diff --git a/test/main.test.ts b/test/main.test.ts
new file mode 100644
index 0000000..d32b275
--- /dev/null
+++ b/test/main.test.ts
@@ -0,0 +1,130 @@
+import { describe, it, expect, vi, afterAll } from "vitest";
+import consola from "consola";
+import {
+  createMain,
+  defineCommand,
+  renderUsage,
+  runMain,
+  showUsage,
+} from "../src";
+import * as mainModule from "../src/main";
+import * as commandModule from "../src/command";
+
+describe("runMain", () => {
+  vi.spyOn(process, "exit").mockImplementation(() => 0 as never);
+
+  const consoleMock = vi
+    .spyOn(consola, "log")
+    .mockImplementation(() => undefined);
+
+  const consolaErrorMock = vi
+    .spyOn(consola, "error")
+    .mockImplementation(() => undefined);
+
+  afterAll(() => {
+    consoleMock.mockReset();
+  });
+
+  it("shows version with flag `--version`", async () => {
+    const command = defineCommand({
+      meta: {
+        version: "1.0.0",
+      },
+    });
+
+    await runMain(command, { rawArgs: ["--version"] });
+
+    expect(consoleMock).toHaveBeenCalledWith("1.0.0");
+  });
+
+  it("shows version with flag `--version` with meta specified as async function", async () => {
+    const command = defineCommand({
+      // eslint-disable-next-line unicorn/no-useless-promise-resolve-reject, require-await
+      meta: async () => Promise.resolve({ version: "1.0.0" }),
+    });
+
+    await runMain(command, { rawArgs: ["--version"] });
+
+    expect(consoleMock).toHaveBeenCalledWith("1.0.0");
+  });
+
+  it("shows usage with flag `--version` but without version specified", async () => {
+    const command = defineCommand({
+      meta: {
+        name: "test",
+        description: "Test command",
+      },
+    });
+
+    await runMain(command, { rawArgs: ["--version"] });
+
+    const usage = await renderUsage(command);
+    expect(consoleMock).toHaveBeenCalledWith(usage + "\n");
+    expect(consolaErrorMock).toHaveBeenCalledWith("No version specified");
+  });
+
+  it.each([["--help"], ["-h"]])("shows usage with flag `%s`", async (flag) => {
+    const command = defineCommand({
+      meta: {
+        name: "test",
+        description: "Test command",
+      },
+    });
+
+    await runMain(command, { rawArgs: [flag] });
+
+    const usage = await renderUsage(command);
+    expect(consoleMock).toHaveBeenCalledWith(usage + "\n");
+  });
+
+  it.each([["--help"], ["-h"]])(
+    "can show custom usage with flag `%s`",
+    async (flag) => {
+      const command = defineCommand({
+        meta: {
+          name: "test",
+          description: "Test command",
+        },
+      });
+
+      // eslint-disable-next-line require-await, unicorn/consistent-function-scoping
+      const customUsage: typeof showUsage = async () => {
+        consola.log("Custom usage");
+      };
+
+      await runMain(command, { rawArgs: [flag], showUsage: customUsage });
+
+      expect(consoleMock).toHaveBeenCalledWith("Custom usage");
+    },
+  );
+
+  it("runs the command", async () => {
+    const mockRunCommand = vi.spyOn(commandModule, "runCommand");
+
+    const command = defineCommand({});
+
+    await runMain(command);
+
+    expect(mockRunCommand).toHaveBeenCalledWith(command, { rawArgs: [] });
+  });
+
+  it("runs the command with raw arguments", async () => {
+    const mockRunCommand = vi.spyOn(commandModule, "runCommand");
+
+    const command = defineCommand({});
+
+    const rawArgs = ["--foo", "bar"];
+
+    await runMain(command, { rawArgs });
+
+    expect(mockRunCommand).toHaveBeenCalledWith(command, { rawArgs });
+  });
+});
+
+describe("createMain", () => {
+  it("creates and returns a function", () => {
+    const main = createMain(defineCommand({}));
+
+    expect(main).toBeInstanceOf(Function);
+  });
+});