original checker and new tests/result

Author: craigphicks

tests/cases/compiler/arrayFilterBooleanExternalOverload1.ts

@@ -0,0 +1,19 @@
+// @strict: true
+// @target: es6
+// @declaration: true
+
+// #56013
+
+// For reference, thise cases work as expected (no errors) when no external BooleanConstrudtor like overload is present
+declare const maybe: boolean;
+{
+    const id = <T>() => (t: T) => !!t;
+
+    const result1 = (maybe ? ['foo', 'bar', undefined] : [1] ).filter(id());
+
+    result1;
+
+    const result2 = ['foo', 'bar', undefined].filter(id()); // want id() = (t: string) => boolean
+
+    result2;
+}

tests/cases/compiler/arrayFilterBooleanExternalOverload2.ts

@@ -0,0 +1,31 @@
+// @strict: true
+// @target: es6
+// @declaration: true
+
+// #56013
+
+const symbool = Symbol("MyBooleanSymbol");
+declare const MyBoolean: typeof Boolean & { prototype: typeof symbool };
+interface Array<T> {
+    filter(predicate: typeof MyBoolean): (T extends (0 | 0n | "" | false | null | undefined) ? never : T)[];
+}
+
+declare const maybe: boolean;
+{
+    const id = <T>() => (t: T) => !!t;
+
+    const result1 = (maybe ? ['foo', 'bar', undefined] : [1] ).filter(id()); // error before and after fix (so ignore type)
+    // Errors before and after fix are different.
+    // The error in the #56013 fixed case is:
+    //                                                                ~~~~
+    // error TS2345: Argument of type '(t: unknown) => boolean' is not assignable to parameter of type 'BooleanConstructor & { prototype: unique symbol; }'.
+    // error TS2345:   Type '(t: unknown) => boolean' is not assignable to type 'BooleanConstructor'.
+    // error TS2345:     Type '(t: unknown) => boolean' provides no match for the signature 'new (value?: any): Boolean'.
+
+
+    result1;
+
+    const result2 = ['foo', 'bar', undefined].filter(id()); // want id() = (t: string) => boolean
+
+    result2;
+}

tests/cases/compiler/arrayFilterBooleanExternalOverload3.ts

@@ -0,0 +1,24 @@
+// @strict: true
+// @target: es6
+// @declaration: true
+
+// #56013
+
+const symbool = Symbol("MyBooleanSymbol");
+declare const MyBoolean: typeof Boolean & { prototype: typeof symbool };
+interface Array<T> {
+    filter(predicate: typeof MyBoolean): (T extends (0 | 0n | "" | false | null | undefined) ? never : T)[];
+}
+
+declare const maybe: boolean;
+{
+    const id = <T,>() => (t: T) => !!t;
+
+    const result1 = (maybe ? ['foo', 'bar', undefined] : [1] ).filter(MyBoolean);
+
+    result1;
+
+    const result2 = ['foo', 'bar', undefined].filter(MyBoolean); // want id() = (t: string) => boolean
+
+    result2;
+}

tests/cases/compiler/arrayFilterBooleanExternalOverload4.ts

@@ -0,0 +1,27 @@
+// @strict: true
+// @target: es6
+// @declaration: true
+
+// #56013
+
+interface F2<T extends number,U extends number> {
+    (p1:(t:1)=>T,p2:(u:1)=>U):11;
+    (p1:(t:1)=>T,p2:(u:U)=>U):19;
+    (p1:(t:T)=>T,p2:(u:1)=>U):91;
+    (p1:(t:T)=>T,p2:(u:U)=>U):99;
+}
+type ID = <I>() => (i:I) => I;
+
+declare const id: ID;
+
+
+const t11 = (0 as any as F2<1,1>)(id(),id());
+const t12 = (0 as any as F2<1,2>)(id(),id());
+const t21 = (0 as any as F2<2,1>)(id(),id());
+const t22 = (0 as any as F2<2,2>)(id(),id());
+
+t11 satisfies 11;
+t12 satisfies 19;
+t21 satisfies 91;
+t22 satisfies 99;
+