All files / src/node-transformers/obfuscation-transformers TemplateLiteralTransformer.ts

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
1x
1x
 
 
 
 
 
 
 
 
1x
1x
1x
 
 
 
 
 
 
1x
 
 
 
 
 
 
 
 
 
 
 
 
 
4x
 
4x
 
 
 
 
 
 
 
6x
 
 
 
 
 
 
 
 
4x
 
4x
 
9x
9x
 
9x
 
9x
4x
 
 
5x
 
 
4x
14x
 
 
 
 
4x
 
 
 
1x
 
 
4x
3x
 
 
 
 
 
3x
1x
 
 
3x
 
 
1x
 
 
 
import { injectable, inject } from 'inversify';
import { ServiceIdentifiers } from '../../container/ServiceIdentifiers';
 
import * as ESTree from 'estree';
 
import { IOptions } from '../../interfaces/options/IOptions';
import { IObfuscationReplacer } from '../../interfaces/node-transformers/IObfuscationReplacer';
 
import { NodeObfuscatorsReplacers } from '../../enums/container/NodeObfuscationReplacers';
 
import { AbstractNodeTransformer } from '../AbstractNodeTransformer';
import { Node } from '../../node/Node';
import { Nodes } from '../../node/Nodes';
 
/**
 * Transform ES2015 template literals to ES5
 * Thanks to Babel for algorithm
 */
@injectable()
export class TemplateLiteralTransformer extends AbstractNodeTransformer {
    /**
     * @type {(replacer: NodeObfuscatorsReplacers) => IObfuscationReplacer}
     */
    private readonly replacersFactory: (replacer: NodeObfuscatorsReplacers) => IObfuscationReplacer;
 
    /**
     * @param replacersFactory
     * @param options
     */
    constructor(
        @inject(ServiceIdentifiers.Factory__IObfuscatorReplacer) replacersFactory: (replacer: NodeObfuscatorsReplacers) => IObfuscationReplacer,
        @inject(ServiceIdentifiers.IOptions) options: IOptions
    ) {
        super(options);
 
        this.replacersFactory = replacersFactory;
    }
 
    /**
     * @param node
     * @return {boolean}
     */
    private static isLiteralNodeWithStringValue (node: ESTree.Node): boolean {
        return node && Node.isLiteralNode(node) && typeof node.value === 'string';
    }
 
    /**
     * @param templateLiteralNode
     * @param parentNode
     * @returns {ESTree.Node}
     */
    public transformNode (templateLiteralNode: ESTree.TemplateLiteral, parentNode: ESTree.Node): ESTree.Node {
        const templateLiteralExpressions: ESTree.Expression[] = templateLiteralNode.expressions;
 
        let nodes: (ESTree.Literal | ESTree.Expression)[] = [];
 
        for (const templateElement of templateLiteralNode.quasis) {
            nodes.push(Nodes.getLiteralNode(templateElement.value.cooked));
 
            const expression: ESTree.Expression | undefined = templateLiteralExpressions.shift();
 
            if (!expression) {
                continue;
            }
 
            nodes.push(expression);
        }
 
        nodes = nodes.filter((node: ESTree.Literal | ESTree.Expression) => {
            return !(Node.isLiteralNode(node) && node.value === '');
        });
 
        // since `+` is left-to-right associative
        // ensure the first node is a string if first/second isn't
        if (
            !TemplateLiteralTransformer.isLiteralNodeWithStringValue(nodes[0]) &&
            !TemplateLiteralTransformer.isLiteralNodeWithStringValue(nodes[1])
        ) {
            nodes.unshift(Nodes.getLiteralNode(''));
        }
 
        if (nodes.length > 1) {
            let root: ESTree.BinaryExpression = Nodes.getBinaryExpressionNode(
                '+',
                <ESTree.Literal>nodes.shift(),
                <ESTree.Expression>nodes.shift()
            );
 
            for (const node of nodes) {
                root = Nodes.getBinaryExpressionNode('+', root, <ESTree.Literal | ESTree.Expression>node);
            }
 
            return root;
        }
 
        return nodes[0];
    }
}