[(level - 1) as usize])
         }
     }
 }
@@ -50,7 +53,7 @@ pub(crate) mod tests {
         pub GrowthRate {}
         impl GrowthRate for GrowthRate {
             fn calculate_level(&self, experience: u32) -> LevelInt;
-            fn calculate_experience(&self, level: LevelInt) -> u32;
+            fn calculate_experience(&self, level: LevelInt) -> Result<u32>;
         }
     }
 }
diff --git a/src/static_data/libraries/growth_rate_library.rs b/src/static_data/libraries/growth_rate_library.rs
index 6b5579e..3e7f810 100755
--- a/src/static_data/libraries/growth_rate_library.rs
+++ b/src/static_data/libraries/growth_rate_library.rs
@@ -1,3 +1,4 @@
+use anyhow::Result;
 use std::fmt;
 use std::fmt::{Debug, Formatter};
 
@@ -12,7 +13,7 @@ pub trait GrowthRateLibrary: Debug + ValueIdentifiable {
     /// Calculates the level for a given growth key name and a certain experience.
     fn calculate_level(&self, growth_rate: &StringKey, experience: u32) -> LevelInt;
     /// Calculates the experience for a given growth key name and a certain level.
-    fn calculate_experience(&self, growth_rate: &StringKey, level: LevelInt) -> u32;
+    fn calculate_experience(&self, growth_rate: &StringKey, level: LevelInt) -> Result<u32>;
     /// Adds a new growth rate with a name and value.
     fn add_growth_rate(&mut self, key: &StringKey, value: Box<dyn GrowthRate>);
 }
@@ -41,7 +42,7 @@ impl GrowthRateLibrary for GrowthRateLibraryImpl {
         self.growth_rates[growth_rate].calculate_level(experience)
     }
     /// Calculates the experience for a given growth key name and a certain level.
-    fn calculate_experience(&self, growth_rate: &StringKey, level: LevelInt) -> u32 {
+    fn calculate_experience(&self, growth_rate: &StringKey, level: LevelInt) -> Result<u32> {
         self.growth_rates[growth_rate].calculate_experience(level)
     }
 
@@ -89,7 +90,7 @@ pub mod tests {
         pub GrowthRateLibrary{}
         impl GrowthRateLibrary for GrowthRateLibrary {
             fn calculate_level(&self, growth_rate: &StringKey, experience: u32) -> LevelInt;
-            fn calculate_experience(&self, growth_rate: &StringKey, level: LevelInt) -> u32;
+            fn calculate_experience(&self, growth_rate: &StringKey, level: LevelInt) -> Result<u32>;
             fn add_growth_rate(&mut self, key: &StringKey, value: Box<dyn GrowthRate>);
         }
         impl ValueIdentifiable for GrowthRateLibrary {
@@ -109,7 +110,7 @@ pub mod tests {
     #[test]
     fn add_growth_rate_to_library_and_calculate_experience() {
         let lib = build();
-        assert_eq!(lib.calculate_experience(&"test_growthrate".into(), 1), 0);
-        assert_eq!(lib.calculate_experience(&"test_growthrate".into(), 3), 10);
+        assert_eq!(lib.calculate_experience(&"test_growthrate".into(), 1).unwrap(), 0);
+        assert_eq!(lib.calculate_experience(&"test_growthrate".into(), 3).unwrap(), 10);
     }
 }
diff --git a/src/static_data/libraries/library_settings.rs b/src/static_data/libraries/library_settings.rs
index 56f19c3..e0752bc 100755
--- a/src/static_data/libraries/library_settings.rs
+++ b/src/static_data/libraries/library_settings.rs
@@ -1,5 +1,7 @@
 use crate::defines::LevelInt;
 use crate::{ValueIdentifiable, ValueIdentifier};
+use anyhow::Result;
+use anyhow_ext::ensure;
 use std::fmt::Debug;
 
 /// This library holds several misc settings for the library.
@@ -30,14 +32,14 @@ impl LibrarySettingsImpl {
     /// - `shiny_rate` is the chance of a Pokemon being shiny, as the denominator of a fraction, where
     /// the nominator is 1. For example, if this is 1000, then the chance of a Pokemon being shiny is
     /// 1/1000.
-    pub fn new(maximum_level: LevelInt, shiny_rate: u32) -> Self {
-        assert!(shiny_rate >= 1);
-        assert!(maximum_level >= 1);
-        Self {
+    pub fn new(maximum_level: LevelInt, shiny_rate: u32) -> Result<Self> {
+        ensure!(shiny_rate >= 1);
+        ensure!(maximum_level >= 1);
+        Ok(Self {
             identifier: Default::default(),
             maximum_level,
             shiny_rate,
-        }
+        })
     }
 }
 
diff --git a/src/static_data/libraries/nature_library.rs b/src/static_data/libraries/nature_library.rs
index 994f1f8..9701547 100644
--- a/src/static_data/libraries/nature_library.rs
+++ b/src/static_data/libraries/nature_library.rs
@@ -140,4 +140,18 @@ pub mod tests {
         let name2 = lib.get_nature_name(&n2);
         assert_eq!(name2, "bar".into());
     }
+
+    #[test]
+    fn create_nature_library_insert_single_and_retrieve_random() {
+        let mut lib = NatureLibraryImpl::new(2);
+        lib.load_nature(
+            "foo".into(),
+            NatureImpl::new(Statistic::HP, Statistic::Attack, 1.1, 0.9),
+        );
+        let n1 = lib.get_random_nature(&mut Random::new(0));
+        assert_eq!(n1.increased_stat(), Statistic::HP);
+        assert_eq!(n1.decreased_stat(), Statistic::Attack);
+        assert_eq!(n1.get_stat_modifier(n1.increased_stat()), 1.1);
+        assert_eq!(n1.get_stat_modifier(n1.decreased_stat()), 0.9);
+    }
 }
diff --git a/src/static_data/libraries/static_data.rs b/src/static_data/libraries/static_data.rs
index 7c98076..b1aa2af 100755
--- a/src/static_data/libraries/static_data.rs
+++ b/src/static_data/libraries/static_data.rs
@@ -199,7 +199,7 @@ pub mod test {
     pub fn build() -> StaticDataImpl {
         StaticDataImpl {
             identifier: Default::default(),
-            settings: Box::new(LibrarySettingsImpl::new(100, 100)),
+            settings: Box::new(LibrarySettingsImpl::new(100, 100).unwrap()),
             species: crate::static_data::libraries::species_library::tests::build(),
             moves: crate::static_data::libraries::move_library::tests::build(),
             items: crate::static_data::libraries::item_library::tests::build(),
diff --git a/tests/common/library_loader.rs b/tests/common/library_loader.rs
index bdba6f5..a511af2 100755
--- a/tests/common/library_loader.rs
+++ b/tests/common/library_loader.rs
@@ -65,7 +65,7 @@ pub fn load_library() -> LoadResult {
     let species_load_time = t2 - t1;
 
     let data = StaticDataImpl::new(
-        Box::new(LibrarySettingsImpl::new(100, 100)),
+        Box::new(LibrarySettingsImpl::new(100, 100).unwrap()),
         species,
         moves,
         items,
diff --git a/tests/common/test_case.rs b/tests/common/test_case.rs
index 01ca3de..378cd1d 100755
--- a/tests/common/test_case.rs
+++ b/tests/common/test_case.rs
@@ -79,6 +79,6 @@ impl TestPokemon {
             builder = builder.learn_move(StringKey::new(move_name));
         }
 
-        builder.build()
+        builder.build().unwrap()
     }
 }
diff --git a/tests/integration.rs b/tests/integration.rs
index e86d46e..d7810e7 100755
--- a/tests/integration.rs
+++ b/tests/integration.rs
@@ -45,18 +45,56 @@ fn validate_library_load() {
     );
 }
 
+#[test]
+fn load_non_existing_wasm_script() {
+    let start_time = chrono::Utc::now();
+    let result = library_loader::load_library();
+    let end_time = chrono::Utc::now();
+    println!(
+        "Built library in {} ms\
+              \n\t- Types load time: {} ms\
+              \n\t- Natures load time: {} ms\
+              \n\t- Items load time: {} ms\
+              \n\t- Growth Rate load time: {} ms\
+              \n\t- Abilities load time: {} ms\
+              \n\t- Moves load time: {} ms\
+              \n\t- Species load time: {} ms\
+              \n\t- WASM load time: {} ms\
+              ",
+        (end_time - start_time).num_milliseconds(),
+        result.types_load_time.num_milliseconds(),
+        result.natures_load_time.num_milliseconds(),
+        result.items_load_time.num_milliseconds(),
+        result.growth_rate_load_time.num_milliseconds(),
+        result.abilities_load_time.num_milliseconds(),
+        result.moves_load_time.num_milliseconds(),
+        result.species_load_time.num_milliseconds(),
+        result.wasm_load_time.num_milliseconds(),
+    );
+    let script = result
+        .library
+        .load_script(ScriptOwnerData::None, ScriptCategory::Move, &"_____non_existing".into())
+        .unwrap();
+
+    assert!(script.is_none());
+}
+
 /// Assurance has the interesting properties that it creates a special data script internally, and
 /// deletes that data script through the get_owner functionality.
 #[test]
-#[cfg_attr(miri, ignore)]
 fn validate_assurance() {
     let lib = get_library();
     let p1 = Arc::new(
         PokemonBuilder::new(lib.clone(), "charizard".into(), 100)
             .learn_move("assurance".into())
-            .build(),
+            .build()
+            .unwrap(),
+    );
+    let p2 = Arc::new(
+        PokemonBuilder::new(lib.clone(), "venusaur".into(), 100)
+            .build()
+            .unwrap(),
     );
-    let p2 = Arc::new(PokemonBuilder::new(lib.clone(), "venusaur".into(), 100).build());
 
     let party1 = BattleParty::new(
         Arc::new(PokemonParty::new_from_vec(vec![Some(p1.clone())])),