javascript-obfuscator/src/node-transformers/converting-transformers/MethodDefinitionTransformer.ts

import { injectable, inject } from 'inversify';
import { ServiceIdentifiers } from '../../container/ServiceIdentifiers';

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

import { IOptions } from '../../interfaces/options/IOptions';

import { NodeType } from '../../enums/NodeType';

import { AbstractNodeTransformer } from '../AbstractNodeTransformer';
import { Node } from '../../node/Node';

/**
 * replaces:
 *     foo () { //... };
 *
 * on:
 *     ['foo'] { //... };
 *
 * Literal node will be obfuscated by LiteralTransformer
 */
@injectable()
export class MethodDefinitionTransformer extends AbstractNodeTransformer {
    /**
     * @type {string[]}
     */
    private static readonly ignoredNames: string[] = ['constructor'];

    /**
     * @param options
     */
    constructor (
        @inject(ServiceIdentifiers.IOptions) options: IOptions
    ) {
        super(options);
    }

    /**
     * @return {estraverse.Visitor}
     */
    public getVisitor (): estraverse.Visitor {
        return {
            enter: (node: ESTree.Node, parentNode: ESTree.Node) => {
                if (Node.isMethodDefinitionNode(node)) {
                    return this.transformNode(node, parentNode);
                }
            }
        };
    }

    /**
     * replaces:
     *     object.identifier = 1;
     *
     * on:
     *     object['identifier'] = 1;
     *
     * and skip:
     *     object[identifier] = 1;
     * Literal node will be obfuscated by LiteralTransformer
     *
     * @param methodDefinitionNode
     * @param parentNode
     * @returns {ESTree.Node}
     */
    private transformNode (methodDefinitionNode: ESTree.MethodDefinition, parentNode: ESTree.Node): ESTree.Node {
        if (
            Node.isIdentifierNode(methodDefinitionNode.key) &&
            !MethodDefinitionTransformer.ignoredNames.includes(methodDefinitionNode.key.name) &&
            methodDefinitionNode.computed === false
        ) {
            methodDefinitionNode.computed = true;
            methodDefinitionNode.key = {
                type: NodeType.Literal,
                value: methodDefinitionNode.key.name,
                raw: `'${methodDefinitionNode.key.name}'`
            };
        }

        return methodDefinitionNode;
    }
}