Method flushPendingToolResultsToHistory

src/core/task/Task.ts:935–997

* Flush any pending tool results to the API conversation history. * * This is critical when the task is about to be * delegated (e.g., via new_task). Before delegation, if other tools were * called in the same turn before new_task, their tool_result blocks are * accumulated in `userMessage

()

	 * So we usually only need to flush the pending user message with tool_results.
	 */
	public async flushPendingToolResultsToHistory(): Promise<boolean> {
		// Only flush if there's actually pending content to save
		if (this.userMessageContent.length === 0) {
			return true
		}

		// CRITICAL: Wait for the assistant message to be saved to API history first.
		// Without this, tool_result blocks would appear BEFORE tool_use blocks in the
		// conversation history, causing API errors like:
		// "unexpected `tool_use_id` found in `tool_result` blocks"
		//
		// This can happen when parallel tools are called (e.g., update_todo_list + new_task).
		// Tools execute during streaming via presentAssistantMessage, BEFORE the assistant
		// message is saved. When new_task triggers delegation, it calls this method to
		// flush pending results - but the assistant message hasn't been saved yet.
		//
		// The assistantMessageSavedToHistory flag is:
		// - Reset to false at the start of each API request
		// - Set to true after the assistant message is saved in recursivelyMakeClineRequests
		if (!this.assistantMessageSavedToHistory) {
			await pWaitFor(() => this.assistantMessageSavedToHistory || this.abort, {
				interval: 50,
				timeout: 30_000, // 30 second timeout as safety net
			}).catch(() => {
				// If timeout or abort, log and proceed anyway to avoid hanging
				console.warn(
					`[Task#${this.taskId}] flushPendingToolResultsToHistory: timed out waiting for assistant message to be saved`,
				)
			})
		}

		// If task was aborted while waiting, don't flush
		if (this.abort) {
			return false
		}

		// Save the user message with tool_result blocks
		const userMessage: Anthropic.MessageParam = {
			role: "user",
			content: this.userMessageContent,
		}

		// Validate and fix tool_result IDs when the previous *effective* message is an assistant message.
		const effectiveHistoryForValidation = getEffectiveApiHistory(this.apiConversationHistory)
		const lastEffective = effectiveHistoryForValidation[effectiveHistoryForValidation.length - 1]
		const historyForValidation = lastEffective?.role === "assistant" ? effectiveHistoryForValidation : []
		const validatedMessage = validateAndFixToolResultIds(userMessage, historyForValidation)
		const userMessageWithTs = { ...validatedMessage, ts: Date.now() }
		this.apiConversationHistory.push(userMessageWithTs as ApiMessage)

		const saved = await this.saveApiConversationHistory()

		if (saved) {
			// Clear the pending content since it's now saved
			this.userMessageContent = []
		} else {
			console.warn(
				`[Task#${this.taskId}] flushPendingToolResultsToHistory: save failed, retaining pending tool results in memory`,