diff --git a/app/src/test/java/gq/kirmanak/mealie/data/auth/impl/AuthDataSourceImplTest.kt b/app/src/test/java/gq/kirmanak/mealie/data/auth/impl/AuthDataSourceImplTest.kt
new file mode 100644
index 0000000..52e0cb7
--- /dev/null
+++ b/app/src/test/java/gq/kirmanak/mealie/data/auth/impl/AuthDataSourceImplTest.kt
@@ -0,0 +1,112 @@
+package gq.kirmanak.mealie.data.auth.impl
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.google.common.truth.Truth.assertThat
+import dagger.hilt.android.testing.HiltAndroidRule
+import dagger.hilt.android.testing.HiltAndroidTest
+import dagger.hilt.android.testing.HiltTestApplication
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.runBlocking
+import kotlinx.serialization.ExperimentalSerializationApi
+import okhttp3.mockwebserver.MockResponse
+import okhttp3.mockwebserver.MockWebServer
+import okhttp3.mockwebserver.RecordedRequest
+import org.junit.After
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.annotation.Config
+import retrofit2.HttpException
+import java.nio.charset.Charset
+import javax.inject.Inject
+
+@ExperimentalSerializationApi
+@ExperimentalCoroutinesApi
+@HiltAndroidTest
+@RunWith(AndroidJUnit4::class)
+@Config(application = HiltTestApplication::class)
+class AuthDataSourceImplTest {
+    @get:Rule
+    var hiltRule = HiltAndroidRule(this)
+
+    @Inject
+    lateinit var subject: AuthDataSourceImpl
+    private lateinit var mockServer: MockWebServer
+    private lateinit var serverUrl: String
+
+    @Before
+    fun inject() {
+        hiltRule.inject()
+    }
+
+    @Before
+    fun startMockServer() {
+        mockServer = MockWebServer().apply {
+            start()
+        }
+        serverUrl = mockServer.url("/").toString()
+    }
+
+    @After
+    fun stopMockServer() {
+        mockServer.shutdown()
+    }
+
+    @Test
+    fun `when authentication is successful then token is correct`() = runBlocking {
+        enqueueSuccessfulResponse()
+        val token = subject.authenticate(TEST_USERNAME, TEST_PASSWORD, serverUrl)
+        assertThat(token).isEqualTo(TEST_TOKEN)
+    }
+
+    @Test(expected = HttpException::class)
+    fun `when authentication isn't successful then throws`(): Unit = runBlocking {
+        enqueueUnsuccessfulResponse()
+        subject.authenticate(TEST_USERNAME, TEST_PASSWORD, serverUrl)
+    }
+
+    @Test
+    fun `when authentication is requested then body is correct`() = runBlocking {
+        enqueueSuccessfulResponse()
+        subject.authenticate(TEST_USERNAME, TEST_PASSWORD, serverUrl)
+        val body = mockServer.takeRequest().body()
+        assertThat(body).isEqualTo("username=$TEST_USERNAME&password=$TEST_PASSWORD")
+    }
+
+    @Test
+    fun `when authentication is requested then path is correct`() = runBlocking {
+        enqueueSuccessfulResponse()
+        subject.authenticate(TEST_USERNAME, TEST_PASSWORD, serverUrl)
+        val path = mockServer.takeRequest().path
+        assertThat(path).isEqualTo("/api/auth/token")
+    }
+
+    private fun RecordedRequest.body() = body.readString(Charset.defaultCharset())
+
+    private fun enqueueUnsuccessfulResponse() {
+        val response = MockResponse()
+            .setBody(UNSUCCESSFUL_AUTH_RESPONSE)
+            .setHeader("Content-Type", "application/json")
+            .setResponseCode(401)
+        mockServer.enqueue(response)
+    }
+
+    private fun enqueueSuccessfulResponse() {
+        val response = MockResponse()
+            .setBody(SUCCESSFUL_AUTH_RESPONSE)
+            .setHeader("Content-Type", "application/json")
+            .setResponseCode(200)
+        mockServer.enqueue(response)
+    }
+
+    companion object {
+        private const val TEST_USERNAME = "TEST_USERNAME"
+        private const val TEST_PASSWORD = "TEST_PASSWORD"
+        private const val TEST_TOKEN = "TEST_TOKEN"
+        private const val SUCCESSFUL_AUTH_RESPONSE =
+            "{\"access_token\":\"$TEST_TOKEN\",\"token_type\":\"TEST_TOKEN_TYPE\"}"
+        private const val UNSUCCESSFUL_AUTH_RESPONSE =
+            "{\"detail\":\"Unauthorized\"}"
+    }
+}
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