feat: support link.config.json (#2)

README.md

@@ -14,6 +14,37 @@ From the project you want to link a package to:
 npx link <package-path>
 ```
 
+### Configuration file
+
+Create a `link.config.json` configuration file at the root of your npm project to automatically setup links to multiple packages.
+
+Example _link.config.json_:
+```json5
+{
+    "packages": [
+        "/path/to/package-path-a",
+        "../package-path-b"
+    ]
+}
+```
+
+The configuration has the following type schema:
+```ts
+type LinkConfig = {
+
+    // List of packages to link
+    packages?: string[]
+}
+```
+
+> Note: It's not recommended to commit this file to source control since this is for local development with local paths.
+
+
+To link the dependencies defined in `link.config.json`, run:
+```sh
+npx link
+```
+
 ## FAQ
 
 ### Why should I use this over `npm link`?

src/cli.ts

@@ -1,20 +1,42 @@
 import { cli } from 'cleye';
 import { linkPackage } from './link-package';
+import { loadConfig } from './utils/load-config';
 
 (async () => {
 	const argv = cli({
 		name: 'link',
-		parameters: ['<package paths...>'],
+		parameters: ['[package paths...]'],
 		help: {
 			description: 'A better `npm link` - Link a package to the current project',
 		},
 	});
 
 	const { packagePaths } = argv._;
 
+	if (packagePaths.length > 0) {
+		await Promise.all(
+			packagePaths.map(
+				packagePath => linkPackage(packagePath),
+			),
+		);
+
+		return;
+	}
+
+	const config = await loadConfig();
+
+	if (!config) {
+		console.warn('Warning: Config file "link.config.json" not found in current directory.');
+		return;
+	}
+
+	if (!config.packages) {
+		return;
+	}
+
 	await Promise.all(
-		packagePaths.map(
-			packagePath => linkPackage(packagePath),
+		config.packages.map(
+			async linkPath => await linkPackage(linkPath),
 		),
 	);
 })().catch((error) => {

src/types.ts

@@ -0,0 +1,3 @@
+export type LinkConfig = {
+	packages?: string[];
+}

src/utils/load-config.ts

@@ -0,0 +1,19 @@
+import type { LinkConfig } from '../types';
+import { fsExists } from './fs-exists';
+import { readJsonFile } from './read-json-file';
+
+const configPath = 'link.config.json';
+
+export async function loadConfig() {
+	const configExists = await fsExists(configPath);
+
+	if (!configExists) {
+		return null;
+	}
+
+	try {
+		return readJsonFile<LinkConfig>(configPath);
+	} catch (error) {
+		throw new Error(`Failed to parse config JSON: ${(error as any).message}`);
+	}
+}

tests/index.ts

@@ -1,6 +1,7 @@
 import { describe } from 'manten';
 import getNode from 'get-node';
 import specCli from './specs/cli';
+import specLinkConfig from './specs/link-config';
 
 const nodeVersions = [
 	'12.22.9',
@@ -19,6 +20,7 @@ const nodeVersions = [
 		const node = await getNode(nodeVersion);
 		await describe(`Node ${node.version}`, ({ runTestSuite }) => {
 			runTestSuite(specCli, node.path);
+			runTestSuite(specLinkConfig, node.path);
 		});
 	}
 })();

tests/specs/cli.ts

@@ -136,18 +136,16 @@ export default testSuite(({ describe }, nodePath: string) => {
 			);
 			expect(packageA.stdout).toBe('["package-entry","package-binary","package-files","@organization/package-organization"]');
 
-			// Test binary
-			await fixture.writeJson('package-entry/package.json', {
-				scripts: {
-					test: 'binary',
-				},
-			});
-
 			// Executable
 			const binary = await execa(path.join(entryPackagePath, 'node_modules/.bin/binary'));
 			expect(binary.stdout).toMatch('package-binary');
 
 			// Executable via npm
+			await fixture.writeJson('package-entry/package.json', {
+				scripts: {
+					test: 'binary',
+				},
+			});
 			const binaryNpm = await execa('npm', ['test'], {
 				cwd: entryPackagePath,
 			});

tests/specs/link-config.ts

@@ -0,0 +1,62 @@
+import path from 'path';
+import { testSuite, expect } from 'manten';
+import { execa, execaNode } from 'execa';
+import { createFixture } from '../utils/create-fixture';
+import { link } from '../utils/link';
+
+export default testSuite(({ describe }, nodePath: string) => {
+	describe('link.config.json', ({ test }) => {
+		test('symlink', async () => {
+			const fixture = await createFixture('./tests/fixtures/');
+
+			const entryPackagePath = path.join(fixture.path, 'package-entry');
+
+			await fixture.writeJson('package-entry/link.config.json', {
+				packages: [
+					// Relative path & binary
+					'../package-binary',
+
+					// Absolute path
+					path.join(fixture.path, 'package-files'),
+
+					// Package with @org in name
+					'../package-organization',
+				],
+			});
+
+			await link([], {
+				cwd: entryPackagePath,
+				nodePath,
+			});
+
+			const packageA = await execaNode(
+				path.join(entryPackagePath, 'index.js'),
+				[],
+				{
+					nodePath,
+					nodeOptions: [],
+				},
+			);
+			expect(packageA.stdout).toBe('["package-entry","package-binary","package-files","@organization/package-organization"]');
+
+			// Executable via npm
+			await fixture.writeJson('package-entry/package.json', {
+				scripts: {
+					test: 'binary',
+				},
+			});
+			const binaryNpm = await execa('npm', ['test'], {
+				cwd: entryPackagePath,
+			});
+			expect(binaryNpm.stdout).toMatch('package-binary');
+
+			const binary = await execa(path.join(entryPackagePath, 'node_modules/.bin/binary'));
+			expect(binary.stdout).toBe('package-binary');
+
+			const nonPublishFileExists = await fixture.exists('package-entry/node_modules/package-files/non-publish-file.js');
+			expect(nonPublishFileExists).toBe(true);
+
+			await fixture.rm();
+		});
+	});
+});