webpack/lib/APIPlugin.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 {
	getExternalModuleNodeCommonjsInitFragment
} = require("./ExternalModule");
const {
	JAVASCRIPT_MODULE_TYPE_AUTO,
	JAVASCRIPT_MODULE_TYPE_DYNAMIC,
	JAVASCRIPT_MODULE_TYPE_ESM
} = require("./ModuleTypeConstants");
const RuntimeGlobals = require("./RuntimeGlobals");
const ConstDependency = require("./dependencies/ConstDependency");
const ModuleInitFragmentDependency = require("./dependencies/ModuleInitFragmentDependency");
const RuntimeRequirementsDependency = require("./dependencies/RuntimeRequirementsDependency");
const WebpackError = require("./errors/WebpackError");
const BasicEvaluatedExpression = require("./javascript/BasicEvaluatedExpression");
const JavascriptModulesPlugin = require("./javascript/JavascriptModulesPlugin");
const {
	evaluateToString,
	toConstantDependency
} = require("./javascript/JavascriptParserHelpers");
const ChunkNameRuntimeModule = require("./runtime/ChunkNameRuntimeModule");
const GetFullHashRuntimeModule = require("./runtime/GetFullHashRuntimeModule");

/** @typedef {import("./Compiler")} Compiler */
/** @typedef {import("./Dependency").DependencyLocation} DependencyLocation */
/** @typedef {import("./Module").BuildInfo} BuildInfo */
/** @typedef {import("./javascript/JavascriptModule").JavascriptModuleBuildInfo} JavascriptModuleBuildInfo */
/** @typedef {import("./Compilation")} Compilation */
/** @typedef {import("./javascript/JavascriptParser")} JavascriptParser */
/** @typedef {import("./javascript/JavascriptParser").Range} Range */

// Compilations where a module reassigns `__webpack_public_path__` at runtime.
// A baked analyzable specifier can't reflect that, so those forms fall back.
/** @type {WeakSet<Compilation>} */
const runtimePublicPathOverride = new WeakSet();

/**
 * @param {Compilation} compilation compilation
 * @returns {boolean} true when a module reassigns `__webpack_public_path__` at runtime
 */
const usesRuntimePublicPathOverride = (compilation) =>
	runtimePublicPathOverride.has(compilation);

/**
 * Returns the replacement definitions used for webpack API identifiers.
 * @returns {Record<string, { expr: string, req: string[] | null, type?: string, assign: boolean }>} replacements
 */
function getReplacements() {
	return {
		__webpack_require__: {
			expr: RuntimeGlobals.require,
			req: [RuntimeGlobals.require],
			type: "function",
			assign: false
		},
		__webpack_global__: {
			expr: RuntimeGlobals.require,
			req: [RuntimeGlobals.require],
			type: "function",
			assign: false
		},
		__webpack_public_path__: {
			expr: RuntimeGlobals.publicPath,
			req: [RuntimeGlobals.publicPath],
			type: "string",
			assign: true
		},
		__webpack_base_uri__: {
			expr: RuntimeGlobals.baseURI,
			req: [RuntimeGlobals.baseURI],
			type: "string",
			assign: true
		},
		__webpack_modules__: {
			expr: RuntimeGlobals.moduleFactories,
			req: [RuntimeGlobals.moduleFactories],
			type: "object",
			assign: false
		},
		__webpack_chunk_load__: {
			expr: RuntimeGlobals.ensureChunk,
			req: [RuntimeGlobals.ensureChunk],
			type: "function",
			assign: true
		},
		__non_webpack_require__: {
			expr: "require",
			req: null,
			type: undefined, // type is not known, depends on environment
			assign: true
		},
		__webpack_nonce__: {
			expr: RuntimeGlobals.scriptNonce,
			req: [RuntimeGlobals.scriptNonce],
			type: "string",
			assign: true
		},
		__webpack_hash__: {
			expr: `${RuntimeGlobals.getFullHash}()`,
			req: [RuntimeGlobals.getFullHash],
			type: "string",
			assign: false
		},
		__webpack_chunkname__: {
			expr: RuntimeGlobals.chunkName,
			req: [RuntimeGlobals.chunkName],
			type: "string",
			assign: false
		},
		__webpack_get_script_filename__: {
			expr: RuntimeGlobals.getChunkScriptFilename,
			req: [RuntimeGlobals.getChunkScriptFilename],
			type: "function",
			assign: true
		},
		__webpack_runtime_id__: {
			expr: RuntimeGlobals.runtimeId,
			req: [RuntimeGlobals.runtimeId],
			assign: false
		},
		"require.onError": {
			expr: RuntimeGlobals.uncaughtErrorHandler,
			req: [RuntimeGlobals.uncaughtErrorHandler],
			type: undefined, // type is not known, could be function or undefined
			assign: true // is never a pattern
		},
		__system_context__: {
			expr: RuntimeGlobals.systemContext,
			req: [RuntimeGlobals.systemContext],
			type: "object",
			assign: false
		},
		__webpack_share_scopes__: {
			expr: RuntimeGlobals.shareScopeMap,
			req: [RuntimeGlobals.shareScopeMap],
			type: "object",
			assign: false
		},
		__webpack_init_sharing__: {
			expr: RuntimeGlobals.initializeSharing,
			req: [RuntimeGlobals.initializeSharing],
			type: "function",
			assign: true
		}
	};
}

const PLUGIN_NAME = "APIPlugin";

class APIPlugin {
	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			PLUGIN_NAME,
			(compilation, { normalModuleFactory }) => {
				const moduleOutput = compilation.options.output.module;
				const nodeTarget = compiler.platform.node;
				const nodeEsm = moduleOutput && nodeTarget;

				const REPLACEMENTS = getReplacements();
				if (nodeEsm) {
					REPLACEMENTS.__non_webpack_require__.expr =
						"__WEBPACK_EXTERNAL_createRequire_require";
				}

				compilation.dependencyTemplates.set(
					ConstDependency,
					new ConstDependency.Template()
				);
				compilation.dependencyTemplates.set(
					ModuleInitFragmentDependency,
					new ModuleInitFragmentDependency.Template()
				);

				compilation.hooks.runtimeRequirementInTree
					.for(RuntimeGlobals.chunkName)
					.tap(PLUGIN_NAME, (chunk) => {
						compilation.addRuntimeModule(
							chunk,
							new ChunkNameRuntimeModule(/** @type {string} */ (chunk.name))
						);
						return true;
					});

				compilation.hooks.runtimeRequirementInTree
					.for(RuntimeGlobals.getFullHash)
					.tap(PLUGIN_NAME, (chunk, _set) => {
						compilation.addRuntimeModule(chunk, new GetFullHashRuntimeModule());
						return true;
					});

				const hooks = JavascriptModulesPlugin.getCompilationHooks(compilation);

				hooks.renderModuleContent.tap(
					PLUGIN_NAME,
					(source, module, renderContext) => {
						if (
							/** @type {JavascriptModuleBuildInfo} */ (module.buildInfo)
								.needCreateRequire
						) {
							const chunkInitFragments = [
								getExternalModuleNodeCommonjsInitFragment(
									renderContext.runtimeTemplate
								)
							];

							renderContext.chunkInitFragments.push(...chunkInitFragments);
						}

						return source;
					}
				);

				/**
				 * Handles the hook callback for this code path.
				 * @param {JavascriptParser} parser the parser
				 */
				const handler = (parser) => {
					parser.hooks.preDeclarator.tap(PLUGIN_NAME, (declarator) => {
						if (
							parser.scope.topLevelScope === true &&
							declarator.id.type === "Identifier" &&
							declarator.id.name === "module"
						) {
							/** @type {BuildInfo} */
							(parser.state.module.buildInfo).moduleArgument =
								"__webpack_module__";
						}
					});

					/**
					 * @param {import("estree").Statement | import("estree").ModuleDeclaration | import("estree").MaybeNamedFunctionDeclaration | import("estree").MaybeNamedClassDeclaration} statement statement
					 */
					const moduleDeclarationHandler = (statement) => {
						if (
							parser.scope.topLevelScope === true &&
							(statement.type === "FunctionDeclaration" ||
								statement.type === "ClassDeclaration") &&
							statement.id &&
							statement.id.name === "module"
						) {
							/** @type {BuildInfo} */
							(parser.state.module.buildInfo).moduleArgument =
								"__webpack_module__";
						}
					};
					parser.hooks.preStatementByType
						.for("FunctionDeclaration")
						.tap(PLUGIN_NAME, moduleDeclarationHandler);
					parser.hooks.preStatementByType
						.for("ClassDeclaration")
						.tap(PLUGIN_NAME, moduleDeclarationHandler);

					for (const key of Object.keys(REPLACEMENTS)) {
						const info = REPLACEMENTS[key];
						parser.hooks.expression.for(key).tap(PLUGIN_NAME, (expression) => {
							const dep = toConstantDependency(parser, info.expr, info.req);

							if (key === "__non_webpack_require__" && moduleOutput) {
								if (nodeTarget) {
									/** @type {JavascriptModuleBuildInfo} */
									(parser.state.module.buildInfo).needCreateRequire = true;
								} else {
									const warning = new WebpackError(
										`${PLUGIN_NAME}\n__non_webpack_require__ is only allowed in target node`
									);
									warning.loc = parser.getLocation(expression);
									warning.module = parser.state.module;
									compilation.warnings.push(warning);
								}
							}

							return dep(expression);
						});
						if (info.assign === false) {
							parser.hooks.assign.for(key).tap(PLUGIN_NAME, (expr) => {
								const err = new WebpackError(`${key} must not be assigned`);
								err.loc = parser.getLocation(expr);
								throw err;
							});
						} else if (key === "__webpack_public_path__") {
							// Flag the runtime override (still let the default handler emit
							// `__webpack_require__.p = …`); returning nothing keeps that path.
							parser.hooks.assign.for(key).tap(PLUGIN_NAME, () => {
								runtimePublicPathOverride.add(compilation);
							});
						}
						if (info.type) {
							parser.hooks.evaluateTypeof
								.for(key)
								.tap(PLUGIN_NAME, evaluateToString(info.type));
						}
					}

					parser.hooks.expression
						.for("__webpack_layer__")
						.tap(PLUGIN_NAME, (expr) => {
							const dep = new ConstDependency(
								JSON.stringify(parser.state.module.layer),
								/** @type {Range} */ (expr.range)
							);
							dep.loc = parser.getLocation(expr);
							parser.state.module.addPresentationalDependency(dep);
							return true;
						});
					parser.hooks.evaluateIdentifier
						.for("__webpack_layer__")
						.tap(PLUGIN_NAME, (expr) =>
							(parser.state.module.layer === null
								? new BasicEvaluatedExpression().setNull()
								: new BasicEvaluatedExpression().setString(
										parser.state.module.layer
									)
							).setRange(/** @type {Range} */ (expr.range))
						);
					parser.hooks.evaluateTypeof
						.for("__webpack_layer__")
						.tap(PLUGIN_NAME, (expr) =>
							new BasicEvaluatedExpression()
								.setString(
									parser.state.module.layer === null ? "object" : "string"
								)
								.setRange(/** @type {Range} */ (expr.range))
						);

					parser.hooks.expression
						.for("__webpack_module__.id")
						.tap(PLUGIN_NAME, (expr) => {
							/** @type {JavascriptModuleBuildInfo} */
							(parser.state.module.buildInfo).moduleConcatenationBailout =
								"__webpack_module__.id";
							const moduleArgument = parser.state.module.moduleArgument;
							if (moduleArgument === "__webpack_module__") {
								const dep = new RuntimeRequirementsDependency([
									RuntimeGlobals.moduleId
								]);
								dep.loc = parser.getLocation(expr);
								parser.state.module.addPresentationalDependency(dep);
							} else {
								const initDep = new ModuleInitFragmentDependency(
									`var __webpack_internal_module_id__ = ${moduleArgument}.id;\n`,
									[RuntimeGlobals.moduleId],
									"__webpack_internal_module_id__"
								);
								parser.state.module.addPresentationalDependency(initDep);
								const dep = new ConstDependency(
									"__webpack_internal_module_id__",
									/** @type {Range} */ (expr.range),
									[]
								);
								dep.loc = parser.getLocation(expr);
								parser.state.module.addPresentationalDependency(dep);
							}
							return true;
						});

					parser.hooks.expression
						.for("__webpack_module__")
						.tap(PLUGIN_NAME, (expr) => {
							/** @type {JavascriptModuleBuildInfo} */
							(parser.state.module.buildInfo).moduleConcatenationBailout =
								"__webpack_module__";
							const moduleArgument = parser.state.module.moduleArgument;
							if (moduleArgument === "__webpack_module__") {
								const dep = new RuntimeRequirementsDependency([
									RuntimeGlobals.module
								]);
								dep.loc = parser.getLocation(expr);
								parser.state.module.addPresentationalDependency(dep);
							} else {
								const initDep = new ModuleInitFragmentDependency(
									`var __webpack_internal_module__ = ${moduleArgument};\n`,
									[RuntimeGlobals.module],
									"__webpack_internal_module__"
								);
								parser.state.module.addPresentationalDependency(initDep);
								const dep = new ConstDependency(
									"__webpack_internal_module__",
									/** @type {Range} */ (expr.range),
									[]
								);
								dep.loc = parser.getLocation(expr);
								parser.state.module.addPresentationalDependency(dep);
							}
							return true;
						});
					parser.hooks.evaluateTypeof
						.for("__webpack_module__")
						.tap(PLUGIN_NAME, evaluateToString("object"));
				};

				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_AUTO)
					.tap(PLUGIN_NAME, handler);
				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_DYNAMIC)
					.tap(PLUGIN_NAME, handler);
				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_ESM)
					.tap(PLUGIN_NAME, handler);
			}
		);
	}
}

module.exports = APIPlugin;
module.exports.usesRuntimePublicPathOverride = usesRuntimePublicPathOverride;