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// @strictNullChecks: true
// @declaration: true
function f(addUndefined1 = "J", addUndefined2?: number) {
return addUndefined1.length + (addUndefined2 || 0);
}
function g(addUndefined = "J", addDefined: number) {
return addUndefined.length + addDefined;
}
let total = f() + f('a', 1) + f('b') + f(undefined, 2);
total = g('c', 3) + g(undefined, 4);
function foo1(x: string = "string", b: number) {
x.length;
}
function foo2(x = "string", b: number) {
x.length; // ok, should be string
}
function foo3(x: string | undefined = "string", b: number) {
x.length; // ok, should be string
x = undefined;
}
function foo4(x: string | undefined = undefined, b: number) {
x; // should be string | undefined
x = undefined;
}
type OptionalNullableString = string | null | undefined;
function allowsNull(val: OptionalNullableString = "") {
val = null;
val = 'string and null are both ok';
}
allowsNull(null); // still allows passing null
// .d.ts should have `string | undefined` for foo1, foo2, foo3 and foo4
foo1(undefined, 1);
foo2(undefined, 1);
foo3(undefined, 1);
foo4(undefined, 1);
function removeUndefinedButNotFalse(x = true) {
if (x === false) {
return x;
}
}
declare const cond: boolean;
function removeNothing(y = cond ? true : undefined) {
if (y !== undefined) {
if (y === false) {
return y;
}
}
return true;
}
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