Fix @lroStatus not detecting default states correctly when using un…

…ion (#392)

.chronus/changes/fix-lro-autodetect-from-union-2024-2-8-22-32-28.md

@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: fix
+packages:
+  - "@azure-tools/typespec-azure-core"
+---
+
+Fix `@lroStatus` not detecting default states correctly when using union

packages/typespec-azure-core/src/decorators.ts

@@ -351,7 +351,12 @@ export function extractLroStates(
 
         return diagnostics.wrap(undefined);
       } else {
-        storeLroState(program, result, option.value, variant);
+        storeLroState(
+          program,
+          result,
+          typeof variant.name === "string" ? variant.name : option.value,
+          variant
+        );
       }
     }
   } else {

packages/typespec-azure-core/test/decorators.test.ts

@@ -497,6 +497,26 @@ describe("typespec-azure-core: decorators", () => {
         states: ["Donezo", "Borked", "Chucked", "HaveAnother"],
       });
     });
+
+    it("resolve default state from union variant name", async () => {
+      const { DefaultLroStates } = (await runner.compile(`
+        @test
+        @lroStatus
+        union DefaultLroStates {
+          Succeeded: "uSucceeded",
+          Failed: "uFailed",
+          Canceled: "uCancelled",
+          Extra: "uExtra",
+        }
+      `)) as { DefaultLroStates: Model };
+
+      deepStrictEqual(getLongRunningStates(runner.program, DefaultLroStates), {
+        succeededState: ["Succeeded"],
+        failedState: ["Failed"],
+        canceledState: ["Canceled"],
+        states: ["Succeeded", "Failed", "Canceled", "Extra"],
+      });
+    });
   });
 
   describe("@operationLink", () => {