source: trip-planner-front/node_modules/webpack/lib/dependencies/RequireContextDependencyParserPlugin.js

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

"use strict";

const RequireContextDependency = require("./RequireContextDependency");

module.exports = class RequireContextDependencyParserPlugin {
        apply(parser) {
                parser.hooks.call
                        .for("require.context")
                        .tap("RequireContextDependencyParserPlugin", expr => {
                                let regExp = /^\.\/.*$/;
                                let recursive = true;
                                let mode = "sync";
                                switch (expr.arguments.length) {
                                        case 4: {
                                                const modeExpr = parser.evaluateExpression(expr.arguments[3]);
                                                if (!modeExpr.isString()) return;
                                                mode = modeExpr.string;
                                        }
                                        // falls through
                                        case 3: {
                                                const regExpExpr = parser.evaluateExpression(expr.arguments[2]);
                                                if (!regExpExpr.isRegExp()) return;
                                                regExp = regExpExpr.regExp;
                                        }
                                        // falls through
                                        case 2: {
                                                const recursiveExpr = parser.evaluateExpression(expr.arguments[1]);
                                                if (!recursiveExpr.isBoolean()) return;
                                                recursive = recursiveExpr.bool;
                                        }
                                        // falls through
                                        case 1: {
                                                const requestExpr = parser.evaluateExpression(expr.arguments[0]);
                                                if (!requestExpr.isString()) return;
                                                const dep = new RequireContextDependency(
                                                        {
                                                                request: requestExpr.string,
                                                                recursive,
                                                                regExp,
                                                                mode,
                                                                category: "commonjs"
                                                        },
                                                        expr.range
                                                );
                                                dep.loc = expr.loc;
                                                dep.optional = !!parser.scope.inTry;
                                                parser.state.current.addDependency(dep);
                                                return true;
                                        }
                                }
                        });
        }
};