diff --git a/gen_7_scripts/src/moves/assist.rs b/gen_7_scripts/src/moves/assist.rs
index 2a3e09a..ecd6005 100755
--- a/gen_7_scripts/src/moves/assist.rs
+++ b/gen_7_scripts/src/moves/assist.rs
@@ -7,24 +7,23 @@ use pkmn_lib_interface::handling::{Script, ScriptCapabilities};
 script!(Assist, "assist");
 
 impl Assist {
+    /// Gets all the learned moves from the entire party, except the ones from the user, and the ones
+    /// that are not allowed to be copied.
     fn get_party_moves(party: &Party, user: &Pokemon) -> Vec<MoveData> {
         let mut possible_moves = Vec::new();
         // Iterate over every mon in the party
-        for mon_index in 0..party.length() {
-            let mon = party.get_pokemon(mon_index);
-            if let Some(mon) = mon {
-                // Ignore moves from the user
-                if mon.equals(user) {
-                    continue;
-                }
-                // Iterate over all moves. We make the assumption of 4 moves.
-                for move_index in 0..4 {
-                    let mv = mon.get_learned_move(move_index);
-                    if let Some(mv) = mv {
-                        // Make sure we can copy the move, otherwise add it as possible move.
-                        if crate::utils::copyable_moves::can_copy_move(&mv.move_data()) {
-                            possible_moves.push(mv.move_data())
-                        }
+        for mon in party.into_iter().flatten() {
+            // Ignore moves from the user
+            if mon.equals(user) {
+                continue;
+            }
+            // Iterate over all moves. We make the assumption of 4 moves.
+            for move_index in 0..4 {
+                let mv = mon.get_learned_move(move_index);
+                if let Some(mv) = mv {
+                    // Make sure we can copy the move, otherwise add it as possible move.
+                    if crate::utils::copyable_moves::can_copy_move(&mv.move_data()) {
+                        possible_moves.push(mv.move_data())
                     }
                 }
             }
@@ -49,7 +48,13 @@ impl Script for Assist {
     fn change_move(&self, choice: TurnChoice, move_name: &mut StringKey) {
         let user = choice.user();
         let battle = user.battle().unwrap();
-        let party = battle.find_party_for_pokemon(&user).unwrap().party();
+        let party = battle.find_party_for_pokemon(&user);
+        if party.is_none() {
+            choice.fail();
+            return;
+        }
+
+        let party = party.unwrap().party();
         let possible_moves = Self::get_party_moves(&party, &user);
 
         if possible_moves.is_empty() {
@@ -64,3 +69,211 @@ impl Script for Assist {
         self
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use alloc::boxed::Box;
+    use alloc::rc::Rc;
+    use alloc::vec;
+    use pkmn_lib_interface::app_interface::{
+        MockBaseTurnChoiceData, MockBattle, MockBattleParty, MockBattleRandom, MockLearnedMove,
+        MockMoveData, MockMoveTurnChoiceData, MockParty, MockPokemon,
+    };
+
+    fn mock_pokemon_with_moves(moves: Vec<StringKey>, equals_user: bool) -> Pokemon {
+        let mut mon = MockPokemon::new();
+        let moves = Rc::new(moves);
+        mon.expect_get_learned_move().returning_st(move |index| {
+            let moves = moves.clone();
+            if index < moves.len() {
+                let mut learned_move = MockLearnedMove::new();
+                learned_move.expect_move_data().returning_st(move || {
+                    let mut move_data = MockMoveData::new();
+                    let moves = moves.clone();
+                    move_data
+                        .expect_name()
+                        .returning_st(move || moves.get(index).unwrap().clone());
+                    Rc::new(move_data)
+                });
+                Some(Rc::new(learned_move))
+            } else {
+                None
+            }
+        });
+        mon.expect_equals().return_const(equals_user);
+        Rc::new(mon)
+    }
+
+    #[test]
+    fn get_party_moves_returns_moves_from_party_length_1() {
+        let mut party = MockParty::new();
+        party.expect_length().once().return_const(1usize);
+        party
+            .expect_get_pokemon()
+            .times(1)
+            .returning_st(move |_| Some(mock_pokemon_with_moves(vec!["tackle".into()], false)));
+
+        let party: Party = Rc::new(party);
+        let user: Pokemon = Rc::new(MockPokemon::new());
+
+        let moves = Assist::get_party_moves(&party, &user);
+        assert_eq!(1, moves.len());
+        assert_eq!(moves[0].name(), "tackle".into())
+    }
+
+    #[test]
+    fn get_party_moves_returns_moves_from_party_length_7() {
+        let mut party = MockParty::new();
+        party.expect_length().once().return_const(3usize);
+        party
+            .expect_get_pokemon()
+            .times(3)
+            .returning_st(move |index| {
+                if index == 0 {
+                    Some(mock_pokemon_with_moves(
+                        vec!["move1".into(), "move2".into(), "move3".into()],
+                        false,
+                    ))
+                } else if index == 1 {
+                    Some(mock_pokemon_with_moves(
+                        vec!["move1".into(), "move4".into()],
+                        false,
+                    ))
+                } else if index == 2 {
+                    Some(mock_pokemon_with_moves(
+                        vec!["move2".into(), "move5".into()],
+                        false,
+                    ))
+                } else {
+                    None
+                }
+            });
+
+        let party: Party = Rc::new(party);
+        let user: Pokemon = Rc::new(MockPokemon::new());
+
+        let moves = Assist::get_party_moves(&party, &user);
+        assert_eq!(7, moves.len());
+        assert_eq!(moves[0].name(), "move1".into());
+        assert_eq!(moves[1].name(), "move2".into());
+        assert_eq!(moves[2].name(), "move3".into());
+        assert_eq!(moves[3].name(), "move1".into());
+        assert_eq!(moves[4].name(), "move4".into());
+        assert_eq!(moves[5].name(), "move2".into());
+        assert_eq!(moves[6].name(), "move5".into());
+    }
+
+    #[test]
+    fn get_party_moves_ignores_user() {
+        let mut party = MockParty::new();
+        party.expect_length().once().return_const(3usize);
+        party
+            .expect_get_pokemon()
+            .times(3)
+            .returning_st(move |index| {
+                if index == 0 {
+                    Some(mock_pokemon_with_moves(
+                        vec!["move1".into(), "move2".into(), "move3".into()],
+                        false,
+                    ))
+                } else if index == 1 {
+                    Some(mock_pokemon_with_moves(
+                        vec!["move1".into(), "move4".into()],
+                        true,
+                    ))
+                } else if index == 2 {
+                    Some(mock_pokemon_with_moves(
+                        vec!["move2".into(), "move5".into()],
+                        false,
+                    ))
+                } else {
+                    None
+                }
+            });
+
+        let party: Party = Rc::new(party);
+        let user: Pokemon = Rc::new(MockPokemon::new());
+
+        let moves = Assist::get_party_moves(&party, &user);
+        assert_eq!(5, moves.len());
+        assert_eq!(moves[0].name(), "move1".into());
+        assert_eq!(moves[1].name(), "move2".into());
+        assert_eq!(moves[2].name(), "move3".into());
+        assert_eq!(moves[3].name(), "move2".into());
+        assert_eq!(moves[4].name(), "move5".into());
+    }
+
+    #[test]
+    fn get_party_moves_ignores_non_copyable_move() {
+        let mut party = MockParty::new();
+        party.expect_length().once().return_const(1usize);
+        party
+            .expect_get_pokemon()
+            .times(1)
+            .returning_st(move |_| Some(mock_pokemon_with_moves(vec!["chatter".into()], false)));
+        let party: Party = Rc::new(party);
+        let user: Pokemon = Rc::new(MockPokemon::new());
+
+        let moves = Assist::get_party_moves(&party, &user);
+        assert_eq!(0, moves.len());
+    }
+
+    #[test]
+    fn if_moves_found_assist_uses_that_move() {
+        let mut party = MockParty::new();
+        party.expect_length().once().return_const(1usize);
+        party
+            .expect_get_pokemon()
+            .times(1)
+            .returning_st(move |_| Some(mock_pokemon_with_moves(vec!["tackle".into()], false)));
+
+        let party: Party = Rc::new(party);
+
+        let mut base_turn_choice = MockBaseTurnChoiceData::new();
+
+        base_turn_choice.expect_user().once().returning_st(move || {
+            let party = party.clone();
+            let mut user = MockPokemon::new();
+            user.expect_battle().once().returning_st(move || {
+                let party = party.clone();
+                let mut battle = MockBattle::new();
+                battle
+                    .expect_find_party_for_pokemon()
+                    .once()
+                    .returning_st(move |_| {
+                        let party = party.clone();
+                        let mut p = MockBattleParty::new();
+                        p.expect_party().returning_st(move || party.clone());
+
+                        Some(Rc::new(p))
+                    });
+
+                battle.expect_random().returning_st(|| {
+                    let mut random = MockBattleRandom::new();
+                    random.expect_get_max().return_const(0);
+                    Rc::new(random)
+                });
+
+                Some(Rc::new(battle))
+            });
+
+            Rc::new(user)
+        });
+        base_turn_choice.expect_fail().never();
+
+        let base_turn_choice = Rc::new(base_turn_choice);
+
+        let mut move_turn_choice = MockMoveTurnChoiceData::new();
+        move_turn_choice
+            .expect_base()
+            .returning_st(move || base_turn_choice.clone());
+
+        let choice_data = TurnChoice::Move(Box::new(move_turn_choice));
+
+        let mut move_name: StringKey = "".into();
+        let script = Assist::new();
+        script.change_move(choice_data, &mut move_name);
+        assert_eq!(move_name, "tackle".into())
+    }
+}
diff --git a/gen_7_scripts/src/utils/copyable_moves.rs b/gen_7_scripts/src/utils/copyable_moves.rs
index 822c7ef..a904191 100755
--- a/gen_7_scripts/src/utils/copyable_moves.rs
+++ b/gen_7_scripts/src/utils/copyable_moves.rs
@@ -16,8 +16,7 @@ macro_rules! non_copyable {
 }
 
 pub fn can_copy_move(mv: &MoveData) -> bool {
-    // A list of all moves that cannot be copied. This expands to a match statement, so is fast on
-    // runtime.
+    // A list of all moves that cannot be copied. This expands to a match statement on the move name.
     non_copyable!(
         mv,
         "assist",
diff --git a/pkmn_lib_interface/src/app_interface/dynamic_data/battle_party.rs b/pkmn_lib_interface/src/app_interface/dynamic_data/battle_party.rs
index 619e621..8eb3afc 100755
--- a/pkmn_lib_interface/src/app_interface/dynamic_data/battle_party.rs
+++ b/pkmn_lib_interface/src/app_interface/dynamic_data/battle_party.rs
@@ -1,11 +1,14 @@
 use crate::app_interface::Party;
 use alloc::rc::Rc;
 
+#[cfg_attr(feature = "mock_data", mockall::automock)]
 pub trait BattlePartyTrait {
     fn party(&self) -> Party;
 }
 
 pub type BattleParty = Rc<dyn BattlePartyTrait>;
+#[cfg(feature = "mock_data")]
+pub type MockBattleParty = MockBattlePartyTrait;
 
 #[cfg(not(feature = "mock_data"))]
 mod implementation {
diff --git a/pkmn_lib_interface/src/app_interface/dynamic_data/learned_move.rs b/pkmn_lib_interface/src/app_interface/dynamic_data/learned_move.rs
index ec0dbf3..155cbb6 100755
--- a/pkmn_lib_interface/src/app_interface/dynamic_data/learned_move.rs
+++ b/pkmn_lib_interface/src/app_interface/dynamic_data/learned_move.rs
@@ -11,6 +11,7 @@ pub enum MoveLearnMethod {
     Level = 1,
 }
 
+#[cfg_attr(feature = "mock_data", mockall::automock)]
 pub trait LearnedMoveTrait {
     fn move_data(&self) -> MoveData;
     fn learn_method(&self) -> MoveLearnMethod;
@@ -19,6 +20,8 @@ pub trait LearnedMoveTrait {
 }
 
 pub type LearnedMove = Rc<dyn LearnedMoveTrait>;
+#[cfg(feature = "mock_data")]
+pub type MockLearnedMove = MockLearnedMoveTrait;
 
 #[cfg(not(feature = "mock_data"))]
 mod implementation {
diff --git a/pkmn_lib_interface/src/app_interface/dynamic_data/party.rs b/pkmn_lib_interface/src/app_interface/dynamic_data/party.rs
index a6e1507..259df19 100755
--- a/pkmn_lib_interface/src/app_interface/dynamic_data/party.rs
+++ b/pkmn_lib_interface/src/app_interface/dynamic_data/party.rs
@@ -1,6 +1,9 @@
 use crate::app_interface::Pokemon;
+use alloc::boxed::Box;
 use alloc::rc::Rc;
+use core::iter::IntoIterator;
 
+#[cfg_attr(feature = "mock_data", mockall::automock)]
 pub trait PartyTrait {
     fn get_pokemon(&self, index: usize) -> Option<Pokemon>;
     fn length(&self) -> usize;
@@ -8,6 +11,18 @@ pub trait PartyTrait {
 
 pub type Party = Rc<dyn PartyTrait>;
 
+impl<'a> IntoIterator for &'a dyn PartyTrait {
+    type Item = Option<Pokemon>;
+    type IntoIter = ExternIterator<'a, Self::Item>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        ExternIterator::new(self.length(), Box::new(move |i| self.get_pokemon(i)))
+    }
+}
+
+#[cfg(feature = "mock_data")]
+pub type MockParty = MockPartyTrait;
+
 #[cfg(not(feature = "mock_data"))]
 mod implementation {
     use super::*;
@@ -54,5 +69,6 @@ mod implementation {
     }
 }
 
+use crate::utils::ExternIterator;
 #[cfg(not(feature = "mock_data"))]
 pub use implementation::*;
diff --git a/pkmn_lib_interface/src/app_interface/dynamic_data/turn_choices.rs b/pkmn_lib_interface/src/app_interface/dynamic_data/turn_choices.rs
index ea54ec1..70d6317 100755
--- a/pkmn_lib_interface/src/app_interface/dynamic_data/turn_choices.rs
+++ b/pkmn_lib_interface/src/app_interface/dynamic_data/turn_choices.rs
@@ -36,6 +36,7 @@ impl TurnChoice {
     }
 }
 
+#[cfg_attr(feature = "mock_data", mockall::automock)]
 pub trait BaseTurnChoiceDataTrait {
     fn reference(&self) -> u32;
     fn user(&self) -> Pokemon;
@@ -45,15 +46,20 @@ pub trait BaseTurnChoiceDataTrait {
 }
 
 pub type BaseTurnChoiceData = Rc<dyn BaseTurnChoiceDataTrait>;
+#[cfg(feature = "mock_data")]
+pub type MockBaseTurnChoiceData = MockBaseTurnChoiceDataTrait;
 
+#[cfg_attr(feature = "mock_data", mockall::automock)]
 pub trait MoveTurnChoiceDataTrait {
     fn base(&self) -> BaseTurnChoiceData;
     fn used_move(&self) -> LearnedMove;
     fn target_side(&self) -> u8;
     fn target_index(&self) -> u8;
     fn priority(&self) -> i8;
-    fn move_script(&self) -> Option<&Box<dyn Script>>;
+    fn move_script<'a>(&self) -> Option<&'a Box<dyn Script>>;
 }
+#[cfg(feature = "mock_data")]
+pub type MockMoveTurnChoiceData = MockMoveTurnChoiceDataTrait;
 
 #[cfg(not(feature = "mock_data"))]
 mod implementation {
diff --git a/pkmn_lib_interface/src/app_interface/static_data/move_data.rs b/pkmn_lib_interface/src/app_interface/static_data/move_data.rs
index 8df5d6a..34b5511 100755
--- a/pkmn_lib_interface/src/app_interface/static_data/move_data.rs
+++ b/pkmn_lib_interface/src/app_interface/static_data/move_data.rs
@@ -29,6 +29,7 @@ pub enum MoveTarget {
     OnSelf,
 }
 
+#[cfg_attr(feature = "mock_data", mockall::automock)]
 pub trait MoveDataTrait {
     fn name(&self) -> StringKey;
     fn move_type(&self) -> u8;
@@ -42,6 +43,8 @@ pub trait MoveDataTrait {
 }
 
 pub type MoveData = Rc<dyn MoveDataTrait>;
+#[cfg(feature = "mock_data")]
+pub type MockMoveData = MockMoveDataTrait;
 
 #[cfg(not(feature = "mock_data"))]
 mod implementation {
diff --git a/pkmn_lib_interface/src/app_interface/string_key.rs b/pkmn_lib_interface/src/app_interface/string_key.rs
index f668582..345567c 100755
--- a/pkmn_lib_interface/src/app_interface/string_key.rs
+++ b/pkmn_lib_interface/src/app_interface/string_key.rs
@@ -4,7 +4,7 @@ use crate::handling::Cacheable;
 use crate::{ExternRef, ExternalReferenceType};
 use alloc::rc::Rc;
 use core::cell::RefCell;
-use core::fmt::{Display, Formatter};
+use core::fmt::{Debug, Display, Formatter};
 use cstr_core::CString;
 
 struct StringKeyInner {
@@ -19,6 +19,12 @@ pub struct StringKey {
     data: Rc<StringKeyInner>,
 }
 
+impl Debug for StringKey {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
+        write!(f, "\"{}\"", self.str().to_str().unwrap())
+    }
+}
+
 impl StringKey {
     #[cfg(not(feature = "mock_data"))]
     pub(crate) fn new(ptr: ExternRef<Self>) -> Self {
@@ -185,4 +191,10 @@ mod test {
             }
         }
     }
+
+    impl From<&str> for StringKey {
+        fn from(value: &str) -> Self {
+            StringKey::new(value)
+        }
+    }
 }
diff --git a/pkmn_lib_interface/src/utils.rs b/pkmn_lib_interface/src/utils.rs
index 2421dbe..841e7b0 100755
--- a/pkmn_lib_interface/src/utils.rs
+++ b/pkmn_lib_interface/src/utils.rs
@@ -1,3 +1,5 @@
+use alloc::boxed::Box;
+
 #[macro_export]
 #[cfg(not(feature = "mock_data"))]
 macro_rules! println { ($($args:tt)*) => { crate::utils::print_raw(alloc::format!($($args)*).as_bytes()); } }
@@ -77,3 +79,33 @@ mod implementation {
 
 #[cfg(not(feature = "mock_data"))]
 pub use implementation::*;
+
+pub struct ExternIterator<'a, T> {
+    len: usize,
+    index: usize,
+    getter: Box<dyn Fn(usize) -> T + 'a>,
+}
+
+impl<'a, T> ExternIterator<'a, T> {
+    pub fn new(len: usize, f: Box<dyn Fn(usize) -> T + 'a>) -> Self {
+        Self {
+            len,
+            index: 0,
+            getter: f,
+        }
+    }
+}
+
+impl<'a, T> Iterator for ExternIterator<'a, T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let index = self.index;
+        if index >= self.len {
+            None
+        } else {
+            self.index += 1;
+            Some((self.getter)(index))
+        }
+    }
+}