webpack/lib/runtime/GetTrustedTypesPolicyRuntimeModule.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
*/

"use strict";

const RuntimeGlobals = require("../RuntimeGlobals");
const Template = require("../Template");
const HelperRuntimeModule = require("./HelperRuntimeModule");

/** @typedef {import("../Compilation")} Compilation */
/** @typedef {import("../Module").ReadOnlyRuntimeRequirements} ReadOnlyRuntimeRequirements */

class GetTrustedTypesPolicyRuntimeModule extends HelperRuntimeModule {
	/**
	 * @param {ReadOnlyRuntimeRequirements} runtimeRequirements runtime requirements
	 */
	constructor(runtimeRequirements) {
		super("trusted types policy");
		this.runtimeRequirements = runtimeRequirements;
	}

	/**
	 * @returns {string | null} runtime code
	 */
	generate() {
		const compilation = /** @type {Compilation} */ (this.compilation);
		const { runtimeTemplate, outputOptions } = compilation;
		const { trustedTypes } = outputOptions;
		const fn = RuntimeGlobals.getTrustedTypesPolicy;
		const wrapPolicyCreationInTryCatch = trustedTypes
			? trustedTypes.onPolicyCreationFailure === "continue"
			: false;

		return Template.asString([
			"var policy;",
			`${fn} = ${runtimeTemplate.basicFunction("", [
				"// Create Trusted Type policy if Trusted Types are available and the policy doesn't exist yet.",
				"if (policy === undefined) {",
				Template.indent([
					"policy = {",
					Template.indent(
						[
							...(this.runtimeRequirements.has(RuntimeGlobals.createScript)
								? [
										`createScript: ${runtimeTemplate.returningFunction(
											"script",
											"script"
										)}`
									]
								: []),
							...(this.runtimeRequirements.has(RuntimeGlobals.createScriptUrl)
								? [
										`createScriptURL: ${runtimeTemplate.returningFunction(
											"url",
											"url"
										)}`
									]
								: [])
						].join(",\n")
					),
					"};",
					...(trustedTypes
						? [
								'if (typeof trustedTypes !== "undefined" && trustedTypes.createPolicy) {',
								Template.indent([
									...(wrapPolicyCreationInTryCatch ? ["try {"] : []),
									...[
										`policy = trustedTypes.createPolicy(${JSON.stringify(
											trustedTypes.policyName
										)}, policy);`
									].map(line =>
										wrapPolicyCreationInTryCatch ? Template.indent(line) : line
									),
									...(wrapPolicyCreationInTryCatch
										? [
												"} catch (e) {",
												Template.indent([
													`console.warn('Could not create trusted-types policy ${JSON.stringify(
														trustedTypes.policyName
													)}');`
												]),
												"}"
											]
										: [])
								]),
								"}"
							]
						: [])
				]),
				"}",
				"return policy;"
			])};`
		]);
	}
}

module.exports = GetTrustedTypesPolicyRuntimeModule;