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//// [typeAssertions.ts]
// Function call whose argument is a 1 arg generic function call with explicit type arguments
function fn1<T>(t: T) { }
function fn2(t: any) { }
fn1(fn2<string>(4)); // Error
var a: any;
var s: string;
// Type assertion of non - unary expression
var a = <any>"" + 4;
var s = "" + <any>4;
class SomeBase {
private p;
}
class SomeDerived extends SomeBase {
private x;
}
class SomeOther {
private q;
}
// Type assertion should check for assignability in either direction
var someBase = new SomeBase();
var someDerived = new SomeDerived();
var someOther = new SomeOther();
someBase = <SomeBase>someDerived;
someBase = <SomeBase>someBase;
someBase = <SomeBase>someOther; // Error
someDerived = <SomeDerived>someDerived;
someDerived = <SomeDerived>someBase;
someDerived = <SomeDerived>someOther; // Error
someOther = <SomeOther>someDerived; // Error
someOther = <SomeOther>someBase; // Error
someOther = <SomeOther>someOther;
// Type assertion cannot be a type-predicate type
var numOrStr: number | string;
var str: string;
if(<numOrStr is string>(numOrStr === undefined)) { // Error
str = numOrStr; // Error, no narrowing occurred
}
if((numOrStr === undefined) as numOrStr is string) { // Error
}
//// [typeAssertions.js]
var __extends = (this && this.__extends) || (function () {
var extendStatics = function (d, b) {
extendStatics = Object.setPrototypeOf ||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
return extendStatics(d, b);
};
return function (d, b) {
extendStatics(d, b);
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
})();
// Function call whose argument is a 1 arg generic function call with explicit type arguments
function fn1(t) { }
function fn2(t) { }
fn1(fn2(4)); // Error
var a;
var s;
// Type assertion of non - unary expression
var a = "" + 4;
var s = "" + 4;
var SomeBase = /** @class */ (function () {
function SomeBase() {
}
return SomeBase;
}());
var SomeDerived = /** @class */ (function (_super) {
__extends(SomeDerived, _super);
function SomeDerived() {
return _super !== null && _super.apply(this, arguments) || this;
}
return SomeDerived;
}(SomeBase));
var SomeOther = /** @class */ (function () {
function SomeOther() {
}
return SomeOther;
}());
// Type assertion should check for assignability in either direction
var someBase = new SomeBase();
var someDerived = new SomeDerived();
var someOther = new SomeOther();
someBase = someDerived;
someBase = someBase;
someBase = someOther; // Error
someDerived = someDerived;
someDerived = someBase;
someDerived = someOther; // Error
someOther = someDerived; // Error
someOther = someBase; // Error
someOther = someOther;
// Type assertion cannot be a type-predicate type
var numOrStr;
var str;
if (is)
string > (numOrStr === undefined);
{ // Error
str = numOrStr; // Error, no narrowing occurred
}
if ((numOrStr === undefined))
is;
string;
{ // Error
}
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