Support invalidation in MealieAuthenticator

datasource/src/main/kotlin/gq/kirmanak/mealient/datasource/AuthenticationProvider.kt

@@ -4,4 +4,5 @@ interface AuthenticationProvider {
 
     suspend fun getAuthHeader(): String?
 
+    suspend fun invalidateAuthHeader()
 }

datasource/src/main/kotlin/gq/kirmanak/mealient/datasource/impl/MealieAuthenticator.kt

@@ -18,16 +18,26 @@ class MealieAuthenticator @Inject constructor(
 
     override fun authenticate(route: Route?, response: Response): Request? {
         val supportsBearer = response.challenges().any { it.scheme == BEARER_SCHEME }
+        if (!supportsBearer) {
+            return null
+        }
+
         val request = response.request
-        return if (supportsBearer && request.header(HEADER_NAME) == null) {
+        val previousHeader = request.header(HEADER_NAME)
-            getAuthHeader()?.let { request.copyWithHeader(HEADER_NAME, it) }
+            ?: return getAuthHeader()?.let { request.copyWithHeader(HEADER_NAME, it) }
-        } else {
+
-            null // Either Bearer is not supported or we've already tried to authenticate
+        invalidateAuthHeader()
+        return getAuthHeader()?.takeUnless { it == previousHeader }?.let {
+            request.copyWithHeader(HEADER_NAME, it)
         }
     }
 
     private fun getAuthHeader() = runBlocking { authenticationProvider.get().getAuthHeader() }
 
+    private fun invalidateAuthHeader() {
+        runBlocking { authenticationProvider.get().invalidateAuthHeader() }
+    }
+
     companion object {
         @VisibleForTesting
         const val HEADER_NAME = "Authorization"

datasource/src/test/kotlin/gq/kirmanak/mealient/datasource/MealieAuthenticatorTest.kt

@@ -17,7 +17,7 @@ class MealieAuthenticatorTest : BaseUnitTest() {
 
     private lateinit var subject: MealieAuthenticator
 
-    @MockK
+    @MockK(relaxUnitFun = true)
     lateinit var authenticationProvider: AuthenticationProvider
 
     @Before
@@ -48,11 +48,34 @@ class MealieAuthenticatorTest : BaseUnitTest() {
     }
 
     @Test
-    fun `when no auth header was set expect authenticate to return null`() {
+    fun `when had auth header but can't invalidate expect authenticate return null`() {
+        coEvery { authenticationProvider.getAuthHeader() } returns null
         val response = buildResponse(authHeader = "token")
         assertThat(subject.authenticate(null, response)).isNull()
     }
 
+    @Test
+    fun `when had auth header and invalidate doesn't change it expect authenticate return null`() {
+        coEvery { authenticationProvider.getAuthHeader() } returns "token"
+        val response = buildResponse(authHeader = "token")
+        assertThat(subject.authenticate(null, response)).isNull()
+    }
+
+    @Test
+    fun `when had auth header and invalidate succeeds expect authenticate return new`() {
+        coEvery { authenticationProvider.getAuthHeader() } returns "newToken"
+        val response = buildResponse(authHeader = "token")
+        assertThat(subject.authenticate(null, response)?.header(HEADER_NAME)).isEqualTo("newToken")
+    }
+
+    @Test
+    fun `when had auth header expect authenticate to invalidate it`() {
+        coEvery { authenticationProvider.getAuthHeader() } returns null
+        val response = buildResponse(authHeader = "token")
+        subject.authenticate(null, response)
+        coVerify { authenticationProvider.invalidateAuthHeader() }
+    }
+
     @Test
     fun `when auth header exists expect authenticate to return request`() {
         coEvery { authenticationProvider.getAuthHeader() } returns "token"