diff --git a/__tests__/get-latest-version.test.ts b/__tests__/get-latest-version.test.ts
new file mode 100644
index 0000000..e0adbd8
--- /dev/null
+++ b/__tests__/get-latest-version.test.ts
@@ -0,0 +1,59 @@
+import {getURL, getLatestVersion} from '../src/get-latest-version';
+import nock from 'nock';
+import {FetchError} from 'node-fetch';
+import {Tool} from '../src/constants';
+import jsonTestBrew from './data/brew.json';
+import jsonTestGithub from './data/github.json';
+
+beforeEach(() => {
+  jest.resetModules();
+});
+
+afterEach(() => {
+  nock.cleanAll();
+});
+
+describe('getURL()', () => {
+  test('return expected URL', () => {
+    const urlBrewExpected = `https://formulae.brew.sh/api/formula/${Tool.Repo}.json`;
+    const urlBrew: string = getURL(Tool.Org, Tool.Repo, 'brew');
+    expect(urlBrew).toMatch(urlBrewExpected);
+
+    const urlGithubExpected = `https://api.github.com/repos/${Tool.Org}/${Tool.Repo}/releases/latest`;
+    const urlGithub: string = getURL(Tool.Org, Tool.Repo, 'github');
+    expect(urlGithub).toMatch(urlGithubExpected);
+  });
+});
+
+describe('getLatestVersion()', () => {
+  test('return latest version via brew', async () => {
+    nock('https://formulae.brew.sh')
+      .get(`/api/formula/${Tool.Repo}.json`)
+      .reply(200, jsonTestBrew);
+
+    const versionLatest: string = await getLatestVersion(Tool.Org, Tool.Repo, 'brew');
+    expect(versionLatest).toMatch(Tool.TestVersionLatest);
+  });
+
+  test('return latest version via GitHub', async () => {
+    nock('https://api.github.com')
+      .get(`/repos/${Tool.Org}/${Tool.Repo}/releases/latest`)
+      .reply(200, jsonTestGithub);
+
+    const versionLatest: string = await getLatestVersion(Tool.Org, Tool.Repo, 'github');
+    expect(versionLatest).toMatch(Tool.TestVersionLatest);
+  });
+
+  test('return exception 404', async () => {
+    nock('https://formulae.brew.sh')
+      .get(`/api/formula/${Tool.Repo}.json`)
+      .reply(404);
+
+    try {
+      const versionLatest: string = await getLatestVersion(Tool.Org, Tool.Repo, 'brew');
+      console.debug(versionLatest);
+    } catch (e) {
+      expect(e).toThrow(FetchError);
+    }
+  });
+});
diff --git a/src/constants.ts b/src/constants.ts
index e305ca4..7078254 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -3,5 +3,7 @@ export enum Tool {
   Org = 'gohugoio',
   Repo = 'hugo',
   CmdName = 'hugo',
-  CmdOptVersion = 'version'
+  CmdOptVersion = 'version',
+  TestVersionLatest = '0.62.2',
+  TestVersionSpec = '0.61.0'
 }