Destructuring crash (#1170)

Perryvw · web-flow · commit 7dc3e92e300b · 2021-11-21T14:21:56.000+01:00
* Update TS to 4.5.x

* Fix crash when destructing nested array patterns

* Made test deterministic

* Fixed test again
diff --git a/src/transformation/visitors/variable-declaration.ts b/src/transformation/visitors/variable-declaration.ts
@@ -21,10 +21,14 @@ export function transformArrayBindingElement(
     } else if (ts.isIdentifier(name)) {
         return transformIdentifier(context, name);
     } else if (ts.isBindingElement(name)) {
-        // TODO: It should always be true when called from `transformVariableDeclaration`,
-        // but could be false from `transformForOfLuaIteratorStatement`.
-        assert(ts.isIdentifier(name.name));
-        return transformIdentifier(context, name.name);
+        if (ts.isIdentifier(name.name)) {
+            return transformIdentifier(context, name.name);
+        } else {
+            // ts.isBindingPattern(name.name)
+            const tempName = context.createTempNameForNode(name.name);
+            context.addPrecedingStatements(transformBindingPattern(context, name.name, tempName));
+            return tempName;
+        }
     } else {
         assertNever(name);
     }
diff --git a/test/unit/loops.spec.ts b/test/unit/loops.spec.ts
@@ -279,6 +279,18 @@ test("forof destructing", () => {
     `.expectToMatchJsResult();
 });
 
+test("forof nested destructing", () => {
+    util.testFunction`
+        const obj = { a: [3], b: [5] };
+        let result = 0;
+
+        for(const [k, [v]] of Object.entries(obj)){
+            result += v;
+        }
+        return result;
+    `.expectToMatchJsResult();
+});
+
 test("forof destructing with existing variables", () => {
     const input = [
         [1, 2],
