fix(xai): bridge the abort signal only after request construction

Review follow-up: mapToolChoice throws for malformed allowed_tools entries, and the abort bridge cleanup only covers the request that follows. The bridge now registers after the whole request body (including the tool-choice mapping) is built, so a construction failure cannot leave a listener on metadata.abortSignal. The malformed-entry test now passes an abortSignal and asserts addEventListener was never called. xai.spec.ts 49 passed; tsc clean.

Author: easonLiangWorldedtech

src/api/providers/__tests__/xai.spec.ts

@@ -397,8 +397,13 @@ describe("XAIHandler", () => {
 			{ type: "function", function: { name: 123 } },
 		]
 		for (const entry of malformedEntries) {
+			// The mapping throws during request construction; the abort bridge must not have
+			// registered a listener yet, or a malformed tool choice would leak it.
+			const abortController = new AbortController()
+			const addListenerSpy = vi.spyOn(abortController.signal, "addEventListener")
 			const stream = handler.createMessage("test prompt", [], {
 				taskId: "test-task-id",
+				abortSignal: abortController.signal,
 				tools: testTools,
 				tool_choice: {
 					type: "allowed_tools",
@@ -411,6 +416,8 @@ describe("XAIHandler", () => {
 			await expect(stream.next()).rejects.toThrow(
 				'allowed_tools entry of type "function" is missing a valid function name',
 			)
+			expect(addListenerSpy).not.toHaveBeenCalled()
+			addListenerSpy.mockRestore()
 		}
 		expect(mockResponsesCreate.mock.calls.length).toBe(callsBefore)
 	})

src/api/providers/xai.ts

@@ -159,15 +159,6 @@ export class XAIHandler extends BaseProvider implements SingleCompletionHandler
 		const toolChoice = metadata?.tool_choice
 		const parallelToolCalls = metadata?.parallelToolCalls
 
-		// Bridge the external abort signal from request metadata into a per-request
-		// controller so the SDK call is cancelled when the owning request is aborted
-		// (or when the signal is already aborted). Without an external signal the
-		// client-level timeout configured in the constructor remains the only
-		// cancellation mechanism, preserving the existing behavior.
-		const externalAbortSignal = metadata?.abortSignal
-		const { signal: abortSignal, dispose: removeExternalAbortListener } =
-			bridgeExternalAbortSignal(externalAbortSignal)
-
 		// Build request options
 		const requestBody: OpenAI.Responses.ResponseCreateParamsStreaming = {
 			model: model.id,
@@ -197,6 +188,14 @@ export class XAIHandler extends BaseProvider implements SingleCompletionHandler
 			requestBody.reasoning = { effort: model.reasoning.reasoning_effort }
 		}
 
+		// Bridge the external abort signal only after every throw-prone part of the request
+		// construction (notably mapToolChoice, which rejects malformed allowed_tools entries)
+		// has run: the bridge's cleanup covers the request below, not construction failures,
+		// so registering earlier would leak a listener on metadata.abortSignal.
+		const externalAbortSignal = metadata?.abortSignal
+		const { signal: abortSignal, dispose: removeExternalAbortListener } =
+			bridgeExternalAbortSignal(externalAbortSignal)
+
 		try {
 			let stream: AsyncIterable<any>
 			try {