feat(prettier-plugin): create new @liferay/prettier-plugin package

.eslintrc.js

@@ -59,6 +59,7 @@ module.exports = {
 	],
 	plugins: ['@liferay'],
 	rules: {
+		'@liferay/import-extensions': 'off',
 		'notice/notice': [
 			'error',
 			{

.github/workflows/prettier-plugin.yml

@@ -0,0 +1,67 @@
+# Based on: https://github.com/actions/starter-workflows/blob/master/ci/node.js.yml
+
+name: prettier-plugin
+
+on:
+    push:
+        branches: [master]
+        paths:
+            - 'projects/prettier-plugin/**'
+    pull_request:
+        branches: [master]
+        paths:
+            - 'projects/prettier-plugin/**'
+
+env:
+    CI: true
+    yarn-cache-name: yarn-cache-3
+    yarn-cache-path: .yarn
+
+jobs:
+    check-lockfile:
+        runs-on: ubuntu-latest
+
+        strategy:
+            matrix:
+                node-version: [20.x]
+
+        steps:
+            - uses: actions/checkout@v2
+            - name: Use Node.js ${{ matrix.node-version }}
+              uses: actions/setup-node@v3
+              with:
+                  node-version: ${{ matrix.node-version }}
+            - name: Use or update Yarn cache
+              uses: actions/cache@v2
+              with:
+                  path: ${{ env.yarn-cache-path }}
+                  key: ${{ runner.os }}-${{ env.yarn-cache-name }}-${{ hashFiles('**/yarn.lock') }}
+            - run: yarn --cache-folder=${{ env.yarn-cache-path }}
+              working-directory: projects/prettier-plugin
+            - run: git diff --quiet -- yarn.lock
+              working-directory: projects/prettier-plugin
+
+    test:
+        runs-on: ubuntu-latest
+
+        strategy:
+            matrix:
+                node-version: [20.x]
+
+        steps:
+            - uses: actions/checkout@v2
+            - name: Use Node.js ${{ matrix.node-version }}
+              uses: actions/setup-node@v3
+              with:
+                  node-version: ${{ matrix.node-version }}
+            - name: Use or update Yarn cache
+              uses: actions/cache@v2
+              with:
+                  path: ${{ env.yarn-cache-path }}
+                  key: ${{ runner.os }}-${{ env.yarn-cache-name }}-${{ hashFiles('**/yarn.lock') }}-prettier-plugin
+            - run: yarn --cache-folder=../../../${{ env.yarn-cache-path }} --frozen-lockfile
+              working-directory: projects/prettier-plugin
+            - run: yarn --cache-folder=../../../${{ env.yarn-cache-path }} build
+              working-directory: projects/prettier-plugin
+            - run: yarn --cache-folder=../../../${{ env.yarn-cache-path }} test
+              working-directory: projects/prettier-plugin

jest.config.js

@@ -37,6 +37,7 @@ module.exports = {
 		'<rootDir>/projects/js-themes-toolkit',
 		'<rootDir>/projects/js-toolkit',
 		'<rootDir>/projects/npm-tools/packages/npm-scripts',
+		'<rootDir>/projects/prettier-plugin',
 
 		// Third-party.
 

projects/prettier-plugin/index.js

@@ -0,0 +1,7 @@
+/**
+ * SPDX-FileCopyrightText: © 2020 Liferay, Inc. <https://liferay.com>
+ * SPDX-License-Identifier: MIT
+ */
+
+export {parsers} from './parsers.js';
+export {printers} from './printers.js';

projects/prettier-plugin/package.json

@@ -0,0 +1,17 @@
+{
+	"dependencies": {
+		"prettier": "3.2.5"
+	},
+	"exports": "./index.js",
+	"name": "@liferay/prettier-plugin",
+	"scripts": {
+		"build": "true",
+		"format": "liferay-workspace-scripts format",
+		"format:check": "liferay-workspace-scripts format:check",
+		"postversion": "liferay-workspace-scripts publish",
+		"preversion": "liferay-workspace-scripts ci",
+		"test": "node test"
+	},
+	"type": "module",
+	"version": "1.0.0"
+}

projects/prettier-plugin/parsers.js

@@ -0,0 +1,45 @@
+/**
+ * SPDX-FileCopyrightText: © 2020 Liferay, Inc. <https://liferay.com>
+ * SPDX-License-Identifier: MIT
+ */
+
+import {format} from 'prettier';
+import {parsers as babelParsers} from 'prettier/plugins/babel';
+import {parsers as typescriptParsers} from 'prettier/plugins/typescript';
+
+import {linesAroundComments} from './rules/lines-around-comments.js';
+
+function transformParser(parserName, defaultParser) {
+	return {
+		...defaultParser,
+		astFormat: 'liferay-style-ast',
+		parse: async (text, options) => {
+
+			/*
+			 * We need to filter out our own plugin before calling default prettier
+			 */
+			const plugins = options.plugins.filter(
+				(plugin) => !plugin.printers['liferay-style-ast']
+			);
+
+			let formattedText = await format(text, {
+				...options,
+				plugins,
+			});
+
+			const ast = defaultParser.parse(formattedText, options);
+
+			formattedText = linesAroundComments(formattedText, ast, parserName);
+
+			return {
+				body: formattedText,
+				type: 'FormattedText',
+			};
+		},
+	};
+}
+
+export const parsers = {
+	babel: transformParser('babel', babelParsers.babel),
+	typescript: transformParser('typescript', typescriptParsers.typescript),
+};

projects/prettier-plugin/printers.js

@@ -0,0 +1,24 @@
+/**
+ * SPDX-FileCopyrightText: © 2020 Liferay, Inc. <https://liferay.com>
+ * SPDX-License-Identifier: MIT
+ */
+
+function createPrinter() {
+	function main(path) {
+		const {node} = path;
+
+		if (node.type === 'FormattedText') {
+			return node.body;
+		}
+
+		throw new Error(`Unknown node type: ${node?.type}`);
+	}
+
+	return {
+		print: main,
+	};
+}
+
+export const printers = {
+	'liferay-style-ast': createPrinter(),
+};

projects/prettier-plugin/rules/lines-around-comments.js

@@ -0,0 +1,68 @@
+/**
+ * SPDX-FileCopyrightText: © 2020 Liferay, Inc. <https://liferay.com>
+ * SPDX-License-Identifier: MIT
+ */
+
+export function linesAroundComments(formattedText, ast, parserName) {
+	let contentLengthIncrease = 0;
+
+	ast.comments.forEach((commentNode) => {
+		if (isEndofLineComment(commentNode)) {
+			return;
+		}
+
+		const nodeStart =
+			parserName === 'typescript'
+				? commentNode.range[0]
+				: commentNode.start;
+		const nodeEnd =
+			parserName === 'typescript'
+				? commentNode.range[1]
+				: commentNode.end;
+
+		const commentStartIndex = nodeStart + contentLengthIncrease;
+
+		if (!isNewLineBefore(formattedText, commentStartIndex)) {
+			const position = commentStartIndex - 1;
+
+			formattedText = insertNewLine(formattedText, position);
+
+			contentLengthIncrease += 1;
+		}
+
+		const commentEndIndex = nodeEnd + contentLengthIncrease;
+
+		if (
+			!isBlockComment(commentNode) &&
+			!isNewLineAfter(formattedText, commentEndIndex)
+		) {
+			const position = commentEndIndex + 1;
+
+			formattedText = insertNewLine(formattedText, position);
+
+			contentLengthIncrease += 1;
+		}
+	});
+
+	return formattedText;
+}
+
+function isBlockComment(node) {
+	return node.type === 'CommentBlock' || node.type === 'Block';
+}
+
+function isEndofLineComment(node) {
+	return node.loc.start.column !== 0;
+}
+
+function isNewLineBefore(text, index) {
+	return text.charAt(index - 2) === '\n';
+}
+
+function isNewLineAfter(text, index) {
+	return text.charAt(index + 2) === '\n';
+}
+
+function insertNewLine(text, index) {
+	return [text.slice(0, index), '\n', text.slice(index)].join('');
+}

projects/prettier-plugin/test/index.js

@@ -0,0 +1,92 @@
+/**
+ * SPDX-FileCopyrightText: © 2020 Liferay, Inc. <https://liferay.com>
+ * SPDX-License-Identifier: MIT
+ */
+
+import assert from 'node:assert';
+import {describe, test} from 'node:test';
+import {format} from 'prettier';
+
+import * as liferayPrettierPlugin from '../index.js';
+
+const baseConfig = {
+	bracketSpacing: false,
+	plugins: [liferayPrettierPlugin],
+	singleQuote: true,
+	tabWidth: 4,
+	useTabs: true,
+};
+
+const babelConfig = {
+	...baseConfig,
+	parser: 'babel',
+};
+
+const tsConfig = {
+	...baseConfig,
+	parser: 'typescript',
+};
+
+const fixtures = [
+	{
+		_name: 'inline comment',
+		code: `const foo = 'foo';
+		// test
+		const bar = 'bar';`,
+		expected: `const foo = 'foo';
+
+// test
+
+const bar = 'bar';
+`,
+	},
+	{
+		_name: 'block comment',
+		code: `const foo = 'foo';
+/*
+ * blah
+ */
+const bar = 'bar';`,
+		expected: `const foo = 'foo';
+
+/*
+ * blah
+ */
+const bar = 'bar';
+`,
+	},
+];
+
+describe('babel', () => {
+	test('prettier runs', async () => {
+		const code = `if (foo) {}`;
+
+		assert.ok(await format(code, babelConfig));
+	});
+
+	fixtures.forEach((fixture) => {
+		test(fixture._name, async () => {
+			assert.equal(
+				await format(fixture.code, babelConfig),
+				fixture.expected
+			);
+		});
+	});
+});
+
+describe('typescript', () => {
+	test('prettier runs', async () => {
+		const code = `if (foo) {}`;
+
+		assert.ok(await format(code, tsConfig));
+	});
+
+	fixtures.forEach((fixture) => {
+		test(fixture._name, async () => {
+			assert.equal(
+				await format(fixture.code, tsConfig),
+				fixture.expected
+			);
+		});
+	});
+});