🌿 Add test for calling method that fails internally

Author: lambdalisue

tests/denops/runtime/functions/denops/request_async_test.ts

@@ -115,6 +115,40 @@ testHost({
         );
       });
 
+      await t.step("if the dispatcher method throws an error", async (t) => {
+        await t.step("returns immediately", async () => {
+          await host.call("execute", [
+            "let g:__test_denops_events = []",
+            "call denops#request_async('dummy', 'fail', ['foo'], 'TestDenopsRequestAsyncSuccess', 'TestDenopsRequestAsyncFailure')",
+            "let g:__test_denops_events_after_called = g:__test_denops_events->copy()",
+          ], "");
+
+          assertEquals(
+            await host.call("eval", "g:__test_denops_events_after_called"),
+            [],
+          );
+        });
+
+        await t.step("calls failure callback", async () => {
+          await wait(() => host.call("eval", "len(g:__test_denops_events)"));
+          assertObjectMatch(
+            await host.call("eval", "g:__test_denops_events") as unknown[],
+            {
+              0: [
+                "TestDenopsRequestAsyncFailure:Called",
+                [
+                  {
+                    message:
+                      "Failed to call 'fail' API in 'dummy': Dummy failure",
+                    name: "Error",
+                  },
+                ],
+              ],
+            },
+          );
+        });
+      });
+
       await t.step("if the dispatcher method is not exist", async (t) => {
         await t.step("returns immediately", async () => {
           await host.call("execute", [

tests/denops/runtime/functions/denops/request_test.ts

@@ -66,6 +66,22 @@ testHost({
         assertEquals(result, { result: "OK", args: ["foo"] });
       });
 
+      await t.step("if the dispatcher method throws an error", async (t) => {
+        await t.step("throws an error", async () => {
+          await assertRejects(
+            () =>
+              host.call(
+                "denops#request",
+                "dummy",
+                "fail",
+                ["foo"],
+              ),
+            Error,
+            "Failed to call 'fail' API in 'dummy': Dummy failure",
+          );
+        });
+      });
+
       await t.step("if the dispatcher method is not exist", async (t) => {
         await t.step("throws an error", async () => {
           await assertRejects(

tests/denops/testdata/dummy_dispatcher_plugin.ts

@@ -14,5 +14,9 @@ export const main: Entrypoint = (denops) => {
       );
       return { result: "OK", args };
     },
+    fail: async () => {
+      await delay(MIMIC_DISPATCHER_METHOD_DELAY);
+      throw new Error("Dummy failure");
+    },
   };
 };