merge pull request #7 from lorenzoferre/reconstruct-variable-declarat…

…ions

reconstruct varaible declarations

src/deobfuscator.js

@@ -2,6 +2,7 @@ import { transform } from "@babel/core";
 import { changed, setChanged } from "./utils/util.js";
 import removeDeadCode from "./techniques/remove-dead-code.js";
 import renameVariableSameScope from "./techniques/rename-variable-same-scope.js";
+import reconstructVariableDeclaration from "./techniques/reconstruct-variable-declaration.js";
 import constantPropagation from "./techniques/constant-propagation.js";
 import evaluate from "./techniques/evaluate.js";
 import replaceSingleConstantViolation from "./techniques/replace-single-constant-violation.js";
@@ -22,6 +23,7 @@ export default function deobfuscate(code) {
       plugins: [
         removeDeadCode,
         renameVariableSameScope,
+        reconstructVariableDeclaration,
         constantPropagation,
         evaluate,
         replaceSingleConstantViolation,

src/techniques/reconstruct-variable-declaration.js

@@ -0,0 +1,23 @@
+import { setChanged } from "../utils/util.js";
+
+export default function (babel) {
+  const { types: t } = babel;
+
+  return {
+    name: "reconstruct-variable-declaration",
+    visitor: {
+      VariableDeclaration(path) {
+        const { node } = path;
+        const { kind } = node;
+        let { declarations } = node;
+        if (declarations.length === 1) return;
+        declarations.reverse();
+        for (const declaration of declarations) {
+          path.insertAfter(t.variableDeclaration(kind, [declaration]));
+        }
+        path.remove();
+        setChanged(true);
+      },
+    },
+  };
+}

test/test.js

@@ -7,6 +7,17 @@ function removeNewLinesAndTabs(pieceOfCode) {
   return pieceOfCode.split("\n").join(" ").split("  ").join("");
 }
 
+test("reconstruct variable declarations", () => {
+  assert.strictEqual(
+    removeNewLinesAndTabs(
+      deobfuscate(`
+        var a,b,c;
+        console.log(a,b,c);`)
+    ),
+    `var a; var b; var c; console.log(a, b, c);`
+  );
+});
+
 test("hex to value", () => {
   assert.strictEqual(deobfuscate(`console.log("\x61\x61\x61")`), `console.log("aaa");`);
 });