Fix derive tests

crates/compiler/derive/src/lib.rs

@@ -150,7 +150,7 @@ impl DerivedModule {
         &self,
         lambda_set_var: Variable,
         target: &mut Subs,
-        target_rank: Rank,
+        _target_rank: Rank,
     ) -> Variable {
         let ambient_function_var = self.subs.get_lambda_set(lambda_set_var).ambient_function;
 
@@ -198,8 +198,19 @@ impl DerivedModule {
             .collect()
     }
 
-    pub fn decompose(self) -> IdentIds {
+    /// # Safety
-        self.derived_ident_ids
+    ///
+    /// Prefer using a fresh Derived module with [`Derived::default`]. Use this only in testing.
+    pub unsafe fn from_components(subs: Subs, ident_ids: IdentIds) -> Self {
+        Self {
+            map: Default::default(),
+            subs,
+            derived_ident_ids: ident_ids,
+        }
+    }
+
+    pub fn decompose(self) -> (Subs, IdentIds) {
+        (self.subs, self.derived_ident_ids)
     }
 }
 

crates/compiler/load_internal/src/file.rs

@@ -2680,7 +2680,7 @@ fn finish_specialization(
     let mut all_ident_ids = state.constrained_ident_ids;
 
     // Associate the ident IDs from the derived synth module
-    let derived_synth_ident_ids = Arc::try_unwrap(state.derived_module)
+    let (_, derived_synth_ident_ids) = Arc::try_unwrap(state.derived_module)
         .unwrap_or_else(|_| internal_error!("Outstanding references to the derived module"))
         .into_inner()
         .unwrap()
@@ -2805,7 +2805,7 @@ fn finish(
         .into_module_ids();
 
     // Associate the ident IDs from the derived synth module
-    let derived_synth_ident_ids = Arc::try_unwrap(state.derived_module)
+    let (_, derived_synth_ident_ids) = Arc::try_unwrap(state.derived_module)
         .unwrap_or_else(|_| internal_error!("Outstanding references to the derived module"))
         .into_inner()
         .unwrap()

crates/compiler/test_derive/src/encoding.rs

@@ -22,12 +22,12 @@ use roc_can::{
 use roc_collections::VecSet;
 use roc_constrain::expr::constrain_decls;
 use roc_debug_flags::dbg_do;
-use roc_derive::{synth_var, DerivedModule, StolenFromDerived};
+use roc_derive::{synth_var, DerivedModule};
 use roc_derive_key::{DeriveKey, Derived};
 use roc_load_internal::file::{add_imports, default_aliases, LoadedModule, Threading};
 use roc_module::{
     ident::TagName,
-    symbol::{Interns, ModuleId, Symbol},
+    symbol::{IdentIds, Interns, ModuleId, Symbol},
 };
 use roc_region::all::LineInfo;
 use roc_reporting::report::{type_problem, RocDocAllocator};
@@ -244,12 +244,12 @@ where
     )
     .unwrap();
 
-    let mut derived_module = DerivedModule::default();
+    let mut subs = Subs::new();
+    let ident_ids = IdentIds::default();
+    let source_var = synth_input(&mut subs);
+    let key = get_key(&subs, source_var);
 
-    let mut stolen = derived_module.steal();
+    let mut derived_module = unsafe { DerivedModule::from_components(subs, ident_ids) };
-    let source_var = synth_input(&mut stolen.subs);
-    let key = get_key(&stolen.subs, source_var);
-    derived_module.return_stolen(stolen);
 
     let mut exposed_by_module = ExposedByModule::default();
     exposed_by_module.insert(
@@ -260,13 +260,12 @@ where
         },
     );
 
-    let (derived_symbol, derived_def, specialization_lsets) =
+    let (_derived_symbol, derived_def, specialization_lsets) =
         derived_module.get_or_insert(&exposed_by_module, key);
-    let derived_symbol = *derived_symbol;
     let specialization_lsets = specialization_lsets.clone();
     let derived_def = derived_def.clone();
 
-    let StolenFromDerived { ident_ids, subs } = derived_module.steal();
+    let (subs, ident_ids) = derived_module.decompose();
 
     interns.all_ident_ids.insert(DERIVED_MODULE, ident_ids);
     DERIVED_MODULE.register_debug_idents(interns.all_ident_ids.get(&DERIVED_MODULE).unwrap());