🐛 Fix import resolution for src layout projects and bare relative imports (#140)

Author: savannahostrowski

src/core/extractors.ts

@@ -404,25 +404,33 @@ export function importExtractor(node: Node): ImportInfo | null {
     moduleNode?.text ?? "",
   )
 
-  // Aliased imports (e.g., "router as users_router")
-  const aliasedImports = getNodesByType(node).get("aliased_import") ?? []
-  for (const aliased of aliasedImports) {
-    const nameNode = aliased.childForFieldName("name")
-    const aliasNode = aliased.childForFieldName("alias")
-    if (nameNode) {
-      const alias = aliasNode?.text ?? null
-      names.push(alias ?? nameNode.text)
-      namedImports.push({ name: nameNode.text, alias })
+  // Collect imported names: everything after the "import" keyword.
+  let afterImport = false
+  for (let i = 0; i < node.childCount; i++) {
+    const child = node.child(i)
+    if (!child) continue
+
+    // Phase 1: scan forward looking for the "import" keyword
+    if (!afterImport) {
+      if (child.type === "import") afterImport = true
+      continue // skip this child either way (module path or the keyword itself)
     }
-  }
 
-  // Non-aliased imports (skip first dotted_name which is the module path)
-  const nameNodes = getNodesByType(node).get("dotted_name") ?? []
-  for (let i = 1; i < nameNodes.length; i++) {
-    const nameNode = nameNodes[i]
-    if (!hasAncestor(nameNode, "aliased_import")) {
-      names.push(nameNode.text)
-      namedImports.push({ name: nameNode.text, alias: null })
+    // Phase 2: we're past "import", so each child is an imported name
+    // (commas and other punctuation are silently skipped by the else branch)
+    if (child.type === "aliased_import") {
+      // e.g. "router as users_router"
+      const nameNode = child.childForFieldName("name")
+      const aliasNode = child.childForFieldName("alias")
+      if (nameNode) {
+        const alias = aliasNode?.text ?? null
+        names.push(alias ?? nameNode.text)
+        namedImports.push({ name: nameNode.text, alias })
+      }
+    } else if (child.type === "dotted_name") {
+      // e.g. "users"
+      names.push(child.text)
+      namedImports.push({ name: child.text, alias: null })
     }
   }
 

src/core/importResolver.ts

@@ -122,7 +122,28 @@ export async function resolveImport(
     projectRootUri,
     fs,
   )
-  return resolvePythonModule(resolvedUri, fs)
+  const result = await resolvePythonModule(resolvedUri, fs)
+  if (result) {
+    return result
+  }
+
+  // Fallback for src layout: if the module wasn't found under the
+  // project root, try under projectRoot/src/. This handles projects where
+  // pyproject.toml is at the root but source lives under src/.
+  // Only applies to absolute imports — relative imports already resolve
+  // relative to the current file, not the project root.
+  if (!importInfo.isRelative) {
+    const srcRootUri = fs.joinPath(projectRootUri, "src")
+    const srcResolvedUri = modulePathToDir(
+      importInfo,
+      currentFileUri,
+      srcRootUri,
+      fs,
+    )
+    return resolvePythonModule(srcResolvedUri, fs)
+  }
+
+  return null
 }
 
 /**

src/test/core/extractors.test.ts

@@ -706,6 +706,23 @@ router = f.APIRouter(prefix="/items")
       assert.strictEqual(result.relativeDots, 1)
     })
 
+    test("extracts bare relative import (from . import X)", () => {
+      const code = "from . import users"
+      const tree = parse(code)
+      const nodesByType = getNodesByType(tree.rootNode)
+      const imports = nodesByType.get("import_from_statement") ?? []
+      const result = importExtractor(imports[0])
+
+      assert.ok(result)
+      assert.strictEqual(result.modulePath, "")
+      assert.strictEqual(result.isRelative, true)
+      assert.strictEqual(result.relativeDots, 1)
+      assert.deepStrictEqual(result.names, ["users"])
+      assert.deepStrictEqual(result.namedImports, [
+        { name: "users", alias: null },
+      ])
+    })
+
     test("extracts relative import with double dot", () => {
       const code = "from ..api import router"
       const tree = parse(code)

src/test/core/importResolver.test.ts

@@ -99,6 +99,22 @@ suite("importResolver", () => {
       assert.ok(result.endsWith("users.py"))
     })
 
+    test("falls back to src/ for absolute imports in src layout", async () => {
+      // Project root is the pyproject.toml dir, but source is under src/
+      const currentFile = fixtures.srcLayout.mainPy
+      const projectRoot = fixtures.srcLayout.workspaceRoot
+
+      const result = await resolveImport(
+        { modulePath: "app.api", isRelative: false, relativeDots: 0 },
+        currentFile,
+        projectRoot,
+        nodeFileSystem,
+      )
+
+      assert.ok(result)
+      assert.ok(result.endsWith("api/__init__.py"))
+    })
+
     test("returns null for non-existent module", async () => {
       const currentFile = nodeFileSystem.joinPath(standardRoot, "main.py")
       const projectRoot = standardRoot
@@ -242,6 +258,28 @@ suite("importResolver", () => {
       assert.ok(result.endsWith("api_routes.py"))
     })
 
+    test("resolves named import via src/ fallback for src layout", async () => {
+      const currentFile = fixtures.srcLayout.mainPy
+      const projectRoot = fixtures.srcLayout.workspaceRoot
+
+      // "from app.api import api_router" — the actual import from the issue
+      const result = await resolveNamedImport(
+        {
+          modulePath: "app.api",
+          names: ["api_router"],
+          isRelative: false,
+          relativeDots: 0,
+        },
+        currentFile,
+        projectRoot,
+        nodeFileSystem,
+        (uri) => analyzeFile(uri, parser, nodeFileSystem),
+      )
+
+      assert.ok(result)
+      assert.ok(result.endsWith("api/__init__.py"))
+    })
+
     test("resolves variable import from .py file (not submodule)", async () => {
       // This tests "from .neon import router" where router is a variable in neon.py,
       // NOT a submodule. Should return neon.py, not look for router.py

src/test/core/routerResolver.test.ts

@@ -604,6 +604,47 @@ suite("routerResolver", () => {
       assert.strictEqual(result, null)
     })
 
+    test("resolves absolute imports in src layout projects", async () => {
+      const projectRoot = await findProjectRoot(
+        fixtures.srcLayout.mainPy,
+        fixtures.srcLayout.workspaceRoot,
+        nodeFileSystem,
+      )
+      const result = await buildRouterGraph(
+        fixtures.srcLayout.mainPy,
+        parser,
+        projectRoot,
+        nodeFileSystem,
+      )
+
+      assert.ok(result)
+      assert.strictEqual(result.type, "FastAPI")
+      assert.strictEqual(result.routes.length, 1, "Should have the root route")
+      assert.strictEqual(result.routes[0].path, "/")
+      assert.strictEqual(
+        result.children.length,
+        1,
+        "Should have one child router (api_router)",
+      )
+
+      const apiRouter = result.children[0].router
+      assert.strictEqual(apiRouter.type, "APIRouter")
+      assert.strictEqual(
+        apiRouter.children.length,
+        1,
+        "api_router should include users router",
+      )
+      assert.strictEqual(apiRouter.children[0].prefix, "/api/v1/users")
+
+      const usersRouter = apiRouter.children[0].router
+      assert.strictEqual(usersRouter.routes.length, 2)
+      const methods = usersRouter.routes
+        .map((r) => r.method.toLowerCase())
+        .sort()
+      assert.deepStrictEqual(methods, ["get", "post"])
+      assert.ok(usersRouter.routes.every((r) => r.path === "/"))
+    })
+
     test("resolves custom APIRouter subclass as child router", async () => {
       const result = await buildRouterGraph(
         fixtures.customSubclass.mainPy,

src/test/fixtures/src-layout/pyproject.toml

@@ -0,0 +1,2 @@
+[project]
+name = "src-layout-app"

src/test/fixtures/src-layout/src/app/api/__init__.py

@@ -0,0 +1,6 @@
+from fastapi import APIRouter
+from . import users
+
+api_router = APIRouter()
+
+api_router.include_router(users.router, prefix="/api/v1/users", tags=["users"])

src/test/fixtures/src-layout/src/app/api/users.py

@@ -0,0 +1,13 @@
+from fastapi import APIRouter
+
+router = APIRouter()
+
+
+@router.get("/")
+async def list_users():
+    return []
+
+
+@router.post("/")
+async def create_user():
+    return {}

src/test/fixtures/src-layout/src/app/main.py

@@ -0,0 +1,13 @@
+from fastapi import FastAPI
+
+from app.api import api_router
+
+app = FastAPI()
+
+
+@app.get("/")
+async def root():
+    return {"message": "Hello"}
+
+
+app.include_router(api_router)

src/test/testUtils.ts

@@ -93,6 +93,10 @@ export const fixtures = {
       join(fixturesPath, "reexport", "app", "integrations", "__init__.py"),
     ),
   },
+  srcLayout: {
+    workspaceRoot: uri(join(fixturesPath, "src-layout")),
+    mainPy: uri(join(fixturesPath, "src-layout", "src", "app", "main.py")),
+  },
   sameFile: {
     root: uri(join(fixturesPath, "same-file")),
     mainPy: uri(join(fixturesPath, "same-file", "main.py")),