fix: import from overlay fall back to main pack

bolt/module.py

@@ -174,6 +174,21 @@ def current_path(self) -> str:
             "Currently executing module has no associated resource location."
         )
 
+    def lookup(self, path: str) -> TextFileBase[Any]:
+        """Lookup the associated source file in the compilation database.
+
+        If we're currently in an overlay, fall back to the source file in the main
+        data pack.
+        """
+        if current := self.database.index.get(path):
+            return current
+
+        current_pack = self.database[self.database.current].pack
+        if current_pack is None or current_pack.overlay_parent is None:
+            raise KeyError(path)
+
+        return self.database.indices[current_pack.overlay_parent][path]
+
     def match_ast(
         self,
         node: AstRoot,
@@ -183,7 +198,7 @@ def match_ast(
         if not current:
             current = self.database.current
         elif isinstance(current, str):
-            current = self.database.index[current]
+            current = self.lookup(current)
 
         compilation_unit = self.database[current]
         compilation_unit.ast = node
@@ -192,7 +207,7 @@ def match_ast(
 
     def __getitem__(self, current: Union[TextFileBase[Any], str]) -> CompiledModule:
         if isinstance(current, str):
-            current = self.database.index[current]
+            current = self.lookup(current)
 
         compilation_unit = self.database[current]
         name = compilation_unit.resource_location or "<unknown>"
@@ -267,9 +282,10 @@ def __len__(self) -> int:
     def get(self, current: Union[TextFileBase[Any], str]) -> Optional[CompiledModule]:
         """Return executable module if exists."""
         if isinstance(current, str):
-            if current not in self.database.index:
+            try:
+                current = self.lookup(current)
+            except KeyError:
                 return None
-            current = self.database.index[current]
 
         if current not in self.database:
             return None

examples/bolt_overlay/src/data/demo/functions/foo.mcfunction

@@ -1 +1,2 @@
-say ("my" + "stuff")
+from ./vars import stuff
+say f"my {stuff}"

examples/bolt_overlay/src/data/demo/modules/vars.bolt

@@ -0,0 +1 @@
+stuff = 123

examples/bolt_overlay/src/dummy_overlay/data/demo/functions/foo.mcfunction

@@ -1 +1,3 @@
+from ./vars import stuff
 say (1 + 2)
+say stuff

tests/snapshots/examples__build_bolt_overlay__0.pack.md

@@ -18,7 +18,7 @@
 `@function demo:foo`
 
 ```mcfunction
-say mystuff
+say my 123
 ```
 
 ## Overlay `dummy_overlay`
@@ -31,6 +31,7 @@ say mystuff
 
 ```mcfunction
 say 3
+say 123
 ```
 
 `@endoverlay`