fix(coding-agent): report settings diagnostic paths

packages/coding-agent/src/core/settings-diagnostics.ts

@@ -0,0 +1,25 @@
+import type { AgentSessionRuntimeDiagnostic } from "./agent-session-services.ts";
+import type { SettingsManager } from "./settings-manager.ts";
+
+export function collectSettingsDiagnostics(settingsManager: SettingsManager): AgentSessionRuntimeDiagnostic[] {
+	return settingsManager.drainErrors().map(({ scope, path, error }) => ({
+		type: "warning",
+		message: path ? `Invalid settings file ${path}: ${error.message}` : `Invalid ${scope} settings: ${error.message}`,
+	}));
+}
+
+/**
+ * Remove duplicate type/message diagnostics while preserving their first occurrence.
+ * Startup and runtime settings managers can report the same file error.
+ */
+export function deduplicateDiagnostics(
+	diagnostics: readonly AgentSessionRuntimeDiagnostic[],
+): AgentSessionRuntimeDiagnostic[] {
+	const seen = new Set<string>();
+	return diagnostics.filter((diagnostic) => {
+		const key = `${diagnostic.type}\0${diagnostic.message}`;
+		if (seen.has(key)) return false;
+		seen.add(key);
+		return true;
+	});
+}

packages/coding-agent/src/main.ts

@@ -56,6 +56,7 @@ import {
 	type SessionCwdIssue,
 } from "./core/session-cwd.ts";
 import { assertValidSessionId, SessionManager } from "./core/session-manager.ts";
+import { collectSettingsDiagnostics } from "./core/settings-diagnostics.ts";
 import { SettingsManager } from "./core/settings-manager.ts";
 import { printTimings, resetTimings, time } from "./core/timings.ts";
 import { hasTrustRequiringProjectResources, ProjectTrustStore } from "./core/trust-manager.ts";
@@ -92,16 +93,6 @@ async function readPipedStdin(): Promise<string | undefined> {
 	});
 }
 
-function collectSettingsDiagnostics(
-	settingsManager: SettingsManager,
-	context: string,
-): AgentSessionRuntimeDiagnostic[] {
-	return settingsManager.drainErrors().map(({ scope, error }) => ({
-		type: "warning",
-		message: `(${context}, ${scope} settings) ${error.message}`,
-	}));
-}
-
 function reportDiagnostics(diagnostics: readonly AgentSessionRuntimeDiagnostic[]): void {
 	for (const diagnostic of diagnostics) {
 		const color = diagnostic.type === "error" ? chalk.red : diagnostic.type === "warning" ? chalk.yellow : chalk.dim;
@@ -656,7 +647,7 @@ export async function main(args: string[], options?: MainOptions) {
 	time("runMigrations");
 
 	const startupSettingsManager = SettingsManager.create(cwd, agentDir);
-	reportDiagnostics(collectSettingsDiagnostics(startupSettingsManager, "startup session lookup"));
+	reportDiagnostics(collectSettingsDiagnostics(startupSettingsManager));
 
 	// Experimental first-time setup: theme choice and analytics opt-in.
 	// Runs before any runtime services are created so the chosen settings apply everywhere.
@@ -784,7 +775,7 @@ export async function main(args: string[], options?: MainOptions) {
 		const diagnostics: AgentSessionRuntimeDiagnostic[] = [
 			...projectTrustDiagnostics,
 			...services.diagnostics,
-			...collectSettingsDiagnostics(settingsManager, "runtime creation"),
+			...collectSettingsDiagnostics(settingsManager),
 			...resourceLoader.getExtensions().errors.map(({ path, error }) => ({
 				type: "error" as const,
 				message: `Failed to load extension "${path}": ${error}`,

packages/coding-agent/test/settings-diagnostics.test.ts

@@ -0,0 +1,47 @@
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { describe, expect, it } from "vitest";
+import { collectSettingsDiagnostics, deduplicateDiagnostics } from "../src/core/settings-diagnostics.ts";
+import { SettingsManager, type SettingsStorage } from "../src/core/settings-manager.ts";
+
+describe("settings diagnostics", () => {
+	it("includes the settings file path for file-backed storage", () => {
+		const tempDir = mkdtempSync(join(tmpdir(), "pi-settings-diagnostics-"));
+		const agentDir = join(tempDir, "agent");
+		const settingsPath = join(agentDir, "settings.json");
+		mkdirSync(agentDir);
+		writeFileSync(settingsPath, "{");
+
+		try {
+			const diagnostics = collectSettingsDiagnostics(SettingsManager.create(tempDir, agentDir));
+
+			expect(diagnostics).toHaveLength(1);
+			expect(diagnostics[0]?.type).toBe("warning");
+			expect(diagnostics[0]?.message).toContain(`Invalid settings file ${settingsPath}:`);
+		} finally {
+			rmSync(tempDir, { recursive: true, force: true });
+		}
+	});
+
+	it("falls back to the settings scope for storage without file paths", () => {
+		const storage: SettingsStorage = {
+			withLock(scope, fn) {
+				if (scope === "global") throw new Error("backend failed");
+				fn(undefined);
+			},
+		};
+		const diagnostics = collectSettingsDiagnostics(SettingsManager.fromStorage(storage));
+
+		expect(diagnostics).toEqual([{ type: "warning", message: "Invalid global settings: backend failed" }]);
+	});
+
+	it("deduplicates diagnostics by type and message", () => {
+		const warning = { type: "warning" as const, message: "Invalid settings file /tmp/settings.json" };
+
+		expect(deduplicateDiagnostics([warning, warning, { ...warning, type: "error" }])).toEqual([
+			warning,
+			{ ...warning, type: "error" },
+		]);
+	});
+});