webpack/lib/dependencies/HarmonyImportSpecifierDependency.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 DependencyReference = require("./DependencyReference");
const HarmonyImportDependency = require("./HarmonyImportDependency");
const HarmonyLinkingError = require("../HarmonyLinkingError");

class HarmonyImportSpecifierDependency extends HarmonyImportDependency {
	constructor(
		request,
		originModule,
		sourceOrder,
		parserScope,
		id,
		name,
		range,
		strictExportPresence
	) {
		super(request, originModule, sourceOrder, parserScope);
		this.id = id === null ? null : `${id}`;
		this.redirectedId = undefined;
		this.name = name;
		this.range = range;
		this.strictExportPresence = strictExportPresence;
		this.namespaceObjectAsContext = false;
		this.callArgs = undefined;
		this.call = undefined;
		this.directImport = undefined;
		this.shorthand = undefined;
	}

	get type() {
		return "harmony import specifier";
	}

	get _id() {
		return this.redirectedId || this.id;
	}

	getReference() {
		if (!this._module) return null;
		return new DependencyReference(
			this._module,
			this._id && !this.namespaceObjectAsContext ? [this._id] : true,
			false,
			this.sourceOrder
		);
	}

	getWarnings() {
		if (
			this.strictExportPresence ||
			this.originModule.buildMeta.strictHarmonyModule
		) {
			return [];
		}
		return this._getErrors();
	}

	getErrors() {
		if (
			this.strictExportPresence ||
			this.originModule.buildMeta.strictHarmonyModule
		) {
			return this._getErrors();
		}
		return [];
	}

	_getErrors() {
		const importedModule = this._module;
		if (!importedModule) {
			return;
		}

		if (!importedModule.buildMeta || !importedModule.buildMeta.exportsType) {
			// It's not an harmony module
			if (
				this.originModule.buildMeta.strictHarmonyModule &&
				this._id &&
				this._id !== "default"
			) {
				// In strict harmony modules we only support the default export
				return [
					new HarmonyLinkingError(
						`Can't import the named export '${this._id}' from non EcmaScript module (only default export is available)`
					)
				];
			}
			return;
		}

		if (!this._id) {
			return;
		}

		if (importedModule.isProvided(this._id) !== false) {
			// It's provided or we are not sure
			return;
		}

		// We are sure that it's not provided
		const idIsNotNameMessage =
			this._id !== this.name ? ` (imported as '${this.name}')` : "";
		const errorMessage = `"export '${this._id}'${idIsNotNameMessage} was not found in '${this.userRequest}'`;
		return [new HarmonyLinkingError(errorMessage)];
	}

	// implement this method to allow the occurrence order plugin to count correctly
	getNumberOfIdOccurrences() {
		return 0;
	}

	updateHash(hash) {
		super.updateHash(hash);
		const importedModule = this._module;
		hash.update((importedModule && this._id) + "");
		hash.update(
			(importedModule && this._id && importedModule.isUsed(this._id)) + ""
		);
		hash.update(
			(importedModule &&
				(!importedModule.buildMeta || importedModule.buildMeta.exportsType)) +
				""
		);
		hash.update(
			(importedModule &&
				importedModule.used + JSON.stringify(importedModule.usedExports)) + ""
		);
	}

	disconnect() {
		super.disconnect();
		this.redirectedId = undefined;
	}
}

HarmonyImportSpecifierDependency.Template = class HarmonyImportSpecifierDependencyTemplate extends HarmonyImportDependency.Template {
	apply(dep, source, runtime) {
		super.apply(dep, source, runtime);
		const content = this.getContent(dep, runtime);
		source.replace(dep.range[0], dep.range[1] - 1, content);
	}

	getContent(dep, runtime) {
		const exportExpr = runtime.exportFromImport({
			module: dep._module,
			request: dep.request,
			exportName: dep._id,
			originModule: dep.originModule,
			asiSafe: dep.shorthand,
			isCall: dep.call,
			callContext: !dep.directImport,
			importVar: dep.getImportVar()
		});
		return dep.shorthand ? `${dep.name}: ${exportExpr}` : exportExpr;
	}
};

module.exports = HarmonyImportSpecifierDependency;