Method getLazyOnceSource

lib/ContextModule.js:1037–1091

* @param {AsyncDependenciesBlock} block block * @param {Dependency[]} dependencies dependencies * @param {ModuleId} id module id * @param {ImportPhaseType} phase import phase * @param {object} options options object * @param {RuntimeTemplate} options.runtimeTemplate the runtime template

(
		block,
		dependencies,
		id,
		phase,
		{ runtimeTemplate, chunkGraph }
	)

	 * @returns {string} source code
	 */
	getLazyOnceSource(
		block,
		dependencies,
		id,
		phase,
		{ runtimeTemplate, chunkGraph }
	) {
		const promise = runtimeTemplate.blockPromise({
			chunkGraph,
			block,
			message: "lazy-once context",
			/** @type {RuntimeRequirements} */
			runtimeRequirements: new Set()
		});
		const map = this.getUserRequestMap(dependencies, chunkGraph);
		const fakeMap = this.getFakeMap(dependencies, chunkGraph);
		const asyncDepsMap =
			ImportPhaseUtils.isDefer(phase) &&
			this.getModuleDeferredAsyncDepsMap(dependencies, chunkGraph);
		const thenFunction = runtimeTemplate.returningFunction(
			this.getReturnModuleObjectSource(
				fakeMap,
				true,
				asyncDepsMap ? "asyncDepsMap[id]" : undefined
			),
			"id"
		);

		const cst = runtimeTemplate.renderConst();
		return `${cst} map = ${JSON.stringify(map, null, "\t")};
${this.getFakeMapInitStatement(fakeMap, runtimeTemplate)}
${this.getModuleDeferredAsyncDepsMapInitStatement(asyncDepsMap, runtimeTemplate)}

function webpackAsyncContext(req) {
	return webpackAsyncContextResolve(req).then(${thenFunction});
}
function webpackAsyncContextResolve(req) {
	return ${promise}.then(${runtimeTemplate.basicFunction("", [
		`if(!${RuntimeGlobals.hasOwnProperty}(map, req)) {`,
		Template.indent([
			`${cst} e = new Error("Cannot find module '" + req + "'");`,
			"e.code = 'MODULE_NOT_FOUND';",
			"throw e;"
		]),
		"}",
		"return map[req];"
	])});
}
webpackAsyncContext.keys = ${runtimeTemplate.returningFunction(
			"Object.keys(map)"
		)};
webpackAsyncContext.resolve = webpackAsyncContextResolve;
webpackAsyncContext.id = ${JSON.stringify(id)};
module.exports = webpackAsyncContext;`;
	}

	/**
	 * @param {AsyncDependenciesBlock[]} blocks blocks