Merge pull request #199 from wagenet/fix-or

Fix types for `{{or}}` helper with fallback argument
jmurphyau · Sep 7, 2023 · aa85aaa · aa85aaa
2 parents dac1476 + 2e3377d
commit aa85aaa
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Showing 5 changed files with 13 additions and 1 deletion.
diff --git a/packages/ember-truth-helpers/src/helpers/or.ts b/packages/ember-truth-helpers/src/helpers/or.ts
@@ -11,7 +11,7 @@ type FirstTruthy<T> = T extends [infer Item]
     ? Head
     : TruthConvert<Head> extends false
     ? FirstTruthy<Tail>
-    : Head | FirstTruthy<Tail>
+    : NonNullable<Head> | FirstTruthy<Tail>
   : undefined;
 
 interface OrSignature<T extends MaybeTruthy[]> {

diff --git a/packages/ember-truth-helpers/type-tests/helpers/or.test.ts b/packages/ember-truth-helpers/type-tests/helpers/or.test.ts
@@ -26,3 +26,6 @@ expectTypeOf(computeOr({ isTruthy: false }, 1)).toEqualTypeOf<1>();
 
 const foo: { isTruthy: true } = { isTruthy: true };
 expectTypeOf(computeOr(foo, 1)).toEqualTypeOf(foo);
+
+let maybeString: string | undefined;
+expectTypeOf(computeOr(maybeString, 'foo')).toEqualTypeOf<string>();
diff --git a/packages/modern-test-app/app/components/and-or-type-checking.ts b/packages/modern-test-app/app/components/and-or-type-checking.ts
@@ -8,6 +8,7 @@ interface Signature {
     andArg3: true;
     andArg4: { isTruthy: true };
     orArg: object;
+    stringArg: string;
   };
 }
 

diff --git a/...modern-test-app/app/templates/helpers.hbs → ...odern-test-app/app/components/helpers.hbs b/...modern-test-app/app/templates/helpers.hbs → ...odern-test-app/app/components/helpers.hbs
@@ -17,4 +17,5 @@
   @andArg3={{and true true}}
   @andArg4={{and 1 (hash isTruthy=true)}}
   @orArg={{or (hash) (array)}}
+  @stringArg={{or this.maybeString "string"}}
 />
diff --git a/packages/modern-test-app/app/components/helpers.ts b/packages/modern-test-app/app/components/helpers.ts
@@ -0,0 +1,7 @@
+import Component from '@glimmer/component';
+
+export default class extends Component {
+  get maybeString(): string | undefined {
+    return Date.now() === 0 ? 'now has gone' : undefined;
+  }
+}