fix(plugin-typescript): include extended options

Author: BioPhoton

packages/plugin-typescript/mocks/fixtures/basic-setup/tsconfig.extends-base.json

@@ -0,0 +1,7 @@
+{
+  "compilerOptions": {
+    "rootDir": "./src",
+    "verbatimModuleSyntax": false
+  },
+  "include": ["src/**/*.ts"]
+}

packages/plugin-typescript/mocks/fixtures/basic-setup/tsconfig.extends-extending.json

@@ -0,0 +1,8 @@
+{
+  "extends": "./tsconfig.extends-base.json",
+  "compilerOptions": {
+    "verbatimModuleSyntax": true,
+    "module": "CommonJS"
+  },
+  "exclude": ["src/*-errors/**/*.ts"]
+}

packages/plugin-typescript/src/lib/runner/ts-runner.ts

@@ -13,7 +13,7 @@ export type DiagnosticsOptions = {
 export async function getTypeScriptDiagnostics({
   tsconfig,
 }: DiagnosticsOptions): Promise<readonly Diagnostic[]> {
-  const { fileNames, options } = await loadTargetConfig(tsconfig);
+  const { fileNames, options } = loadTargetConfig(tsconfig);
   try {
     const program = createProgram(fileNames, options);
     return getPreEmitDiagnostics(program);

packages/plugin-typescript/src/lib/runner/utils.int.test.ts

@@ -3,26 +3,23 @@ import { describe, expect } from 'vitest';
 import { loadTargetConfig } from './utils.js';
 
 describe('loadTargetConfig', () => {
-  const parseConfigFileTextToJsonSpy = vi.spyOn(
-    tsModule,
-    'parseConfigFileTextToJson',
-  );
+  const readConfigFileSpy = vi.spyOn(tsModule, 'readConfigFile');
   const parseJsonConfigFileContentSpy = vi.spyOn(
     tsModule,
     'parseJsonConfigFileContent',
   );
 
-  it('should return the parsed content of a tsconfig file and ist TypeScript helper to parse it', async () => {
-    await expect(
+  it('should return the parsed content of a tsconfig file and ist TypeScript helper to parse it', () => {
+    expect(
       loadTargetConfig(
         'packages/plugin-typescript/mocks/fixtures/basic-setup/tsconfig.init.json',
       ),
-    ).resolves.toStrictEqual(
+    ).toStrictEqual(
       expect.objectContaining({
         fileNames: expect.any(Array),
         options: {
           module: 1,
-          configFilePath: undefined,
+          configFilePath: expect.stringContaining('tsconfig.init.json'),
           esModuleInterop: true,
           forceConsistentCasingInFileNames: true,
           skipLibCheck: true,
@@ -31,25 +28,40 @@ describe('loadTargetConfig', () => {
         },
       }),
     );
-    expect(parseConfigFileTextToJsonSpy).toHaveBeenCalledTimes(1);
-    expect(parseConfigFileTextToJsonSpy).toHaveBeenCalledWith(
-      'packages/plugin-typescript/mocks/fixtures/basic-setup/tsconfig.init.json',
-      expect.stringContaining('/* Projects */'),
+    expect(readConfigFileSpy).toHaveBeenCalledTimes(1);
+    expect(readConfigFileSpy).toHaveBeenCalledWith(
+      expect.stringContaining('tsconfig.init.json'),
+      expect.any(Function),
     );
     expect(parseJsonConfigFileContentSpy).toHaveBeenCalledTimes(1);
-    expect(parseJsonConfigFileContentSpy).toHaveBeenCalledWith(
+    // parseJsonConfigFileContent is called with complex internal objects
+  });
+
+  it('should return the parsed content of a tsconfig file that extends another config', () => {
+    expect(
+      loadTargetConfig(
+        'packages/plugin-typescript/mocks/fixtures/basic-setup/tsconfig.extends-extending.json',
+      ),
+    ).toStrictEqual(
       expect.objectContaining({
-        compilerOptions: expect.objectContaining({
-          esModuleInterop: true,
-          forceConsistentCasingInFileNames: true,
-          module: 'commonjs',
-          skipLibCheck: true,
-          strict: true,
-          target: 'es2016',
+        fileNames: expect.arrayContaining([
+          // from tsconfig.extends-base.json#includes and tsconfig.extends-extending.json#excludes
+          expect.stringContaining('src/0-no-diagnostics/'),
+        ]),
+        options: expect.objectContaining({
+          // Options from tsconfig.extends-base.json
+          rootDir: expect.stringContaining('src'),
+          // Options from tsconfig.extends-extending.json
+          module: 1,
+          configFilePath: expect.stringContaining(
+            'tsconfig.extends-extending.json',
+          ),
+          verbatimModuleSyntax: true, // Overrides base config's false
         }),
       }),
-      expect.any(Object),
-      expect.any(String),
     );
+
+    expect(readConfigFileSpy).toHaveBeenCalledTimes(1);
+    expect(parseJsonConfigFileContentSpy).toHaveBeenCalledTimes(1);
   });
 });

packages/plugin-typescript/src/lib/runner/utils.ts

@@ -1,15 +1,14 @@
-// eslint-disable-next-line unicorn/import-style
-import { dirname } from 'node:path';
+import path from 'node:path';
 import {
   type Diagnostic,
   DiagnosticCategory,
   flattenDiagnosticMessageText,
-  parseConfigFileTextToJson,
   parseJsonConfigFileContent,
+  readConfigFile,
   sys,
 } from 'typescript';
 import type { Issue } from '@code-pushup/models';
-import { readTextFile, truncateIssueMessage } from '@code-pushup/utils';
+import { truncateIssueMessage } from '@code-pushup/utils';
 import { TS_CODE_RANGE_NAMES } from './ts-error-codes.js';
 import type { CodeRangeName } from './types.js';
 
@@ -84,7 +83,7 @@ export function getIssueFromDiagnostic(diag: Diagnostic) {
   return {
     ...issue,
     source: {
-      file: diag.file.fileName,
+      file: path.relative(process.cwd(), diag.file.fileName),
       ...(startLine
         ? {
             position: {
@@ -96,16 +95,22 @@ export function getIssueFromDiagnostic(diag: Diagnostic) {
   } satisfies Issue;
 }
 
-export async function loadTargetConfig(tsConfigPath: string) {
-  const { config } = parseConfigFileTextToJson(
-    tsConfigPath,
-    await readTextFile(tsConfigPath),
-  );
+export function loadTargetConfig(tsConfigPath: string) {
+  const resolvedConfigPath = path.resolve(tsConfigPath);
+  const { config, error } = readConfigFile(resolvedConfigPath, sys.readFile);
+
+  if (error) {
+    throw new Error(
+      `Error reading TypeScript config file: \n${error.messageText}`,
+    );
+  }
 
   const parsedConfig = parseJsonConfigFileContent(
     config,
     sys,
-    dirname(tsConfigPath),
+    path.dirname(resolvedConfigPath),
+    {},
+    resolvedConfigPath,
   );
 
   if (parsedConfig.fileNames.length === 0) {