improve test coverage

app/Http/Controllers/UserController.php

@@ -292,7 +292,7 @@ public function generateOtp(Request $request, Otp $otp)
     {
         $identifier = (string) $request->get('identifier');
 
-        $token =  $otp->generate(
+        $token = $otp->generate(
             $identifier,
             config('services.otp.digits'),
             config('services.otp.validity')

tests/Feature/OtpTest.php

@@ -0,0 +1,113 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Feature;
+
+use App\Mail\OtpWasGenerated;
+use Faker\Factory;
+use Illuminate\Http\Response;
+use Illuminate\Support\Facades\Log;
+use Illuminate\Support\Facades\Mail;
+use Illuminate\Support\Str;
+use TestCase;
+
+class OtpTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function it_can_generate_otp_success()
+    {
+        Mail::fake();
+
+        $faker = Factory::create();
+
+        $this
+            ->json('POST', '/api/v1/otp/generate', [
+                'identifier' => $faker->email
+            ])->assertStatus(Response::HTTP_OK);
+
+        Mail::assertSent(OtpWasGenerated::class);
+    }
+
+    /**
+     * @test
+     */
+    public function it_can_generate_otp_fails()
+    {
+        $randStr = Str::random(10);
+
+        $this
+            ->json('POST', '/api/v1/otp/generate', [
+                'identifier' => $randStr
+            ])
+            ->assertExactJson([
+                "message" => "There was an error processing this request. Please try again."
+            ]);
+
+        Log::shouldReceive('debug')
+            ->with(
+                'Error sending OTP email',
+                [
+                    'identifier' => $randStr,
+                    'errorMsg' => 'zazu'
+                ]
+            );
+    }
+
+    /**
+     * @dataProvider OtpValidationDataProvider
+     * @test
+     */
+    public function it_can_validate_a_token(?string $identifier, ?string $token, array $response)
+    {
+        $this
+            ->json('POST', '/api/v1/otp/validate', [
+                'identifier' => $identifier,
+                'token' => $token
+            ])
+            ->assertStatus(Response::HTTP_OK)
+            ->assertExactJson($response);
+    }
+
+    public static function OtpValidationDataProvider(): array
+    {
+        $faker = Factory::create();
+
+        return [
+            'With null identifier and token' => [
+                null,
+                null,
+                [
+                    'status' => false,
+                    'message' => 'OTP does not exist'
+                ]
+            ],
+            'With null token only' => [
+                $faker->email,
+                null,
+                [
+                    'status' => false,
+                    'message' => 'OTP does not exist'
+                ]
+            ],
+            'With null identifier only' => [
+                null,
+                (string)$faker->randomNumber(6),
+                [
+                    'status' => false,
+                    'message' => 'OTP does not exist'
+                ]
+            ],
+            'Identifier and token not matching db' => [
+                $faker->email,
+                (string)$faker->randomNumber(6),
+                [
+                    'status' => false,
+                    'message' => 'OTP does not exist'
+                ]
+            ],
+        ];
+    }
+}

tests/TestCase.php

@@ -3,10 +3,12 @@
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Contracts\Console\Kernel;
 use Illuminate\Foundation\Testing\TestCase as BaseTestCase;
+use Illuminate\Foundation\Testing\WithFaker;
 
 abstract class TestCase extends BaseTestCase
 {
     use RefreshDatabase;
+    use WithFaker;
 
     public function createApplication()
     {