webpack/lib/runtime/EnsureChunkRuntimeModule.js

50 lines
1.5 KiB
JavaScript
Raw Normal View History

/*
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(callHandlers) {
super("ensure chunk");
this.callHandlers = callHandlers;
}
/**
* @returns {string} runtime code
*/
generate() {
// Check if there are non initial chunks which need to be imported using require-ensure
if (this.callHandlers) {
const handlers = RuntimeGlobals.ensureChunkHandlers;
return Template.asString([
`${handlers} = [];`,
"// This file contains only the entry chunk.",
"// The chunk loading function for additional chunks",
`${RuntimeGlobals.ensureChunk} = function requireEnsure(chunkId) {`,
Template.indent([
`return Promise.all(${handlers}.reduce(function(promises, h) { return h(chunkId, promises), promises; }, []));`
]),
"};"
]);
} else {
// There ensureChunk is used somewhere in the tree, so we need an empty requireEnsure
// function. This can happen with multiple entrypoints.
return Template.asString([
"// The chunk loading function for additional chunks",
"// Since all referenced chunks are already included",
"// in this file, this function is empty here.",
`${RuntimeGlobals.ensureChunk} = function requireEnsure() {`,
Template.indent("return Promise.resolve();"),
"};"
]);
}
}
}
module.exports = EnsureChunkRuntimeModule;