import assert from 'node:assert/strict';

import { readdir } from 'node:fs/promises';

import { replaceInFile } from '../../utils/fs';

import { execWithEnv, ng } from '../../utils/process';

import { installPackage, uninstallPackage } from '../../utils/packages';

export default async function () {

// Case 1: Force on with true/1 with 1 lazy chunk

await ng('generate', 'component', 'lazy-a');

await replaceInFile(

'src/app/app.routes.ts',

'routes: Routes = [];',

`routes: Routes = [

{

path: 'lazy-a',

loadComponent: () => import('./lazy-a/lazy-a').then(m => m.LazyA),

},

];`,

);

// Build with forced optimization

await execWithEnv('ng', ['build', '--output-hashing=none'], {

...process.env,

NG_BUILD_OPTIMIZE_CHUNKS: 'true',

});

const files1Opt = await readdir('dist/test-project/browser');

const jsFiles1Opt = files1Opt.filter((f) => f.endsWith('.js'));

// Build with forced off

await execWithEnv('ng', ['build', '--output-hashing=none'], {

...process.env,

NG_BUILD_OPTIMIZE_CHUNKS: 'false',

});

const files1Unopt = await readdir('dist/test-project/browser');

const jsFiles1Unopt = files1Unopt.filter((f) => f.endsWith('.js'));

// We just verify it runs without error.

// With 1 chunk it might not be able to optimize further, so counts might be equal.

// Case 2: Force off with false/0 with 3 lazy chunks

await ng('generate', 'component', 'lazy-b');

await ng('generate', 'component', 'lazy-c');

await replaceInFile(

'src/app/app.routes.ts',

`path: 'lazy-a',

loadComponent: () => import('./lazy-a/lazy-a').then(m => m.LazyA),

},`,

`path: 'lazy-a',

loadComponent: () => import('./lazy-a/lazy-a').then(m => m.LazyA),

},

{

path: 'lazy-b',

loadComponent: () => import('./lazy-b/lazy-b').then(m => m.LazyB),

},

{

path: 'lazy-c',

loadComponent: () => import('./lazy-c/lazy-c').then(m => m.LazyC),

},`,

);

// Build with forced off

await execWithEnv('ng', ['build', '--output-hashing=none'], {

...process.env,

NG_BUILD_OPTIMIZE_CHUNKS: 'false',

});

const files3Unopt = await readdir('dist/test-project/browser');

const jsFiles3Unopt = files3Unopt.filter((f) => f.endsWith('.js'));

// Build with default (should optimize because 3 chunks)

await ng('build', '--output-hashing=none');

const files3Default = await readdir('dist/test-project/browser');

const jsFiles3Default = files3Default.filter((f) => f.endsWith('.js'));

assert.ok(

jsFiles3Default.length < jsFiles3Unopt.length,

`Expected default build (3 chunks) to be optimized compared to forced off. Default: ${jsFiles3Default.length}, Forced Off: ${jsFiles3Unopt.length}`,

);

// Case 3: Custom threshold

// Set threshold to 4 with 3 chunks -> should NOT optimize!

await execWithEnv('ng', ['build', '--output-hashing=none'], {

...process.env,

NG_BUILD_OPTIMIZE_CHUNKS: '4',

});

const files3Thresh4 = await readdir('dist/test-project/browser');

const jsFiles3Thresh4 = files3Thresh4.filter((f) => f.endsWith('.js'));

assert.ok(

jsFiles3Thresh4.length >= jsFiles3Unopt.length,

`Expected build with threshold 4 and 3 chunks to NOT be optimized. Thresh 4: ${jsFiles3Thresh4.length}, Unoptimized: ${jsFiles3Unopt.length}`,

);

// Case 4: Opt into Rolldown

await installPackage('rolldown@1.0.0-rc.12');

try {

await execWithEnv('ng', ['build', '--output-hashing=none'], {

...process.env,

NG_BUILD_CHUNKS_ROLLDOWN: '1',

NG_BUILD_OPTIMIZE_CHUNKS: 'true',

});

const filesRolldown = await readdir('dist/test-project/browser');

const jsFilesRolldown = filesRolldown.filter((f) => f.endsWith('.js'));

assert.ok(jsFilesRolldown.length > 0, 'Expected Rolldown build to produce output files.');

} finally {

// Clean up

await uninstallPackage('rolldown');

}

}