Validation crash fix (#326)

tomblind · Perryvw · commit 79094335cde1 · 2019-01-09T18:24:09.000+01:00
* fix for crash when validating assignments of arrays/tuples

* added re-assignment code to tuple return test

* added new tuple assignment test and fixed others
diff --git a/src/Transpiler.ts b/src/Transpiler.ts
@@ -1529,13 +1529,23 @@ export abstract class LuaTranspiler {
             }
         }
 
-        const fromTypeReference = fromType as ts.TypeReference;
-        const toTypeReference = toType as ts.TypeReference;
-        if (fromTypeReference.typeArguments && toTypeReference.typeArguments) {
-            // Recurse into tuples/arrays
-            toTypeReference.typeArguments.forEach((t, i) => {
-                this.validateFunctionAssignment(node, fromTypeReference.typeArguments[i], t, toName);
-            });
+        const fromTypeNode = this.checker.typeToTypeNode(fromType);
+        const toTypeNode = this.checker.typeToTypeNode(toType);
+
+        if ((ts.isArrayTypeNode(toTypeNode) || ts.isTupleTypeNode(toTypeNode))
+            && (ts.isArrayTypeNode(fromTypeNode) || ts.isTupleTypeNode(fromTypeNode))) {
+            // Recurse into arrays/tuples
+            const fromTypeReference = fromType as ts.TypeReference;
+            const toTypeReference = toType as ts.TypeReference;
+            const count = Math.min(fromTypeReference.typeArguments.length, toTypeReference.typeArguments.length);
+            for (let i = 0; i < count; ++i) {
+                this.validateFunctionAssignment(
+                    node,
+                    fromTypeReference.typeArguments[i],
+                    toTypeReference.typeArguments[i],
+                    toName
+                );
+            }
         }
 
         if ((toType.flags & ts.TypeFlags.Object) !== 0
diff --git a/test/unit/assignments.spec.ts b/test/unit/assignments.spec.ts
@@ -91,10 +91,19 @@ export class AssignmentTests {
             .toThrowError(Error, "Ellipsis destruction is not allowed.");
     }
 
+    @Test("Tuple Assignment")
+    public tupleAssignment(): void {
+        const code = `function abc() { return [1, 2]; };
+                      let t: [number, number] = abc();
+                      return t[0] + t[1];`;
+        const result = util.transpileAndExecute(code);
+        Expect(result).toBe(3);
+    }
+
     @Test("TupleReturn assignment")
     public tupleReturnFunction(): void {
         const code = `/** @tupleReturn */\n`
-                   + `declare function abc() { return [1,2,3]; }\n`
+                   + `declare function abc(): number[]\n`
                    + `let [a,b] = abc();`;
 
         const lua = util.transpileString(code);
@@ -104,7 +113,7 @@ export class AssignmentTests {
     @Test("TupleReturn Single assignment")
     public tupleReturnSingleAssignment(): void {
         const code = `/** @tupleReturn */\n`
-                   + `declare function abc(): [number, string]; }\n`
+                   + `declare function abc(): [number, string];\n`
                    + `let a = abc();`
                    + `a = abc();`;
 
