import {readdirSync} from 'fs';

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

import {appendToFile, writeFile, prependToFile, replaceInFile} from '../../utils/fs';

export default function() {

let oldNumberOfFiles = 0;

return Promise.resolve()

.then(() => ng('build'))

.then(() => oldNumberOfFiles = readdirSync('dist').length)

.then(() => ng('generate', 'module', 'lazy', '--routing'))

.then(() => ng('generate', 'module', 'too/lazy', '--routing'))

.then(() => prependToFile('src/app/app.module.ts', `

import { RouterModule } from '@angular/router';

`))

.then(() => replaceInFile('src/app/app.module.ts', 'imports: [', `imports: [

RouterModule.forRoot([{ path: "lazy", loadChildren: "src/app/lazy/lazy.module#LazyModule" }]),

RouterModule.forRoot([{ path: "lazy1", loadChildren: "./lazy/lazy.module#LazyModule" }]),

RouterModule.forRoot([{ path: "lazy2", loadChildren: "./too/lazy/lazy.module#LazyModule" }]),

`))

.then(() => ng('build', '--named-chunks'))

.then(() => readdirSync('dist/test-project'))

.then((distFiles) => {

const currentNumberOfDistFiles = distFiles.length;

if (oldNumberOfFiles >= currentNumberOfDistFiles) {

throw new Error('A bundle for the lazy module was not created.');

}

oldNumberOfFiles = currentNumberOfDistFiles;

if (!distFiles.includes('lazy-lazy-module.js')) {

throw new Error('The lazy module chunk did not have a name.');

}

if (!distFiles.includes('too-lazy-lazy-module.js')) {

throw new Error('The lazy module chunk did not use a unique name.');

}

})

// verify System.import still works

.then(() => writeFile('src/app/lazy-file.ts', ''))

.then(() => appendToFile('src/app/app.component.ts', `

// verify other System.import still work

declare var System: any;

const lazyFile = 'file';

System.import(/*webpackChunkName: '[request]'*/'./lazy-' + lazyFile);

`))

.then(() => ng('build', '--named-chunks'))

.then(() => readdirSync('dist/test-project'))

.then((distFiles) => {

const currentNumberOfDistFiles = distFiles.length;

if (oldNumberOfFiles >= currentNumberOfDistFiles) {

throw new Error('A bundle for the lazy file was not created.');

}

if (!distFiles.includes('lazy-file.js')) {

throw new Error('The lazy file chunk did not have a name.');

}

oldNumberOfFiles = currentNumberOfDistFiles;

})

// verify 'import *' syntax doesn't break lazy modules

.then(() => silentNpm('install', 'moment'))

.then(() => appendToFile('src/app/app.component.ts', `

import * as moment from 'moment';

console.log(moment);

`))

.then(() => ng('build'))

.then(() => readdirSync('dist/test-project').length)

.then(currentNumberOfDistFiles => {

if (oldNumberOfFiles != currentNumberOfDistFiles) {

throw new Error('Bundles were not created after adding \'import *\'.');

}

})

.then(() => ng('build', '--no-named-chunks'))

.then(() => readdirSync('dist/test-project'))

.then((distFiles) => {

if (distFiles.includes('lazy-lazy-module.js')

|| distFiles.includes('too-lazy-lazy-module.js')

) {

throw new Error('Lazy chunks shouldn\'t have a name but did.');

}

})

// Check for AoT and lazy routes.

.then(() => ng('build', '--aot'))

.then(() => readdirSync('dist/test-project').length)

.then(currentNumberOfDistFiles => {

if (oldNumberOfFiles != currentNumberOfDistFiles) {

throw new Error('AoT build contains a different number of files.');

}

});

}