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tests/cases/conformance/types/tuple/variadicTuples2.ts(7,34): error TS1265: A rest element cannot follow another rest element.
tests/cases/conformance/types/tuple/variadicTuples2.ts(8,34): error TS1266: An optional element cannot follow a rest element.
tests/cases/conformance/types/tuple/variadicTuples2.ts(9,30): error TS1257: A required element cannot follow an optional element.
tests/cases/conformance/types/tuple/variadicTuples2.ts(42,1): error TS2322: Type '[string, string, number, number]' is not assignable to type '[...string[], number]'.
Type at positions 0 through 2 in source is not compatible with type at position 0 in target.
Type 'number' is not assignable to type 'string'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(48,5): error TS2345: Argument of type '["abc", "def", 5, 6]' is not assignable to parameter of type '[...strs: string[], num: number]'.
Type at positions 0 through 2 in source is not compatible with type at position 0 in target.
Type 'number' is not assignable to type 'string'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(51,1): error TS2322: Type '[number]' is not assignable to type '[number, ...string[], number]'.
Source has 1 element(s) but target requires 2.
tests/cases/conformance/types/tuple/variadicTuples2.ts(53,1): error TS2322: Type '[number, number, number]' is not assignable to type '[number, ...string[], number]'.
Type at position 1 in source is not compatible with type at position 1 in target.
Type 'number' is not assignable to type 'string'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(56,1): error TS2322: Type '[number, string, number, string]' is not assignable to type '[number, ...string[], number]'.
Type at positions 1 through 2 in source is not compatible with type at position 1 in target.
Type 'number' is not assignable to type 'string'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(57,8): error TS2322: Type 'boolean' is not assignable to type 'number'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(58,1): error TS2322: Type '[number, string, string, boolean]' is not assignable to type '[number, ...string[], number]'.
Type at position 3 in source is not compatible with type at position 2 in target.
Type 'boolean' is not assignable to type 'number'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(61,1): error TS2345: Argument of type '[]' is not assignable to parameter of type '[...strs: string[], n2: number]'.
Source has 0 element(s) but target requires 1.
tests/cases/conformance/types/tuple/variadicTuples2.ts(63,8): error TS2345: Argument of type '[1, 2]' is not assignable to parameter of type '[...strs: string[], n2: number]'.
Type at position 0 in source is not compatible with type at position 0 in target.
Type 'number' is not assignable to type 'string'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(66,8): error TS2345: Argument of type '["abc", 1, "def"]' is not assignable to parameter of type '[...strs: string[], n2: number]'.
Type at positions 0 through 1 in source is not compatible with type at position 0 in target.
Type 'number' is not assignable to type 'string'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(67,5): error TS2345: Argument of type 'boolean' is not assignable to parameter of type 'number'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(68,8): error TS2345: Argument of type '["abc", "def", true]' is not assignable to parameter of type '[...strs: string[], n2: number]'.
Type at position 2 in source is not compatible with type at position 1 in target.
Type 'boolean' is not assignable to type 'number'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(71,5): error TS2322: Type '[number, number]' is not assignable to type '[number, ...T]'.
Source provides no match for variadic element at position 1 in target.
tests/cases/conformance/types/tuple/variadicTuples2.ts(72,5): error TS2322: Type '[number, ...number[]]' is not assignable to type '[number, ...T]'.
Target requires 2 element(s) but source may have fewer.
tests/cases/conformance/types/tuple/variadicTuples2.ts(73,5): error TS2322: Type '[number, ...T]' is not assignable to type '[number, number]'.
Variadic element at position 1 in source does not match element at position 1 in target.
tests/cases/conformance/types/tuple/variadicTuples2.ts(74,5): error TS2322: Type '[number, ...T]' is not assignable to type '[number, ...number[]]'.
Type at position 1 in source is not compatible with type at position 1 in target.
Type 'T' is not assignable to type 'number[]'.
Type 'unknown[]' is not assignable to type 'number[]'.
Type 'unknown' is not assignable to type 'number'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(79,5): error TS2322: Type '[number, string, ...any[]]' is not assignable to type '[number, ...number[]]'.
Type at positions 1 through 2 in source is not compatible with type at position 1 in target.
Type 'string' is not assignable to type 'number'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(111,16): error TS2345: Argument of type '[1, 2, 3, 4]' is not assignable to parameter of type '[...number[], (...values: number[]) => void]'.
Type at position 3 in source is not compatible with type at position 1 in target.
Type 'number' is not assignable to type '(...values: number[]) => void'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(112,6): error TS2345: Argument of type 'string[]' is not assignable to parameter of type '[...string[], (...values: string[]) => void]'.
Source provides no match for required element at position 1 in target.
tests/cases/conformance/types/tuple/variadicTuples2.ts(115,5): error TS2345: Argument of type '[]' is not assignable to parameter of type '[...unknown[], unknown, unknown]'.
Source has 0 element(s) but target requires 2.
tests/cases/conformance/types/tuple/variadicTuples2.ts(116,5): error TS2345: Argument of type '[number]' is not assignable to parameter of type '[...unknown[], unknown, unknown]'.
Source has 1 element(s) but target requires 2.
tests/cases/conformance/types/tuple/variadicTuples2.ts(121,5): error TS2345: Argument of type '[]' is not assignable to parameter of type '[unknown, ...unknown[], unknown]'.
Source has 0 element(s) but target requires 2.
tests/cases/conformance/types/tuple/variadicTuples2.ts(122,5): error TS2345: Argument of type '[number]' is not assignable to parameter of type '[unknown, ...unknown[], unknown]'.
Source has 1 element(s) but target requires 2.
tests/cases/conformance/types/tuple/variadicTuples2.ts(132,16): error TS2345: Argument of type 'number' is not assignable to parameter of type 'string'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(133,16): error TS2345: Argument of type 'number' is not assignable to parameter of type 'string'.
tests/cases/conformance/types/tuple/variadicTuples2.ts(134,25): error TS2345: Argument of type '["blah2", 1, 2, 3]' is not assignable to parameter of type '[...string[], number]'.
Type at positions 0 through 2 in source is not compatible with type at position 0 in target.
Type 'number' is not assignable to type 'string'.
==== tests/cases/conformance/types/tuple/variadicTuples2.ts (29 errors) ====
// Declarations
type V00 = [number, ...string[]];
type V01 = [...string[], number];
type V03 = [number, ...string[], number];
type V10 = [number, ...string[], ...boolean[]]; // Error
~~~~~~~~~~~~
!!! error TS1265: A rest element cannot follow another rest element.
type V11 = [number, ...string[], boolean?]; // Error
~~~~~~~~
!!! error TS1266: An optional element cannot follow a rest element.
type V12 = [number, string?, boolean]; // Error
~~~~~~~
!!! error TS1257: A required element cannot follow an optional element.
// Normalization
type Tup3<T extends unknown[], U extends unknown[], V extends unknown[]> = [...T, ...U, ...V];
type V20 = Tup3<[number], string[], [number]>; // [number, ...string[], number]
type V21 = Tup3<[number], [string?], [boolean]>; // [number, string | undefined, boolean]
type V22 = Tup3<[number], string[], boolean[]>; // [number, (string | boolean)[]]
type V23 = Tup3<[number], string[], [boolean?]>; // [number, (string | boolean | undefined)[]]
type V24 = Tup3<[number], [boolean?], string[]>; // [number, boolean?, ...string[]]
type V25 = Tup3<string[], number[], boolean[]>; // (string | number | boolean)[]
type V26 = Tup3<string[], number[], [boolean]>; // [...(string | number)[], boolean]
type V27 = Tup3<[number?], [string], [boolean?]>; // [number | undefined, string, boolean?]
type V30<A extends unknown[]> = Tup3<A, string[], number[]>; // [...A, ...(string | number)[]]
type V31<A extends unknown[]> = Tup3<string[], A, number[]>; // (string | number | A[number])[]
type V32<A extends unknown[]> = Tup3<string[], number[], A>; // [...(string | number)[], ...A]
type V40<A extends unknown[]> = Tup3<A, [string?], number[]>; // [...A, string?, ...number[]]
type V41<A extends unknown[]> = Tup3<[string?], A, number[]>; // [string?, ...A, ...number[]]
type V42<A extends unknown[]> = Tup3<[string?], number[], A>; // [string?, ...number[], ...A]
type V50<A extends unknown[]> = Tup3<A, string[], [number?]>; // [...A, ...(string | number | undefined)[]]
type V51<A extends unknown[]> = Tup3<string[], A, [number?]>; // (string | number | A[number] | undefined)[]
type V52<A extends unknown[]> = Tup3<string[], [number?], A>; // [...(string | number | undefined)[], ...A]
// Assignability
declare let tt1: [...string[], number];
tt1 = [5];
tt1 = ['abc', 5];
tt1 = ['abc', 'def', 5];
tt1 = ['abc', 'def', 5, 6]; // Error
~~~
!!! error TS2322: Type '[string, string, number, number]' is not assignable to type '[...string[], number]'.
!!! error TS2322: Type at positions 0 through 2 in source is not compatible with type at position 0 in target.
!!! error TS2322: Type 'number' is not assignable to type 'string'.
declare function ft1(...args: [...strs: string[], num: number]): void;
ft1(5);
ft1('abc', 5);
ft1('abc', 'def', 5);
ft1('abc', 'def', 5, 6); // Error
~~~~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '["abc", "def", 5, 6]' is not assignable to parameter of type '[...strs: string[], num: number]'.
!!! error TS2345: Type at positions 0 through 2 in source is not compatible with type at position 0 in target.
!!! error TS2345: Type 'number' is not assignable to type 'string'.
declare let tt2: [number, ...string[], number];
tt2 = [0]; // Error
~~~
!!! error TS2322: Type '[number]' is not assignable to type '[number, ...string[], number]'.
!!! error TS2322: Source has 1 element(s) but target requires 2.
tt2 = [0, 1];
tt2 = [0, 1, 2]; // Error
~~~
!!! error TS2322: Type '[number, number, number]' is not assignable to type '[number, ...string[], number]'.
!!! error TS2322: Type at position 1 in source is not compatible with type at position 1 in target.
!!! error TS2322: Type 'number' is not assignable to type 'string'.
tt2 = [0, 'abc', 1];
tt2 = [0, 'abc', 'def', 1];
tt2 = [0, 'abc', 1, 'def']; // Error
~~~
!!! error TS2322: Type '[number, string, number, string]' is not assignable to type '[number, ...string[], number]'.
!!! error TS2322: Type at positions 1 through 2 in source is not compatible with type at position 1 in target.
!!! error TS2322: Type 'number' is not assignable to type 'string'.
tt2 = [true, 'abc', 'def', 1]; // Error
~~~~
!!! error TS2322: Type 'boolean' is not assignable to type 'number'.
tt2 = [0, 'abc', 'def', true]; // Error
~~~
!!! error TS2322: Type '[number, string, string, boolean]' is not assignable to type '[number, ...string[], number]'.
!!! error TS2322: Type at position 3 in source is not compatible with type at position 2 in target.
!!! error TS2322: Type 'boolean' is not assignable to type 'number'.
declare function ft2(n1: number, ...rest: [...strs: string[], n2: number]): void;
ft2(0); // Error
~~~~~~
!!! error TS2345: Argument of type '[]' is not assignable to parameter of type '[...strs: string[], n2: number]'.
!!! error TS2345: Source has 0 element(s) but target requires 1.
ft2(0, 1);
ft2(0, 1, 2); // Error
~~~~
!!! error TS2345: Argument of type '[1, 2]' is not assignable to parameter of type '[...strs: string[], n2: number]'.
!!! error TS2345: Type at position 0 in source is not compatible with type at position 0 in target.
!!! error TS2345: Type 'number' is not assignable to type 'string'.
ft2(0, 'abc', 1);
ft2(0, 'abc', 'def', 1);
ft2(0, 'abc', 1, 'def'); // Error
~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '["abc", 1, "def"]' is not assignable to parameter of type '[...strs: string[], n2: number]'.
!!! error TS2345: Type at positions 0 through 1 in source is not compatible with type at position 0 in target.
!!! error TS2345: Type 'number' is not assignable to type 'string'.
ft2(true, 'abc', 'def', 1); // Error
~~~~
!!! error TS2345: Argument of type 'boolean' is not assignable to parameter of type 'number'.
ft2(0, 'abc', 'def', true); // Error
~~~~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '["abc", "def", true]' is not assignable to parameter of type '[...strs: string[], n2: number]'.
!!! error TS2345: Type at position 2 in source is not compatible with type at position 1 in target.
!!! error TS2345: Type 'boolean' is not assignable to type 'number'.
function ft3<T extends unknown[]>(x: [number, ...T], y: [number, number], z: [number, ...number[]]) {
x = y; // Error
~
!!! error TS2322: Type '[number, number]' is not assignable to type '[number, ...T]'.
!!! error TS2322: Source provides no match for variadic element at position 1 in target.
x = z; // Error
~
!!! error TS2322: Type '[number, ...number[]]' is not assignable to type '[number, ...T]'.
!!! error TS2322: Target requires 2 element(s) but source may have fewer.
y = x; // Error
~
!!! error TS2322: Type '[number, ...T]' is not assignable to type '[number, number]'.
!!! error TS2322: Variadic element at position 1 in source does not match element at position 1 in target.
z = x; // Error
~
!!! error TS2322: Type '[number, ...T]' is not assignable to type '[number, ...number[]]'.
!!! error TS2322: Type at position 1 in source is not compatible with type at position 1 in target.
!!! error TS2322: Type 'T' is not assignable to type 'number[]'.
!!! error TS2322: Type 'unknown[]' is not assignable to type 'number[]'.
!!! error TS2322: Type 'unknown' is not assignable to type 'number'.
}
// repro #50216
declare let tt3: [number, string, ...any[]]
let tt4: [number, ...number[]] = tt3 // Error
~~~
!!! error TS2322: Type '[number, string, ...any[]]' is not assignable to type '[number, ...number[]]'.
!!! error TS2322: Type at positions 1 through 2 in source is not compatible with type at position 1 in target.
!!! error TS2322: Type 'string' is not assignable to type 'number'.
// Inference
function pipe<T extends readonly unknown[]>(...args: [...T, (...values: T) => void]) {
const callback = args[args.length - 1] as (...values: T) => void;
const values = args.slice(0, -1) as unknown as T;
callback(...values);
}
pipe("foo", 123, true, (a, b, c) => {
a; // string
b; // number
c; // boolean
})
pipe("foo", 123, true, (...x) => {
x; // [string, number, boolean]
});
declare const sa: string[];
pipe(...sa, (...x) => {
x; // string[]
});
pipe(1, ...sa, 2, (...x) => {
x; // [number, ...string[], number]
let qq = x[x.length - 1];
let ww = x[0]
});
pipe<number[]>(1, 2, 3, 4); // Error
~~~~~~~~~~
!!! error TS2345: Argument of type '[1, 2, 3, 4]' is not assignable to parameter of type '[...number[], (...values: number[]) => void]'.
!!! error TS2345: Type at position 3 in source is not compatible with type at position 1 in target.
!!! error TS2345: Type 'number' is not assignable to type '(...values: number[]) => void'.
pipe(...sa); // Error
~~~~~
!!! error TS2345: Argument of type 'string[]' is not assignable to parameter of type '[...string[], (...values: string[]) => void]'.
!!! error TS2345: Source provides no match for required element at position 1 in target.
declare function fn1<T, U>(t: [...unknown[], T, U]): [T, U];
fn1([]); // Error
~~
!!! error TS2345: Argument of type '[]' is not assignable to parameter of type '[...unknown[], unknown, unknown]'.
!!! error TS2345: Source has 0 element(s) but target requires 2.
fn1([1]); // Error
~~~
!!! error TS2345: Argument of type '[number]' is not assignable to parameter of type '[...unknown[], unknown, unknown]'.
!!! error TS2345: Source has 1 element(s) but target requires 2.
fn1([1, 'abc']); // [number, string]
fn1([1, 'abc', true]); // [string, boolean]
declare function fn2<T, U>(t: [T, ...unknown[], U]): [T, U];
fn2([]); // Error
~~
!!! error TS2345: Argument of type '[]' is not assignable to parameter of type '[unknown, ...unknown[], unknown]'.
!!! error TS2345: Source has 0 element(s) but target requires 2.
fn2([1]); // Error
~~~
!!! error TS2345: Argument of type '[number]' is not assignable to parameter of type '[unknown, ...unknown[], unknown]'.
!!! error TS2345: Source has 1 element(s) but target requires 2.
fn2([1, 'abc']); // [number, string]
fn2([1, 'abc', true]); // [number, boolean]
// Repro from #39595
declare function foo<S extends readonly [string, ...string[]]>(...stringsAndNumber: readonly [...S, number]): [...S, number];
const a1 = foo('blah1', 1);
const b1 = foo('blah1', 'blah2', 1);
const c1 = foo(1); // Error
~
!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'string'.
const d1 = foo(1, 2); // Error
~
!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'string'.
const e1 = foo('blah1', 'blah2', 1, 2, 3); // Error
~~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '["blah2", 1, 2, 3]' is not assignable to parameter of type '[...string[], number]'.
!!! error TS2345: Type at positions 0 through 2 in source is not compatible with type at position 0 in target.
!!! error TS2345: Type 'number' is not assignable to type 'string'.
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