fix: make run log creation atomic

src/main/database-base.ts

@@ -1,4 +1,4 @@
-import { mkdirSync } from "node:fs";
+import { mkdirSync, rmSync, writeFileSync } from "node:fs";
 import { join } from "node:path";
 import { DatabaseSync, type SQLInputValue } from "node:sqlite";
 import { buildThreadMethods } from "./database/threads";
@@ -38,6 +38,15 @@ function nowIso() {
   return new Date().toISOString();
 }
 
+function assertWritableDirectory(dir: string, label: string): void {
+  const probePath = join(dir, `.agentcompany-${label}-write-probe-${process.pid}-${Date.now()}`);
+  try {
+    writeFileSync(probePath, "", { encoding: "utf8", flag: "wx" });
+  } finally {
+    rmSync(probePath, { force: true });
+  }
+}
+
 export interface AppDatabaseCoreModules {
   threads: ReturnType<typeof buildThreadMethods>;
   company: ReturnType<typeof buildCompanyMethods>;
@@ -101,6 +110,7 @@ export class AppDatabaseBase {
     this.appVersion = options.appVersion ?? "unknown";
     mkdirSync(rootDir, { recursive: true });
     mkdirSync(this.logsDir, { recursive: true });
+    assertWritableDirectory(this.logsDir, "logs");
     mkdirSync(this.artifactsDir, { recursive: true });
     mkdirSync(this.backupsDir, { recursive: true });
     this.vault = new SecretVault(rootDir, { isPackaged: options.isPackaged });

src/main/database/runs.ts

@@ -1,5 +1,5 @@
 import { randomUUID } from "node:crypto";
-import { writeFileSync } from "node:fs";
+import { rmSync, writeFileSync } from "node:fs";
 import { join } from "node:path";
 import type { DatabaseSync, SQLInputValue } from "node:sqlite";
 import type { ConnectorId, RunRecord, RunUsageStatus } from "@shared/types";
@@ -24,6 +24,14 @@ export function buildRunMethods(
     logsDir: string;
   },
 ) {
+  function createEmptyRunLog(logPath: string): void {
+    writeFileSync(logPath, "", { encoding: "utf8", flag: "wx" });
+  }
+
+  function cleanupEmptyRunLog(logPath: string): void {
+    rmSync(logPath, { force: true });
+  }
+
   function insertRunRow(input: {
     id: string;
     companyId: string;
@@ -85,10 +93,15 @@ export function buildRunMethods(
       const id = input.id ?? randomUUID();
       const ts = nowIso();
       const logPath = join(deps.logsDir, `${id}.log`);
-      transaction(() => {
-        insertRunRow({ ...input, id, logPath, ts });
-      });
-      writeFileSync(logPath, "", "utf8");
+      createEmptyRunLog(logPath);
+      try {
+        transaction(() => {
+          insertRunRow({ ...input, id, logPath, ts });
+        });
+      } catch (error) {
+        cleanupEmptyRunLog(logPath);
+        throw error;
+      }
       return { id, logPath };
     },
 
@@ -103,6 +116,7 @@ export function buildRunMethods(
       const id = input.id ?? randomUUID();
       const ts = nowIso();
       const logPath = join(deps.logsDir, `${id}.log`);
+      createEmptyRunLog(logPath);
       try {
         transaction(() => {
           insertRunRow({ ...input, id, logPath, ts });
@@ -112,12 +126,12 @@ export function buildRunMethods(
           }
         });
       } catch (error) {
+        cleanupEmptyRunLog(logPath);
         if (error instanceof TaskCheckoutConflict) {
           return null;
         }
         throw error;
       }
-      writeFileSync(logPath, "", "utf8");
       return { id, logPath };
     },
 

tests/unit/run-log-atomicity.test.ts

@@ -0,0 +1,155 @@
+import { randomUUID } from "node:crypto";
+import { existsSync, mkdirSync } from "node:fs";
+import { mkdtemp, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("electron", () => ({
+  safeStorage: {
+    isEncryptionAvailable: () => false,
+    getSelectedStorageBackend: () => "basic_text",
+    encryptString: (value: string) => Buffer.from(value, "utf8"),
+    decryptString: (value: Buffer) => value.toString("utf8"),
+  },
+}));
+
+import { AppDatabase } from "../../src/main/database";
+
+type RawDb = {
+  db: {
+    prepare: (sql: string) => {
+      get: (...args: unknown[]) => unknown;
+    };
+  };
+};
+
+function createCompany(db: AppDatabase): string {
+  return db.core.company.saveCompany({
+    name: "Run Log Atomicity Co",
+    description: "Run log creation tests",
+    status: "active",
+  });
+}
+
+function createConnector(db: AppDatabase): void {
+  db.core.connectors.saveConnector({
+    id: "openai-codex",
+    model: "gpt-5",
+    envBindingText: "",
+    notes: "Test connector",
+  });
+}
+
+function createWorkspace(db: AppDatabase, companyId: string): string {
+  return db.core.workspaces.saveWorkspace({
+    companyId,
+    name: "Workspace",
+    localPath: "/tmp/run-log-atomicity",
+    repoUrl: "",
+    repoRef: "",
+    isPrimary: true,
+  });
+}
+
+function createAgent(db: AppDatabase, companyId: string, workspaceId: string): string {
+  return db.core.agents.saveAgent({
+    companyId,
+    name: "Agent",
+    role: "IC",
+    title: "Agent",
+    status: "active",
+    reportsTo: null,
+    connectorId: "openai-codex",
+    workspaceId,
+    model: null,
+    capabilities: "Executes tasks",
+    budgetMonthlyUsd: 100,
+  });
+}
+
+function createTask(db: AppDatabase, companyId: string, agentId: string | null, workspaceId: string): string {
+  return db.core.tasks.saveTask({
+    companyId,
+    title: "Task",
+    description: "A task",
+    assigneeAgentId: agentId,
+    workspaceId,
+    priority: "medium",
+    status: "todo",
+  });
+}
+
+describe("run log creation atomicity", () => {
+  let tempDir: string;
+  let db: AppDatabase;
+
+  beforeEach(async () => {
+    tempDir = await mkdtemp(join(tmpdir(), "agentcompany-run-log-"));
+    db = new AppDatabase(tempDir);
+    db.init();
+  });
+
+  afterEach(async () => {
+    db.close();
+    await rm(tempDir, { recursive: true, force: true });
+  });
+
+  it("createRun rejects before inserting the run row when the log path is unavailable", () => {
+    const companyId = createCompany(db);
+    createConnector(db);
+    const workspaceId = createWorkspace(db, companyId);
+    const agentId = createAgent(db, companyId, workspaceId);
+    const taskId = createTask(db, companyId, null, workspaceId);
+    const blockedRunId = randomUUID();
+    mkdirSync(join(db.logsDir, `${blockedRunId}.log`));
+
+    expect(() =>
+      db.core.runs.createRun({
+        id: blockedRunId,
+        companyId,
+        taskId,
+        agentId,
+        workspaceId,
+        connectorId: "openai-codex",
+      }),
+    ).toThrow();
+
+    const storedRun = (db as unknown as RawDb).db
+      .prepare("SELECT id FROM runs WHERE id = ?")
+      .get(blockedRunId);
+    expect(storedRun).toBeUndefined();
+    const task = db.core.entity.getTask(taskId);
+    expect(task.activeRunId).toBeNull();
+    expect(task.status).toBe("todo");
+  });
+
+  it("createTaskRun removes the empty log when checkout loses the race", () => {
+    const companyId = createCompany(db);
+    createConnector(db);
+    const workspaceId = createWorkspace(db, companyId);
+    const agentId = createAgent(db, companyId, workspaceId);
+    const taskId = createTask(db, companyId, null, workspaceId);
+    const firstRun = db.core.runs.createTaskRun({
+      companyId,
+      taskId,
+      agentId,
+      workspaceId,
+      connectorId: "openai-codex",
+    });
+    expect(firstRun).not.toBeNull();
+
+    const losingRunId = randomUUID();
+    const secondRun = db.core.runs.createTaskRun({
+      id: losingRunId,
+      companyId,
+      taskId,
+      agentId,
+      workspaceId,
+      connectorId: "openai-codex",
+    });
+
+    expect(secondRun).toBeNull();
+    expect(existsSync(join(db.logsDir, `${losingRunId}.log`))).toBe(false);
+  });
+});