Fix module resolution bug

src/codegen/sdk/core/external_module.py

@@ -35,14 +35,16 @@ class ExternalModule(
     """
 
     node_type: Literal[NodeType.EXTERNAL] = NodeType.EXTERNAL
+    _import: Import | None = None
 
-    def __init__(self, ts_node: TSNode, file_node_id: NodeId, G: CodebaseGraph, import_name: Name) -> None:
+    def __init__(self, ts_node: TSNode, file_node_id: NodeId, G: CodebaseGraph, import_name: Name, import_node: Import | None = None) -> None:
         self.node_id = G.add_node(self)
         super().__init__(ts_node, file_node_id, G, None)
         self._name_node = import_name
         self.return_type = StubPlaceholder(parent=self)
         assert self._idx_key not in self.G._ext_module_idx
         self.G._ext_module_idx[self._idx_key] = self.node_id
+        self._import = import_node
 
     @property
     def _idx_key(self) -> str:
@@ -68,7 +70,7 @@ def from_import(cls, imp: Import) -> ExternalModule:
         Returns:
             ExternalModule: A new ExternalModule instance representing the external module.
         """
-        return cls(imp.ts_node, imp.file_node_id, imp.G, imp._unique_node)
+        return cls(imp.ts_node, imp.file_node_id, imp.G, imp._unique_node, imp)
 
     @property
     @reader
@@ -136,7 +138,7 @@ def viz(self) -> VizNode:
     @noapidoc
     @reader
     def resolve_attribute(self, name: str) -> ExternalModule | None:
-        return self
+        return self._import.resolve_attribute(name) or self
 
     @noapidoc
     @commiter

src/codegen/sdk/core/import_resolution.py

@@ -11,6 +11,7 @@
 from codegen.sdk.core.expressions.name import Name
 from codegen.sdk.core.external_module import ExternalModule
 from codegen.sdk.core.interfaces.chainable import Chainable
+from codegen.sdk.core.interfaces.has_attribute import HasAttribute
 from codegen.sdk.core.interfaces.usable import Usable
 from codegen.sdk.core.statements.import_statement import ImportStatement
 from codegen.sdk.enums import EdgeType, ImportType, NodeType
@@ -57,7 +58,7 @@ class ImportResolution(Generic[TSourceFile]):
 
 
 @apidoc
-class Import(Usable[ImportStatement], Chainable, Generic[TSourceFile]):
+class Import(Usable[ImportStatement], Chainable, Generic[TSourceFile], HasAttribute[TSourceFile]):
     """Represents a single symbol being imported.
 
     For example, this is one `Import` in Python (and similar applies to Typescript, etc.):
@@ -115,7 +116,7 @@ def __rich_repr__(self) -> rich.repr.Result:
 
     @noapidoc
     @abstractmethod
-    def resolve_import(self, base_path: str | None = None) -> ImportResolution[TSourceFile] | None:
+    def resolve_import(self, base_path: str | None = None, *, add_module_name: str | None = None) -> ImportResolution[TSourceFile] | None:
         """Resolves the import to a symbol defined outside the file.
 
         Returns an ImportResolution object.
@@ -662,6 +663,17 @@ def remove_if_unused(self) -> None:
         ):
             self.remove()
 
+    @noapidoc
+    @reader
+    def resolve_attribute(self, attribute: str) -> TSourceFile | None:
+        # Handles implicit namespace imports in python
+        if not isinstance(self._imported_symbol(), ExternalModule):
+            return None
+        resolved = self.resolve_import(add_module_name=attribute)
+        if resolved:
+            return resolved.symbol or resolved.from_file
+        return None
+
 
 TImport = TypeVar("TImport", bound="Import")
 

src/codegen/sdk/python/file.py

@@ -6,7 +6,7 @@
 from codegen.sdk.core.file import SourceFile
 from codegen.sdk.core.interface import Interface
 from codegen.sdk.enums import ImportType, ProgrammingLanguage
-from codegen.sdk.extensions.utils import iter_all_descendants
+from codegen.sdk.extensions.utils import cached_property, iter_all_descendants
 from codegen.sdk.python import PyAssignment
 from codegen.sdk.python.class_definition import PyClass
 from codegen.sdk.python.detached_symbols.code_block import PyCodeBlock
@@ -20,6 +20,7 @@
 
 if TYPE_CHECKING:
     from codegen.sdk.codebase.codebase_graph import CodebaseGraph
+    from codegen.sdk.core.import_resolution import WildcardImport
     from codegen.sdk.python.symbol import PySymbol
 
 
@@ -173,3 +174,20 @@ def add_import_from_import_string(self, import_string: str) -> None:
     def remove_unused_exports(self) -> None:
         """Removes unused exports from the file. NO-OP for python"""
         pass
+
+    @cached_property
+    @noapidoc
+    @reader(cache=True)
+    def valid_import_names(self) -> dict[str, PySymbol | PyImport | WildcardImport[PyImport]]:
+        """Returns a dict mapping name => Symbol (or import) in this file that can be imported from
+        another file.
+        """
+        if self.name == "__init__":
+            ret = {}
+            if self.directory:
+                for file in self.directory:
+                    if file.name == "__init__":
+                        continue
+                    ret[file.name] = file
+            return ret
+        return super().valid_import_names

src/codegen/sdk/python/import_resolution.py

@@ -82,10 +82,13 @@ def imported_exports(self) -> list[Exportable]:
 
     @noapidoc
     @reader
-    def resolve_import(self, base_path: str | None = None) -> ImportResolution[PyFile] | None:
+    def resolve_import(self, base_path: str | None = None, *, add_module_name: str | None = None) -> ImportResolution[PyFile] | None:
         base_path = base_path or self.G.projects[0].base_path or ""
         module_source = self.module.source if self.module else ""
-
+        symbol_name = self.symbol_name.source if self.symbol_name else ""
+        if add_module_name:
+            module_source += f".{symbol_name}"
+            symbol_name = add_module_name
         # If import is relative, convert to absolute path
         if module_source.startswith("."):
             module_source = self._relative_to_absolute_import(module_source)
@@ -99,7 +102,7 @@ def resolve_import(self, base_path: str | None = None) -> ImportResolution[PyFil
             # `from a.b.c import foo`
             filepath = os.path.join(
                 base_path,
-                module_source.replace(".", "/") + "/" + self.symbol_name.source + ".py",
+                module_source.replace(".", "/") + "/" + symbol_name + ".py",
             )
         if file := self.G.get_file(filepath):
             return ImportResolution(from_file=file, symbol=None, imports_file=True)
@@ -114,22 +117,22 @@ def resolve_import(self, base_path: str | None = None) -> ImportResolution[PyFil
         filepath = module_source.replace(".", "/") + ".py"
         filepath = os.path.join(base_path, filepath)
         if file := self.G.get_file(filepath):
-            symbol = file.get_node_by_name(self.symbol_name.source)
+            symbol = file.get_node_by_name(symbol_name)
             return ImportResolution(from_file=file, symbol=symbol)
 
         # =====[ Check if `module/__init__.py` file exists in the graph ]=====
         filepath = filepath.replace(".py", "/__init__.py")
         if from_file := self.G.get_file(filepath):
-            symbol = from_file.get_node_by_name(self.symbol_name.source)
+            symbol = from_file.get_node_by_name(symbol_name)
             return ImportResolution(from_file=from_file, symbol=symbol)
 
         # =====[ Case: Can't resolve the import ]=====
         if base_path == "":
             # Try to resolve with "src" as the base path
-            return self.resolve_import(base_path="src")
+            return self.resolve_import(base_path="src", add_module_name=add_module_name)
         if base_path == "src":
             # Try "test" next
-            return self.resolve_import(base_path="test")
+            return self.resolve_import(base_path="test", add_module_name=add_module_name)
 
         # if not G_override:
         #     for resolver in G.import_resolvers:

src/codegen/sdk/typescript/import_resolution.py

@@ -197,7 +197,7 @@ def resolved_symbol(self) -> Symbol | ExternalModule | TSFile | None:
         return resolved_symbol
 
     @reader
-    def resolve_import(self, base_path: str | None = None) -> ImportResolution[TSFile] | None:
+    def resolve_import(self, base_path: str | None = None, *, add_module_name: str | None = None) -> ImportResolution[TSFile] | None:
         """Resolves an import statement to its target file and symbol.
 
         This method is used by GraphBuilder to resolve import statements to their target files and symbols. It handles both relative and absolute imports,

tests/unit/codegen/sdk/python/import_resolution/test_import_resolution.py

@@ -249,3 +249,64 @@ def c_sym():
         assert "c_sym" in b_file.valid_symbol_names
         assert "a_sym" in c_file.valid_symbol_names
         assert "b_sym" in c_file.valid_symbol_names.keys()
+
+
+def test_import_resolution_nested_module(tmpdir: str) -> None:
+    """Tests import resolution works with nested module imports"""
+    # language=python
+    with get_codebase_session(
+        tmpdir,
+        files={
+            "a/b/c.py": """
+def d():
+    pass
+""",
+            "consumer.py": """
+from a import b
+
+b.c.d()
+""",
+        },
+    ) as codebase:
+        consumer_file: SourceFile = codebase.get_file("consumer.py")
+        c_file: SourceFile = codebase.get_file("a/b/c.py")
+
+        # Verify import resolution
+        assert len(consumer_file.imports) == 1
+
+        # Verify function call resolution
+        d_func = c_file.get_function("d")
+        call_sites = d_func.call_sites
+        assert len(call_sites) == 1
+        assert call_sites[0].file == consumer_file
+
+
+def test_import_resolution_nested_module_init(tmpdir: str) -> None:
+    """Tests import resolution works with nested module imports"""
+    # language=python
+    with get_codebase_session(
+        tmpdir,
+        files={
+            "a/b/c.py": """
+def d():
+    pass
+""",
+            "a/b/__init__.py": """""",
+            "consumer.py": """
+from a import b
+
+b.c.d()
+""",
+        },
+    ) as codebase:
+        consumer_file: SourceFile = codebase.get_file("consumer.py")
+        c_file: SourceFile = codebase.get_file("a/b/c.py")
+
+        # Verify import resolution
+        assert len(consumer_file.imports) == 1
+
+        # Verify function call resolution
+        d_func = c_file.get_function("d")
+        call_sites = d_func.call_sites
+        assert len(call_sites) == 1
+        assert call_sites[0].file == consumer_file