More tests of initialised parameters adding undefined

Author: sandersn

tests/baselines/reference/defaultParameterAddsUndefinedWithStrictNullChecks.js

@@ -1,9 +1,68 @@
 //// [defaultParameterAddsUndefinedWithStrictNullChecks.ts]
 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 | 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
+}
+
+foo1(undefined, 1);
+foo2(undefined, 1);
+foo3(undefined, 1);
+
+
+// .d.ts should have `T | undefined` for all of them
+// need to remove special-case code to allow calling foo1(undefined) for x: string = "string"
 
 
 //// [defaultParameterAddsUndefinedWithStrictNullChecks.js]
 function f(addUndefined1, addUndefined2) {
     if (addUndefined1 === void 0) { addUndefined1 = "J"; }
+    return addUndefined1.length + (addUndefined2 || 0);
+}
+function g(addUndefined, addDefined) {
+    if (addUndefined === void 0) { addUndefined = "J"; }
+    return addUndefined.length + addDefined;
 }
+var total = f() + f('a', 1) + f('b') + f(undefined, 2);
+total = g('c', 3) + g(undefined, 4);
+function foo1(x, b) {
+    if (x === void 0) { x = "string"; }
+    x.length;
+}
+function foo2(x, b) {
+    if (x === void 0) { x = "string"; }
+    x.length; // ok, should be narrowed to string
+}
+function foo3(x, b) {
+    if (x === void 0) { x = "string"; }
+    x.length; // ok, should be narrowed to string
+}
+foo1(undefined, 1);
+foo2(undefined, 1);
+foo3(undefined, 1);
+// .d.ts should have `T | undefined` for all of them
+// need to remove special-case code to allow calling foo1(undefined) for x: string = "string"
+
+
+//// [defaultParameterAddsUndefinedWithStrictNullChecks.d.ts]
+declare function f(addUndefined1?: string | undefined, addUndefined2?: number): number;
+declare function g(addUndefined: string | undefined, addDefined: number): number;
+declare let total: number;
+declare function foo1(x: string | undefined, b: number): void;
+declare function foo2(x: string | undefined, b: number): void;
+declare function foo3(x: string | undefined, b: number): void;

tests/baselines/reference/destructureOptionalParameter.types

@@ -8,7 +8,7 @@ declare function f1({ a, b }?: { a: number, b: string }): void;
 >b : string
 
 function f2({ a, b }: { a: number, b: number } = { a: 0, b: 0 }) {
->f2 : ({a, b}?: { a: number; b: number; }) => void
+>f2 : ({a, b}?: { a: number; b: number; } | undefined) => void
 >a : number
 >b : number
 >a : number

tests/cases/compiler/defaultParameterAddsUndefinedWithStrictNullChecks.ts

@@ -26,5 +26,4 @@ foo2(undefined, 1);
 foo3(undefined, 1);
 
 
-// .d.ts should have `T | undefined` for all of them
-// need to remove special-case code to allow calling foo1(undefined) for x: string = "string"
+// .d.ts should have `T | undefined` for foo1, foo2, foo3