webpack/lib/dependencies/HarmonyImportDependencyParserPlugin.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support 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 HotModuleReplacementPlugin = require("../HotModuleReplacementPlugin");
const InnerGraph = require("../optimize/InnerGraph");
const ConstDependency = require("./ConstDependency");
const HarmonyAcceptDependency = require("./HarmonyAcceptDependency");
const HarmonyAcceptImportDependency = require("./HarmonyAcceptImportDependency");
const HarmonyExports = require("./HarmonyExports");
const HarmonyImportSideEffectDependency = require("./HarmonyImportSideEffectDependency");
const HarmonyImportSpecifierDependency = require("./HarmonyImportSpecifierDependency");

/** @typedef {import("estree").Identifier} Identifier */
/** @typedef {import("../javascript/JavascriptParser")} JavascriptParser */
/** @typedef {import("../optimize/InnerGraph").InnerGraph} InnerGraph */
/** @typedef {import("../optimize/InnerGraph").TopLevelSymbol} TopLevelSymbol */
/** @typedef {import("./HarmonyImportDependency")} HarmonyImportDependency */

const harmonySpecifierTag = Symbol("harmony import");

/**
 * @typedef {Object} HarmonySettings
 * @property {string[]} ids
 * @property {string} source
 * @property {number} sourceOrder
 * @property {string} name
 * @property {boolean} await
 */

module.exports = class HarmonyImportDependencyParserPlugin {
	constructor(options) {
		const { module: moduleOptions } = options;
		this.strictExportPresence = moduleOptions.strictExportPresence;
		this.strictThisContextOnImports = moduleOptions.strictThisContextOnImports;
	}

	/**
	 * @param {JavascriptParser} parser the parser
	 * @returns {void}
	 */
	apply(parser) {
		parser.hooks.isPure
			.for("Identifier")
			.tap("HarmonyImportDependencyParserPlugin", expression => {
				const expr = /** @type {Identifier} */ (expression);
				if (
					parser.isVariableDefined(expr.name) ||
					parser.getTagData(expr.name, harmonySpecifierTag)
				) {
					return true;
				}
			});
		parser.hooks.import.tap(
			"HarmonyImportDependencyParserPlugin",
			(statement, source) => {
				parser.state.lastHarmonyImportOrder =
					(parser.state.lastHarmonyImportOrder || 0) + 1;
				const clearDep = new ConstDependency("", statement.range);
				clearDep.loc = statement.loc;
				parser.state.module.addPresentationalDependency(clearDep);
				const sideEffectDep = new HarmonyImportSideEffectDependency(
					source,
					parser.state.lastHarmonyImportOrder
				);
				sideEffectDep.loc = statement.loc;
				parser.state.module.addDependency(sideEffectDep);
				return true;
			}
		);
		parser.hooks.importSpecifier.tap(
			"HarmonyImportDependencyParserPlugin",
			(statement, source, id, name) => {
				const ids = id === null ? [] : [id];
				parser.tagVariable(name, harmonySpecifierTag, {
					name,
					source,
					ids,
					sourceOrder: parser.state.lastHarmonyImportOrder
				});
				return true;
			}
		);
		parser.hooks.expression
			.for(harmonySpecifierTag)
			.tap("HarmonyImportDependencyParserPlugin", expr => {
				const settings = /** @type {HarmonySettings} */ (parser.currentTagData);
				const dep = new HarmonyImportSpecifierDependency(
					settings.source,
					settings.sourceOrder,
					settings.ids,
					settings.name,
					expr.range,
					this.strictExportPresence
				);
				dep.shorthand = parser.scope.inShorthand;
				dep.directImport = true;
				dep.asiSafe = !parser.isAsiPosition(expr.range[0]);
				dep.loc = expr.loc;
				parser.state.module.addDependency(dep);
				InnerGraph.onUsage(parser.state, e => (dep.usedByExports = e));
				return true;
			});
		parser.hooks.expressionMemberChain
			.for(harmonySpecifierTag)
			.tap("HarmonyImportDependencyParserPlugin", (expr, members) => {
				const settings = /** @type {HarmonySettings} */ (parser.currentTagData);
				const ids = settings.ids.concat(members);
				const dep = new HarmonyImportSpecifierDependency(
					settings.source,
					settings.sourceOrder,
					ids,
					settings.name,
					expr.range,
					this.strictExportPresence
				);
				dep.asiSafe = !parser.isAsiPosition(expr.range[0]);
				dep.loc = expr.loc;
				parser.state.module.addDependency(dep);
				InnerGraph.onUsage(parser.state, e => (dep.usedByExports = e));
				return true;
			});
		parser.hooks.callMemberChain
			.for(harmonySpecifierTag)
			.tap("HarmonyImportDependencyParserPlugin", (expr, members) => {
				const { arguments: args, callee } = expr;
				const settings = /** @type {HarmonySettings} */ (parser.currentTagData);
				const ids = settings.ids.concat(members);
				const dep = new HarmonyImportSpecifierDependency(
					settings.source,
					settings.sourceOrder,
					ids,
					settings.name,
					callee.range,
					this.strictExportPresence
				);
				dep.directImport = members.length === 0;
				dep.call = true;
				dep.asiSafe = !parser.isAsiPosition(callee.range[0]);
				// only in case when we strictly follow the spec we need a special case here
				dep.namespaceObjectAsContext =
					members.length > 0 && this.strictThisContextOnImports;
				dep.loc = callee.loc;
				parser.state.module.addDependency(dep);
				if (args) parser.walkExpressions(args);
				InnerGraph.onUsage(parser.state, e => (dep.usedByExports = e));
				return true;
			});
		const {
			hotAcceptCallback,
			hotAcceptWithoutCallback
		} = HotModuleReplacementPlugin.getParserHooks(parser);
		hotAcceptCallback.tap(
			"HarmonyImportDependencyParserPlugin",
			(expr, requests) => {
				if (!HarmonyExports.isEnabled(parser.state)) {
					// This is not a harmony module, skip it
					return;
				}
				const dependencies = requests.map(request => {
					const dep = new HarmonyAcceptImportDependency(request);
					dep.loc = expr.loc;
					parser.state.module.addDependency(dep);
					return dep;
				});
				if (dependencies.length > 0) {
					const dep = new HarmonyAcceptDependency(
						expr.range,
						dependencies,
						true
					);
					dep.loc = expr.loc;
					parser.state.module.addDependency(dep);
				}
			}
		);
		hotAcceptWithoutCallback.tap(
			"HarmonyImportDependencyParserPlugin",
			(expr, requests) => {
				if (!HarmonyExports.isEnabled(parser.state)) {
					// This is not a harmony module, skip it
					return;
				}
				const dependencies = requests.map(request => {
					const dep = new HarmonyAcceptImportDependency(request);
					dep.loc = expr.loc;
					parser.state.module.addDependency(dep);
					return dep;
				});
				if (dependencies.length > 0) {
					const dep = new HarmonyAcceptDependency(
						expr.range,
						dependencies,
						false
					);
					dep.loc = expr.loc;
					parser.state.module.addDependency(dep);
				}
			}
		);
	}
};

module.exports.harmonySpecifierTag = harmonySpecifierTag;