webpack/lib/dependencies/RequireEnsureDependenciesBlockParserPlugin.js

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

const RequireEnsureDependenciesBlock = require("./RequireEnsureDependenciesBlock");
const RequireEnsureDependency = require("./RequireEnsureDependency");
const RequireEnsureItemDependency = require("./RequireEnsureItemDependency");
const getFunctionExpression = require("./getFunctionExpression");

/** @typedef {import("../ChunkGroup").ChunkGroupOptions} ChunkGroupOptions */
/** @typedef {import("../Dependency").DependencyLocation} DependencyLocation */
/** @typedef {import("../javascript/BasicEvaluatedExpression")} BasicEvaluatedExpression */
/** @typedef {import("../javascript/JavascriptParser")} JavascriptParser */
/** @typedef {import("../javascript/JavascriptParser").Range} Range */

module.exports = class RequireEnsureDependenciesBlockParserPlugin {
	/**
	 * @param {JavascriptParser} parser the parser
	 * @returns {void}
	 */
	apply(parser) {
		parser.hooks.call
			.for("require.ensure")
			.tap("RequireEnsureDependenciesBlockParserPlugin", expr => {
				let chunkName = null;
				let errorExpressionArg = null;
				let errorExpression = null;
				switch (expr.arguments.length) {
					case 4: {
						const chunkNameExpr = parser.evaluateExpression(expr.arguments[3]);
						if (!chunkNameExpr.isString()) return;
						chunkName = chunkNameExpr.string;
					}
					// falls through
					case 3: {
						errorExpressionArg = expr.arguments[2];
						errorExpression = getFunctionExpression(errorExpressionArg);

						if (!errorExpression && !chunkName) {
							const chunkNameExpr = parser.evaluateExpression(
								expr.arguments[2]
							);
							if (!chunkNameExpr.isString()) return;
							chunkName = chunkNameExpr.string;
						}
					}
					// falls through
					case 2: {
						const dependenciesExpr = parser.evaluateExpression(
							expr.arguments[0]
						);
						const dependenciesItems =
							/** @type {BasicEvaluatedExpression[]} */ (
								dependenciesExpr.isArray()
									? dependenciesExpr.items
									: [dependenciesExpr]
							);
						const successExpressionArg = expr.arguments[1];
						const successExpression =
							getFunctionExpression(successExpressionArg);

						if (successExpression) {
							parser.walkExpressions(successExpression.expressions);
						}
						if (errorExpression) {
							parser.walkExpressions(errorExpression.expressions);
						}

						const depBlock = new RequireEnsureDependenciesBlock(
							/** @type {ChunkGroupOptions & { entryOptions?: TODO }} */
							(chunkName),
							/** @type {DependencyLocation} */ (expr.loc)
						);
						const errorCallbackExists =
							expr.arguments.length === 4 ||
							(!chunkName && expr.arguments.length === 3);
						const dep = new RequireEnsureDependency(
							/** @type {Range} */ (expr.range),
							/** @type {Range} */ (expr.arguments[1].range),
							errorCallbackExists &&
								/** @type {Range} */ (expr.arguments[2].range)
						);
						dep.loc = /** @type {DependencyLocation} */ (expr.loc);
						depBlock.addDependency(dep);
						const old = parser.state.current;
						parser.state.current = /** @type {TODO} */ (depBlock);
						try {
							let failed = false;
							parser.inScope([], () => {
								for (const ee of dependenciesItems) {
									if (ee.isString()) {
										const ensureDependency = new RequireEnsureItemDependency(
											/** @type {string} */ (ee.string)
										);
										ensureDependency.loc =
											/** @type {DependencyLocation} */
											(expr.loc);
										depBlock.addDependency(ensureDependency);
									} else {
										failed = true;
									}
								}
							});
							if (failed) {
								return;
							}
							if (successExpression) {
								if (successExpression.fn.body.type === "BlockStatement") {
									parser.walkStatement(successExpression.fn.body);
								} else {
									parser.walkExpression(successExpression.fn.body);
								}
							}
							old.addBlock(depBlock);
						} finally {
							parser.state.current = old;
						}
						if (!successExpression) {
							parser.walkExpression(successExpressionArg);
						}
						if (errorExpression) {
							if (errorExpression.fn.body.type === "BlockStatement") {
								parser.walkStatement(errorExpression.fn.body);
							} else {
								parser.walkExpression(errorExpression.fn.body);
							}
						} else if (errorExpressionArg) {
							parser.walkExpression(errorExpressionArg);
						}
						return true;
					}
				}
			});
	}
};