fix: After an API error, all subsequent calls fail with the same error (#420)

* fix: After an API error, all subsequent calls fail with the same error

* Format

* Refactored error handling in _sendPromise, replacing try/catch with .catch() to simplify the code.

* refactor: Move error handling inside promise chain

* test: Ensure generateContent errors do not persist across calls

Author: josejefferson

src/methods/chat-session.test.ts

@@ -46,6 +46,27 @@ describe("ChatSession", () => {
         match.any,
       );
     });
+    it("generateContent errors should not persist", async () => {
+      const generateContentStub = stub(
+        generateContentMethods,
+        "generateContent",
+      ).rejects("generateContent failed");
+      const chatSession = new ChatSession("MY_API_KEY", "a-model");
+      await expect(chatSession.sendMessage("hello")).to.be.rejected;
+      expect(generateContentStub).to.be.calledWith(
+        "MY_API_KEY",
+        "a-model",
+        match.any,
+      );
+      restore();
+
+      // Subsequent call should succeed.
+      const mockResponse = getMockResponse(
+        "unary-success-basic-reply-short.json",
+      );
+      stub(request, "makeModelRequest").resolves(mockResponse as Response);
+      await expect(chatSession.sendMessage("hello")).to.not.be.rejected;
+    });
   });
   describe("sendMessageRecitationErrorNotAddingResponseToHistory()", () => {
     it("generateContent errors should be catchable", async () => {

src/methods/chat-session.ts

@@ -126,6 +126,11 @@ export class ChatSession {
           }
         }
         finalResult = result;
+      })
+      .catch((e) => {
+        // Resets _sendPromise to avoid subsequent calls failing and throw error.
+        this._sendPromise = Promise.resolve();
+        throw e;
       });
     await this._sendPromise;
     return finalResult;