Merge pull request #30916 from jack-williams/array-elaboration

Elaborate array and tuple relation errors

src/compiler/checker.ts

@@ -12241,6 +12241,40 @@ namespace ts {
                 }
             }
 
+            /**
+             * Try and elaborate array and tuple errors. Returns false
+             * 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)) {
+                        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);
+                }
+                if (isTupleLikeType(target)) {
+                    return isArrayLikeType(source);
+                }
+                if (isReadonlyArrayType(source) && isArrayType(target) && !isReadonlyArrayType(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 true;
+            }
+
             function isUnionOrIntersectionTypeWithoutNullableConstituents(type: Type): boolean {
                 if (!(type.flags & TypeFlags.UnionOrIntersection)) {
                     return false;
@@ -12413,6 +12447,9 @@ namespace ts {
                 if (!result && reportErrors) {
                     const maybeSuppress = suppressNextError;
                     suppressNextError = false;
+                    if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Object) {
+                        tryElaborateArrayLikeErrors(source, target, reportErrors);
+                    }
                     if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Primitive) {
                         tryElaborateErrorsForPrimitivesAndObjects(source, target);
                     }
@@ -13143,11 +13180,13 @@ namespace ts {
                                 associateRelatedInfo(createDiagnosticForNode(unmatchedProperty.declarations[0], Diagnostics._0_is_declared_here, propName));
                             }
                         }
-                        else if (props.length > 5) { // arbitrary cutoff for too-long list form
-                            reportError(Diagnostics.Type_0_is_missing_the_following_properties_from_type_1_Colon_2_and_3_more, typeToString(source), typeToString(target), map(props.slice(0, 4), p => symbolToString(p)).join(", "), props.length - 4);
-                        }
-                        else {
-                            reportError(Diagnostics.Type_0_is_missing_the_following_properties_from_type_1_Colon_2, typeToString(source), typeToString(target), map(props, p => symbolToString(p)).join(", "));
+                        else if (tryElaborateArrayLikeErrors(source, target, /*reportErrors*/ false)) {
+                            if (props.length > 5) { // arbitrary cutoff for too-long list form
+                                reportError(Diagnostics.Type_0_is_missing_the_following_properties_from_type_1_Colon_2_and_3_more, typeToString(source), typeToString(target), map(props.slice(0, 4), p => symbolToString(p)).join(", "), props.length - 4);
+                            }
+                            else {
+                                reportError(Diagnostics.Type_0_is_missing_the_following_properties_from_type_1_Colon_2, typeToString(source), typeToString(target), map(props, p => symbolToString(p)).join(", "));
+                            }
                         }
                     }
                     return Ternary.False;

src/compiler/diagnosticMessages.json

@@ -2947,7 +2947,11 @@
         "category": "Error",
         "code": 4103
     },
-
+    "The type '{0}' is 'readonly' and cannot be assigned to the mutable type '{1}'.": {
+        "category": "Error",
+        "code": 4104
+    },
+
     "The current host does not support the '{0}' option.": {
         "category": "Error",
         "code": 5001

tests/baselines/reference/iterableArrayPattern10.errors.txt

@@ -1,5 +1,4 @@
 tests/cases/conformance/es6/destructuring/iterableArrayPattern10.ts(17,5): error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[any, any]'.
-  Type 'FooIterator' is missing the following properties from type '[any, any]': 0, 1, length, pop, and 26 more.
 
 
 ==== tests/cases/conformance/es6/destructuring/iterableArrayPattern10.ts (1 errors) ====
@@ -21,5 +20,4 @@ tests/cases/conformance/es6/destructuring/iterableArrayPattern10.ts(17,5): error
     function fun([a, b]) { }
     fun(new FooIterator);
         ~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[any, any]'.
-!!! error TS2345:   Type 'FooIterator' is missing the following properties from type '[any, any]': 0, 1, length, pop, and 26 more.
+!!! error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[any, any]'.

tests/baselines/reference/iterableArrayPattern13.errors.txt

@@ -1,5 +1,4 @@
 tests/cases/conformance/es6/destructuring/iterableArrayPattern13.ts(17,5): error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[any, ...any[]]'.
-  Type 'FooIterator' is missing the following properties from type '[any, ...any[]]': 0, length, pop, push, and 25 more.
 
 
 ==== tests/cases/conformance/es6/destructuring/iterableArrayPattern13.ts (1 errors) ====
@@ -21,5 +20,4 @@ tests/cases/conformance/es6/destructuring/iterableArrayPattern13.ts(17,5): error
     function fun([a, ...b]) { }
     fun(new FooIterator);
         ~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[any, ...any[]]'.
-!!! error TS2345:   Type 'FooIterator' is missing the following properties from type '[any, ...any[]]': 0, length, pop, push, and 25 more.
+!!! error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[any, ...any[]]'.

tests/baselines/reference/iterableArrayPattern16.errors.txt

@@ -1,5 +1,4 @@
 tests/cases/conformance/es6/destructuring/iterableArrayPattern16.ts(2,5): error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[Bar, Bar]'.
-  Type 'FooIterator' is missing the following properties from type '[Bar, Bar]': 0, 1, length, pop, and 26 more.
 tests/cases/conformance/es6/destructuring/iterableArrayPattern16.ts(2,12): error TS2449: Class 'FooIteratorIterator' used before its declaration.
 
 
@@ -8,7 +7,6 @@ tests/cases/conformance/es6/destructuring/iterableArrayPattern16.ts(2,12): error
     fun(...new FooIteratorIterator);
         ~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[Bar, Bar]'.
-!!! error TS2345:   Type 'FooIterator' is missing the following properties from type '[Bar, Bar]': 0, 1, length, pop, and 26 more.
                ~~~~~~~~~~~~~~~~~~~
 !!! error TS2449: Class 'FooIteratorIterator' used before its declaration.
 !!! related TS2728 tests/cases/conformance/es6/destructuring/iterableArrayPattern16.ts:18:7: 'FooIteratorIterator' is declared here.

tests/baselines/reference/iterableArrayPattern26.errors.txt

@@ -1,10 +1,8 @@
 tests/cases/conformance/es6/destructuring/iterableArrayPattern26.ts(2,21): error TS2345: Argument of type 'Map<string, number>' is not assignable to parameter of type '[string, number]'.
-  Type 'Map<string, number>' is missing the following properties from type '[string, number]': 0, 1, length, pop, and 22 more.
 
 
 ==== tests/cases/conformance/es6/destructuring/iterableArrayPattern26.ts (1 errors) ====
     function takeFirstTwoEntries(...[[k1, v1], [k2, v2]]: [string, number][]) { }
     takeFirstTwoEntries(new Map([["", 0], ["hello", 1]]));
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type 'Map<string, number>' is not assignable to parameter of type '[string, number]'.
-!!! error TS2345:   Type 'Map<string, number>' is missing the following properties from type '[string, number]': 0, 1, length, pop, and 22 more.
+!!! error TS2345: Argument of type 'Map<string, number>' is not assignable to parameter of type '[string, number]'.

tests/baselines/reference/readonlyArraysAndTuples.errors.txt

@@ -2,11 +2,11 @@ tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(9,12): error TS13
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(10,15): error TS1354: 'readonly' type modifier is only permitted on array and tuple literal types.
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(11,12): error TS1354: 'readonly' type modifier is only permitted on array and tuple literal types.
 tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(12,12): error TS1354: 'readonly' type modifier is only permitted on array and tuple literal types.
-tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(15,5): error TS2740: Type 'readonly string[]' is missing the following properties from type 'string[]': pop, push, reverse, shift, and 3 more.
-tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(17,5): error TS2740: Type 'readonly [string, string]' is missing the following properties from type 'string[]': pop, push, reverse, shift, and 3 more.
+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(23,5): error TS2740: Type 'readonly [string, string]' is missing the following properties from type '[string, string]': pop, push, reverse, shift, and 3 more.
+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
 
@@ -36,11 +36,11 @@ tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(25,5): error TS27
     function f1(ma: string[], ra: readonly string[], mt: [string, string], rt: readonly [string, string]) {
         ma = ra;  // Error
         ~~
-!!! error TS2740: Type 'readonly string[]' is missing the following properties from type 'string[]': pop, push, reverse, shift, and 3 more.
+!!! error TS4104: The type 'readonly string[]' is 'readonly' and cannot be assigned to the mutable type 'string[]'.
         ma = mt;
         ma = rt;  // Error
         ~~
-!!! error TS2740: Type 'readonly [string, string]' is missing the following properties from type 'string[]': pop, push, reverse, shift, and 3 more.
+!!! error TS4104: The type 'readonly [string, string]' is 'readonly' and cannot be assigned to the mutable type 'string[]'.
         ra = ma;
         ra = mt;
         ra = rt;
@@ -52,7 +52,7 @@ tests/cases/conformance/types/tuple/readonlyArraysAndTuples.ts(25,5): error TS27
 !!! error TS2740: Type 'readonly string[]' is missing the following properties from type '[string, string]': 0, 1, pop, push, and 5 more.
         mt = rt;  // Error
         ~~
-!!! error TS2740: Type 'readonly [string, string]' is missing the following properties from type '[string, string]': pop, push, reverse, shift, and 3 more.
+!!! error TS4104: The type 'readonly [string, string]' is 'readonly' and cannot be assigned to the mutable type '[string, string]'.
         rt = ma;  // Error
         ~~
 !!! error TS2739: Type 'string[]' is missing the following properties from type 'readonly [string, string]': 0, 1

tests/baselines/reference/readonlyTupleAndArrayElaboration.errors.txt

@@ -0,0 +1,58 @@
+tests/cases/compiler/readonlyTupleAndArrayElaboration.ts(10,20): error TS2345: Argument of type 'readonly [3, 4]' is not assignable to parameter of type '[number, number]'.
+  The type 'readonly [3, 4]' is 'readonly' and cannot be assigned to the mutable type '[number, number]'.
+tests/cases/compiler/readonlyTupleAndArrayElaboration.ts(13,8): error TS2345: Argument of type 'readonly [3, 4]' is not assignable to parameter of type 'number[]'.
+  The type 'readonly [3, 4]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+tests/cases/compiler/readonlyTupleAndArrayElaboration.ts(16,9): error TS2345: Argument of type 'readonly [3, 4]' is not assignable to parameter of type 'number[]'.
+  The type 'readonly [3, 4]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+tests/cases/compiler/readonlyTupleAndArrayElaboration.ts(22,9): error TS2345: Argument of type 'readonly number[]' is not assignable to parameter of type 'number[]'.
+  The type 'readonly number[]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+tests/cases/compiler/readonlyTupleAndArrayElaboration.ts(23,9): error TS2345: Argument of type 'readonly number[]' is not assignable to parameter of type 'number[]'.
+  The type 'readonly number[]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+tests/cases/compiler/readonlyTupleAndArrayElaboration.ts(24,9): error TS2345: Argument of type 'readonly number[]' is not assignable to parameter of type 'number[]'.
+  The type 'readonly number[]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+
+
+==== tests/cases/compiler/readonlyTupleAndArrayElaboration.ts (6 errors) ====
+    // @strict
+    // #Repro from #30839
+
+    let point = [3, 4] as const;
+
+    function distanceFromOrigin([x, y]: [number, number]) {
+        return Math.sqrt(x ** 2 + y ** 2);
+    }
+
+    distanceFromOrigin(point);
+                       ~~~~~
+!!! error TS2345: Argument of type 'readonly [3, 4]' is not assignable to parameter of type '[number, number]'.
+!!! error TS2345:   The type 'readonly [3, 4]' is 'readonly' and cannot be assigned to the mutable type '[number, number]'.
+
+    declare function arryFn(x: number[]): void;
+    arryFn(point);
+           ~~~~~
+!!! error TS2345: Argument of type 'readonly [3, 4]' is not assignable to parameter of type 'number[]'.
+!!! error TS2345:   The type 'readonly [3, 4]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+
+    declare function arryFn2(x: Array<number>): void;
+    arryFn2(point);
+            ~~~~~
+!!! error TS2345: Argument of type 'readonly [3, 4]' is not assignable to parameter of type 'number[]'.
+!!! error TS2345:   The type 'readonly [3, 4]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+
+    declare const a: readonly number[];
+    declare const b: Readonly<number[]>;
+    declare const c: ReadonlyArray<number>;
+
+    arryFn2(a);
+            ~
+!!! error TS2345: Argument of type 'readonly number[]' is not assignable to parameter of type 'number[]'.
+!!! error TS2345:   The type 'readonly number[]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+    arryFn2(b);
+            ~
+!!! error TS2345: Argument of type 'readonly number[]' is not assignable to parameter of type 'number[]'.
+!!! error TS2345:   The type 'readonly number[]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+    arryFn2(c);
+            ~
+!!! error TS2345: Argument of type 'readonly number[]' is not assignable to parameter of type 'number[]'.
+!!! error TS2345:   The type 'readonly number[]' is 'readonly' and cannot be assigned to the mutable type 'number[]'.
+

tests/baselines/reference/readonlyTupleAndArrayElaboration.js

@@ -0,0 +1,41 @@
+//// [readonlyTupleAndArrayElaboration.ts]
+// @strict
+// #Repro from #30839
+
+let point = [3, 4] as const;
+
+function distanceFromOrigin([x, y]: [number, number]) {
+    return Math.sqrt(x ** 2 + y ** 2);
+}
+
+distanceFromOrigin(point);
+
+declare function arryFn(x: number[]): void;
+arryFn(point);
+
+declare function arryFn2(x: Array<number>): void;
+arryFn2(point);
+
+declare const a: readonly number[];
+declare const b: Readonly<number[]>;
+declare const c: ReadonlyArray<number>;
+
+arryFn2(a);
+arryFn2(b);
+arryFn2(c);
+
+
+//// [readonlyTupleAndArrayElaboration.js]
+// @strict
+// #Repro from #30839
+var point = [3, 4];
+function distanceFromOrigin(_a) {
+    var x = _a[0], y = _a[1];
+    return Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
+}
+distanceFromOrigin(point);
+arryFn(point);
+arryFn2(point);
+arryFn2(a);
+arryFn2(b);
+arryFn2(c);