Add parsePackage method, bump dependencies, target Node.js 16 (#29)

.github/workflows/main.yml

@@ -10,10 +10,11 @@ jobs:
       fail-fast: false
       matrix:
         node-version:
+          - 18
           - 16
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-node@v2
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install

index.d.ts

@@ -1,7 +1,8 @@
-import * as typeFest from 'type-fest';
-import * as normalize from 'normalize-package-data';
+/* eslint-disable @typescript-eslint/no-redundant-type-constituents */
+import type {PackageJson as typeFestPackageJson} from 'type-fest';
+import type {Package as normalizePackage} from 'normalize-package-data';
 
-export interface Options {
+export type Options = {
 	/**
 	Current working directory.
 
@@ -15,14 +16,20 @@ export interface Options {
 	@default true
 	*/
 	readonly normalize?: boolean;
-}
+};
 
-export interface NormalizeOptions extends Options {
+// eslint-disable-next-line @typescript-eslint/naming-convention
+type _NormalizeOptions = {
 	readonly normalize?: true;
-}
+};
 
-export type NormalizedPackageJson = PackageJson & normalize.Package;
-export type PackageJson = typeFest.PackageJson;
+export type NormalizeOptions = _NormalizeOptions & Options;
+
+export type ParseOptions = Omit<Options, 'cwd'>;
+export type NormalizeParseOptions = _NormalizeOptions & ParseOptions;
+
+export type NormalizedPackageJson = PackageJson & normalizePackage;
+export type PackageJson = typeFestPackageJson;
 
 /**
 @returns The parsed JSON.
@@ -57,3 +64,6 @@ console.log(readPackageSync({cwd: 'some-other-directory'});
 */
 export function readPackageSync(options?: NormalizeOptions): NormalizedPackageJson;
 export function readPackageSync(options: Options): PackageJson;
+
+export function parsePackage(packageFile: PackageJson | string, options?: NormalizeParseOptions): NormalizedPackageJson;
+export function parsePackage(packageFile: PackageJson | string, options: ParseOptions): PackageJson;

index.js

@@ -7,26 +7,48 @@ import normalizePackageData from 'normalize-package-data';
 
 const toPath = urlOrPath => urlOrPath instanceof URL ? fileURLToPath(urlOrPath) : urlOrPath;
 
-export async function readPackage({cwd, normalize = true} = {}) {
-	cwd = toPath(cwd) || process.cwd();
-	const filePath = path.resolve(cwd, 'package.json');
-	const json = parseJson(await fsPromises.readFile(filePath, 'utf8'));
+const getPackagePath = cwd => {
+	const packageDir = toPath(cwd) || process.cwd();
+	return path.resolve(packageDir, 'package.json');
+};
+
+const _readPackage = (file, normalize) => {
+	const json = typeof file === 'string'
+		? parseJson(file)
+		: file;
 
 	if (normalize) {
 		normalizePackageData(json);
 	}
 
 	return json;
+};
+
+export async function readPackage({cwd, normalize = true} = {}) {
+	const packageFile = await fsPromises.readFile(getPackagePath(cwd), 'utf8');
+	return _readPackage(packageFile, normalize);
 }
 
 export function readPackageSync({cwd, normalize = true} = {}) {
-	cwd = toPath(cwd) || process.cwd();
-	const filePath = path.resolve(cwd, 'package.json');
-	const json = parseJson(fs.readFileSync(filePath, 'utf8'));
+	const packageFile = fs.readFileSync(getPackagePath(cwd), 'utf8');
+	return _readPackage(packageFile, normalize);
+}
 
-	if (normalize) {
-		normalizePackageData(json);
+export function parsePackage(packageFile, {normalize = true} = {}) {
+	const isObject = packageFile !== null && typeof packageFile === 'object' && !Array.isArray(packageFile);
+	const isString = typeof packageFile === 'string';
+
+	if (!isObject && !isString) {
+		throw new TypeError('`packageFile` should be either an `object` or a `string`.');
 	}
 
-	return json;
+	// Input should not be modified - if `structuredClone` is available, do a deep clone, shallow otherwise
+	// TODO: Remove shallow clone when targeting Node.js 18
+	const clonedPackageFile = isObject
+		? (globalThis.structuredClone === undefined
+			? {...packageFile}
+			: structuredClone(packageFile))
+		: packageFile;
+
+	return _readPackage(clonedPackageFile, normalize);
 }

index.test-d.ts

@@ -1,5 +1,11 @@
 import {expectType, expectError, expectAssignable} from 'tsd';
-import {readPackage, readPackageSync, NormalizedPackageJson, PackageJson} from './index.js';
+import {
+	readPackage,
+	readPackageSync,
+	parsePackage,
+	type NormalizedPackageJson,
+	type PackageJson,
+} from './index.js';
 
 expectError<NormalizedPackageJson>({});
 expectAssignable<PackageJson>({});
@@ -19,3 +25,12 @@ expectType<PackageJson>(readPackageSync({normalize: false}));
 expectError<NormalizedPackageJson>(readPackageSync({normalize: false}));
 expectType<NormalizedPackageJson>(readPackageSync({cwd: '.'}));
 expectType<NormalizedPackageJson>(readPackageSync({cwd: new URL('file:///path/to/cwd/')}));
+
+expectType<NormalizedPackageJson>(parsePackage(''));
+expectType<NormalizedPackageJson>(parsePackage({name: 'unicorn'}));
+expectType<NormalizedPackageJson>(parsePackage('', {normalize: true}));
+expectType<PackageJson>(parsePackage('', {normalize: false}));
+expectType<PackageJson>(parsePackage({name: 'unicorn'}, {normalize: false}));
+expectError(parsePackage());
+expectError<NormalizedPackageJson>(parsePackage('', {normalize: false}));
+expectError(parsePackage('', {cwd: '.'}));

package.json

@@ -13,10 +13,10 @@
 	"type": "module",
 	"exports": "./index.js",
 	"engines": {
-		"node": ">=12.20"
+		"node": ">=16"
 	},
 	"scripts": {
-		"test": "xo && ava && tsd"
+		"test": "xo && tsd && cd test && ava"
 	},
 	"files": [
 		"index.js",
@@ -35,18 +35,13 @@
 	],
 	"dependencies": {
 		"@types/normalize-package-data": "^2.4.1",
-		"normalize-package-data": "^3.0.2",
-		"parse-json": "^5.2.0",
-		"type-fest": "^2.0.0"
+		"normalize-package-data": "^5.0.0",
+		"parse-json": "^7.0.0",
+		"type-fest": "^3.8.0"
 	},
 	"devDependencies": {
-		"ava": "^3.15.0",
-		"tsd": "^0.17.0",
-		"xo": "^0.44.0"
-	},
-	"xo": {
-		"ignores": [
-			"test/test.js"
-		]
+		"ava": "^5.2.0",
+		"tsd": "^0.28.1",
+		"xo": "^0.54.0"
 	}
 }

readme.md

@@ -53,6 +53,29 @@ Default: `true`
 
 [Normalize](https://github.com/npm/normalize-package-data#what-normalization-currently-entails) the package data.
 
+### parsePackage(packageFile, options?)
+
+Parses an object or string into JSON.
+
+Note: `packageFile` is cloned using [`structuredClone`](https://developer.mozilla.org/en-US/docs/Web/API/structuredClone) to prevent modification to the input object. This function is available from Node.js 18 on. In environments without `structuredClone` (such as Node.js 16), a shallow spread is used instead, which can cause deep properties of the object to be modified. Consider cloning the object before using `parsePackage` if that's the case.
+
+#### packageFile
+
+Type: `object | string`\
+
+An object or a stringified object to be parsed as a package.json.
+
+#### options
+
+Type: `object`
+
+##### normalize
+
+Type: `boolean`\
+Default: `true`
+
+[Normalize](https://github.com/npm/normalize-package-data#what-normalization-currently-entails) the package data.
+
 ## Related
 
 - [read-pkg-up](https://github.com/sindresorhus/read-pkg-up) - Read the closest package.json file

test/package.json

@@ -1,5 +1,5 @@
 {
-	"name": "unicorn",
+	"name": "unicorn ",
 	"version": "1.0.0",
 	"type": "module"
 }

test/test.js

@@ -1,10 +1,9 @@
-import {fileURLToPath, pathToFileURL} from 'url';
-import path from 'path';
+import {fileURLToPath, pathToFileURL} from 'node:url';
+import path from 'node:path';
 import test from 'ava';
-import {readPackage, readPackageSync} from '../index.js';
+import {readPackage, readPackageSync, parsePackage} from '../index.js';
 
-const dirname = path.dirname(fileURLToPath(import.meta.url));
-process.chdir(dirname);
+const dirname = path.dirname(fileURLToPath(test.meta.file));
 const rootCwd = path.join(dirname, '..');
 
 test('async', async t => {
@@ -22,6 +21,11 @@ test('async - cwd option', async t => {
 	);
 });
 
+test('async - normalize option', async t => {
+	const package_ = await readPackage({normalize: false});
+	t.is(package_.name, 'unicorn ');
+});
+
 test('sync', t => {
 	const package_ = readPackageSync();
 	t.is(package_.name, 'unicorn');
@@ -36,3 +40,65 @@ test('sync - cwd option', t => {
 		package_,
 	);
 });
+
+test('sync - normalize option', t => {
+	const package_ = readPackageSync({normalize: false});
+	t.is(package_.name, 'unicorn ');
+});
+
+const pkgJson = {
+	name: 'unicorn ',
+	version: '1.0.0',
+	type: 'module',
+};
+
+test('parsePackage - json input', t => {
+	const package_ = parsePackage(pkgJson);
+	t.is(package_.name, 'unicorn');
+	t.deepEqual(
+		readPackageSync(),
+		package_,
+	);
+});
+
+test('parsePackage - string input', t => {
+	const package_ = parsePackage(JSON.stringify(pkgJson));
+	t.is(package_.name, 'unicorn');
+	t.deepEqual(
+		readPackageSync(),
+		package_,
+	);
+});
+
+test('parsePackage - normalize option', t => {
+	const package_ = parsePackage(pkgJson, {normalize: false});
+	t.is(package_.name, 'unicorn ');
+	t.deepEqual(
+		readPackageSync({normalize: false}),
+		package_,
+	);
+});
+
+test('parsePackage - errors on invalid input', t => {
+	t.throws(
+		() => parsePackage(['foo', 'bar']),
+		{message: '`packageFile` should be either an `object` or a `string`.'},
+	);
+
+	t.throws(
+		() => parsePackage(null),
+		{message: '`packageFile` should be either an `object` or a `string`.'},
+	);
+
+	t.throws(
+		() => parsePackage(() => ({name: 'unicorn'})),
+		{message: '`packageFile` should be either an `object` or a `string`.'},
+	);
+});
+
+test('parsePackage - does not modify source object', t => {
+	const pkgObject = {name: 'unicorn', version: '1.0.0'};
+	const package_ = parsePackage(pkgObject);
+
+	t.not(pkgObject, package_);
+});