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More test cases and notes

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This commit is contained in:
Nathan Shively-Sanders 2016-12-13 11:10:12 -08:00
parent d62dd291bd
commit caad486a46
1 changed files with 28 additions and 0 deletions
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28
tests/cases/compiler/defaultParameterAddsUndefinedWithStrictNullChecks.ts
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@ -1,4 +1,5 @@
// @strictNullChecks: true
// @declaration: true
function f(addUndefined1 = "J", addUndefined2?: number) {
return addUndefined1.length + (addUndefined2 || 0);
}
@ -7,3 +8,30 @@ function g(addUndefined = "J", addDefined: number) {
}
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 | undefined = "string", b: number) {
x.length; // ok, should be narrowed to string
}
function foo3(x = "string", b: number) {
x.length; // ok, should be narrowed to string
}
function foo4(x: string | undefined, b: number) {
x.length; // error, Object is possibly 'undefined'
}
foo1(undefined, 1);
foo2(undefined, 1);
foo3(undefined, 1);
foo4(undefined, 1);
// all four functions should have `x: string| undefined` in their type
// .d.ts should have `T | undefined` for all of them
// foo2 to have x be initialized on the first line
// need to remove special-case code to allow calling foo1(undefined) for x: string = "string"