Add test

Author: ahejlsberg

tests/baselines/reference/variadicTuples1.errors.txt

@@ -1,26 +1,26 @@
 tests/cases/conformance/types/tuple/variadicTuples1.ts(6,48): error TS1256: A rest element must be last in a tuple type.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(46,5): error TS2555: Expected at least 3 arguments, but got 2.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(47,17): error TS2345: Argument of type '45' is not assignable to parameter of type 'boolean'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(125,9): error TS2344: Type 'V' does not satisfy the constraint 'unknown[]'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(52,5): error TS2555: Expected at least 3 arguments, but got 2.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(53,17): error TS2345: Argument of type '45' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(131,9): error TS2344: Type 'V' does not satisfy the constraint 'unknown[]'.
   The type 'readonly unknown[]' is 'readonly' and cannot be assigned to the mutable type 'unknown[]'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(143,5): error TS2322: Type '[string, ...unknown[]]' is not assignable to type '[string, ...T]'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(149,5): error TS2322: Type '[string, ...unknown[]]' is not assignable to type '[string, ...T]'.
   Target requires 2 element(s) but source may have fewer.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(145,5): error TS2322: Type '[string, ...unknown[]]' is not assignable to type '[string, ...U]'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(151,5): error TS2322: Type '[string, ...unknown[]]' is not assignable to type '[string, ...U]'.
   Target requires 2 element(s) but source may have fewer.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(146,5): error TS2322: Type '[string, ...T]' is not assignable to type '[string, ...U]'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(152,5): error TS2322: Type '[string, ...T]' is not assignable to type '[string, ...U]'.
   Type 'T' is not assignable to type 'U'.
     'T' is assignable to the constraint of type 'U', but 'U' could be instantiated with a different subtype of constraint 'string[]'.
       Type 'string[]' is not assignable to type 'U'.
         'U' could be instantiated with an arbitrary type which could be unrelated to 'string[]'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(154,5): error TS2322: Type 'readonly [...T]' is not assignable to type 'T'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(160,5): error TS2322: Type 'readonly [...T]' is not assignable to type 'T'.
   'T' could be instantiated with an arbitrary type which could be unrelated to 'readonly [...T]'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(156,5): error TS4104: The type 'readonly [...T]' is 'readonly' and cannot be assigned to the mutable type '[...T]'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(163,5): error TS2322: Type 'readonly [...T]' is not assignable to type 'T'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(162,5): error TS4104: The type 'readonly [...T]' is 'readonly' and cannot be assigned to the mutable type '[...T]'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(169,5): error TS2322: Type 'readonly [...T]' is not assignable to type 'T'.
   'readonly [...T]' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'readonly unknown[]'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(164,5): error TS2322: Type 'T' is not assignable to type '[...T]'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(170,5): error TS2322: Type 'T' is not assignable to type '[...T]'.
   The type 'readonly unknown[]' is 'readonly' and cannot be assigned to the mutable type '[...T]'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(165,5): error TS4104: The type 'readonly [...T]' is 'readonly' and cannot be assigned to the mutable type '[...T]'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(297,14): error TS7019: Rest parameter 'x' implicitly has an 'any[]' type.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(171,5): error TS4104: The type 'readonly [...T]' is 'readonly' and cannot be assigned to the mutable type '[...T]'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(303,14): error TS7019: Rest parameter 'x' implicitly has an 'any[]' type.
 
 
 ==== tests/cases/conformance/types/tuple/variadicTuples1.ts (13 errors) ====
@@ -62,6 +62,12 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(297,14): error TS7019: Re
     const tc3 = concat([1, 2, 3], sa);
     const tc4 = concat(sa, [1, 2, 3]);  // Ideally would be [...string[], number, number, number]
 
+    function concat2<T extends readonly unknown[], U extends readonly unknown[]>(t: T, u: U) {
+        return [...t, ...u];  // (T[number] | U[number])[]
+    }
+    
+    const tc5 = concat2([1, 2, 3] as const, [4, 5, 6] as const);  // (1 | 2 | 3 | 4 | 5 | 6)[]
+    
     // Spread arguments
 
     declare function foo1(a: number, b: string, c: boolean, ...d: number[]): void;
@@ -74,7 +80,7 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(297,14): error TS7019: Re
         foo1(...t1);  // Error
         ~~~~~~~~~~~
 !!! error TS2555: Expected at least 3 arguments, but got 2.
-!!! related TS6210 tests/cases/conformance/types/tuple/variadicTuples1.ts:39:45: An argument for 'c' was not provided.
+!!! related TS6210 tests/cases/conformance/types/tuple/variadicTuples1.ts:45:45: An argument for 'c' was not provided.
         foo1(...t1, 45);  // Error
                     ~~
 !!! error TS2345: Argument of type '45' is not assignable to parameter of type 'boolean'.

tests/baselines/reference/variadicTuples1.js

@@ -35,6 +35,12 @@ const tc2 = concat(['hello'], [42]);
 const tc3 = concat([1, 2, 3], sa);
 const tc4 = concat(sa, [1, 2, 3]);  // Ideally would be [...string[], number, number, number]
 
+function concat2<T extends readonly unknown[], U extends readonly unknown[]>(t: T, u: U) {
+    return [...t, ...u];  // (T[number] | U[number])[]
+}
+
+const tc5 = concat2([1, 2, 3] as const, [4, 5, 6] as const);  // (1 | 2 | 3 | 4 | 5 | 6)[]
+
 // Spread arguments
 
 declare function foo1(a: number, b: string, c: boolean, ...d: number[]): void;
@@ -320,6 +326,10 @@ var tc1 = concat([], []);
 var tc2 = concat(['hello'], [42]);
 var tc3 = concat([1, 2, 3], sa);
 var tc4 = concat(sa, [1, 2, 3]); // Ideally would be [...string[], number, number, number]
+function concat2(t, u) {
+    return __spreadArrays(t, u); // (T[number] | U[number])[]
+}
+var tc5 = concat2([1, 2, 3], [4, 5, 6]); // (1 | 2 | 3 | 4 | 5 | 6)[]
 function foo2(t1, t2, a1) {
     foo1(1, 'abc', true, 42, 43, 44);
     foo1.apply(void 0, __spreadArrays(t1, [true, 42, 43, 44]));
@@ -483,6 +493,8 @@ declare const tc1: [];
 declare const tc2: [string, number];
 declare const tc3: [number, number, number, ...string[]];
 declare const tc4: (string | number)[];
+declare function concat2<T extends readonly unknown[], U extends readonly unknown[]>(t: T, u: U): (T[number] | U[number])[];
+declare const tc5: (2 | 4 | 1 | 3 | 6 | 5)[];
 declare function foo1(a: number, b: string, c: boolean, ...d: number[]): void;
 declare function foo2(t1: [number, string], t2: [boolean], a1: number[]): void;
 declare function foo3<T extends unknown[]>(x: number, ...args: [...T, number]): T;