feat: add environment variables validation

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

test/env.test.js

@@ -0,0 +1,45 @@
+import { describe, it, expect, beforeAll } from "bun:test";
+import { config } from "../src/env.js";
+
+describe("Environment Variables Validation", () => {
+  it("config should have all required fields", () => {
+    expect(config).toHaveProperty("botToken");
+    expect(config).toHaveProperty("storageChatId");
+    expect(config).toHaveProperty("baseUrl");
+    expect(config).toHaveProperty("databaseUrl");
+    expect(config).toHaveProperty("port");
+    expect(config).toHaveProperty("nodeEnv");
+    expect(config).toHaveProperty("logLevel");
+    expect(config).toHaveProperty("rateLimitWindowMs");
+    expect(config).toHaveProperty("rateLimitMaxRequests");
+  });
+
+  it("config.botToken should return BOT_TOKEN from process.env", () => {
+    expect(config.botToken).toBe(process.env.BOT_TOKEN);
+  });
+
+  it("config.storageChatId should be parsed as integer from STORAGE_CHANNEL_ID", () => {
+    expect(typeof config.storageChatId).toBe("number");
+    expect(config.storageChatId).toBe(parseInt(process.env.STORAGE_CHANNEL_ID, 10));
+  });
+
+  it("config.port should default to 3000 when not specified", () => {
+    expect(typeof config.port).toBe("number");
+  });
+
+  it("nodeEnv should be 'test' or 'development'", () => {
+    expect(["test", "development"]).toContain(config.nodeEnv);
+  });
+
+  it("logLevel should default to 'info'", () => {
+    expect(config.logLevel).toBe("info");
+  });
+
+  it("rateLimitWindowMs should default to 60000 when not specified", () => {
+    expect(config.rateLimitWindowMs).toBe(60000);
+  });
+
+  it("rateLimitMaxRequests should default to 30 when not specified", () => {
+    expect(config.rateLimitMaxRequests).toBe(30);
+  });
+});