feat: add implicit compilerOptions

src/parse-tsconfig/index.ts

@@ -256,6 +256,167 @@ const compilerFieldsWithConfigDir = [
 	'tsBuildInfoFile',
 ] as const;
 
+const normalizeCompilerOptions = (
+	compilerOptions: TsConfigJson.CompilerOptions,
+) => {
+	if (compilerOptions.strict) {
+		const strictOptions = [
+			'noImplicitAny',
+			'noImplicitThis',
+			'strictNullChecks',
+			'strictFunctionTypes',
+			'strictBindCallApply',
+			'strictPropertyInitialization',
+			'strictBuiltinIteratorReturn',
+			'alwaysStrict',
+			'useUnknownInCatchVariables',
+		] as const;
+
+		for (const key of strictOptions) {
+			if (compilerOptions[key] === undefined) {
+				compilerOptions[key] = true;
+			}
+		}
+	}
+
+	if (compilerOptions.target) {
+		let target = compilerOptions.target.toLowerCase() as TsConfigJson.CompilerOptions.Target;
+
+		if (target === 'es2015') {
+			target = 'es6';
+		}
+
+		// Lower case
+		compilerOptions.target = target;
+
+		if (target === 'esnext') {
+			compilerOptions.module ??= 'es6';
+			compilerOptions.moduleResolution ??= 'classic';
+			compilerOptions.useDefineForClassFields ??= true;
+		}
+
+		if (
+			target === 'es6'
+			|| target === 'es2016'
+			|| target === 'es2017'
+			|| target === 'es2018'
+			|| target === 'es2019'
+			|| target === 'es2020'
+			|| target === 'es2021'
+			|| target === 'es2022'
+			|| target === 'es2023'
+			|| target === 'es2024'
+		) {
+			compilerOptions.module ??= 'es6';
+			compilerOptions.moduleResolution ??= 'classic';
+		}
+
+		if (
+			target === 'es2022'
+			|| target === 'es2023'
+			|| target === 'es2024'
+		) {
+			compilerOptions.useDefineForClassFields ??= true;
+		}
+	}
+
+	if (compilerOptions.module) {
+		let module = compilerOptions.module.toLowerCase() as TsConfigJson.CompilerOptions.Module;
+
+		if (module === 'es2015') {
+			module = 'es6';
+		}
+
+		compilerOptions.module = module;
+
+		if (
+			module === 'es6'
+			|| module === 'es2020'
+			|| module === 'es2022'
+			|| module === 'esnext'
+			|| module === 'none'
+			|| module === 'system'
+			|| module === 'umd'
+			|| module === 'amd'
+		) {
+			compilerOptions.moduleResolution ??= 'classic';
+		}
+
+		if (module === 'system') {
+			compilerOptions.allowSyntheticDefaultImports ??= true;
+		}
+
+		if (
+			module === 'node16'
+			|| module === 'nodenext'
+			|| module === 'preserve'
+		) {
+			compilerOptions.esModuleInterop ??= true;
+			compilerOptions.allowSyntheticDefaultImports ??= true;
+		}
+
+		if (
+			module === 'node16'
+			|| module === 'nodenext'
+		) {
+			compilerOptions.moduleDetection ??= 'force';
+			compilerOptions.useDefineForClassFields ??= true;
+		}
+
+		if (module === 'node16') {
+			compilerOptions.target ??= 'es2022';
+			compilerOptions.moduleResolution ??= 'node16';
+		}
+
+		if (module === 'nodenext') {
+			compilerOptions.target ??= 'esnext';
+			compilerOptions.moduleResolution ??= 'nodenext';
+		}
+
+		if (module === 'preserve') {
+			compilerOptions.moduleResolution ??= 'bundler';
+		}
+	}
+
+	if (compilerOptions.moduleResolution) {
+		let moduleResolution = compilerOptions.moduleResolution.toLowerCase() as
+				TsConfigJson.CompilerOptions.ModuleResolution;
+
+		if (moduleResolution === 'node') {
+			moduleResolution = 'node10';
+		}
+
+		compilerOptions.moduleResolution = moduleResolution;
+
+		if (
+			moduleResolution === 'node16'
+			|| moduleResolution === 'nodenext'
+			|| moduleResolution === 'bundler'
+		) {
+			compilerOptions.resolvePackageJsonExports ??= true;
+			compilerOptions.resolvePackageJsonImports ??= true;
+		}
+
+		if (moduleResolution === 'bundler') {
+			compilerOptions.allowSyntheticDefaultImports ??= true;
+			compilerOptions.resolveJsonModule ??= true;
+		}
+	}
+
+	if (compilerOptions.esModuleInterop) {
+		compilerOptions.allowSyntheticDefaultImports ??= true;
+	}
+
+	if (compilerOptions.verbatimModuleSyntax) {
+		compilerOptions.isolatedModules ??= true;
+		compilerOptions.preserveConstEnums ??= true;
+	}
+
+	if (compilerOptions.isolatedModules) {
+		compilerOptions.preserveConstEnums ??= true;
+	}
+};
+
 /**
  * Parses a tsconfig file at a given path
  *
@@ -299,6 +460,8 @@ export const parseTsconfig = (
 				);
 			}
 		}
+
+		normalizeCompilerOptions(compilerOptions);
 	}
 
 	for (const property of filesProperties) {

tests/fixtures/yarn-pnp/index.js

@@ -1,18 +1,10 @@
 const { parseTsconfig } = require('get-tsconfig');
-const tests = [
-	() => parseTsconfig('./tsconfig.package.json'),
-	() => parseTsconfig('./tsconfig.package-path.json'),
-	() => parseTsconfig('./tsconfig.package-path-directory.json'),
-	() => parseTsconfig('./tsconfig.org-package.json'),
-	() => parseTsconfig('./tsconfig.missing-extends.json'),
-	() => parseTsconfig('./tsconfig.invalid-extends.json'),
-];
 
-for (const test of tests) {
-	try {
-		console.log(test());
-	} catch (error) {
-		console.log('Error:', error.message);
-		process.exitCode = 1;
-	}
+const tsconfigPath = process.argv[2];
+
+try {
+    const parsed = parseTsconfig(tsconfigPath);
+    console.log(JSON.stringify(parsed));
+} catch (error) {
+    console.error(error);
 }

tests/specs/get-tsconfig.ts

@@ -2,6 +2,7 @@ import path from 'node:path';
 import { testSuite, expect } from 'manten';
 import { createFixture } from 'fs-fixture';
 import slash from 'slash';
+import { getTscTsconfig } from '../utils.js';
 import { getTsconfig } from '#get-tsconfig';
 
 const compilerOptions = {
@@ -33,48 +34,64 @@ export default testSuite(({ describe }) => {
 		test('from directory path', async () => {
 			await using fixture = await createFixture({
 				'tsconfig.json': tsconfigJson,
+				'a.ts': '',
 			});
 
+			const expected = await getTscTsconfig(fixture.path);
+			delete expected.files;
+
 			const tsconfig = getTsconfig(fixture.path);
 			expect(tsconfig).toStrictEqual({
 				path: slash(fixture.getPath('tsconfig.json')),
-				config: { compilerOptions },
+				config: expected,
 			});
 		});
 
 		test('from index.js path', async () => {
 			await using fixture = await createFixture({
 				'tsconfig.json': tsconfigJson,
+				'a.ts': '',
 			});
 
+			const expected = await getTscTsconfig(fixture.path);
+			delete expected.files;
+
 			const tsconfig = getTsconfig(fixture.getPath('index.js'));
 			expect(tsconfig).toStrictEqual({
 				path: slash(fixture.getPath('tsconfig.json')),
-				config: { compilerOptions },
+				config: expected,
 			});
 		});
 
 		test('custom name', async () => {
 			const customName = 'tsconfig-custom-name.json';
 			await using fixture = await createFixture({
 				[customName]: tsconfigJson,
+				'a.ts': '',
 			});
 
+			const expected = await getTscTsconfig(fixture.path, customName);
+			delete expected.files;
+
 			const tsconfig = getTsconfig(fixture.path, customName);
 			expect(tsconfig).toStrictEqual({
 				path: slash(path.join(fixture.path, customName)),
-				config: { compilerOptions },
+				config: expected,
 			});
 		});
 
 		test('cache', async () => {
 			await using fixture = await createFixture({
 				'tsconfig.json': tsconfigJson,
+				'a.ts': '',
 			});
 
+			const expected = await getTscTsconfig(fixture.path);
+			delete expected.files;
+
 			const expectedResult = {
 				path: slash(fixture.getPath('tsconfig.json')),
-				config: { compilerOptions },
+				config: expected,
 			};
 
 			const cache = new Map();

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

@@ -111,8 +111,7 @@ export default testSuite(({ describe }) => {
 
 			const tsconfig = parseTsconfig(fixture.getPath('tsconfig.json'));
 
-			// TODO: TS 5.5 --showConfig returns extra default fields
-			expect(expectedTsconfig).toMatchObject(tsconfig);
+			expect(expectedTsconfig).toStrictEqual(tsconfig);
 		});
 
 		describe('files', ({ test }) => {
@@ -424,8 +423,8 @@ export default testSuite(({ describe }) => {
 			delete expectedTsconfig.files;
 
 			const tsconfig = parseTsconfig(fixture.getPath('tsconfig.json'));
-			// TODO: TS 5.5 --showConfig returns extra default fields
-			expect(expectedTsconfig).toMatchObject(tsconfig);
+
+			expect(expectedTsconfig).toStrictEqual(tsconfig);
 		});
 
 		test('watchOptions', async () => {

tests/specs/parse-tsconfig/extends/resolves/absolute-path.spec.ts

@@ -23,8 +23,8 @@ export default testSuite(({ describe }) => {
 			delete expectedTsconfig.files;
 
 			const tsconfig = parseTsconfig(fixture.getPath('tsconfig.json'));
-			// TODO: TS 5.5 --showConfig returns extra default fields
-			expect(expectedTsconfig).toMatchObject(tsconfig);
+
+			expect(expectedTsconfig).toStrictEqual(tsconfig);
 		});
 
 		test('no extension', async () => {
@@ -45,8 +45,8 @@ export default testSuite(({ describe }) => {
 			delete expectedTsconfig.files;
 
 			const tsconfig = parseTsconfig(fixture.getPath('tsconfig.json'));
-			// TODO: TS 5.5 --showConfig returns extra default fields
-			expect(expectedTsconfig).toMatchObject(tsconfig);
+
+			expect(expectedTsconfig).toStrictEqual(tsconfig);
 		});
 
 		test('arbitrary extension', async () => {
@@ -67,8 +67,8 @@ export default testSuite(({ describe }) => {
 			delete expectedTsconfig.files;
 
 			const tsconfig = parseTsconfig(fixture.getPath('tsconfig.json'));
-			// TODO: TS 5.5 --showConfig returns extra default fields
-			expect(expectedTsconfig).toMatchObject(tsconfig);
+
+			expect(expectedTsconfig).toStrictEqual(tsconfig);
 		});
 	});
 });