fix: readonly tuples were recognized as arrays

Resolves #1534 Co-Authored-By: Vladimir Ivakin <7985223+Minhir@users.noreply.github.com>
TypeStrong · Mar 14, 2021 · 99c6a13 · 99c6a13
1 parent b908c09
commit 99c6a13
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Showing 3 changed files with 145 additions and 88 deletions.
diff --git a/src/lib/converter/types.ts b/src/lib/converter/types.ts
@@ -936,12 +936,13 @@ const typeOperatorConverter: TypeConverter<ts.TypeOperatorNode> = {
     convertType(context, type, node) {
         // readonly is only valid on array and tuple literal types.
         if (node.operator === ts.SyntaxKind.ReadonlyKeyword) {
-            assert(isObjectType(type));
+            const resolved = resolveReference(type);
+            assert(isObjectType(resolved));
             const args = context.checker
                 .getTypeArguments(type as ts.TypeReference)
                 .map((type) => convertType(context, type));
             const inner =
-                type.objectFlags & ts.ObjectFlags.Tuple
+                resolved.objectFlags & ts.ObjectFlags.Tuple
                     ? new TupleType(args)
                     : new ArrayType(args[0]);
 
@@ -1027,6 +1028,13 @@ function isObjectType(type: ts.Type): type is ts.ObjectType {
     return typeof (type as any).objectFlags === "number";
 }
 
+function resolveReference(type: ts.Type) {
+    if (isObjectType(type) && type.objectFlags & ts.ObjectFlags.Reference) {
+        return (type as ts.TypeReference).target;
+    }
+    return type;
+}
+
 function kindToModifier(
     kind:
         | ts.SyntaxKind.PlusToken

diff --git a/src/test/converter/function/function.ts b/src/test/converter/function/function.ts
@@ -207,3 +207,5 @@ export function boolOrUndef(x: number) {
 
 export function merged() {}
 merged.nsFn = function () {};
+
+export function gh1534(rt: readonly [number, string]) {}