feat: add more tests for tool built-ins (#5)

src/tests/tools/write.test.ts

@@ -0,0 +1,51 @@
+import { afterEach, describe, expect, test } from "bun:test";
+import { existsSync, readFileSync } from "node:fs";
+import { write } from "../../tools/impl/Write";
+import { TestDirectory } from "../helpers/testFs";
+
+describe("Write tool", () => {
+  let testDir: TestDirectory;
+
+  afterEach(() => {
+    testDir?.cleanup();
+  });
+
+  test("creates a new file", async () => {
+    testDir = new TestDirectory();
+    const filePath = testDir.resolve("new.txt");
+
+    await write({ file_path: filePath, content: "Hello, World!" });
+
+    expect(existsSync(filePath)).toBe(true);
+    expect(readFileSync(filePath, "utf-8")).toBe("Hello, World!");
+  });
+
+  test("overwrites existing file", async () => {
+    testDir = new TestDirectory();
+    const filePath = testDir.createFile("existing.txt", "Old content");
+
+    await write({ file_path: filePath, content: "New content" });
+
+    expect(readFileSync(filePath, "utf-8")).toBe("New content");
+  });
+
+  test("creates nested directories automatically", async () => {
+    testDir = new TestDirectory();
+    const filePath = testDir.resolve("nested/deep/file.txt");
+
+    await write({ file_path: filePath, content: "Nested file" });
+
+    expect(existsSync(filePath)).toBe(true);
+    expect(readFileSync(filePath, "utf-8")).toBe("Nested file");
+  });
+
+  test("writes UTF-8 content correctly", async () => {
+    testDir = new TestDirectory();
+    const filePath = testDir.resolve("unicode.txt");
+    const content = "Hello 世界 🌍\n╔═══╗";
+
+    await write({ file_path: filePath, content });
+
+    expect(readFileSync(filePath, "utf-8")).toBe(content);
+  });
+});