Replace generic Exception with sealed ApiException hierarchy

app/src/main/kotlin/com/nativeapptemplate/nativeapptemplatefree/data/login/LoginRepositoryImpl.kt

@@ -5,6 +5,7 @@ import com.nativeapptemplate.nativeapptemplatefree.datastore.NatPreferencesDataS
 import com.nativeapptemplate.nativeapptemplatefree.model.*
 import com.nativeapptemplate.nativeapptemplatefree.model.LoggedInShopkeeper
 import com.nativeapptemplate.nativeapptemplatefree.model.Login
+import com.nativeapptemplate.nativeapptemplatefree.network.ApiException
 import com.nativeapptemplate.nativeapptemplatefree.network.Dispatcher
 import com.nativeapptemplate.nativeapptemplatefree.network.NatDispatchers
 import com.nativeapptemplate.nativeapptemplatefree.network.emitApiResponse
@@ -46,7 +47,7 @@ class LoginRepositoryImpl @Inject constructor(
       emit(true)
     }.suspendOnFailure {
       clearUserPreferences()
-      throw Exception(message())
+      throw ApiException.UnprocessableError(rawMessage = message())
     }
   }.flowOn(ioDispatcher)
 

app/src/main/kotlin/com/nativeapptemplate/nativeapptemplatefree/network/ApiException.kt

@@ -0,0 +1,23 @@
+package com.nativeapptemplate.nativeapptemplatefree.network
+
+/**
+ * Base exception for API errors thrown by repository implementations.
+ */
+sealed class ApiException(message: String, cause: Throwable? = null) : Exception(message, cause) {
+
+  /**
+   * The API returned a structured error response that was successfully deserialized.
+   */
+  class ApiError(
+    val code: Int,
+    val apiMessage: String,
+  ) : ApiException("$apiMessage [Status: $code]")
+
+  /**
+   * The API returned an error response that could not be deserialized.
+   */
+  class UnprocessableError(
+    val rawMessage: String,
+    cause: Throwable? = null,
+  ) : ApiException("Not processable error($rawMessage).", cause)
+}

app/src/main/kotlin/com/nativeapptemplate/nativeapptemplatefree/network/ApiResponseExtensions.kt

@@ -53,8 +53,11 @@ inline fun <reified T : Any> throwApiError(
   }
 
   if (nativeAppTemplateApiError != null) {
-    throw Exception("${nativeAppTemplateApiError.message} [Status: ${nativeAppTemplateApiError.code}]")
+    throw ApiException.ApiError(
+      code = nativeAppTemplateApiError.code,
+      apiMessage = nativeAppTemplateApiError.message,
+    )
   } else {
-    throw Exception("Not processable error($errorMessage).")
+    throw ApiException.UnprocessableError(rawMessage = errorMessage)
   }
 }

app/src/test/kotlin/com/nativeapptemplate/nativeapptemplatefree/network/ApiResponseExtensionsTest.kt

@@ -8,6 +8,7 @@ import org.junit.Assert.assertEquals
 import org.junit.Assert.assertTrue
 import org.junit.Test
 import kotlin.test.assertFailsWith
+import kotlin.test.assertIs
 
 class ApiResponseExtensionsTest {
 
@@ -26,45 +27,48 @@ class ApiResponseExtensionsTest {
   }
 
   @Test
-  fun emitApiResponse_onFailure_throwsException() = runTest {
+  fun emitApiResponse_onFailure_throwsUnprocessableError() = runTest {
     val response = ApiResponse.Failure.Exception(Exception("network error"))
-    assertFailsWith<Exception> {
+    val exception = assertFailsWith<ApiException.UnprocessableError> {
       flow { emitApiResponse<String>(response) }.first()
     }
+    assertEquals("network error", exception.rawMessage)
   }
 
   @Test
-  fun emitApiResponse_withTransform_onFailure_throwsException() = runTest {
+  fun emitApiResponse_withTransform_onFailure_throwsUnprocessableError() = runTest {
     val response = ApiResponse.Failure.Exception(Exception("network error"))
-    assertFailsWith<Exception> {
+    val exception = assertFailsWith<ApiException.UnprocessableError> {
       flow { emitApiResponse<String, Boolean>(response) { true } }.first()
     }
+    assertEquals("network error", exception.rawMessage)
   }
 
   @Test
-  fun throwApiError_includesErrorMessageInException() {
+  fun throwApiError_throwsUnprocessableError_withMessage() {
     val response: ApiResponse<String> = ApiResponse.Failure.Exception(Exception("timeout"))
-    val exception = assertFailsWith<Exception> {
+    val exception = assertFailsWith<ApiException.UnprocessableError> {
       throwApiError(response, "timeout")
     }
+    assertEquals("timeout", exception.rawMessage)
     assertEquals("Not processable error(timeout).", exception.message)
   }
 
   @Test
-  fun emitApiResponse_onFailure_exceptionContainsNotProcessableError() = runTest {
+  fun emitApiResponse_onFailure_exceptionIsApiException() = runTest {
     val response: ApiResponse<String> = ApiResponse.Failure.Exception(Exception("server error"))
-    val exception = assertFailsWith<Exception> {
+    val exception = assertFailsWith<ApiException> {
       flow { emitApiResponse<String>(response) }.first()
     }
-    assertTrue(exception.message!!.contains("Not processable error"))
+    assertIs<ApiException.UnprocessableError>(exception)
   }
 
   @Test
-  fun emitApiResponse_withTransform_onFailure_exceptionContainsNotProcessableError() = runTest {
+  fun emitApiResponse_withTransform_onFailure_exceptionIsApiException() = runTest {
     val response: ApiResponse<String> = ApiResponse.Failure.Exception(Exception("server error"))
-    val exception = assertFailsWith<Exception> {
+    val exception = assertFailsWith<ApiException> {
       flow { emitApiResponse<String, Boolean>(response) { true } }.first()
     }
-    assertTrue(exception.message!!.contains("Not processable error"))
+    assertIs<ApiException.UnprocessableError>(exception)
   }
 }