Improve TruthConvert accuracy

jmurphyau · Sep 11, 2023 · f467900 · f467900
1 parent e7fe699
commit f467900
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 5 deletions.
diff --git a/packages/ember-truth-helpers/src/utils/truth-convert.ts b/packages/ember-truth-helpers/src/utils/truth-convert.ts
@@ -11,13 +11,11 @@ export type Falsy =
   | ''
   | never[];
 
-type ConvertTruthyObject<T> = T extends { isTruthy: infer U } ? U : T;
-
 // We check here in the order of the following function to maintain parity
 // Note that this will not handle EmberArray correctly.
 // We don't use Falsy since we want to be able to more definitively determine
 // truthy results.
-type _TruthConvert<T> = T extends { isTruthy: true }
+export type TruthConvert<T> = T extends { isTruthy: true }
   ? true
   : T extends { isTruthy: false }
   ? false
@@ -30,14 +28,20 @@ type _TruthConvert<T> = T extends { isTruthy: true }
   : T extends number
   ? T extends 0 | -0
     ? false
+    : number extends T
+    ? boolean
     : true
   : T extends bigint
   ? T extends 0n
     ? false
+    : bigint extends T
+    ? boolean
     : true
   : T extends string
   ? T extends ''
     ? false
+    : string extends T
+    ? boolean
     : true
   : T extends never[]
   ? false
@@ -46,7 +50,6 @@ type _TruthConvert<T> = T extends { isTruthy: true }
   : T extends object
   ? true
   : boolean;
-export type TruthConvert<T> = _TruthConvert<ConvertTruthyObject<T>>;
 
 export type MaybeTruthy =
   | { isTruthy: boolean }

diff --git a/packages/ember-truth-helpers/type-tests/utils/truth-convert.test.ts b/packages/ember-truth-helpers/type-tests/utils/truth-convert.test.ts
@@ -7,21 +7,27 @@ expectTypeOf<TruthConvert<undefined>>().toEqualTypeOf<false>();
 
 expectTypeOf<TruthConvert<true>>().toEqualTypeOf<true>();
 expectTypeOf<TruthConvert<false>>().toEqualTypeOf<false>();
+expectTypeOf<TruthConvert<boolean>>().toEqualTypeOf<boolean>();
 
 expectTypeOf<TruthConvert<0>>().toEqualTypeOf<false>();
 expectTypeOf<TruthConvert<-0>>().toEqualTypeOf<false>();
-expectTypeOf<TruthConvert<0n>>().toEqualTypeOf<false>();
 expectTypeOf<TruthConvert<1>>().toEqualTypeOf<true>();
+expectTypeOf<TruthConvert<number>>().toEqualTypeOf<boolean>();
+expectTypeOf<TruthConvert<0n>>().toEqualTypeOf<false>();
+expectTypeOf<TruthConvert<1n>>().toEqualTypeOf<true>();
+expectTypeOf<TruthConvert<bigint>>().toEqualTypeOf<boolean>();
 
 expectTypeOf<TruthConvert<''>>().toEqualTypeOf<false>();
 expectTypeOf<TruthConvert<'A String'>>().toEqualTypeOf<true>();
+expectTypeOf<TruthConvert<string>>().toEqualTypeOf<boolean>();
 
 expectTypeOf<TruthConvert<{ foo: 1; isTruthy: true }>>().toEqualTypeOf<true>();
 expectTypeOf<
   TruthConvert<{ foo: 1; isTruthy: false }>
 >().toEqualTypeOf<false>();
 // isTruthy isn't a boolean but we still have a real object so it's truthy
 expectTypeOf<TruthConvert<{ foo: 1; isTruthy: 1 }>>().toEqualTypeOf<true>();
+expectTypeOf<TruthConvert<{ isTruthy: boolean }>>().toEqualTypeOf<boolean>();
 
 expectTypeOf<TruthConvert<never[]>>().toEqualTypeOf<false>();
 expectTypeOf<TruthConvert<string[]>>().toEqualTypeOf<boolean>();
@@ -30,6 +36,9 @@ expectTypeOf<
   TruthConvert<never[] & { isTruthy: true }>
 >().toEqualTypeOf<true>();
 
+expectTypeOf<TruthConvert<1 | false>>().toEqualTypeOf<boolean>();
+expectTypeOf<TruthConvert<0 | false>>().toEqualTypeOf<false>();
+
 expectTypeOf(truthConvert(null)).toEqualTypeOf<false>();
 expectTypeOf(truthConvert(undefined)).toEqualTypeOf<false>();