Fix #35060 (#35065)

* Fix 35060

* Refactor and check ro-array to tuple case

* Lint

Author: jack-williams

src/compiler/checker.ts

@@ -14528,32 +14528,33 @@ namespace ts {
              * if we have found an elaboration, or we should ignore
              * any other elaborations when relating the `source` and
              * `target` types.
-             *
-             * @param source
-             * @param target
-             * @param reportErrors
              */
             function tryElaborateArrayLikeErrors(source: Type, target: Type, reportErrors: boolean): boolean {
-                if (isTupleLikeType(source)) {
-                    const sourceTuple: TupleType | undefined  = (source as TupleTypeReference).target;
-                    if (sourceTuple && sourceTuple.readonly && isArrayOrTupleLikeType(target) &&
-                        (!isReadonlyArrayType(target) || isTupleType(target) && !target.target.readonly)) {
+                /**
+                 * The spec for elaboration is:
+                 * - If the source is a readonly tuple and the target is a mutable array or tuple, elaborate on mutability and skip property elaborations.
+                 * - If the source is a tuple then skip property elaborations if the target is an array or tuple.
+                 * - If the source is a readonly array and the target is a mutable array or tuple, elaborate on mutability and skip property elaborations.
+                 * - If the source an array then skip property elaborations if the target is a tuple.
+                 */
+                if (isTupleType(source)) {
+                    if (source.target.readonly && isMutableArrayOrTuple(target)) {
                         if (reportErrors) {
                             reportError(Diagnostics.The_type_0_is_readonly_and_cannot_be_assigned_to_the_mutable_type_1, typeToString(source), typeToString(target));
                         }
                         return false;
                     }
-                    return isArrayLikeType(target);
+                    return isTupleType(target) || isArrayType(target);
                 }
-                if (isTupleLikeType(target)) {
-                    return isArrayLikeType(source);
-                }
-                if (isReadonlyArrayType(source) && isArrayType(target) && !isReadonlyArrayType(target)) {
+                if (isReadonlyArrayType(source) && isMutableArrayOrTuple(target)) {
                     if (reportErrors) {
                         reportError(Diagnostics.The_type_0_is_readonly_and_cannot_be_assigned_to_the_mutable_type_1, typeToString(source), typeToString(target));
                     }
                     return false;
                 }
+                if (isTupleType(target)) {
+                    return isArrayType(source);
+                }
                 return true;
             }
 
@@ -16565,6 +16566,10 @@ namespace ts {
             return !!(getObjectFlags(type) & ObjectFlags.Reference) && (<TypeReference>type).target === globalReadonlyArrayType;
         }
 
+        function isMutableArrayOrTuple(type: Type): boolean {
+            return isArrayType(type) && !isReadonlyArrayType(type) || isTupleType(type) && !type.target.readonly;
+        }
+
         function getElementTypeOfArrayType(type: Type): Type | undefined {
             return isArrayType(type) ? getTypeArguments(type as TypeReference)[0] : undefined;
         }

tests/baselines/reference/arityAndOrderCompatibility01.errors.txt

@@ -2,30 +2,30 @@ tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(15,12): erro
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(17,5): error TS2461: Type '{ 0: string; 1: number; length: 2; }' is not an array type.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(18,5): error TS2741: Property '2' is missing in type '[string, number]' but required in type '[number, number, number]'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(19,5): error TS2741: Property '2' is missing in type 'StrNum' but required in type '[number, number, number]'.
-tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(20,5): error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[number, number, number]': 2, pop, push, concat, and 16 more.
+tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(20,5): error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[number, number, number]'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(21,5): error TS2741: Property '2' is missing in type '[string, number]' but required in type '[string, number, number]'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(22,5): error TS2741: Property '2' is missing in type 'StrNum' but required in type '[string, number, number]'.
-tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(23,5): error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[string, number, number]': 2, pop, push, concat, and 16 more.
+tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(23,5): error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[string, number, number]'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(24,5): error TS2322: Type '[string, number]' is not assignable to type '[number]'.
   Types of property '0' are incompatible.
     Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(25,5): error TS2322: Type 'StrNum' is not assignable to type '[number]'.
   Types of property '0' are incompatible.
     Type 'string' is not assignable to type 'number'.
-tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(26,5): error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[number]': pop, push, concat, join, and 15 more.
+tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(26,5): error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[number]'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(27,5): error TS2322: Type '[string, number]' is not assignable to type '[string]'.
   Types of property 'length' are incompatible.
     Type '2' is not assignable to type '1'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(28,5): error TS2322: Type 'StrNum' is not assignable to type '[string]'.
   Types of property 'length' are incompatible.
     Type '2' is not assignable to type '1'.
-tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(29,5): error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[string]': pop, push, concat, join, and 15 more.
+tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(29,5): error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[string]'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(30,5): error TS2322: Type '[string, number]' is not assignable to type '[number, string]'.
   Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(31,5): error TS2322: Type 'StrNum' is not assignable to type '[number, string]'.
   Types of property '0' are incompatible.
     Type 'string' is not assignable to type 'number'.
-tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(32,5): error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[number, string]': pop, push, concat, join, and 15 more.
+tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(32,5): error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[number, string]'.
 
 
 ==== tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts (17 errors) ====
@@ -58,7 +58,7 @@ tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(32,5): error
 !!! error TS2741: Property '2' is missing in type 'StrNum' but required in type '[number, number, number]'.
     var j3: [number, number, number] = z;
         ~~
-!!! error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[number, number, number]': 2, pop, push, concat, and 16 more.
+!!! error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[number, number, number]'.
     var k1: [string, number, number] = x;
         ~~
 !!! error TS2741: Property '2' is missing in type '[string, number]' but required in type '[string, number, number]'.
@@ -67,7 +67,7 @@ tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(32,5): error
 !!! error TS2741: Property '2' is missing in type 'StrNum' but required in type '[string, number, number]'.
     var k3: [string, number, number] = z;
         ~~
-!!! error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[string, number, number]': 2, pop, push, concat, and 16 more.
+!!! error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[string, number, number]'.
     var l1: [number] = x;
         ~~
 !!! error TS2322: Type '[string, number]' is not assignable to type '[number]'.
@@ -80,7 +80,7 @@ tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(32,5): error
 !!! error TS2322:     Type 'string' is not assignable to type 'number'.
     var l3: [number] = z;
         ~~
-!!! error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[number]': pop, push, concat, join, and 15 more.
+!!! error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[number]'.
     var m1: [string] = x;
         ~~
 !!! error TS2322: Type '[string, number]' is not assignable to type '[string]'.
@@ -93,7 +93,7 @@ tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(32,5): error
 !!! error TS2322:     Type '2' is not assignable to type '1'.
     var m3: [string] = z;
         ~~
-!!! error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[string]': pop, push, concat, join, and 15 more.
+!!! error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[string]'.
     var n1: [number, string] = x;
         ~~
 !!! error TS2322: Type '[string, number]' is not assignable to type '[number, string]'.
@@ -105,7 +105,7 @@ tests/cases/conformance/types/tuple/arityAndOrderCompatibility01.ts(32,5): error
 !!! error TS2322:     Type 'string' is not assignable to type 'number'.
     var n3: [number, string] = z;
         ~~
-!!! error TS2740: Type '{ 0: string; 1: number; length: 2; }' is missing the following properties from type '[number, string]': pop, push, concat, join, and 15 more.
+!!! error TS2322: Type '{ 0: string; 1: number; length: 2; }' is not assignable to type '[number, string]'.
     var o1: [string, number] = x;
     var o2: [string, number] = y;
     var o3: [string, number] = y;

tests/baselines/reference/readonlyArraysAndTuples.errors.txt

@@ -5,7 +5,7 @@ tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(12,12): error TS1
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(15,5): error TS4104: The type 'readonly string[]' is 'readonly' and cannot be assigned to the mutable type 'string[]'.
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(17,5): error TS4104: The type 'readonly [string, string]' is 'readonly' and cannot be assigned to the mutable type 'string[]'.
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(21,5): error TS2739: Type 'string[]' is missing the following properties from type '[string, string]': 0, 1
-tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(22,5): error TS2740: Type 'readonly string[]' is missing the following properties from type '[string, string]': 0, 1, pop, push, and 5 more.
+tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(22,5): error TS4104: The type 'readonly string[]' is 'readonly' and cannot be assigned to the mutable type '[string, string]'.
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(23,5): error TS4104: The type 'readonly [string, string]' is 'readonly' and cannot be assigned to the mutable type '[string, string]'.
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(24,5): error TS2739: Type 'string[]' is missing the following properties from type 'readonly [string, string]': 0, 1
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(25,5): error TS2739: Type 'readonly string[]' is missing the following properties from type 'readonly [string, string]': 0, 1
@@ -56,7 +56,7 @@ tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(36,8): error TS25
 !!! error TS2739: Type 'string[]' is missing the following properties from type '[string, string]': 0, 1
         mt = ra;  // Error
         ~~
-!!! error TS2740: Type 'readonly string[]' is missing the following properties from type '[string, string]': 0, 1, pop, push, and 5 more.
+!!! error TS4104: The type 'readonly string[]' is 'readonly' and cannot be assigned to the mutable type '[string, string]'.
         mt = rt;  // Error
         ~~
 !!! error TS4104: The type 'readonly [string, string]' is 'readonly' and cannot be assigned to the mutable type '[string, string]'.