Fix tests

Author: ahejlsberg

tests/baselines/reference/variadicTuples1.errors.txt

@@ -40,8 +40,8 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(191,5): error TS2322: Typ
         'U' could be instantiated with an arbitrary type which could be unrelated to 'readonly string[]'.
 tests/cases/conformance/types/tuple/variadicTuples1.ts(203,5): error TS2322: Type 'string' is not assignable to type 'keyof [1, 2, ...T]'.
   Type '"2"' is not assignable to type 'number | "0" | "length" | "toString" | "toLocaleString" | "pop" | "push" | "concat" | "join" | "reverse" | "shift" | "slice" | "sort" | "splice" | "unshift" | "indexOf" | "lastIndexOf" | "every" | "some" | "forEach" | "map" | "filter" | "reduce" | "reduceRight" | "1"'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(354,26): error TS2322: Type 'string' is not assignable to type 'number | undefined'.
-tests/cases/conformance/types/tuple/variadicTuples1.ts(394,7): error TS2322: Type '[false, false]' is not assignable to type '[...number[], boolean]'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(357,26): error TS2322: Type 'string' is not assignable to type 'number | undefined'.
+tests/cases/conformance/types/tuple/variadicTuples1.ts(397,7): error TS2322: Type '[false, false]' is not assignable to type '[...number[], boolean]'.
   Type at position 0 in source is not compatible with type at position 0 in target.
     Type 'boolean' is not assignable to type 'number'.
 
@@ -52,7 +52,7 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(394,7): error TS2322: Typ
     type TV0<T extends unknown[]> = [string, ...T];
     type TV1<T extends unknown[]> = [string, ...T, number];
     type TV2<T extends unknown[]> = [string, ...T, number, ...T];
-    type TV3<T extends unknown[]> = [string, ...T, ...number[], ...T];  // Error
+    type TV3<T extends unknown[]> = [string, ...T, ...number[], ...T];
 
     // Normalization
 
@@ -315,11 +315,18 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(394,7): error TS2322: Typ
 
     // Inference between variadic tuple types
 
-    type First<T extends readonly unknown[]> = T[0];
-    type DropFirst<T extends readonly unknown[]> = T extends readonly [any?, ...infer U] ? U : [...T];
+    type First<T extends readonly unknown[]> =
+        T extends readonly [unknown, ...unknown[]] ? T[0] :
+        T[0] | undefined;
 
-    type Last<T extends readonly unknown[]> = T extends readonly [...infer _, infer U] ? U : T extends readonly [...infer _, (infer U)?] ? U | undefined : undefined;
-    type DropLast<T extends readonly unknown[]> = T extends readonly [...infer U, any?] ? U : [...T];
+    type DropFirst<T extends readonly unknown[]> = T extends readonly [unknown?, ...infer U] ? U : [...T];
+    
+    type Last<T extends readonly unknown[]> =
+        T extends readonly [...unknown[], infer U] ? U :
+        T extends readonly [unknown, ...unknown[]] ? T[number] :
+        T[number] | undefined;
+    
+    type DropLast<T extends readonly unknown[]> = T extends readonly [...infer U, unknown] ? U : [...T];
 
     type T00 = First<[number, symbol, string]>;
     type T01 = First<[symbol, string]>;
@@ -350,8 +357,8 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(394,7): error TS2322: Typ
     type T24 = Last<[symbol, ...string[]]>;
     type T25 = Last<[string?]>;
     type T26 = Last<string[]>;
-    type T27 = Last<[]>;  // unknown, maybe should undefined
-    type T28 = Last<any>;  // unknown, maybe should be any
+    type T27 = Last<[]>;
+    type T28 = Last<any>;
     type T29 = Last<never>;
 
     type T30 = DropLast<[number, symbol, string]>;
@@ -449,10 +456,6 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(394,7): error TS2322: Typ
     declare function call<T extends unknown[], R>(...args: [...T, (...args: T) => R]): [T, R];
 
     call('hello', 32, (a, b) => 42);
-    
-    // Would be nice to infer [...string[], (...args: string[]) => number] here
-    // Requires [starting-fixed-part, ...rest-part, ending-fixed-part] tuple structure
-    
     call(...sa, (...x) => 42);
 
     // No inference to ending optional elements (except with identical structure)
@@ -503,7 +506,7 @@ tests/cases/conformance/types/tuple/variadicTuples1.ts(394,7): error TS2322: Typ
 
     type Numbers = number[];
     type Unbounded = [...Numbers, boolean];
-    const data: Unbounded = [false, false];
+    const data: Unbounded = [false, false];  // Error
           ~~~~
 !!! error TS2322: Type '[false, false]' is not assignable to type '[...number[], boolean]'.
 !!! error TS2322:   Type at position 0 in source is not compatible with type at position 0 in target.

tests/baselines/reference/variadicTuples1.js

@@ -4,7 +4,7 @@
 type TV0<T extends unknown[]> = [string, ...T];
 type TV1<T extends unknown[]> = [string, ...T, number];
 type TV2<T extends unknown[]> = [string, ...T, number, ...T];
-type TV3<T extends unknown[]> = [string, ...T, ...number[], ...T];  // Error
+type TV3<T extends unknown[]> = [string, ...T, ...number[], ...T];
 
 // Normalization
 
@@ -206,11 +206,18 @@ function f15<T extends string[], U extends T>(k0: keyof T, k1: keyof [...T], k2:
 
 // Inference between variadic tuple types
 
-type First<T extends readonly unknown[]> = T[0];
-type DropFirst<T extends readonly unknown[]> = T extends readonly [any?, ...infer U] ? U : [...T];
+type First<T extends readonly unknown[]> =
+    T extends readonly [unknown, ...unknown[]] ? T[0] :
+    T[0] | undefined;
 
-type Last<T extends readonly unknown[]> = T extends readonly [...infer _, infer U] ? U : T extends readonly [...infer _, (infer U)?] ? U | undefined : undefined;
-type DropLast<T extends readonly unknown[]> = T extends readonly [...infer U, any?] ? U : [...T];
+type DropFirst<T extends readonly unknown[]> = T extends readonly [unknown?, ...infer U] ? U : [...T];
+
+type Last<T extends readonly unknown[]> =
+    T extends readonly [...unknown[], infer U] ? U :
+    T extends readonly [unknown, ...unknown[]] ? T[number] :
+    T[number] | undefined;
+
+type DropLast<T extends readonly unknown[]> = T extends readonly [...infer U, unknown] ? U : [...T];
 
 type T00 = First<[number, symbol, string]>;
 type T01 = First<[symbol, string]>;
@@ -241,8 +248,8 @@ type T23 = Last<[number, symbol, ...string[]]>;
 type T24 = Last<[symbol, ...string[]]>;
 type T25 = Last<[string?]>;
 type T26 = Last<string[]>;
-type T27 = Last<[]>;  // unknown, maybe should undefined
-type T28 = Last<any>;  // unknown, maybe should be any
+type T27 = Last<[]>;
+type T28 = Last<any>;
 type T29 = Last<never>;
 
 type T30 = DropLast<[number, symbol, string]>;
@@ -340,10 +347,6 @@ ft(['a', 'b'], ['c', 'd', 42])
 declare function call<T extends unknown[], R>(...args: [...T, (...args: T) => R]): [T, R];
 
 call('hello', 32, (a, b) => 42);
-
-// Would be nice to infer [...string[], (...args: string[]) => number] here
-// Requires [starting-fixed-part, ...rest-part, ending-fixed-part] tuple structure
-
 call(...sa, (...x) => 42);
 
 // No inference to ending optional elements (except with identical structure)
@@ -392,7 +395,7 @@ callApi(getOrgUser);
 
 type Numbers = number[];
 type Unbounded = [...Numbers, boolean];
-const data: Unbounded = [false, false];
+const data: Unbounded = [false, false];  // Error
 
 type U1 = [string, ...Numbers, boolean];
 type U2 = [...[string, ...Numbers], boolean];
@@ -588,8 +591,6 @@ ft([1, 2], [1, 2, 3]);
 ft(['a', 'b'], ['c', 'd']);
 ft(['a', 'b'], ['c', 'd', 42]);
 call('hello', 32, function (a, b) { return 42; });
-// Would be nice to infer [...string[], (...args: string[]) => number] here
-// Requires [starting-fixed-part, ...rest-part, ending-fixed-part] tuple structure
 call.apply(void 0, __spreadArrays(sa, [function () {
         var x = [];
         for (var _i = 0; _i < arguments.length; _i++) {
@@ -619,7 +620,7 @@ function callApi(method) {
 }
 callApi(getUser);
 callApi(getOrgUser);
-var data = [false, false];
+var data = [false, false]; // Error
 
 
 //// [variadicTuples1.d.ts]
@@ -674,10 +675,10 @@ declare function f12<T extends readonly unknown[]>(t: T, m: [...T], r: readonly
 declare function f13<T extends string[], U extends T>(t0: T, t1: [...T], t2: [...U]): void;
 declare function f14<T extends readonly string[], U extends T>(t0: T, t1: [...T], t2: [...U]): void;
 declare function f15<T extends string[], U extends T>(k0: keyof T, k1: keyof [...T], k2: keyof [...U], k3: keyof [1, 2, ...T]): void;
-declare type First<T extends readonly unknown[]> = T[0];
-declare type DropFirst<T extends readonly unknown[]> = T extends readonly [any?, ...infer U] ? U : [...T];
-declare type Last<T extends readonly unknown[]> = T extends readonly [...infer _, infer U] ? U : T extends readonly [...infer _, (infer U)?] ? U | undefined : undefined;
-declare type DropLast<T extends readonly unknown[]> = T extends readonly [...infer U, any?] ? U : [...T];
+declare type First<T extends readonly unknown[]> = T extends readonly [unknown, ...unknown[]] ? T[0] : T[0] | undefined;
+declare type DropFirst<T extends readonly unknown[]> = T extends readonly [unknown?, ...infer U] ? U : [...T];
+declare type Last<T extends readonly unknown[]> = T extends readonly [...unknown[], infer U] ? U : T extends readonly [unknown, ...unknown[]] ? T[number] : T[number] | undefined;
+declare type DropLast<T extends readonly unknown[]> = T extends readonly [...infer U, unknown] ? U : [...T];
 declare type T00 = First<[number, symbol, string]>;
 declare type T01 = First<[symbol, string]>;
 declare type T02 = First<[string]>;