Merge pull request #3380 from hey-api/copilot/fix-implicit-module-resolution

Detect implicit moduleResolution from module compiler option

Author: mrlubos

.changeset/little-lobsters-think.md

@@ -0,0 +1,5 @@
+---
+"@hey-api/openapi-ts": patch
+---
+
+**output**: detect `importFileExtension` from tsconfig `module` option

packages/openapi-ts/src/config/output/__tests__/config.test.ts

@@ -0,0 +1,180 @@
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+
+import { getOutput } from '../config';
+
+describe('getOutput', () => {
+  let tmpDir: string;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'openapi-ts-test-'));
+  });
+
+  afterEach(() => {
+    if (fs.existsSync(tmpDir)) {
+      fs.rmSync(tmpDir, { force: true, recursive: true });
+    }
+  });
+
+  describe('module resolution detection', () => {
+    it('should set importFileExtension when moduleResolution is NodeNext', () => {
+      const tsconfigPath = path.join(tmpDir, 'tsconfig.json');
+      fs.writeFileSync(
+        tsconfigPath,
+        JSON.stringify({
+          compilerOptions: {
+            moduleResolution: 'nodenext',
+          },
+        }),
+      );
+
+      const output = getOutput({
+        output: {
+          path: tmpDir,
+          tsConfigPath: tsconfigPath,
+        },
+      });
+
+      expect(output.importFileExtension).toBe('.js');
+    });
+
+    it('should set importFileExtension when moduleResolution is Node16', () => {
+      const tsconfigPath = path.join(tmpDir, 'tsconfig.json');
+      fs.writeFileSync(
+        tsconfigPath,
+        JSON.stringify({
+          compilerOptions: {
+            moduleResolution: 'node16',
+          },
+        }),
+      );
+
+      const output = getOutput({
+        output: {
+          path: tmpDir,
+          tsConfigPath: tsconfigPath,
+        },
+      });
+
+      expect(output.importFileExtension).toBe('.js');
+    });
+
+    it('should set importFileExtension when module is NodeNext (implicit moduleResolution)', () => {
+      const tsconfigPath = path.join(tmpDir, 'tsconfig.json');
+      fs.writeFileSync(
+        tsconfigPath,
+        JSON.stringify({
+          compilerOptions: {
+            module: 'nodenext',
+          },
+        }),
+      );
+
+      const output = getOutput({
+        output: {
+          path: tmpDir,
+          tsConfigPath: tsconfigPath,
+        },
+      });
+
+      expect(output.importFileExtension).toBe('.js');
+    });
+
+    it('should set importFileExtension when module is Node16 (implicit moduleResolution)', () => {
+      const tsconfigPath = path.join(tmpDir, 'tsconfig.json');
+      fs.writeFileSync(
+        tsconfigPath,
+        JSON.stringify({
+          compilerOptions: {
+            module: 'node16',
+          },
+        }),
+      );
+
+      const output = getOutput({
+        output: {
+          path: tmpDir,
+          tsConfigPath: tsconfigPath,
+        },
+      });
+
+      expect(output.importFileExtension).toBe('.js');
+    });
+
+    it('should not set importFileExtension for other module types', () => {
+      const tsconfigPath = path.join(tmpDir, 'tsconfig.json');
+      fs.writeFileSync(
+        tsconfigPath,
+        JSON.stringify({
+          compilerOptions: {
+            module: 'esnext',
+          },
+        }),
+      );
+
+      const output = getOutput({
+        output: {
+          path: tmpDir,
+          tsConfigPath: tsconfigPath,
+        },
+      });
+
+      expect(output.importFileExtension).toBeUndefined();
+    });
+
+    it('should not override explicit importFileExtension setting', () => {
+      const tsconfigPath = path.join(tmpDir, 'tsconfig.json');
+      fs.writeFileSync(
+        tsconfigPath,
+        JSON.stringify({
+          compilerOptions: {
+            module: 'nodenext',
+          },
+        }),
+      );
+
+      const output = getOutput({
+        output: {
+          importFileExtension: '.ts',
+          path: tmpDir,
+          tsConfigPath: tsconfigPath,
+        },
+      });
+
+      expect(output.importFileExtension).toBe('.ts');
+    });
+
+    it('should work when both module and moduleResolution are set', () => {
+      const tsconfigPath = path.join(tmpDir, 'tsconfig.json');
+      fs.writeFileSync(
+        tsconfigPath,
+        JSON.stringify({
+          compilerOptions: {
+            module: 'nodenext',
+            moduleResolution: 'nodenext',
+          },
+        }),
+      );
+
+      const output = getOutput({
+        output: {
+          path: tmpDir,
+          tsConfigPath: tsconfigPath,
+        },
+      });
+
+      expect(output.importFileExtension).toBe('.js');
+    });
+
+    it('should handle missing tsconfig gracefully', () => {
+      const output = getOutput({
+        output: {
+          path: tmpDir,
+        },
+      });
+
+      expect(output.importFileExtension).toBeUndefined();
+    });
+  });
+});

packages/openapi-ts/src/config/output/config.ts

@@ -65,7 +65,9 @@ export function getOutput(userConfig: { output: MaybeArray<string | UserOutput>
   if (
     output.importFileExtension === undefined &&
     (output.tsConfig?.options.moduleResolution === ts.ModuleResolutionKind.NodeNext ||
-      output.tsConfig?.options.moduleResolution === ts.ModuleResolutionKind.Node16)
+      output.tsConfig?.options.moduleResolution === ts.ModuleResolutionKind.Node16 ||
+      output.tsConfig?.options.module === ts.ModuleKind.NodeNext ||
+      output.tsConfig?.options.module === ts.ModuleKind.Node16)
   ) {
     output.importFileExtension = '.js';
   }