[lit-html] Add test for sync AsyncDirective.setValue() call (#2128)

lit · Sep 2, 2021 · cc5c3a0 · cc5c3a0
1 parent 61fc945
commit cc5c3a0
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diff --git a/.changeset/twelve-squids-appear.md b/.changeset/twelve-squids-appear.md
@@ -0,0 +1,5 @@
+---
+'lit-html': patch
+---
+
+Add test for AsyncDirectives that synchronously call this.setValue()
diff --git a/packages/lit-html/src/test/lit-html_test.ts b/packages/lit-html/src/test/lit-html_test.ts
@@ -2176,6 +2176,7 @@ suite('lit-html', () => {
     }
     const aDirective = directive(ADirective);
     let aDirectiveInst: ADirective;
+
     const bDirective = directive(
       class extends Directive {
         count = 0;
@@ -2185,6 +2186,24 @@ suite('lit-html', () => {
       }
     );
 
+    const syncAsyncDirective = directive(
+      class extends AsyncDirective {
+        render(x: string) {
+          this.setValue(x);
+          return noChange;
+        }
+      }
+    );
+
+    test('async directive can call setValue synchronously', () => {
+      assertRender(
+        html`<div foo=${syncAsyncDirective('test')}>${syncAsyncDirective(
+          'test'
+        )}</div>`,
+        '<div foo="test">test</div>'
+      );
+    });
+
     test('async directives in ChildPart', async () => {
       const template = (promise: Promise<unknown>) =>
         html`<div>${aDirective(promise)}</div>`;