Closed
Description
TypeScript Version:
$ tsc --version
Version 2.0.0
Code
// concat-bug.ts
var a : Array<[number, number]>= [[1, 2]];
// Typescript detects these first two tuples as arrays of numbers (`number[]`) instead of `[number, number]`
a.concat([[3, 4], [5, 6], [7, 8]]);Expected behavior:
No compile errors. (It works in the 1.8 playground)
Actual behavior:
$ tsc concat-bug.ts
concat-bug.ts(4,10): error TS2345: Argument of type '[number[], number[], [number, number]]' is not assignable to parameter of type '[number, number] | [number, number][]'.
Type '[number[], number[], [number, number]]' is not assignable to type '[number, number][]'.
Types of property 'pop' are incompatible.
Type '() => number[] | [number, number]' is not assignable to type '() => [number, number]'.
Type 'number[] | [number, number]' is not assignable to type '[number, number]'.
Type 'number[]' is not assignable to type '[number, number]'.
Property '0' is missing in type 'number[]'.
Note that the 3rd parameter is correctly detected as a tuple, but the first two are detected as arrays of numbers.