webpack/lib/runtime/EnsureChunkRuntimeModule.js

54 lines
1.7 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
*/
"use strict";
const RuntimeGlobals = require("../RuntimeGlobals");
const RuntimeModule = require("../RuntimeModule");
const Template = require("../Template");
class EnsureChunkRuntimeModule extends RuntimeModule {
constructor(runtimeRequirements) {
super("ensure chunk");
this.runtimeRequirements = runtimeRequirements;
}
/**
* @returns {string} runtime code
*/
generate() {
const { runtimeTemplate } = this.compilation;
// Check if there are non initial chunks which need to be imported using require-ensure
if (this.runtimeRequirements.has(RuntimeGlobals.ensureChunkHandlers)) {
const handlers = RuntimeGlobals.ensureChunkHandlers;
return Template.asString([
`${handlers} = {};`,
"// This file contains only the entry chunk.",
"// The chunk loading function for additional chunks",
`${
RuntimeGlobals.ensureChunk
} = ${runtimeTemplate.basicFunction("chunkId", [
`return Promise.all(Object.keys(${handlers}).reduce(${runtimeTemplate.basicFunction(
"promises, key",
[`${handlers}[key](chunkId, promises);`, "return promises;"]
)}, []));`
])};`
]);
} else {
// There ensureChunk is used somewhere in the tree, so we need an empty requireEnsure
// function. This can happen with multiple entrypoints.
return Template.asString([
"// The chunk loading function for additional chunks",
"// Since all referenced chunks are already included",
"// in this file, this function is empty here.",
`${RuntimeGlobals.ensureChunk} = ${runtimeTemplate.returningFunction(
"Promise.resolve()"
)};`
]);
}
}
}
module.exports = EnsureChunkRuntimeModule;