fix(resolution): an import naming the emitted .js extension resolves to its .ts source (#1767)

Fixes #1705. Lands #1706 (thanks @bompus), rebased onto main.
2026-09-08 08:00:52 -05:00
parent a7ea5ba730
commit 28033f62f8
3 changed files with 168 additions and 1 deletions
@@ -0,0 +1,126 @@
+/**
+ * TypeScript's node16/nodenext/bundler resolution writes the EMITTED extension
+ * in a relative specifier (`./util.js` for `util.ts`). The import resolver must
+ * map that back to the source file that is actually in the repo; otherwise the
+ * imported names fall through to bare-name matching and a method that wraps a
+ * same-named import resolves to itself.
+ */
+
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import * as fs from 'fs';
+import * as path from 'path';
+import * as os from 'os';
+import { CodeGraph } from '../src';
+import { resolveImportPath } from '../src/resolution/import-resolver';
+import type { ResolutionContext } from '../src/resolution';
+
+function contextWithFiles(files: string[]): ResolutionContext {
+  const set = new Set(files);
+  return {
+    getNodesInFile: () => [],
+    getNodesByName: () => [],
+    getNodesByQualifiedName: () => [],
+    getNodesByKind: () => [],
+    fileExists: (p: string) => set.has(p),
+    readFile: () => null,
+    getProjectRoot: () => '/test',
+    getAllFiles: () => files,
+    getNodesByLowerName: () => [],
+    getImportMappings: () => [],
+  } as unknown as ResolutionContext;
+}
+
+describe('emitted-extension import specifiers (`./x.js` naming `x.ts`)', () => {
+  it('maps a relative .js specifier onto the .ts source', () => {
+    const ctx = contextWithFiles(['shared/engine.ts', 'shared/util.ts']);
+    expect(resolveImportPath('./util.js', 'shared/engine.ts', 'typescript', ctx)).toBe('shared/util.ts');
+  });
+
+  it('prefers a real .js file over the remap when both exist', () => {
+    const ctx = contextWithFiles(['shared/engine.ts', 'shared/util.js', 'shared/util.ts']);
+    expect(resolveImportPath('./util.js', 'shared/engine.ts', 'typescript', ctx)).toBe('shared/util.js');
+  });
+
+  it('maps .jsx, .mjs and .cjs onto their TypeScript sources', () => {
+    const ctx = contextWithFiles(['app/a.tsx', 'app/View.tsx', 'app/esm.mts', 'app/cjs.cts']);
+    expect(resolveImportPath('./View.jsx', 'app/a.tsx', 'tsx', ctx)).toBe('app/View.tsx');
+    expect(resolveImportPath('./esm.mjs', 'app/a.tsx', 'tsx', ctx)).toBe('app/esm.mts');
+    expect(resolveImportPath('./cjs.cjs', 'app/a.tsx', 'tsx', ctx)).toBe('app/cjs.cts');
+  });
+
+  it('maps an aliased .js specifier through tsconfig paths', () => {
+    const files = ['src/main.ts', 'src/lib/util.ts'];
+    const ctx = {
+      ...contextWithFiles(files),
+      getProjectAliases: () => ({
+        baseUrl: '/test',
+        patterns: [{ prefix: '@/', suffix: '', hasWildcard: true, replacements: ['src/*'] }],
+      }),
+    } as unknown as ResolutionContext;
+    expect(resolveImportPath('@/lib/util.js', 'src/main.ts', 'typescript', ctx)).toBe('src/lib/util.ts');
+  });
+
+  it('leaves a specifier that names no source unresolved', () => {
+    const ctx = contextWithFiles(['shared/engine.ts']);
+    expect(resolveImportPath('./missing.js', 'shared/engine.ts', 'typescript', ctx)).toBeNull();
+  });
+
+  it('does not remap for a language without TypeScript emit (python)', () => {
+    const ctx = contextWithFiles(['pkg/a.py', 'pkg/b.ts']);
+    expect(resolveImportPath('./b.js', 'pkg/a.py', 'python', ctx)).toBeNull();
+  });
+});
+
+describe('end to end: a wrapper method calling the same-named import it wraps', () => {
+  let tempDir: string;
+  let cg: CodeGraph | null = null;
+
+  beforeEach(() => {
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-emitted-spec-'));
+  });
+
+  afterEach(() => {
+    cg?.destroy();
+    cg = null;
+    try {
+      fs.rmSync(tempDir, { recursive: true, force: true });
+    } catch {
+      // Windows can still hold the SQLite handle for a moment; the OS temp dir is swept anyway.
+    }
+  });
+
+  it('links the call to the imported function, not to the method itself', async () => {
+    fs.writeFileSync(
+      path.join(tempDir, 'template.ts'),
+      'export function renderDockStyles(): string {\n  return ".dock {}";\n}\n'
+    );
+    fs.writeFileSync(
+      path.join(tempDir, 'sidebar.ts'),
+      [
+        'import { renderDockStyles } from "./template.js";',
+        '',
+        'export class Sidebar {',
+        '  renderDockStyles(): string {',
+        '    return renderDockStyles();',
+        '  }',
+        '}',
+        '',
+      ].join('\n')
+    );
+    cg = await CodeGraph.init(tempDir, { index: true });
+    cg.resolveReferences();
+
+    const method = cg.getNodesByKind('method').find((n) => n.name === 'renderDockStyles');
+    const fn = cg
+      .getNodesByKind('function')
+      .find((n) => n.name === 'renderDockStyles' && n.filePath === 'template.ts');
+    expect(method).toBeDefined();
+    expect(fn).toBeDefined();
+    const targets = cg
+      .getOutgoingEdges(method!.id)
+      .filter((e) => e.kind === 'calls')
+      .map((e) => e.target);
+    expect(targets).toContain(fn!.id);
+    expect(targets).not.toContain(method!.id);
+  });
+});