webpack/lib/RuntimeTemplate.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
	Author Tobias Koppers @sokra
*/

"use strict";

const InitFragment = require("./InitFragment");
const RuntimeGlobals = require("./RuntimeGlobals");
const Template = require("./Template");
const {
	getOutgoingAsyncModules
} = require("./async-modules/AsyncModuleHelpers");
const {
	getMakeDeferredNamespaceModeFromExportsType,
	getOptimizedDeferredModule
} = require("./runtime/MakeDeferredNamespaceObjectRuntime");
const { equals } = require("./util/ArrayHelpers");
const compileBooleanMatcher = require("./util/compileBooleanMatcher");
const propertyAccess = require("./util/propertyAccess");
const { forEachRuntime, subtractRuntime } = require("./util/runtime");

/** @typedef {import("./config/defaults").OutputNormalizedWithDefaults} OutputOptions */
/** @typedef {import("./AsyncDependenciesBlock")} AsyncDependenciesBlock */
/** @typedef {import("./Chunk")} Chunk */
/** @typedef {import("./ChunkGraph")} ChunkGraph */
/** @typedef {import("./Compilation")} Compilation */
/** @typedef {import("./Dependency")} Dependency */
/** @typedef {import("./Module")} Module */
/** @typedef {import("./Module").BuildMeta} BuildMeta */
/** @typedef {import("./Module").RuntimeRequirements} RuntimeRequirements */
/** @typedef {import("./ModuleGraph")} ModuleGraph */
/** @typedef {import("./RequestShortener")} RequestShortener */
/** @typedef {import("./util/runtime").RuntimeSpec} RuntimeSpec */

/**
 * @param {Module} module the module
 * @param {ChunkGraph} chunkGraph the chunk graph
 * @returns {string} error message
 */
const noModuleIdErrorMessage = (
	module,
	chunkGraph
) => `Module ${module.identifier()} has no id assigned.
This should not happen.
It's in these chunks: ${
	Array.from(
		chunkGraph.getModuleChunksIterable(module),
		(c) => c.name || c.id || c.debugId
	).join(", ") || "none"
} (If module is in no chunk this indicates a bug in some chunk/module optimization logic)
Module has these incoming connections: ${Array.from(
	chunkGraph.moduleGraph.getIncomingConnections(module),
	(connection) =>
		`\n - ${
			connection.originModule && connection.originModule.identifier()
		} ${connection.dependency && connection.dependency.type} ${
			(connection.explanations && [...connection.explanations].join(", ")) || ""
		}`
).join("")}`;

/**
 * @param {string | undefined} definition global object definition
 * @returns {string | undefined} save to use global object
 */
function getGlobalObject(definition) {
	if (!definition) return definition;
	const trimmed = definition.trim();

	if (
		// identifier, we do not need real identifier regarding ECMAScript/Unicode
		/^[_\p{L}][_0-9\p{L}]*$/iu.test(trimmed) ||
		// iife
		// call expression
		// expression in parentheses
		/^([_\p{L}][_0-9\p{L}]*)?\(.*\)$/iu.test(trimmed)
	) {
		return trimmed;
	}

	return `Object(${trimmed})`;
}

class RuntimeTemplate {
	/**
	 * @param {Compilation} compilation the compilation
	 * @param {OutputOptions} outputOptions the compilation output options
	 * @param {RequestShortener} requestShortener the request shortener
	 */
	constructor(compilation, outputOptions, requestShortener) {
		this.compilation = compilation;
		this.outputOptions = /** @type {OutputOptions} */ (outputOptions || {});
		this.requestShortener = requestShortener;
		this.globalObject =
			/** @type {string} */
			(getGlobalObject(outputOptions.globalObject));
		this.contentHashReplacement = "X".repeat(outputOptions.hashDigestLength);
	}

	isIIFE() {
		return this.outputOptions.iife;
	}

	isModule() {
		return this.outputOptions.module;
	}

	isNeutralPlatform() {
		return (
			!this.compilation.compiler.platform.web &&
			!this.compilation.compiler.platform.node
		);
	}

	supportsConst() {
		return this.outputOptions.environment.const;
	}

	supportsArrowFunction() {
		return this.outputOptions.environment.arrowFunction;
	}

	supportsAsyncFunction() {
		return this.outputOptions.environment.asyncFunction;
	}

	supportsOptionalChaining() {
		return this.outputOptions.environment.optionalChaining;
	}

	supportsForOf() {
		return this.outputOptions.environment.forOf;
	}

	supportsDestructuring() {
		return this.outputOptions.environment.destructuring;
	}

	supportsBigIntLiteral() {
		return this.outputOptions.environment.bigIntLiteral;
	}

	supportsDynamicImport() {
		return this.outputOptions.environment.dynamicImport;
	}

	supportsEcmaScriptModuleSyntax() {
		return this.outputOptions.environment.module;
	}

	supportTemplateLiteral() {
		return this.outputOptions.environment.templateLiteral;
	}

	supportNodePrefixForCoreModules() {
		return this.outputOptions.environment.nodePrefixForCoreModules;
	}

	/**
	 * @param {string} mod a module
	 * @returns {string} a module with `node:` prefix when supported, otherwise an original name
	 */
	renderNodePrefixForCoreModule(mod) {
		return this.outputOptions.environment.nodePrefixForCoreModules
			? `"node:${mod}"`
			: `"${mod}"`;
	}

	/**
	 * @returns {"const" | "var"} return `const` when it is supported, otherwise `var`
	 */
	renderConst() {
		return this.supportsConst() ? "const" : "var";
	}

	/**
	 * @param {string} returnValue return value
	 * @param {string} args arguments
	 * @returns {string} returning function
	 */
	returningFunction(returnValue, args = "") {
		return this.supportsArrowFunction()
			? `(${args}) => (${returnValue})`
			: `function(${args}) { return ${returnValue}; }`;
	}

	/**
	 * @param {string} args arguments
	 * @param {string | string[]} body body
	 * @returns {string} basic function
	 */
	basicFunction(args, body) {
		return this.supportsArrowFunction()
			? `(${args}) => {\n${Template.indent(body)}\n}`
			: `function(${args}) {\n${Template.indent(body)}\n}`;
	}

	/**
	 * @param {(string | { expr: string })[]} args args
	 * @returns {string} result expression
	 */
	concatenation(...args) {
		const len = args.length;

		if (len === 2) return this._es5Concatenation(args);
		if (len === 0) return '""';
		if (len === 1) {
			return typeof args[0] === "string"
				? JSON.stringify(args[0])
				: `"" + ${args[0].expr}`;
		}
		if (!this.supportTemplateLiteral()) return this._es5Concatenation(args);

		// cost comparison between template literal and concatenation:
		// both need equal surroundings: `xxx` vs "xxx"
		// template literal has constant cost of 3 chars for each expression
		// es5 concatenation has cost of 3 + n chars for n expressions in row
		// when a es5 concatenation ends with an expression it reduces cost by 3
		// when a es5 concatenation starts with an single expression it reduces cost by 3
		// e. g. `${a}${b}${c}` (3*3 = 9) is longer than ""+a+b+c ((3+3)-3 = 3)
		// e. g. `x${a}x${b}x${c}x` (3*3 = 9) is shorter than "x"+a+"x"+b+"x"+c+"x" (4+4+4 = 12)

		let templateCost = 0;
		let concatenationCost = 0;

		let lastWasExpr = false;
		for (const arg of args) {
			const isExpr = typeof arg !== "string";
			if (isExpr) {
				templateCost += 3;
				concatenationCost += lastWasExpr ? 1 : 4;
			}
			lastWasExpr = isExpr;
		}
		if (lastWasExpr) concatenationCost -= 3;
		if (typeof args[0] !== "string" && typeof args[1] === "string") {
			concatenationCost -= 3;
		}

		if (concatenationCost <= templateCost) return this._es5Concatenation(args);

		return `\`${args
			.map((arg) => (typeof arg === "string" ? arg : `\${${arg.expr}}`))
			.join("")}\``;
	}

	/**
	 * @param {(string | { expr: string })[]} args args (len >= 2)
	 * @returns {string} result expression
	 * @private
	 */
	_es5Concatenation(args) {
		const str = args
			.map((arg) => (typeof arg === "string" ? JSON.stringify(arg) : arg.expr))
			.join(" + ");

		// when the first two args are expression, we need to prepend "" + to force string
		// concatenation instead of number addition.
		return typeof args[0] !== "string" && typeof args[1] !== "string"
			? `"" + ${str}`
			: str;
	}

	/**
	 * @param {string} expression expression
	 * @param {string} args arguments
	 * @returns {string} expression function code
	 */
	expressionFunction(expression, args = "") {
		return this.supportsArrowFunction()
			? `(${args}) => (${expression})`
			: `function(${args}) { ${expression}; }`;
	}

	/**
	 * @returns {string} empty function code
	 */
	emptyFunction() {
		return this.supportsArrowFunction() ? "x => {}" : "function() {}";
	}

	/**
	 * @param {string[]} items items
	 * @param {string} value value
	 * @returns {string} destructure array code
	 */
	destructureArray(items, value) {
		return this.supportsDestructuring()
			? `var [${items.join(", ")}] = ${value};`
			: Template.asString(
					items.map((item, i) => `var ${item} = ${value}[${i}];`)
				);
	}

	/**
	 * @param {string[]} items items
	 * @param {string} value value
	 * @returns {string} destructure object code
	 */
	destructureObject(items, value) {
		return this.supportsDestructuring()
			? `var {${items.join(", ")}} = ${value};`
			: Template.asString(
					items.map(
						(item) => `var ${item} = ${value}${propertyAccess([item])};`
					)
				);
	}

	/**
	 * @param {string} args arguments
	 * @param {string} body body
	 * @returns {string} IIFE code
	 */
	iife(args, body) {
		return `(${this.basicFunction(args, body)})()`;
	}

	/**
	 * @param {string} variable variable
	 * @param {string} array array
	 * @param {string | string[]} body body
	 * @returns {string} for each code
	 */
	forEach(variable, array, body) {
		return this.supportsForOf()
			? `for(const ${variable} of ${array}) {\n${Template.indent(body)}\n}`
			: `${array}.forEach(function(${variable}) {\n${Template.indent(
					body
				)}\n});`;
	}

	/**
	 * Add a comment
	 * @param {object} options Information content of the comment
	 * @param {string=} options.request request string used originally
	 * @param {(string | null)=} options.chunkName name of the chunk referenced
	 * @param {string=} options.chunkReason reason information of the chunk
	 * @param {string=} options.message additional message
	 * @param {string=} options.exportName name of the export
	 * @returns {string} comment
	 */
	comment({ request, chunkName, chunkReason, message, exportName }) {
		let content;
		if (this.outputOptions.pathinfo) {
			content = [message, request, chunkName, chunkReason]
				.filter(Boolean)
				.map((item) => this.requestShortener.shorten(item))
				.join(" | ");
		} else {
			content = [message, chunkName, chunkReason]
				.filter(Boolean)
				.map((item) => this.requestShortener.shorten(item))
				.join(" | ");
		}
		if (!content) return "";
		if (this.outputOptions.pathinfo) {
			return `${Template.toComment(content)} `;
		}
		return `${Template.toNormalComment(content)} `;
	}

	/**
	 * @param {object} options generation options
	 * @param {string=} options.request request string used originally
	 * @returns {string} generated error block
	 */
	throwMissingModuleErrorBlock({ request }) {
		const err = `Cannot find module '${request}'`;
		return `var e = new Error(${JSON.stringify(
			err
		)}); e.code = 'MODULE_NOT_FOUND'; throw e;`;
	}

	/**
	 * @param {object} options generation options
	 * @param {string=} options.request request string used originally
	 * @returns {string} generated error function
	 */
	throwMissingModuleErrorFunction({ request }) {
		return `function webpackMissingModule() { ${this.throwMissingModuleErrorBlock(
			{ request }
		)} }`;
	}

	/**
	 * @param {object} options generation options
	 * @param {string=} options.request request string used originally
	 * @returns {string} generated error IIFE
	 */
	missingModule({ request }) {
		return `Object(${this.throwMissingModuleErrorFunction({ request })}())`;
	}

	/**
	 * @param {object} options generation options
	 * @param {string=} options.request request string used originally
	 * @returns {string} generated error statement
	 */
	missingModuleStatement({ request }) {
		return `${this.missingModule({ request })};\n`;
	}

	/**
	 * @param {object} options generation options
	 * @param {string=} options.request request string used originally
	 * @returns {string} generated error code
	 */
	missingModulePromise({ request }) {
		return `Promise.resolve().then(${this.throwMissingModuleErrorFunction({
			request
		})})`;
	}

	/**
	 * @param {object} options options object
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {Module} options.module the module
	 * @param {string=} options.request the request that should be printed as comment
	 * @param {string=} options.idExpr expression to use as id expression
	 * @param {"expression" | "promise" | "statements"} options.type which kind of code should be returned
	 * @returns {string} the code
	 */
	weakError({ module, chunkGraph, request, idExpr, type }) {
		const moduleId = chunkGraph.getModuleId(module);
		const errorMessage =
			moduleId === null
				? JSON.stringify("Module is not available (weak dependency)")
				: idExpr
					? `"Module '" + ${idExpr} + "' is not available (weak dependency)"`
					: JSON.stringify(
							`Module '${moduleId}' is not available (weak dependency)`
						);
		const comment = request ? `${Template.toNormalComment(request)} ` : "";
		const errorStatements = `var e = new Error(${errorMessage}); ${
			comment
		}e.code = 'MODULE_NOT_FOUND'; throw e;`;
		switch (type) {
			case "statements":
				return errorStatements;
			case "promise":
				return `Promise.resolve().then(${this.basicFunction(
					"",
					errorStatements
				)})`;
			case "expression":
				return this.iife("", errorStatements);
		}
	}

	/**
	 * @param {object} options options object
	 * @param {Module} options.module the module
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {string=} options.request the request that should be printed as comment
	 * @param {boolean=} options.weak if the dependency is weak (will create a nice error message)
	 * @returns {string} the expression
	 */
	moduleId({ module, chunkGraph, request, weak }) {
		if (!module) {
			return this.missingModule({
				request
			});
		}
		const moduleId = chunkGraph.getModuleId(module);
		if (moduleId === null) {
			if (weak) {
				return "null /* weak dependency, without id */";
			}
			throw new Error(
				`RuntimeTemplate.moduleId(): ${noModuleIdErrorMessage(
					module,
					chunkGraph
				)}`
			);
		}
		return `${this.comment({ request })}${JSON.stringify(moduleId)}`;
	}

	/**
	 * @param {object} options options object
	 * @param {Module | null} options.module the module
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {string=} options.request the request that should be printed as comment
	 * @param {boolean=} options.weak if the dependency is weak (will create a nice error message)
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @returns {string} the expression
	 */
	moduleRaw({ module, chunkGraph, request, weak, runtimeRequirements }) {
		if (!module) {
			return this.missingModule({
				request
			});
		}
		const moduleId = chunkGraph.getModuleId(module);
		if (moduleId === null) {
			if (weak) {
				// only weak referenced modules don't get an id
				// we can always emit an error emitting code here
				return this.weakError({
					module,
					chunkGraph,
					request,
					type: "expression"
				});
			}
			throw new Error(
				`RuntimeTemplate.moduleId(): ${noModuleIdErrorMessage(
					module,
					chunkGraph
				)}`
			);
		}
		runtimeRequirements.add(RuntimeGlobals.require);
		return `${RuntimeGlobals.require}(${this.moduleId({
			module,
			chunkGraph,
			request,
			weak
		})})`;
	}

	/**
	 * @param {object} options options object
	 * @param {Module | null} options.module the module
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {string} options.request the request that should be printed as comment
	 * @param {boolean=} options.weak if the dependency is weak (will create a nice error message)
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @returns {string} the expression
	 */
	moduleExports({ module, chunkGraph, request, weak, runtimeRequirements }) {
		return this.moduleRaw({
			module,
			chunkGraph,
			request,
			weak,
			runtimeRequirements
		});
	}

	/**
	 * @param {object} options options object
	 * @param {Module} options.module the module
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {string} options.request the request that should be printed as comment
	 * @param {boolean=} options.strict if the current module is in strict esm mode
	 * @param {boolean=} options.weak if the dependency is weak (will create a nice error message)
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @returns {string} the expression
	 */
	moduleNamespace({
		module,
		chunkGraph,
		request,
		strict,
		weak,
		runtimeRequirements
	}) {
		if (!module) {
			return this.missingModule({
				request
			});
		}
		if (chunkGraph.getModuleId(module) === null) {
			if (weak) {
				// only weak referenced modules don't get an id
				// we can always emit an error emitting code here
				return this.weakError({
					module,
					chunkGraph,
					request,
					type: "expression"
				});
			}
			throw new Error(
				`RuntimeTemplate.moduleNamespace(): ${noModuleIdErrorMessage(
					module,
					chunkGraph
				)}`
			);
		}
		const moduleId = this.moduleId({
			module,
			chunkGraph,
			request,
			weak
		});
		const exportsType = module.getExportsType(chunkGraph.moduleGraph, strict);
		switch (exportsType) {
			case "namespace":
				return this.moduleRaw({
					module,
					chunkGraph,
					request,
					weak,
					runtimeRequirements
				});
			case "default-with-named":
				runtimeRequirements.add(RuntimeGlobals.createFakeNamespaceObject);
				return `${RuntimeGlobals.createFakeNamespaceObject}(${moduleId}, 3)`;
			case "default-only":
				runtimeRequirements.add(RuntimeGlobals.createFakeNamespaceObject);
				return `${RuntimeGlobals.createFakeNamespaceObject}(${moduleId}, 1)`;
			case "dynamic":
				runtimeRequirements.add(RuntimeGlobals.createFakeNamespaceObject);
				return `${RuntimeGlobals.createFakeNamespaceObject}(${moduleId}, 7)`;
		}
	}

	/**
	 * @param {object} options options object
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {AsyncDependenciesBlock=} options.block the current dependencies block
	 * @param {Module} options.module the module
	 * @param {string} options.request the request that should be printed as comment
	 * @param {string} options.message a message for the comment
	 * @param {boolean=} options.strict if the current module is in strict esm mode
	 * @param {boolean=} options.weak if the dependency is weak (will create a nice error message)
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @returns {string} the promise expression
	 */
	moduleNamespacePromise({
		chunkGraph,
		block,
		module,
		request,
		message,
		strict,
		weak,
		runtimeRequirements
	}) {
		if (!module) {
			return this.missingModulePromise({
				request
			});
		}
		const moduleId = chunkGraph.getModuleId(module);
		if (moduleId === null) {
			if (weak) {
				// only weak referenced modules don't get an id
				// we can always emit an error emitting code here
				return this.weakError({
					module,
					chunkGraph,
					request,
					type: "promise"
				});
			}
			throw new Error(
				`RuntimeTemplate.moduleNamespacePromise(): ${noModuleIdErrorMessage(
					module,
					chunkGraph
				)}`
			);
		}
		const promise = this.blockPromise({
			chunkGraph,
			block,
			message,
			runtimeRequirements
		});

		let appending;
		let idExpr = JSON.stringify(chunkGraph.getModuleId(module));
		const comment = this.comment({
			request
		});
		let header = "";
		if (weak) {
			if (idExpr.length > 8) {
				// 'var x="nnnnnn";x,"+x+",x' vs '"nnnnnn",nnnnnn,"nnnnnn"'
				header += `var id = ${idExpr}; `;
				idExpr = "id";
			}
			runtimeRequirements.add(RuntimeGlobals.moduleFactories);
			header += `if(!${
				RuntimeGlobals.moduleFactories
			}[${idExpr}]) { ${this.weakError({
				module,
				chunkGraph,
				request,
				idExpr,
				type: "statements"
			})} } `;
		}
		const moduleIdExpr = this.moduleId({
			module,
			chunkGraph,
			request,
			weak
		});
		const exportsType = module.getExportsType(chunkGraph.moduleGraph, strict);
		let fakeType = 16;
		switch (exportsType) {
			case "namespace":
				if (header) {
					const rawModule = this.moduleRaw({
						module,
						chunkGraph,
						request,
						weak,
						runtimeRequirements
					});
					appending = `.then(${this.basicFunction(
						"",
						`${header}return ${rawModule};`
					)})`;
				} else {
					runtimeRequirements.add(RuntimeGlobals.require);
					appending = `.then(${RuntimeGlobals.require}.bind(${RuntimeGlobals.require}, ${comment}${idExpr}))`;
				}
				break;
			case "dynamic":
				fakeType |= 4;
			/* fall through */
			case "default-with-named":
				fakeType |= 2;
			/* fall through */
			case "default-only":
				runtimeRequirements.add(RuntimeGlobals.createFakeNamespaceObject);
				if (chunkGraph.moduleGraph.isAsync(module)) {
					if (header) {
						const rawModule = this.moduleRaw({
							module,
							chunkGraph,
							request,
							weak,
							runtimeRequirements
						});
						appending = `.then(${this.basicFunction(
							"",
							`${header}return ${rawModule};`
						)})`;
					} else {
						runtimeRequirements.add(RuntimeGlobals.require);
						appending = `.then(${RuntimeGlobals.require}.bind(${RuntimeGlobals.require}, ${comment}${idExpr}))`;
					}
					appending += `.then(${this.returningFunction(
						`${RuntimeGlobals.createFakeNamespaceObject}(m, ${fakeType})`,
						"m"
					)})`;
				} else {
					fakeType |= 1;
					if (header) {
						const returnExpression = `${RuntimeGlobals.createFakeNamespaceObject}(${moduleIdExpr}, ${fakeType})`;
						appending = `.then(${this.basicFunction(
							"",
							`${header}return ${returnExpression};`
						)})`;
					} else {
						appending = `.then(${RuntimeGlobals.createFakeNamespaceObject}.bind(${RuntimeGlobals.require}, ${comment}${idExpr}, ${fakeType}))`;
					}
				}
				break;
		}

		return `${promise || "Promise.resolve()"}${appending}`;
	}

	/**
	 * @param {object} options options object
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {RuntimeSpec=} options.runtime runtime for which this code will be generated
	 * @param {RuntimeSpec | boolean=} options.runtimeCondition only execute the statement in some runtimes
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @returns {string} expression
	 */
	runtimeConditionExpression({
		chunkGraph,
		runtimeCondition,
		runtime,
		runtimeRequirements
	}) {
		if (runtimeCondition === undefined) return "true";
		if (typeof runtimeCondition === "boolean") return `${runtimeCondition}`;
		/** @type {Set<string>} */
		const positiveRuntimeIds = new Set();
		forEachRuntime(runtimeCondition, (runtime) =>
			positiveRuntimeIds.add(
				`${chunkGraph.getRuntimeId(/** @type {string} */ (runtime))}`
			)
		);
		/** @type {Set<string>} */
		const negativeRuntimeIds = new Set();
		forEachRuntime(subtractRuntime(runtime, runtimeCondition), (runtime) =>
			negativeRuntimeIds.add(
				`${chunkGraph.getRuntimeId(/** @type {string} */ (runtime))}`
			)
		);
		runtimeRequirements.add(RuntimeGlobals.runtimeId);
		return compileBooleanMatcher.fromLists(
			[...positiveRuntimeIds],
			[...negativeRuntimeIds]
		)(RuntimeGlobals.runtimeId);
	}

	/**
	 * @param {object} options options object
	 * @param {boolean=} options.update whether a new variable should be created or the existing one updated
	 * @param {Module} options.module the module
	 * @param {ModuleGraph} options.moduleGraph the module graph
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {string} options.request the request that should be printed as comment
	 * @param {string} options.importVar name of the import variable
	 * @param {Module} options.originModule module in which the statement is emitted
	 * @param {boolean=} options.weak true, if this is a weak dependency
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @param {boolean=} options.defer if set, the module will be deferred
	 * @returns {[string, string]} the import statement and the compat statement
	 */
	importStatement({
		update,
		module,
		moduleGraph,
		chunkGraph,
		request,
		importVar,
		originModule,
		weak,
		defer,
		runtimeRequirements
	}) {
		if (!module) {
			return [
				this.missingModuleStatement({
					request
				}),
				""
			];
		}

		if (chunkGraph.getModuleId(module) === null) {
			if (weak) {
				// only weak referenced modules don't get an id
				// we can always emit an error emitting code here
				return [
					this.weakError({
						module,
						chunkGraph,
						request,
						type: "statements"
					}),
					""
				];
			}
			throw new Error(
				`RuntimeTemplate.importStatement(): ${noModuleIdErrorMessage(
					module,
					chunkGraph
				)}`
			);
		}
		const moduleId = this.moduleId({
			module,
			chunkGraph,
			request,
			weak
		});
		const optDeclaration = update ? "" : "var ";

		const exportsType = module.getExportsType(
			chunkGraph.moduleGraph,
			/** @type {BuildMeta} */
			(originModule.buildMeta).strictHarmonyModule
		);
		runtimeRequirements.add(RuntimeGlobals.require);
		let importContent;
		if (defer && !(/** @type {BuildMeta} */ (module.buildMeta).async)) {
			/** @type {Set<Module>} */
			const outgoingAsyncModules = getOutgoingAsyncModules(moduleGraph, module);

			importContent = `/* deferred harmony import */ ${optDeclaration}${importVar} = ${getOptimizedDeferredModule(
				this,
				exportsType,
				moduleId,
				Array.from(outgoingAsyncModules, (mod) => chunkGraph.getModuleId(mod))
			)};\n`;

			return [importContent, ""];
		}
		importContent = `/* harmony import */ ${optDeclaration}${importVar} = ${RuntimeGlobals.require}(${moduleId});\n`;

		if (exportsType === "dynamic") {
			runtimeRequirements.add(RuntimeGlobals.compatGetDefaultExport);
			return [
				importContent,
				`/* harmony import */ ${optDeclaration}${importVar}_default = /*#__PURE__*/${RuntimeGlobals.compatGetDefaultExport}(${importVar});\n`
			];
		}
		return [importContent, ""];
	}

	/**
	 * @template GenerateContext
	 * @param {object} options options
	 * @param {ModuleGraph} options.moduleGraph the module graph
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {Module} options.module the module
	 * @param {string} options.request the request
	 * @param {string | string[]} options.exportName the export name
	 * @param {Module} options.originModule the origin module
	 * @param {boolean|undefined} options.asiSafe true, if location is safe for ASI, a bracket can be emitted
	 * @param {boolean} options.isCall true, if expression will be called
	 * @param {boolean | null} options.callContext when false, call context will not be preserved
	 * @param {boolean} options.defaultInterop when true and accessing the default exports, interop code will be generated
	 * @param {string} options.importVar the identifier name of the import variable
	 * @param {InitFragment<GenerateContext>[]} options.initFragments init fragments will be added here
	 * @param {RuntimeSpec} options.runtime runtime for which this code will be generated
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @param {boolean=} options.defer if true, the module will be deferred.
	 * @returns {string} expression
	 */
	exportFromImport({
		moduleGraph,
		chunkGraph,
		module,
		request,
		exportName,
		originModule,
		asiSafe,
		isCall,
		callContext,
		defaultInterop,
		importVar,
		initFragments,
		runtime,
		runtimeRequirements,
		defer
	}) {
		if (!module) {
			return this.missingModule({
				request
			});
		}
		if (!Array.isArray(exportName)) {
			exportName = exportName ? [exportName] : [];
		}
		const exportsType = module.getExportsType(
			moduleGraph,
			/** @type {BuildMeta} */
			(originModule.buildMeta).strictHarmonyModule
		);

		const isDeferred =
			defer && !(/** @type {BuildMeta} */ (module.buildMeta).async);

		if (defaultInterop) {
			// when the defaultInterop is used (when a ESM imports a CJS module),
			if (exportName.length > 0 && exportName[0] === "default") {
				if (isDeferred && exportsType !== "namespace") {
					const exportsInfo = moduleGraph.getExportsInfo(module);
					const name = exportName.slice(1);
					const used = exportsInfo.getUsedName(name, runtime);
					if (!used) {
						const comment = Template.toNormalComment(
							`unused export ${propertyAccess(exportName)}`
						);
						return `${comment} undefined`;
					}
					const access = `${importVar}.a${propertyAccess(used)}`;
					if (isCall || asiSafe === undefined) {
						return access;
					}
					return asiSafe ? `(${access})` : `;(${access})`;
				}
				// accessing the .default property is same thing as `require()` the module.

				// For example:
				// import mod from "cjs";    mod.default.x;
				// is translated to
				// var mod = require("cjs"); mod.x;
				switch (exportsType) {
					case "dynamic":
						if (isCall) {
							return `${importVar}_default()${propertyAccess(exportName, 1)}`;
						}
						return asiSafe
							? `(${importVar}_default()${propertyAccess(exportName, 1)})`
							: asiSafe === false
								? `;(${importVar}_default()${propertyAccess(exportName, 1)})`
								: `${importVar}_default.a${propertyAccess(exportName, 1)}`;

					case "default-only":
					case "default-with-named":
						exportName = exportName.slice(1);
						break;
				}
			} else if (exportName.length > 0) {
				// the property used is not .default.
				// For example:
				// import * as ns from "cjs"; cjs.prop;
				if (exportsType === "default-only") {
					// in the strictest case, it is a runtime error (e.g. NodeJS behavior of CJS-ESM interop).
					return `/* non-default import from non-esm module */undefined${propertyAccess(
						exportName,
						1
					)}`;
				} else if (
					exportsType !== "namespace" &&
					exportName[0] === "__esModule"
				) {
					return "/* __esModule */true";
				}
			} else if (isDeferred) {
				// now exportName.length is 0
				// fall through to the end of this function, create the namespace there.
			} else if (
				exportsType === "default-only" ||
				exportsType === "default-with-named"
			) {
				// now exportName.length is 0, which means the namespace object is used in an unknown way
				// for example:
				// import * as ns from "cjs"; console.log(ns);
				// we will need to createFakeNamespaceObject that simulates ES Module namespace object
				runtimeRequirements.add(RuntimeGlobals.createFakeNamespaceObject);
				initFragments.push(
					new InitFragment(
						`var ${importVar}_namespace_cache;\n`,
						InitFragment.STAGE_CONSTANTS,
						-1,
						`${importVar}_namespace_cache`
					)
				);
				return `/*#__PURE__*/ ${
					asiSafe ? "" : asiSafe === false ? ";" : "Object"
				}(${importVar}_namespace_cache || (${importVar}_namespace_cache = ${
					RuntimeGlobals.createFakeNamespaceObject
				}(${importVar}${exportsType === "default-only" ? "" : ", 2"})))`;
			}
		}

		if (exportName.length > 0) {
			const exportsInfo = moduleGraph.getExportsInfo(module);
			// in some case the exported item is renamed (get this by getUsedName). for example,
			// x.default might be emitted as x.Z (default is renamed to Z)
			const used = exportsInfo.getUsedName(exportName, runtime);
			if (!used) {
				const comment = Template.toNormalComment(
					`unused export ${propertyAccess(exportName)}`
				);
				return `${comment} undefined`;
			}
			const comment = equals(used, exportName)
				? ""
				: `${Template.toNormalComment(propertyAccess(exportName))} `;
			const access = `${importVar}${
				isDeferred ? ".a" : ""
			}${comment}${propertyAccess(used)}`;
			if (isCall && callContext === false) {
				return asiSafe
					? `(0,${access})`
					: asiSafe === false
						? `;(0,${access})`
						: `/*#__PURE__*/Object(${access})`;
			}
			return access;
		}
		if (isDeferred) {
			initFragments.push(
				new InitFragment(
					`var ${importVar}_deferred_namespace_cache;\n`,
					InitFragment.STAGE_CONSTANTS,
					-1,
					`${importVar}_deferred_namespace_cache`
				)
			);

			runtimeRequirements.add(RuntimeGlobals.makeDeferredNamespaceObject);
			const id = chunkGraph.getModuleId(module);
			const type = getMakeDeferredNamespaceModeFromExportsType(exportsType);
			const init = `${
				RuntimeGlobals.makeDeferredNamespaceObject
			}(${JSON.stringify(id)}, ${type})`;

			return `/*#__PURE__*/ ${
				asiSafe ? "" : asiSafe === false ? ";" : "Object"
			}(${importVar}_deferred_namespace_cache || (${importVar}_deferred_namespace_cache = ${init}))`;
		}
		// if we hit here, the importVar is either
		// - already a ES module namespace object
		// - or imported by a way that does not need interop.
		return importVar;
	}

	/**
	 * @param {object} options options
	 * @param {AsyncDependenciesBlock | undefined} options.block the async block
	 * @param {string} options.message the message
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @returns {string} expression
	 */
	blockPromise({ block, message, chunkGraph, runtimeRequirements }) {
		if (!block) {
			const comment = this.comment({
				message
			});
			return `Promise.resolve(${comment.trim()})`;
		}
		const chunkGroup = chunkGraph.getBlockChunkGroup(block);
		if (!chunkGroup || chunkGroup.chunks.length === 0) {
			const comment = this.comment({
				message
			});
			return `Promise.resolve(${comment.trim()})`;
		}
		const chunks = chunkGroup.chunks.filter(
			(chunk) => !chunk.hasRuntime() && chunk.id !== null
		);
		const comment = this.comment({
			message,
			chunkName: block.chunkName
		});
		if (chunks.length === 1) {
			const chunkId = JSON.stringify(chunks[0].id);
			runtimeRequirements.add(RuntimeGlobals.ensureChunk);

			const fetchPriority = chunkGroup.options.fetchPriority;

			if (fetchPriority) {
				runtimeRequirements.add(RuntimeGlobals.hasFetchPriority);
			}

			return `${RuntimeGlobals.ensureChunk}(${comment}${chunkId}${
				fetchPriority ? `, ${JSON.stringify(fetchPriority)}` : ""
			})`;
		} else if (chunks.length > 0) {
			runtimeRequirements.add(RuntimeGlobals.ensureChunk);

			const fetchPriority = chunkGroup.options.fetchPriority;

			if (fetchPriority) {
				runtimeRequirements.add(RuntimeGlobals.hasFetchPriority);
			}

			/**
			 * @param {Chunk} chunk chunk
			 * @returns {string} require chunk id code
			 */
			const requireChunkId = (chunk) =>
				`${RuntimeGlobals.ensureChunk}(${JSON.stringify(chunk.id)}${
					fetchPriority ? `, ${JSON.stringify(fetchPriority)}` : ""
				})`;
			return `Promise.all(${comment.trim()}[${chunks
				.map(requireChunkId)
				.join(", ")}])`;
		}
		return `Promise.resolve(${comment.trim()})`;
	}

	/**
	 * @param {object} options options
	 * @param {AsyncDependenciesBlock} options.block the async block
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @param {string=} options.request request string used originally
	 * @returns {string} expression
	 */
	asyncModuleFactory({ block, chunkGraph, runtimeRequirements, request }) {
		const dep = block.dependencies[0];
		const module = chunkGraph.moduleGraph.getModule(dep);
		const ensureChunk = this.blockPromise({
			block,
			message: "",
			chunkGraph,
			runtimeRequirements
		});
		const factory = this.returningFunction(
			this.moduleRaw({
				module,
				chunkGraph,
				request,
				runtimeRequirements
			})
		);
		return this.returningFunction(
			ensureChunk.startsWith("Promise.resolve(")
				? `${factory}`
				: `${ensureChunk}.then(${this.returningFunction(factory)})`
		);
	}

	/**
	 * @param {object} options options
	 * @param {Dependency} options.dependency the dependency
	 * @param {ChunkGraph} options.chunkGraph the chunk graph
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @param {string=} options.request request string used originally
	 * @returns {string} expression
	 */
	syncModuleFactory({ dependency, chunkGraph, runtimeRequirements, request }) {
		const module = chunkGraph.moduleGraph.getModule(dependency);
		const factory = this.returningFunction(
			this.moduleRaw({
				module,
				chunkGraph,
				request,
				runtimeRequirements
			})
		);
		return this.returningFunction(factory);
	}

	/**
	 * @param {object} options options
	 * @param {string} options.exportsArgument the name of the exports object
	 * @param {RuntimeRequirements} options.runtimeRequirements if set, will be filled with runtime requirements
	 * @returns {string} statement
	 */
	defineEsModuleFlagStatement({ exportsArgument, runtimeRequirements }) {
		runtimeRequirements.add(RuntimeGlobals.makeNamespaceObject);
		runtimeRequirements.add(RuntimeGlobals.exports);
		return `${RuntimeGlobals.makeNamespaceObject}(${exportsArgument});\n`;
	}
}

module.exports = RuntimeTemplate;