Fix readonly tuple detection (TypeScriptToLua#674)

ark120202 · Perryvw · commit bd5977fb0263 · 2019-07-19T20:25:46.000+02:00
diff --git a/src/TSHelper.ts b/src/TSHelper.ts
@@ -167,12 +167,12 @@ export function isExplicitArrayType(type: ts.Type, checker: ts.TypeChecker, prog
         return type.types.some(t => isExplicitArrayType(t, checker, program));
     }
 
-    if (isStandardLibraryType(type, "ReadonlyArray", program)) {
-        return true;
+    const flags = ts.NodeBuilderFlags.InTypeAlias | ts.NodeBuilderFlags.AllowEmptyTuple;
+    let typeNode = checker.typeToTypeNode(type, undefined, flags);
+    if (typeNode && ts.isTypeOperatorNode(typeNode) && typeNode.operator === ts.SyntaxKind.ReadonlyKeyword) {
+        typeNode = typeNode.type;
     }
 
-    const flags = ts.NodeBuilderFlags.InTypeAlias | ts.NodeBuilderFlags.AllowEmptyTuple;
-    const typeNode = checker.typeToTypeNode(type, undefined, flags);
     return typeNode !== undefined && (ts.isArrayTypeNode(typeNode) || ts.isTupleTypeNode(typeNode));
 }
 
diff --git a/test/unit/tuples.spec.ts b/test/unit/tuples.spec.ts
@@ -31,6 +31,15 @@ test("Tuple access", () => {
     expect(result).toBe(5);
 });
 
+test("Readonly Tuple access", () => {
+    const result = util.transpileAndExecute(
+        `const tuple: readonly [number, number, number] = [3,5,1];
+        return tuple[1];`
+    );
+
+    expect(result).toBe(5);
+});
+
 test("Tuple union access", () => {
     const result = util.transpileAndExecute(
         `function makeTuple(): [number, number, number] | [string, string, string] { return [3,5,1]; }

Original file line number	Diff line number	Diff line change
`@@ -167,12 +167,12 @@ export function isExplicitArrayType(type: ts.Type, checker: ts.TypeChecker, prog`
`167`	`167`	`return type.types.some(t => isExplicitArrayType(t, checker, program));`
`168`	`168`	`}`
`169`	`169`
`170`		`- if (isStandardLibraryType(type, "ReadonlyArray", program)) {`
`171`		`- return true;`
	`170`	`+ const flags = ts.NodeBuilderFlags.InTypeAlias \| ts.NodeBuilderFlags.AllowEmptyTuple;`
	`171`	`+ let typeNode = checker.typeToTypeNode(type, undefined, flags);`
	`172`	`+ if (typeNode && ts.isTypeOperatorNode(typeNode) && typeNode.operator === ts.SyntaxKind.ReadonlyKeyword) {`
	`173`	`+ typeNode = typeNode.type;`
`172`	`174`	`}`
`173`	`175`
`174`		`- const flags = ts.NodeBuilderFlags.InTypeAlias \| ts.NodeBuilderFlags.AllowEmptyTuple;`
`175`		`- const typeNode = checker.typeToTypeNode(type, undefined, flags);`
`176`	`176`	`return typeNode !== undefined && (ts.isArrayTypeNode(typeNode) \|\| ts.isTupleTypeNode(typeNode));`
`177`	`177`	`}`
`178`	`178`