feat: auto-delete old conversations, and stop a tool call that repeats

src/__tests__/snip.test.ts

@@ -1,5 +1,6 @@
-import { describe, expect, it } from "vitest";
-import { readSnipContext, snipDirectory } from "../lib/snip";
+import { access, mkdir, rm, utimes, writeFile } from "node:fs/promises";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { listSnipFiles, readSnipContext, removeSnipFiles, snipDirectory } from "../lib/snip";
 
 /**
  * The snip handoff crosses a command boundary as a serialized launch context, so
@@ -55,3 +56,97 @@ describe("snipDirectory", () => {
     expect(snipDirectory()).toBe("/tmp/lam-agent-support/snips");
   });
 });
+
+describe("listSnipFiles", () => {
+  const DIRECTORY = "/tmp/lam-agent-support/snips";
+
+  beforeEach(async () => {
+    await rm(DIRECTORY, { recursive: true, force: true });
+  });
+
+  afterEach(async () => {
+    await rm(DIRECTORY, { recursive: true, force: true });
+  });
+
+  it("returns nothing before anything has been snipped", async () => {
+    await expect(listSnipFiles()).resolves.toEqual([]);
+  });
+
+  it("reports each capture with the time it was written", async () => {
+    await mkdir(DIRECTORY, { recursive: true });
+    const path = `${DIRECTORY}/one.png`;
+    await writeFile(path, "png");
+    const when = new Date(Date.now() - 60_000);
+    await utimes(path, when, when);
+
+    const [file] = await listSnipFiles();
+
+    expect(file.path).toBe(path);
+    expect(Date.now() - file.mtimeMs).toBeGreaterThan(30_000);
+  });
+
+  it("ignores a subdirectory, which is not a capture", async () => {
+    await mkdir(`${DIRECTORY}/nested`, { recursive: true });
+
+    await expect(listSnipFiles()).resolves.toEqual([]);
+  });
+});
+
+describe("removeSnipFiles", () => {
+  const DIRECTORY = "/tmp/lam-agent-support/snips";
+  const OUTSIDE = "/tmp/lam-agent-not-a-snip.png";
+
+  beforeEach(async () => {
+    await rm(DIRECTORY, { recursive: true, force: true });
+    await mkdir(DIRECTORY, { recursive: true });
+    await writeFile(OUTSIDE, "do not delete me");
+  });
+
+  afterEach(async () => {
+    await rm(DIRECTORY, { recursive: true, force: true });
+    await rm(OUTSIDE, { force: true });
+  });
+
+  it("deletes a capture inside the snip directory", async () => {
+    const path = `${DIRECTORY}/one.png`;
+    await writeFile(path, "png");
+
+    await removeSnipFiles([path]);
+
+    await expect(access(path)).rejects.toThrow();
+  });
+
+  it("shrugs at a file that is already gone", async () => {
+    await expect(removeSnipFiles([`${DIRECTORY}/never-existed.png`])).resolves.toBeUndefined();
+  });
+
+  it("refuses a path outside the snip directory", async () => {
+    // These paths come out of stored JSON, which is data rather than code, so
+    // this must not be a general-purpose delete-any-file helper.
+    await removeSnipFiles([OUTSIDE]);
+
+    await expect(access(OUTSIDE)).resolves.toBeUndefined();
+  });
+
+  it("refuses a path that climbs out of the directory", async () => {
+    await removeSnipFiles([`${DIRECTORY}/../../lam-agent-not-a-snip.png`]);
+
+    await expect(access(OUTSIDE)).resolves.toBeUndefined();
+  });
+
+  it("refuses the directory itself", async () => {
+    await removeSnipFiles([DIRECTORY]);
+
+    await expect(access(DIRECTORY)).resolves.toBeUndefined();
+  });
+
+  it("keeps going when one path in the batch is refused", async () => {
+    const inside = `${DIRECTORY}/one.png`;
+    await writeFile(inside, "png");
+
+    await removeSnipFiles([OUTSIDE, inside]);
+
+    await expect(access(inside)).rejects.toThrow();
+    await expect(access(OUTSIDE)).resolves.toBeUndefined();
+  });
+});