webpack/lib/dependencies/ImportParserPlugin.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 ImportContextDependency = require("./ImportContextDependency");
const ImportWeakDependency = require("./ImportWeakDependency");
const ImportDependenciesBlock = require("./ImportDependenciesBlock");
const ImportEagerDependency = require("./ImportEagerDependency");
const ContextDependencyHelpers = require("./ContextDependencyHelpers");
const UnsupportedFeatureWarning = require("../UnsupportedFeatureWarning");
const CommentCompilationWarning = require("../CommentCompilationWarning");

class ImportParserPlugin {
	constructor(options) {
		this.options = options;
	}

	apply(parser) {
		parser.hooks.importCall.tap("ImportParserPlugin", expr => {
			if (expr.arguments.length !== 1) {
				throw new Error(
					"Incorrect number of arguments provided to 'import(module: string) -> Promise'."
				);
			}

			const param = parser.evaluateExpression(expr.arguments[0]);

			let chunkName = null;
			let mode = "lazy";
			let include = null;
			let exclude = null;
			const groupOptions = {};

			const {
				options: importOptions,
				errors: commentErrors
			} = parser.parseCommentOptions(expr.range);

			if (commentErrors) {
				for (const e of commentErrors) {
					const { comment } = e;
					parser.state.module.warnings.push(
						new CommentCompilationWarning(
							`Compilation error while processing magic comment(-s): /*${comment.value}*/: ${e.message}`,
							parser.state.module,
							comment.loc
						)
					);
				}
			}

			if (importOptions) {
				if (importOptions.webpackIgnore !== undefined) {
					if (typeof importOptions.webpackIgnore !== "boolean") {
						parser.state.module.warnings.push(
							new UnsupportedFeatureWarning(
								parser.state.module,
								`\`webpackIgnore\` expected a boolean, but received: ${importOptions.webpackIgnore}.`,
								expr.loc
							)
						);
					} else {
						// Do not instrument `import()` if `webpackIgnore` is `true`
						if (importOptions.webpackIgnore) {
							return false;
						}
					}
				}
				if (importOptions.webpackChunkName !== undefined) {
					if (typeof importOptions.webpackChunkName !== "string") {
						parser.state.module.warnings.push(
							new UnsupportedFeatureWarning(
								parser.state.module,
								`\`webpackChunkName\` expected a string, but received: ${importOptions.webpackChunkName}.`,
								expr.loc
							)
						);
					} else {
						chunkName = importOptions.webpackChunkName;
					}
				}
				if (importOptions.webpackMode !== undefined) {
					if (typeof importOptions.webpackMode !== "string") {
						parser.state.module.warnings.push(
							new UnsupportedFeatureWarning(
								parser.state.module,
								`\`webpackMode\` expected a string, but received: ${importOptions.webpackMode}.`,
								expr.loc
							)
						);
					} else {
						mode = importOptions.webpackMode;
					}
				}
				if (importOptions.webpackPrefetch !== undefined) {
					if (importOptions.webpackPrefetch === true) {
						groupOptions.prefetchOrder = 0;
					} else if (typeof importOptions.webpackPrefetch === "number") {
						groupOptions.prefetchOrder = importOptions.webpackPrefetch;
					} else {
						parser.state.module.warnings.push(
							new UnsupportedFeatureWarning(
								parser.state.module,
								`\`webpackPrefetch\` expected true or a number, but received: ${importOptions.webpackPrefetch}.`,
								expr.loc
							)
						);
					}
				}
				if (importOptions.webpackPreload !== undefined) {
					if (importOptions.webpackPreload === true) {
						groupOptions.preloadOrder = 0;
					} else if (typeof importOptions.webpackPreload === "number") {
						groupOptions.preloadOrder = importOptions.webpackPreload;
					} else {
						parser.state.module.warnings.push(
							new UnsupportedFeatureWarning(
								parser.state.module,
								`\`webpackPreload\` expected true or a number, but received: ${importOptions.webpackPreload}.`,
								expr.loc
							)
						);
					}
				}
				if (importOptions.webpackInclude !== undefined) {
					if (
						!importOptions.webpackInclude ||
						importOptions.webpackInclude.constructor.name !== "RegExp"
					) {
						parser.state.module.warnings.push(
							new UnsupportedFeatureWarning(
								parser.state.module,
								`\`webpackInclude\` expected a regular expression, but received: ${importOptions.webpackInclude}.`,
								expr.loc
							)
						);
					} else {
						include = new RegExp(importOptions.webpackInclude);
					}
				}
				if (importOptions.webpackExclude !== undefined) {
					if (
						!importOptions.webpackExclude ||
						importOptions.webpackExclude.constructor.name !== "RegExp"
					) {
						parser.state.module.warnings.push(
							new UnsupportedFeatureWarning(
								parser.state.module,
								`\`webpackExclude\` expected a regular expression, but received: ${importOptions.webpackExclude}.`,
								expr.loc
							)
						);
					} else {
						exclude = new RegExp(importOptions.webpackExclude);
					}
				}
			}

			if (param.isString()) {
				if (mode !== "lazy" && mode !== "eager" && mode !== "weak") {
					parser.state.module.warnings.push(
						new UnsupportedFeatureWarning(
							parser.state.module,
							`\`webpackMode\` expected 'lazy', 'eager' or 'weak', but received: ${mode}.`,
							expr.loc
						)
					);
				}

				if (mode === "eager") {
					const dep = new ImportEagerDependency(
						param.string,
						parser.state.module,
						expr.range
					);
					parser.state.current.addDependency(dep);
				} else if (mode === "weak") {
					const dep = new ImportWeakDependency(
						param.string,
						parser.state.module,
						expr.range
					);
					parser.state.current.addDependency(dep);
				} else {
					const depBlock = new ImportDependenciesBlock(
						param.string,
						expr.range,
						Object.assign(groupOptions, {
							name: chunkName
						}),
						parser.state.module,
						expr.loc,
						parser.state.module
					);
					parser.state.current.addBlock(depBlock);
				}
				return true;
			} else {
				if (
					mode !== "lazy" &&
					mode !== "lazy-once" &&
					mode !== "eager" &&
					mode !== "weak"
				) {
					parser.state.module.warnings.push(
						new UnsupportedFeatureWarning(
							parser.state.module,
							`\`webpackMode\` expected 'lazy', 'lazy-once', 'eager' or 'weak', but received: ${mode}.`,
							expr.loc
						)
					);
					mode = "lazy";
				}

				if (mode === "weak") {
					mode = "async-weak";
				}
				const dep = ContextDependencyHelpers.create(
					ImportContextDependency,
					expr.range,
					param,
					expr,
					this.options,
					{
						chunkName,
						groupOptions,
						include,
						exclude,
						mode,
						namespaceObject: parser.state.module.buildMeta.strictHarmonyModule
							? "strict"
							: true
					},
					parser
				);
				if (!dep) return;
				dep.loc = expr.loc;
				dep.optional = !!parser.scope.inTry;
				parser.state.current.addDependency(dep);
				return true;
			}
		});
	}
}

module.exports = ImportParserPlugin;