diff --git a/app/src/main/java/gq/kirmanak/mealient/data/auth/impl/AuthStorageImpl.kt b/app/src/main/java/gq/kirmanak/mealient/data/auth/impl/AuthStorageImpl.kt
index ec5ab65..6570e95 100644
--- a/app/src/main/java/gq/kirmanak/mealient/data/auth/impl/AuthStorageImpl.kt
+++ b/app/src/main/java/gq/kirmanak/mealient/data/auth/impl/AuthStorageImpl.kt
@@ -1,6 +1,7 @@
 package gq.kirmanak.mealient.data.auth.impl
 
 import android.content.SharedPreferences
+import androidx.annotation.VisibleForTesting
 import androidx.core.content.edit
 import gq.kirmanak.mealient.data.auth.AuthStorage
 import gq.kirmanak.mealient.di.AuthModule.Companion.ENCRYPTED
@@ -53,8 +54,13 @@ class AuthStorageImpl @Inject constructor(
     }
 
     companion object {
-        private const val AUTH_HEADER_KEY = "authHeader"
-        private const val EMAIL_KEY = "email"
-        private const val PASSWORD_KEY = "password"
+        @VisibleForTesting
+        const val AUTH_HEADER_KEY = "authHeader"
+
+        @VisibleForTesting
+        const val EMAIL_KEY = "email"
+
+        @VisibleForTesting
+        const val PASSWORD_KEY = "password"
     }
 }
\ No newline at end of file
diff --git a/app/src/test/java/gq/kirmanak/mealient/data/auth/impl/AuthRepoImplTest.kt b/app/src/test/java/gq/kirmanak/mealient/data/auth/impl/AuthRepoImplTest.kt
new file mode 100644
index 0000000..562dd64
--- /dev/null
+++ b/app/src/test/java/gq/kirmanak/mealient/data/auth/impl/AuthRepoImplTest.kt
@@ -0,0 +1,108 @@
+package gq.kirmanak.mealient.data.auth.impl
+
+import com.google.common.truth.Truth.assertThat
+import gq.kirmanak.mealient.data.auth.AuthDataSource
+import gq.kirmanak.mealient.data.auth.AuthRepo
+import gq.kirmanak.mealient.data.auth.AuthStorage
+import gq.kirmanak.mealient.test.AuthImplTestData.TEST_AUTH_HEADER
+import gq.kirmanak.mealient.test.AuthImplTestData.TEST_PASSWORD
+import gq.kirmanak.mealient.test.AuthImplTestData.TEST_TOKEN
+import gq.kirmanak.mealient.test.AuthImplTestData.TEST_USERNAME
+import io.mockk.*
+import io.mockk.impl.annotations.MockK
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.flow.toList
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Test
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class AuthRepoImplTest {
+
+    @MockK
+    lateinit var dataSource: AuthDataSource
+
+    @MockK(relaxUnitFun = true)
+    lateinit var storage: AuthStorage
+
+    lateinit var subject: AuthRepo
+
+    @Before
+    fun setUp() {
+        MockKAnnotations.init(this)
+        subject = AuthRepoImpl(storage, dataSource)
+    }
+
+    @Test
+    fun `when isAuthorizedFlow then reads from storage`() = runTest {
+        every { storage.authHeaderFlow } returns flowOf("", null, "header")
+        assertThat(subject.isAuthorizedFlow.toList()).isEqualTo(listOf(true, false, true))
+    }
+
+    @Test
+    fun `when authenticate successfully then saves to storage`() = runTest {
+        coEvery { dataSource.authenticate(eq(TEST_USERNAME), eq(TEST_PASSWORD)) } returns TEST_TOKEN
+        subject.authenticate(TEST_USERNAME, TEST_PASSWORD)
+        coVerifyAll {
+            storage.setAuthHeader(TEST_AUTH_HEADER)
+            storage.setEmail(TEST_USERNAME)
+            storage.setPassword(TEST_PASSWORD)
+        }
+        confirmVerified(storage)
+    }
+
+    @Test
+    fun `when authenticate fails then does not change storage`() = runTest {
+        coEvery { dataSource.authenticate(any(), any()) } throws RuntimeException()
+        runCatching { subject.authenticate("invalid", "") }
+        confirmVerified(storage)
+    }
+
+    @Test
+    fun `when logout then removes email, password and header`() = runTest {
+        subject.logout()
+        coVerifyAll {
+            storage.setEmail(null)
+            storage.setPassword(null)
+            storage.setAuthHeader(null)
+        }
+        confirmVerified(storage)
+    }
+
+    @Test
+    fun `when invalidate then does not authenticate without email`() = runTest {
+        coEvery { storage.getEmail() } returns null
+        coEvery { storage.getPassword() } returns TEST_PASSWORD
+        subject.invalidateAuthHeader()
+        confirmVerified(dataSource)
+    }
+
+    @Test
+    fun `when invalidate then does not authenticate without password`() = runTest {
+        coEvery { storage.getEmail() } returns TEST_USERNAME
+        coEvery { storage.getPassword() } returns null
+        subject.invalidateAuthHeader()
+        confirmVerified(dataSource)
+    }
+
+    @Test
+    fun `when invalidate with credentials then calls authenticate`() = runTest {
+        coEvery { storage.getEmail() } returns TEST_USERNAME
+        coEvery { storage.getPassword() } returns TEST_PASSWORD
+        coEvery { dataSource.authenticate(eq(TEST_USERNAME), eq(TEST_PASSWORD)) } returns TEST_TOKEN
+        subject.invalidateAuthHeader()
+        coVerifyAll {
+            dataSource.authenticate(eq(TEST_USERNAME), eq(TEST_PASSWORD))
+        }
+    }
+
+    @Test
+    fun `when invalidate with credentials and auth fails then clears email`() = runTest {
+        coEvery { storage.getEmail() } returns "invalid"
+        coEvery { storage.getPassword() } returns ""
+        coEvery { dataSource.authenticate(any(), any()) } throws RuntimeException()
+        subject.invalidateAuthHeader()
+        coVerify { storage.setEmail(null) }
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/gq/kirmanak/mealient/data/auth/impl/AuthStorageImplTest.kt b/app/src/test/java/gq/kirmanak/mealient/data/auth/impl/AuthStorageImplTest.kt
new file mode 100644
index 0000000..b19f22a
--- /dev/null
+++ b/app/src/test/java/gq/kirmanak/mealient/data/auth/impl/AuthStorageImplTest.kt
@@ -0,0 +1,64 @@
+package gq.kirmanak.mealient.data.auth.impl
+
+import android.content.Context
+import android.content.SharedPreferences
+import androidx.core.content.edit
+import com.google.common.truth.Truth.assertThat
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.android.testing.HiltAndroidTest
+import gq.kirmanak.mealient.data.auth.AuthStorage
+import gq.kirmanak.mealient.data.auth.impl.AuthStorageImpl.Companion.AUTH_HEADER_KEY
+import gq.kirmanak.mealient.data.auth.impl.AuthStorageImpl.Companion.EMAIL_KEY
+import gq.kirmanak.mealient.data.auth.impl.AuthStorageImpl.Companion.PASSWORD_KEY
+import gq.kirmanak.mealient.test.AuthImplTestData.TEST_AUTH_HEADER
+import gq.kirmanak.mealient.test.AuthImplTestData.TEST_PASSWORD
+import gq.kirmanak.mealient.test.AuthImplTestData.TEST_USERNAME
+import gq.kirmanak.mealient.test.HiltRobolectricTest
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Test
+import javax.inject.Inject
+
+@OptIn(ExperimentalCoroutinesApi::class)
+@HiltAndroidTest
+class AuthStorageImplTest : HiltRobolectricTest() {
+
+    @Inject
+    @ApplicationContext
+    lateinit var context: Context
+
+    lateinit var subject: AuthStorage
+
+    lateinit var sharedPreferences: SharedPreferences
+
+    @Before
+    fun setUp() {
+        sharedPreferences = context.getSharedPreferences("test", Context.MODE_PRIVATE)
+        subject = AuthStorageImpl(sharedPreferences)
+    }
+
+    @Test
+    fun `when authHeaderFlow is observed then sends value immediately`() = runTest {
+        sharedPreferences.edit(commit = true) { putString(AUTH_HEADER_KEY, TEST_AUTH_HEADER) }
+        assertThat(subject.authHeaderFlow.first()).isEqualTo(TEST_AUTH_HEADER)
+    }
+
+    @Test
+    fun `when authHeader is observed then sends null if nothing saved`() = runTest {
+        assertThat(subject.authHeaderFlow.first()).isEqualTo(null)
+    }
+
+    @Test
+    fun `when setEmail then edits shared preferences`() = runTest {
+        subject.setEmail(TEST_USERNAME)
+        assertThat(sharedPreferences.getString(EMAIL_KEY, null)).isEqualTo(TEST_USERNAME)
+    }
+
+    @Test
+    fun `when getPassword then reads shared preferences`() = runTest {
+        sharedPreferences.edit(commit = true) { putString(PASSWORD_KEY, TEST_PASSWORD) }
+        assertThat(subject.getPassword()).isEqualTo(TEST_PASSWORD)
+    }
+}
\ No newline at end of file