swc/crates/swc_ecma_parser/tests/tsc/destructuringArrayBindingPatternAndAssignment1ES6.ts

53 lines
2.1 KiB
TypeScript

// @target: es6
/* AssignmentPattern:
* ObjectAssignmentPattern
* ArrayAssignmentPattern
* ArrayAssignmentPattern:
* [Elision<opt> AssignmentRestElementopt ]
* [AssignmentElementList]
* [AssignmentElementList, Elision<opt> AssignmentRestElementopt ]
* AssignmentElementList:
* Elision<opt> AssignmentElement
* AssignmentElementList, Elisionopt AssignmentElement
* AssignmentElement:
* LeftHandSideExpression Initialiseropt
* AssignmentPattern Initialiseropt
* AssignmentRestElement:
* ... LeftHandSideExpression
*/
// In a destructuring assignment expression, the type of the expression on the right must be assignable to the assignment target on the left.
// An expression of type S is considered assignable to an assignment target V if one of the following is true
// V is an array assignment pattern, S is the type Any or an array-like type (section 3.3.2), and, for each assignment element E in V,
// S is the type Any, or
var [a0, a1]: any = undefined;
var [a2 = false, a3 = 1]: any = undefined;
// V is an array assignment pattern, S is the type Any or an array-like type (section 3.3.2), and, for each assignment element E in V,
// S is a tuple- like type (section 3.3.3) with a property named N of a type that is assignable to the target given in E,
// where N is the numeric index of E in the array assignment pattern, or
var [b0, b1, b2] = [2, 3, 4];
var [b3, b4, b5]: [number, number, string] = [1, 2, "string"];
function foo() {
return [1, 2, 3];
}
var [b6, b7] = foo();
var [...b8] = foo();
// S is not a tuple- like type and the numeric index signature type of S is assignable to the target given in E.
var temp = [1,2,3]
var [c0, c1] = [...temp];
var [c2] = [];
var [[[c3]], [[[[c4]]]]] = [[[]], [[[[]]]]]
var [[c5], c6]: [[string|number], boolean] = [[1], true];
var [, c7] = [1, 2, 3];
var [,,, c8] = [1, 2, 3, 4];
var [,,, c9] = [1, 2, 3, 4];
var [,,,...c10] = [1, 2, 3, 4, "hello"];
var [c11, c12, ...c13] = [1, 2, "string"];
var [c14, c15, c16] = [1, 2, "string"];