/**

* @license

* Copyright Google LLC

*

* Use of this source code is governed by an MIT-style license that can be

* found in the LICENSE file at https://angular.dev/license

*/

import fs from 'fs';

import babel from '@babel/core';

import {assertNoPartialDeclaration} from './ensure-no-linker-decl.mjs';

/**

* Creates an ESBuild plugin that configures various Angular optimization Babel plugins.

* The Babel plugins configured usually run in the Angular CLI compilation pipeline.

*

* @param {import('./esbuild-plugin').OptimizationOptions} opts Options

* @param additionalBabelPlugins List of additional Babel plugins that should run as part

* of this ESBuild plugin. This is primarily supported for reducing the amount of ESBuild

* load plugins needed (as they can impact performance significantly).

*/

export async function createEsbuildAngularOptimizePlugin(opts, additionalBabelPlugins = []) {

let linkerCreator = {

compiler: null,

babel: null,

};

let downlevelAsyncGeneratorPlugin = null;

if (opts.enableLinker) {

linkerCreator = {

compiler: await import('@angular/compiler-cli'),

babel: await import('@angular/compiler-cli/linker/babel'),

};

}

if (opts.downlevelAsyncGeneratorsIfPresent) {

downlevelAsyncGeneratorPlugin = (

await import('@babel/plugin-transform-async-generator-functions')

).default.default;

}

const {adjustStaticMembers, adjustTypeScriptEnums, elideAngularMetadata, markTopLevelPure} = (

await import('@angular/build/private')

).default;

return {

name: 'ng-babel-optimize-esbuild',

setup: (build) => {

build.onLoad({filter: /\.[cm]?js$/}, async (args) => {

const filePath = args.path;

const content = await fs.promises.readFile(filePath, 'utf8');

const plugins = [...additionalBabelPlugins];

if (opts.optimize) {

plugins.push(adjustStaticMembers, adjustTypeScriptEnums, elideAngularMetadata);

// If the current file is denoted as explicit side effect free, add the pure

// top-level functions optimization plugin for this file.

if (opts.optimize.isSideEffectFree && opts.optimize.isSideEffectFree(args.path)) {

plugins.push(markTopLevelPure);

}

}

const shouldRunLinker =

opts.enableLinker &&

(opts.enableLinker.filterPaths == null || opts.enableLinker.filterPaths.test(args.path));

if (shouldRunLinker) {

plugins.push(

linkerCreator.babel.createEs2015LinkerPlugin({

...(opts.enableLinker.linkerOptions ?? {}),

fileSystem: new linkerCreator.compiler.NodeJSFileSystem(),

logger: new linkerCreator.compiler.ConsoleLogger(

linkerCreator.compiler.LogLevel.warn,

),

// Workaround for https://github.com/angular/angular/issues/42769 and https://github.com/angular/angular-cli/issues/22647.

sourceMapping: false,

}),

);

}

// Matches Angular CLIs detection:

// https://github.com/angular/angular-cli/blob/afe9feaa45913cbebe7f22c678d693d96f38584a/packages/angular_devkit/build_angular/src/builders/browser-esbuild/javascript-transformer.ts#L74-L76

if (

opts.downlevelAsyncGeneratorsIfPresent &&

content.includes('async') &&

/async(\s+function)?\s*\*/.test(content)

) {

plugins.push(downlevelAsyncGeneratorPlugin);

}

// If no plugins are enabled, return the original code and save time.

if (plugins.length === 0) {

return {contents: content};

}

const ensureNoPartialDeclaration =

opts.enableLinker && opts.enableLinker.ensureNoPartialDeclaration;

const {code, ast} = await babel.transformAsync(content, {

filename: filePath,

filenameRelative: filePath,

plugins: plugins,

// Sourcemaps are generated inline so that ESBuild can process them.

sourceMaps: 'inline',

compact: false,

// AST is needed when we want to ensure no partial declarations later.

ast: ensureNoPartialDeclaration,

});

if (ensureNoPartialDeclaration) {

assertNoPartialDeclaration(filePath, ast, babel.traverse);

}

return {contents: code};

});

},

};

}