[cli] Add CLI login unit test (vercel#6866)

This has just been sitting in my working tree for a while, might as well push it up.

packages/cli/src/util/client.ts

@@ -100,7 +100,7 @@ export default class Client extends EventEmitter {
     let body;
     if (isJSONObject(opts.body)) {
       body = JSON.stringify(opts.body);
-      headers.set('content-type', 'application/json; charset=utf8');
+      headers.set('content-type', 'application/json; charset=utf-8');
     } else {
       body = opts.body;
     }

packages/cli/test/commands/login.test.ts

@@ -1,5 +1,6 @@
-import { client } from '../mocks/client';
 import login from '../../src/commands/login';
+import { client } from '../mocks/client';
+import { useUser } from '../mocks/user';
 
 describe('login', () => {
   it('should not allow the `--token` flag', async () => {
@@ -10,4 +11,16 @@ describe('login', () => {
       'Error! `--token` may not be used with the "login" command\n'
     );
   });
+
+  it('should allow login via email as argument', async () => {
+    const user = useUser();
+    client.setArgv('login', user.email);
+    const exitCode = await login(client);
+    expect(exitCode).toEqual(0);
+    expect(
+      client.outputBuffer.includes(
+        `Success! Email authentication complete for ${user.email}`
+      )
+    ).toEqual(true);
+  });
 });

packages/cli/test/mocks/user.ts

@@ -14,5 +14,19 @@ export function useUser() {
     });
   });
 
+  client.scenario.post('/registration', (_req, res) => {
+    res.json({
+      token: 'T1dmvPu36nmyYisXAs7IRzcR',
+      securityCode: 'Practical Saola',
+    });
+  });
+
+  client.scenario.get('/registration/verify', (_req, res) => {
+    res.json({
+      token: 'hjkjn',
+      email: user.email,
+    });
+  });
+
   return user;
 }