From 31e45dcfecfb14bfac680c4a5f32bed48d470e9b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20Flor=C3=AAncio?= <carlosmflorencio@gmail.com>
Date: Mon, 20 Apr 2026 22:49:26 +0100
Subject: [PATCH] fix(cli): default dev mode db to <repo>/.kandev-dev/data
 (#664)

---
 apps/cli/src/dev.test.ts | 64 ++++++++++++++++++++++++++++++++++++++++
 apps/cli/src/dev.ts      | 42 ++++++++++++++++----------
 2 files changed, 91 insertions(+), 15 deletions(-)
 create mode 100644 apps/cli/src/dev.test.ts

diff --git a/apps/cli/src/dev.test.ts b/apps/cli/src/dev.test.ts
new file mode 100644
index 0000000000..544965c7f3
--- /dev/null
+++ b/apps/cli/src/dev.test.ts
@@ -0,0 +1,64 @@
+import path from "node:path";
+
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { resolveDevBackendEnv } from "./dev";
+
+describe("resolveDevBackendEnv", () => {
+  const originalTaskId = process.env.KANDEV_TASK_ID;
+  const originalDbPath = process.env.KANDEV_DATABASE_PATH;
+  const originalMock = process.env.KANDEV_MOCK_AGENT;
+
+  beforeEach(() => {
+    delete process.env.KANDEV_TASK_ID;
+    delete process.env.KANDEV_DATABASE_PATH;
+    delete process.env.KANDEV_MOCK_AGENT;
+    vi.spyOn(console, "log").mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    restoreEnv("KANDEV_TASK_ID", originalTaskId);
+    restoreEnv("KANDEV_DATABASE_PATH", originalDbPath);
+    restoreEnv("KANDEV_MOCK_AGENT", originalMock);
+    vi.restoreAllMocks();
+  });
+
+  it("defaults to <repo>/.kandev-dev/data/kandev.db in a plain shell", () => {
+    const repoRoot = "/tmp/repo";
+    const { dbPath, extra } = resolveDevBackendEnv(repoRoot);
+
+    expect(dbPath).toBe(path.join(repoRoot, ".kandev-dev", "data", "kandev.db"));
+    expect(extra.KANDEV_HOME_DIR).toBe(path.join(repoRoot, ".kandev-dev"));
+    expect(extra.KANDEV_DATABASE_PATH).toBe("");
+  });
+
+  it("honors an explicit KANDEV_DATABASE_PATH override in a plain shell", () => {
+    process.env.KANDEV_DATABASE_PATH = "/tmp/custom.db";
+
+    const { dbPath, extra } = resolveDevBackendEnv("/tmp/repo");
+
+    expect(dbPath).toBe("/tmp/custom.db");
+    expect(extra.KANDEV_DATABASE_PATH).toBe("/tmp/custom.db");
+    expect(extra.KANDEV_HOME_DIR).toBeUndefined();
+  });
+
+  it("ignores a leaked KANDEV_DATABASE_PATH when running inside a kandev task", () => {
+    process.env.KANDEV_TASK_ID = "fake-task-id";
+    process.env.KANDEV_DATABASE_PATH = "/parent/kandev.db";
+    const repoRoot = "/tmp/repo";
+
+    const { dbPath, extra } = resolveDevBackendEnv(repoRoot);
+
+    expect(dbPath).toBe(path.join(repoRoot, ".kandev-dev", "data", "kandev.db"));
+    expect(extra.KANDEV_HOME_DIR).toBe(path.join(repoRoot, ".kandev-dev"));
+    expect(extra.KANDEV_DATABASE_PATH).toBe("");
+  });
+});
+
+function restoreEnv(name: string, value: string | undefined): void {
+  if (value === undefined) {
+    delete process.env[name];
+  } else {
+    process.env[name] = value;
+  }
+}
diff --git a/apps/cli/src/dev.ts b/apps/cli/src/dev.ts
index 6f4fb3bf0f..0c39039e5b 100644
--- a/apps/cli/src/dev.ts
+++ b/apps/cli/src/dev.ts
@@ -72,25 +72,28 @@ type DevBackendEnv = {
   extra: Record<string, string>;
 };
 
-// Computes the dev-mode backend env. When invoked from inside a kandev task
-// workspace, force-relocates the entire kandev root to <repo>/.kandev-dev so
-// dev state is isolated from the user's production ~/.kandev. In a normal
-// shell, preserves the existing override-friendly behavior (honor an
-// explicit KANDEV_DATABASE_PATH, otherwise default to a repo-local db).
-function resolveDevBackendEnv(repoRoot: string): DevBackendEnv {
+// Computes the dev-mode backend env. Dev mode always roots kandev under
+// <repo>/.kandev-dev so state is isolated from the user's production ~/.kandev
+// and so `make clean-db` (which removes .kandev-dev/) matches what `make dev`
+// writes.
+//
+// When invoked from inside a kandev task workspace, any KANDEV_DATABASE_PATH
+// is assumed to be leaked from the parent backend and is ignored. In a normal
+// shell, an explicit KANDEV_DATABASE_PATH is honored as an escape hatch.
+export function resolveDevBackendEnv(repoRoot: string): DevBackendEnv {
   const baseExtra: Record<string, string> = {
     KANDEV_MOCK_AGENT: process.env.KANDEV_MOCK_AGENT || "true",
     KANDEV_DEBUG_PPROF_ENABLED: "true",
   };
+  const devHome = devKandevHome(repoRoot);
+  // Display only; the backend derives its own DB path from KANDEV_HOME_DIR
+  // via ResolvedDataDir(). Both resolve to the same location.
+  const devDbPath = path.join(devHome, "data", "kandev.db");
 
   if (isInsideKandevTask(repoRoot)) {
-    const devHome = devKandevHome(repoRoot);
-    // Display only; the backend derives its own DB path from KANDEV_HOME_DIR
-    // via ResolvedDataDir(). Both resolve to the same location.
-    const dbPath = path.join(devHome, "data", "kandev.db");
     console.log("[kandev] task workspace detected → using local dev state");
     return {
-      dbPath,
+      dbPath: devDbPath,
       extra: {
         ...baseExtra,
         KANDEV_HOME_DIR: devHome,
@@ -100,10 +103,19 @@ function resolveDevBackendEnv(repoRoot: string): DevBackendEnv {
     };
   }
 
-  const dbPath =
-    process.env.KANDEV_DATABASE_PATH || path.join(repoRoot, "apps", "backend", "kandev.db");
+  const override = process.env.KANDEV_DATABASE_PATH;
+  if (override) {
+    return {
+      dbPath: override,
+      extra: { ...baseExtra, KANDEV_DATABASE_PATH: override },
+    };
+  }
   return {
-    dbPath,
-    extra: { ...baseExtra, KANDEV_DATABASE_PATH: dbPath },
+    dbPath: devDbPath,
+    extra: {
+      ...baseExtra,
+      KANDEV_HOME_DIR: devHome,
+      KANDEV_DATABASE_PATH: "",
+    },
   };
 }