javascript-obfuscator/src/node-obfuscators/CatchClauseObfuscator.ts

import * as estraverse from 'estraverse';
import * as ESTree from 'estree';

import { ICustomNode } from '../interfaces/custom-nodes/ICustomNode';
import { IOptions } from '../interfaces/IOptions';

import { AbstractNodeObfuscator } from './AbstractNodeObfuscator';
import { IdentifierReplacer } from './replacers/IdentifierReplacer';
import { Node } from '../node/Node';

/**
 * replaces:
 *     try {} catch (e) { console.log(e); };
 *
 * on:
 *     try {} catch (_0x12d45f) { console.log(_0x12d45f); };
 *
 */
export class CatchClauseObfuscator extends AbstractNodeObfuscator {
    /**
     * @type {IdentifierReplacer}
     */
    private identifierReplacer: IdentifierReplacer;

    /**
     * @param nodes
     * @param options
     */
    constructor(nodes: Map <string, ICustomNode>, options: IOptions) {
        super(nodes, options);

        this.identifierReplacer = new IdentifierReplacer(this.nodes, this.options);
    }

    /**
     * @param catchClauseNode
     */
    public obfuscateNode (catchClauseNode: ESTree.CatchClause): void {
        this.storeCatchClauseParam(catchClauseNode);
        this.replaceCatchClauseParam(catchClauseNode);
    }

    /**
     * @param catchClauseNode
     */
    private storeCatchClauseParam (catchClauseNode: ESTree.CatchClause): void {
        if (Node.isIdentifierNode(catchClauseNode.param)) {
            this.identifierReplacer.storeNames(catchClauseNode.param.name);
        }
    }

    /**
     * @param catchClauseNode
     */
    private replaceCatchClauseParam (catchClauseNode: ESTree.CatchClause): void {
        estraverse.replace(catchClauseNode, {
            enter: (node: ESTree.Node, parentNode: ESTree.Node): any => {
                if (Node.isReplaceableIdentifierNode(node, parentNode)) {
                    const newNodeName: string = this.identifierReplacer.replace(node.name);

                    if (node.name !== newNodeName) {
                        node.name = newNodeName;
                        node.obfuscated = true;
                    }
                }
            }
        });
    }
}