test(interactive): cover MCP tool output ordering in chat controller

packages/pi-coding-agent/src/core/chat-controller-ordering.test.ts

@@ -0,0 +1,152 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+
+import { handleAgentEvent } from "../modes/interactive/controllers/chat-controller.js";
+
+function makeUsage() {
+	return {
+		input: 0,
+		output: 0,
+		cacheRead: 0,
+		cacheWrite: 0,
+		totalTokens: 0,
+		cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+	};
+}
+
+function makeAssistant(content: any[]) {
+	return {
+		role: "assistant",
+		content,
+		api: "anthropic-messages",
+		provider: "claude-code",
+		model: "claude-sonnet-4",
+		usage: makeUsage(),
+		stopReason: "stop",
+		timestamp: Date.now(),
+	};
+}
+
+function createHost() {
+	const chatContainer = {
+		children: [] as any[],
+		addChild(component: any) {
+			this.children.push(component);
+		},
+		removeChild(component: any) {
+			const idx = this.children.indexOf(component);
+			if (idx !== -1) this.children.splice(idx, 1);
+		},
+		clear() {
+			this.children = [];
+		},
+	};
+
+	const host: any = {
+		isInitialized: true,
+		init: async () => {},
+		defaultEditor: { onEscape: undefined },
+		editor: {},
+		session: { retryAttempt: 0, abortCompaction: () => {}, abortRetry: () => {} },
+		ui: { requestRender: () => {} },
+		footer: { invalidate: () => {} },
+		keybindings: {},
+		statusContainer: { clear: () => {}, addChild: () => {} },
+		chatContainer,
+		settingsManager: { getTimestampFormat: () => "date-time-iso", getShowImages: () => false },
+		pendingTools: new Map(),
+		toolOutputExpanded: false,
+		hideThinkingBlock: false,
+		isBashMode: false,
+		defaultWorkingMessage: "Working...",
+		compactionQueuedMessages: [],
+		editorContainer: {},
+		pendingMessagesContainer: { clear: () => {} },
+		addMessageToChat: () => {},
+		getMarkdownThemeWithSettings: () => ({}),
+		formatWebSearchResult: () => "",
+		getRegisteredToolDefinition: () => undefined,
+		checkShutdownRequested: async () => {},
+		rebuildChatFromMessages: () => {},
+		flushCompactionQueue: async () => {},
+		showStatus: () => {},
+		showError: () => {},
+		updatePendingMessagesDisplay: () => {},
+		updateTerminalTitle: () => {},
+		updateEditorBorderColor: () => {},
+	};
+
+	return host;
+}
+
+test("chat-controller keeps tool output ahead of delayed assistant text for external tool streams", async () => {
+	// ToolExecutionComponent uses the global theme singleton.
+	// Install a minimal no-op theme implementation for this unit test.
+	(globalThis as any)[Symbol.for("@gsd/pi-coding-agent:theme")] = {
+		fg: (_key: string, text: string) => text,
+		bg: (_key: string, text: string) => text,
+		bold: (text: string) => text,
+		italic: (text: string) => text,
+		truncate: (text: string) => text,
+	};
+
+	const host = createHost();
+	const toolId = "mcp-tool-1";
+	const toolCall = {
+		type: "toolCall",
+		id: toolId,
+		name: "exec_command",
+		arguments: { cmd: "echo hi" },
+	};
+
+	await handleAgentEvent(host, { type: "message_start", message: makeAssistant([]) } as any);
+
+	assert.equal(host.streamingComponent, undefined, "assistant component should be deferred at message_start");
+	assert.equal(host.chatContainer.children.length, 0, "nothing should render before content arrives");
+
+	await handleAgentEvent(
+		host,
+		{
+			type: "message_update",
+			message: makeAssistant([toolCall]),
+			assistantMessageEvent: {
+				type: "toolcall_end",
+				contentIndex: 0,
+				toolCall: {
+					...toolCall,
+					externalResult: {
+						content: [{ type: "text", text: "tool output" }],
+						details: {},
+						isError: false,
+					},
+				},
+				partial: makeAssistant([toolCall]),
+			},
+		} as any,
+	);
+
+	assert.equal(host.streamingComponent, undefined, "assistant text container should remain deferred for tool-only updates");
+	assert.equal(host.chatContainer.children.length, 1, "tool execution block should render immediately");
+	assert.equal(host.chatContainer.children[0]?.constructor?.name, "ToolExecutionComponent");
+
+	// Re-assert required host method before the text-bearing update path.
+	host.getMarkdownThemeWithSettings = () => ({});
+
+	await handleAgentEvent(
+		host,
+		{
+			type: "message_update",
+			message: makeAssistant([toolCall, { type: "text", text: "done" }]),
+			assistantMessageEvent: {
+				type: "text_delta",
+				contentIndex: 1,
+				delta: "done",
+				partial: makeAssistant([toolCall, { type: "text", text: "done" }]),
+			},
+		} as any,
+	);
+
+	assert.equal(host.chatContainer.children.length, 2, "assistant content should render after existing tool output");
+	assert.equal(host.chatContainer.children[0]?.constructor?.name, "ToolExecutionComponent");
+	assert.equal(host.chatContainer.children[1]?.constructor?.name, "AssistantMessageComponent");
+});