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

[josejefferson]

Fix #417

[Annhiluc]

Should we apply logic similar to https://github.com/google-gemini/generative-ai-js/pull/420/files#diff-250ed4bb03c096e3830327714961f4dbfde48df60b19c2918a2cdb4df06b6df1R203-R213?

As in, apply a .catch instead of a separate try/catch block here?

[josejefferson]

Do you mean something like this?

await this._sendPromise.catch((error) => {
  this._sendPromise = Promise.resolve();
  throw error;
});

[Annhiluc]

Yes something like that. Could you check to see if this also works?

.then((result) => {
  // ...
  finalResult = result;
})
.catch((e) => {
  // Resets _sendPromise to avoid subsequent calls failing and throw error.
  this._sendPromise = Promise.resolve();
  throw e;
});

[josejefferson]

Yes, it works! I've already made the change.

[Annhiluc]

Yes something like that. Could you check to see if this also works?

.then((result) => {
  // ...
  finalResult = result;
})
.catch((e) => {
  // Resets _sendPromise to avoid subsequent calls failing and throw error.
  this._sendPromise = Promise.resolve();
  throw e;
});

[Annhiluc]

Thank you for making the changes! Could you also help add a unit test for this case in src/methods/chat-session.test.ts?

Something like:

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,
      );

      // Subsequent call should succeed.
      const UpdatedGenerateContentStub = stub(
        generateContentMethods,
        "generateContent",
      );
      await expect(chatSession.sendMessage("hello")).to.not.be.rejected;
      expect(UpdatedGenerateContentStub).to.be.calledWith(
        "MY_API_KEY",
        "a-model",
        match.any,
      );
    });

[josejefferson]

Sure! I've added a unit test for this case in src/methods/chat-session.test.ts. Let me know if you need any adjustments or additional test cases. Thanks for your help!