fix: support jsonc in extended config (#36)

src/parse-tsconfig/resolve-extends.ts

@@ -2,15 +2,10 @@ import path from 'path';
 import fs from 'fs';
 import Module from 'module';
 import { findUp } from '../utils/find-up';
+import { readJsonc } from '../utils/read-jsonc';
 
 const { existsSync } = fs;
 
-const safeJsonParse = (jsonString: string) => {
-	try {
-		return JSON.parse(jsonString);
-	} catch {}
-};
-
 const getPnpApi = () => {
 	const { findPnpApi } = Module;
 
@@ -19,9 +14,7 @@ const getPnpApi = () => {
 };
 
 function resolveFromPackageJsonPath(packageJsonPath: string) {
-	const packageJson = safeJsonParse(
-		fs.readFileSync(packageJsonPath, 'utf8'),
-	);
+	const packageJson = readJsonc(packageJsonPath);
 
 	return path.join(
 		packageJsonPath,

src/utils/read-jsonc.ts

@@ -0,0 +1,6 @@
+import fs from 'fs';
+import { parse } from 'jsonc-parser';
+
+export const readJsonc = (
+	jsonPath: string,
+) => parse(fs.readFileSync(jsonPath, 'utf8'));

tests/specs/parse-tsconfig/extends/extends.spec.ts

@@ -424,6 +424,29 @@ export default testSuite(({ describe }) => {
 			await fixture.rm();
 		});
 
+		test('jsonc', async () => {
+			const fixture = await createFixture({
+				'file.ts': '',
+				'tsconfig.base.json': `{
+					// comment
+					"compilerOptions": {
+						"jsx": "react", // dangling comma
+					},
+				}`,
+				'tsconfig.json': tsconfigJson({
+					extends: './tsconfig.base.json',
+				}),
+			});
+
+			const expectedTsconfig = await getTscTsconfig(fixture.path);
+			delete expectedTsconfig.files;
+
+			const tsconfig = getTsconfig(fixture.path);
+			expect(tsconfig!.config).toStrictEqual(expectedTsconfig);
+
+			await fixture.rm();
+		});
+
 		test('references is ignored', async () => {
 			const fixture = await createFixture({
 				'tsconfig.base.json': tsconfigJson({