webpack/lib/javascript/JavascriptParserHelpers.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 UnsupportedFeatureWarning = require("../UnsupportedFeatureWarning");
const ConstDependency = require("../dependencies/ConstDependency");
const BasicEvaluatedExpression = require("./BasicEvaluatedExpression");

/** @typedef {import("estree").Expression} ExpressionNode */
/** @typedef {import("estree").Node} Node */
/** @typedef {import("./JavascriptParser")} JavascriptParser */

/**
 * @param {JavascriptParser} parser the parser
 * @param {string} value the const value
 * @param {string[]=} runtimeRequirements runtime requirements
 * @returns {function(ExpressionNode): true} plugin function
 */
exports.toConstantDependency = (parser, value, runtimeRequirements) => {
	return function constDependency(expr) {
		const dep = new ConstDependency(value, expr.range, runtimeRequirements);
		dep.loc = expr.loc;
		parser.state.module.addPresentationalDependency(dep);
		return true;
	};
};

/**
 * @param {string} value the string value
 * @returns {function(ExpressionNode): BasicEvaluatedExpression} plugin function
 */
exports.evaluateToString = value => {
	return function stringExpression(expr) {
		return new BasicEvaluatedExpression().setString(value).setRange(expr.range);
	};
};

/**
 * @param {number} value the number value
 * @returns {function(ExpressionNode): BasicEvaluatedExpression} plugin function
 */
exports.evaluateToNumber = value => {
	return function stringExpression(expr) {
		return new BasicEvaluatedExpression().setNumber(value).setRange(expr.range);
	};
};

/**
 * @param {boolean} value the boolean value
 * @returns {function(ExpressionNode): BasicEvaluatedExpression} plugin function
 */
exports.evaluateToBoolean = value => {
	return function booleanExpression(expr) {
		return new BasicEvaluatedExpression()
			.setBoolean(value)
			.setRange(expr.range);
	};
};

/**
 * @param {string} identifier identifier
 * @param {string} rootInfo rootInfo
 * @param {function(): string[]} getMembers getMembers
 * @param {boolean|null=} truthy is truthy, null if nullish
 * @returns {function(ExpressionNode): BasicEvaluatedExpression} callback
 */
exports.evaluateToIdentifier = (identifier, rootInfo, getMembers, truthy) => {
	return function identifierExpression(expr) {
		let evaluatedExpression = new BasicEvaluatedExpression()
			.setIdentifier(identifier, rootInfo, getMembers)
			.setSideEffects(false)
			.setRange(expr.range);
		switch (truthy) {
			case true:
				evaluatedExpression.setTruthy();
				break;
			case null:
				evaluatedExpression.setNullish(true);
				break;
			case false:
				evaluatedExpression.setFalsy();
				break;
		}

		return evaluatedExpression;
	};
};

exports.expressionIsUnsupported = (parser, message) => {
	return function unsupportedExpression(expr) {
		const dep = new ConstDependency("(void 0)", expr.range, null);
		dep.loc = expr.loc;
		parser.state.module.addPresentationalDependency(dep);
		if (!parser.state.module) return;
		parser.state.module.addWarning(
			new UnsupportedFeatureWarning(message, expr.loc)
		);
		return true;
	};
};

exports.skipTraversal = () => true;

exports.approve = () => true;