From 8ccbed3c4dae218ce105ffbaec86dbbe8254529b Mon Sep 17 00:00:00 2001
From: Giulio Vaccari <io@giuliovaccari.it>
Date: Tue, 28 Apr 2026 20:34:31 +0000
Subject: [PATCH] test(signature-store): add unit tests for
 createSignatureStore and createThoughtBuffer

Co-Authored-By: Giulio Vaccari <io@giuliovaccari.it>
---
 src/plugin/stores/signature-store.test.ts | 149 ++++++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 src/plugin/stores/signature-store.test.ts

diff --git a/src/plugin/stores/signature-store.test.ts b/src/plugin/stores/signature-store.test.ts
new file mode 100644
index 0000000..5d9d2df
--- /dev/null
+++ b/src/plugin/stores/signature-store.test.ts
@@ -0,0 +1,149 @@
+import { describe, expect, it } from "vitest";
+import {
+  createSignatureStore,
+  createThoughtBuffer,
+  defaultSignatureStore,
+} from "./signature-store";
+
+// ─── createSignatureStore ─────────────────────────────────────────────────────
+
+describe("createSignatureStore", () => {
+  it("returns undefined for a key that was never set", () => {
+    const store = createSignatureStore();
+    expect(store.get("missing")).toBeUndefined();
+  });
+
+  it("stores and retrieves a value by key", () => {
+    const store = createSignatureStore();
+    store.set("k1", { text: "hello thinking", signature: "sig-abc" });
+    expect(store.get("k1")).toEqual({ text: "hello thinking", signature: "sig-abc" });
+  });
+
+  it("reports has() as false for unknown key", () => {
+    const store = createSignatureStore();
+    expect(store.has("nope")).toBe(false);
+  });
+
+  it("reports has() as true after set()", () => {
+    const store = createSignatureStore();
+    store.set("key", { text: "t", signature: "s" });
+    expect(store.has("key")).toBe(true);
+  });
+
+  it("delete() removes the key so has() returns false", () => {
+    const store = createSignatureStore();
+    store.set("del-me", { text: "x", signature: "y" });
+    store.delete("del-me");
+    expect(store.has("del-me")).toBe(false);
+    expect(store.get("del-me")).toBeUndefined();
+  });
+
+  it("delete() on a non-existent key is a no-op", () => {
+    const store = createSignatureStore();
+    expect(() => store.delete("ghost")).not.toThrow();
+  });
+
+  it("overwriting a key stores the latest value", () => {
+    const store = createSignatureStore();
+    store.set("k", { text: "first", signature: "s1" });
+    store.set("k", { text: "second", signature: "s2" });
+    expect(store.get("k")).toEqual({ text: "second", signature: "s2" });
+  });
+
+  it("each createSignatureStore() call returns an independent store", () => {
+    const storeA = createSignatureStore();
+    const storeB = createSignatureStore();
+    storeA.set("shared-key", { text: "only in A", signature: "sig-a" });
+    expect(storeB.has("shared-key")).toBe(false);
+  });
+
+  it("handles empty-string key", () => {
+    const store = createSignatureStore();
+    store.set("", { text: "empty key", signature: "s" });
+    expect(store.get("")).toEqual({ text: "empty key", signature: "s" });
+  });
+
+  it("handles many keys without collision", () => {
+    const store = createSignatureStore();
+    const N = 50;
+    for (let i = 0; i < N; i++) {
+      store.set(`key-${i}`, { text: `t${i}`, signature: `s${i}` });
+    }
+    for (let i = 0; i < N; i++) {
+      expect(store.get(`key-${i}`)).toEqual({ text: `t${i}`, signature: `s${i}` });
+    }
+  });
+});
+
+// ─── createThoughtBuffer ─────────────────────────────────────────────────────
+
+describe("createThoughtBuffer", () => {
+  it("returns undefined for an index that was never set", () => {
+    const buf = createThoughtBuffer();
+    expect(buf.get(0)).toBeUndefined();
+  });
+
+  it("stores and retrieves text by numeric index", () => {
+    const buf = createThoughtBuffer();
+    buf.set(3, "thinking text");
+    expect(buf.get(3)).toBe("thinking text");
+  });
+
+  it("index 0 is a valid key", () => {
+    const buf = createThoughtBuffer();
+    buf.set(0, "zero index");
+    expect(buf.get(0)).toBe("zero index");
+  });
+
+  it("clear() removes all entries", () => {
+    const buf = createThoughtBuffer();
+    buf.set(0, "a");
+    buf.set(1, "b");
+    buf.set(2, "c");
+    buf.clear();
+    expect(buf.get(0)).toBeUndefined();
+    expect(buf.get(1)).toBeUndefined();
+    expect(buf.get(2)).toBeUndefined();
+  });
+
+  it("clear() on empty buffer is a no-op", () => {
+    const buf = createThoughtBuffer();
+    expect(() => buf.clear()).not.toThrow();
+  });
+
+  it("overwriting an index stores the latest text", () => {
+    const buf = createThoughtBuffer();
+    buf.set(5, "first");
+    buf.set(5, "second");
+    expect(buf.get(5)).toBe("second");
+  });
+
+  it("each createThoughtBuffer() call returns an independent buffer", () => {
+    const bufA = createThoughtBuffer();
+    const bufB = createThoughtBuffer();
+    bufA.set(0, "only in A");
+    expect(bufB.get(0)).toBeUndefined();
+  });
+
+  it("can store empty string", () => {
+    const buf = createThoughtBuffer();
+    buf.set(7, "");
+    expect(buf.get(7)).toBe("");
+  });
+});
+
+// ─── defaultSignatureStore ────────────────────────────────────────────────────
+
+describe("defaultSignatureStore", () => {
+  it("is a SignatureStore instance (has get/set/has/delete)", () => {
+    expect(typeof defaultSignatureStore.get).toBe("function");
+    expect(typeof defaultSignatureStore.set).toBe("function");
+    expect(typeof defaultSignatureStore.has).toBe("function");
+    expect(typeof defaultSignatureStore.delete).toBe("function");
+  });
+
+  it("is a module-level singleton (same reference on re-import)", async () => {
+    const { defaultSignatureStore: imported } = await import("./signature-store");
+    expect(imported).toBe(defaultSignatureStore);
+  });
+});