fix(codex): handle lsp diagnostics failures

packages/omo-codex/plugin/components/lsp/src/codex-hook.ts

@@ -89,13 +89,29 @@ async function collectDiagnostics(
 			nextIndex += 1;
 			const filePath = filePaths[index];
 			if (filePath === undefined) return;
-			results[index] = { filePath, diagnostics: (await runDiagnostics(filePath)).trim() };
+			results[index] = { filePath, diagnostics: await collectFileDiagnostics(filePath, runDiagnostics) };
 		}
 	}
 	await Promise.all(Array.from({ length: workerCount }, () => worker()));
 	return results;
 }
 
+async function collectFileDiagnostics(filePath: string, runDiagnostics: DiagnosticsRunner): Promise<string> {
+	try {
+		return (await runDiagnostics(filePath)).trim();
+	} catch (error) {
+		return formatDiagnosticsError(error);
+	}
+}
+
+function formatDiagnosticsError(error: unknown): string {
+	if (error instanceof Error) {
+		const message = error.message.trim();
+		if (message.length > 0) return message;
+	}
+	return String(error).trim();
+}
+
 function formatDiagnosticBlock({ filePath, diagnostics }: DiagnosticBlock): string {
 	return `LSP diagnostics after editing ${filePath}:\n\n${formatDiagnosticsForDisplay(diagnostics)}`;
 }

packages/omo-codex/plugin/components/lsp/test/codex-hook-errors.test.ts

@@ -0,0 +1,55 @@
+import { describe, expect, it } from "vitest";
+
+import { runLspPostToolUseHook } from "../src/codex-hook.js";
+
+describe("codex PostToolUse diagnostics errors", () => {
+	it("#given diagnostics runner throws for a mutated file #when the hook evaluates diagnostics #then it returns blocked output with the thrown message", async () => {
+		// given
+		const output = await runLspPostToolUseHook(
+			{
+				tool_name: "write",
+				tool_input: { path: "src/missing.ts" },
+				tool_response: { ok: true },
+			},
+			async (filePath) => {
+				expect(filePath).toBe("src/missing.ts");
+				throw new Error("ENOENT: no such file or directory, open 'src/missing.ts'");
+			},
+		);
+
+		// when
+		const parsed: unknown = JSON.parse(output);
+		if (!isPostToolUseHookOutput(parsed)) throw new TypeError("Expected PostToolUse hook output");
+
+		// then
+		expect(parsed.reason).toBe(
+			"LSP diagnostics after editing src/missing.ts:\n\nENOENT: no such file or directory, open 'src/missing.ts'",
+		);
+		expect(parsed.hookSpecificOutput.additionalContext).toBe(parsed.reason);
+	});
+});
+
+interface PostToolUseHookOutput {
+	readonly decision: "block";
+	readonly reason: string;
+	readonly hookSpecificOutput: {
+		readonly hookEventName: "PostToolUse";
+		readonly additionalContext: string;
+	};
+}
+
+function isPostToolUseHookOutput(value: unknown): value is PostToolUseHookOutput {
+	if (!isRecord(value)) return false;
+	const hookSpecificOutput = value["hookSpecificOutput"];
+	return (
+		value["decision"] === "block" &&
+		typeof value["reason"] === "string" &&
+		isRecord(hookSpecificOutput) &&
+		hookSpecificOutput["hookEventName"] === "PostToolUse" &&
+		typeof hookSpecificOutput["additionalContext"] === "string"
+	);
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+	return typeof value === "object" && value !== null && !Array.isArray(value);
+}