fix(ai,agent,coding-agent): normalize null message content at ingestion boundaries (#6343)

The Message types require content to always be present, but untyped JS extension tools, hand-built histories, and old or hand-edited session files can violate that contract, crashing rendering, compaction, and provider request conversion with 'content is not iterable'. Normalize null/missing content to an empty array at the ingestion boundaries instead of guarding every consumer: - transformMessages (choke point before every provider request) - createToolResultMessage in the agent loop - session entry loading (message and custom_message entries) - extension custom messages (sendCustomMessage, before_agent_start) - message_end extension replacements fixes #6259, fixes #6276
2026-07-06 20:47:08 +02:00
parent 6efc09b7eb
commit 8c0ccd14b3
6 changed files with 264 additions and 7 deletions
@@ -0,0 +1,162 @@
+/**
+ * The Message types require `content` to always be present, but untyped JS
+ * extension tools, hand-built histories, and old or hand-edited session files
+ * can violate that contract. We are intentionally lax at the ingestion
+ * boundaries and normalize null/missing content to an empty array so it never
+ * reaches rendering, compaction, or provider request conversion
+ * (issues #6259, #6276).
+ */
+
+import type { AgentMessage, AgentToolResult } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { describe, expect, it } from "vitest";
+import { type SessionEntry, sessionEntryToContextMessages } from "../../src/core/session-manager.ts";
+import type { ExtensionFactory } from "../../src/index.ts";
+import { createHarness } from "./harness.ts";
+
+function messageEntry(message: Record<string, unknown>): SessionEntry {
+	return {
+		type: "message",
+		id: "entry-1",
+		parentId: null,
+		timestamp: new Date().toISOString(),
+		message,
+	} as unknown as SessionEntry;
+}
+
+describe("lax message content handling", () => {
+	it("normalizes tool results from untyped tools that omit content", async () => {
+		const extensionFactories: ExtensionFactory[] = [
+			(pi) => {
+				pi.registerTool({
+					name: "web_search",
+					label: "Web Search",
+					description: "Custom tool that returns a result without content",
+					parameters: Type.Object({}),
+					// Simulate an untyped JS extension tool that omits content.
+					execute: async () => ({ details: {} }) as unknown as AgentToolResult<unknown>,
+				});
+			},
+		];
+		const harness = await createHarness({ extensionFactories });
+
+		try {
+			harness.setResponses([
+				fauxAssistantMessage(fauxToolCall("web_search", {}), { stopReason: "toolUse" }),
+				fauxAssistantMessage("done"),
+			]);
+
+			await harness.session.prompt("search something");
+
+			const toolResults = harness.session.messages.filter((message) => message.role === "toolResult");
+			expect(toolResults).toHaveLength(1);
+			expect(toolResults[0].content).toEqual([]);
+			// The follow-up turn consumed the normalized tool result without crashing.
+			expect(harness.getPendingResponseCount()).toBe(0);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("normalizes null content in message_end extension replacements", async () => {
+		const extensionFactories: ExtensionFactory[] = [
+			(pi) => {
+				pi.on("message_end", async (event) => {
+					if (event.message.role !== "assistant") return undefined;
+					// Simulate an untyped JS extension replacing a message without content.
+					return { message: { ...event.message, content: null } as unknown as AgentMessage };
+				});
+			},
+		];
+		const harness = await createHarness({ extensionFactories });
+
+		try {
+			harness.setResponses([fauxAssistantMessage("hello")]);
+			await harness.session.prompt("hi");
+
+			const assistantMessages = harness.session.messages.filter((message) => message.role === "assistant");
+			expect(assistantMessages).toHaveLength(1);
+			expect(assistantMessages[0].content).toEqual([]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("normalizes null content in custom messages from extensions", async () => {
+		const harness = await createHarness();
+
+		try {
+			await harness.session.sendCustomMessage({
+				customType: "test",
+				content: null as unknown as string,
+				display: false,
+				details: undefined,
+			});
+
+			const customMessages = harness.session.messages.filter((message) => message.role === "custom");
+			expect(customMessages).toHaveLength(1);
+			expect(customMessages[0].content).toEqual([]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("normalizes null or missing content when loading session message entries", () => {
+		const badMessages = [
+			{ role: "user", content: null, timestamp: Date.now() },
+			{
+				role: "assistant",
+				content: null,
+				api: "openai-completions",
+				provider: "openai",
+				model: "test-model",
+				usage: {
+					input: 0,
+					output: 0,
+					cacheRead: 0,
+					cacheWrite: 0,
+					totalTokens: 0,
+					cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+				},
+				stopReason: "stop",
+				timestamp: Date.now(),
+			},
+			{
+				role: "toolResult",
+				toolCallId: "call_1",
+				toolName: "web_search",
+				isError: false,
+				timestamp: Date.now(),
+			},
+		];
+
+		for (const badMessage of badMessages) {
+			const [message] = sessionEntryToContextMessages(messageEntry(badMessage));
+			expect(message).toMatchObject({ role: badMessage.role, content: [] });
+		}
+	});
+
+	it("normalizes null content when loading custom message entries", () => {
+		const entry = {
+			type: "custom_message",
+			id: "entry-1",
+			parentId: null,
+			timestamp: new Date().toISOString(),
+			customType: "test",
+			content: null,
+			display: false,
+			details: undefined,
+		} as unknown as SessionEntry;
+
+		const [message] = sessionEntryToContextMessages(entry);
+		expect(message).toMatchObject({ role: "custom", content: [] });
+	});
+
+	it("keeps valid message content untouched when loading session entries", () => {
+		const [message] = sessionEntryToContextMessages(
+			messageEntry({ role: "user", content: "hello", timestamp: Date.now() }),
+		);
+		expect(message).toMatchObject({ role: "user", content: "hello" });
+	});
+});