Add RetrofitExtension to the lib

app/src/main/kotlin/co/metalab/asyncawaitsample/GithubActivity.kt

@@ -1,11 +1,12 @@
 package co.metalab.asyncawaitsample
 
-import android.support.v7.app.AppCompatActivity
 import android.os.Bundle
+import android.support.v7.app.AppCompatActivity
 import android.util.Log
 import android.view.View
-import co.metalab.asyncawait.AsyncController
+import co.metalab.asyncawait.RetrofitHttpError
 import co.metalab.asyncawait.async
+import co.metalab.asyncawait.awaitSuccessful
 import com.google.gson.Gson
 import kotlinx.android.synthetic.main.activity_github.*
 import retrofit2.Call
@@ -33,42 +34,54 @@ class GitHubActivity : AppCompatActivity() {
    }
 
    private fun refreshRepos() = async {
-      txtRepos.text = ""
-      progressBar.isIndeterminate = true
-      progressBar.visibility = View.VISIBLE
-      btnGetRepos.isEnabled = false
-      txtStatus.text = "Loading repos list..."
+      showLoadingUi()
 
       val userName = txtUserName.text.toString()
-      reposList = await(github.listRepos(userName))
+      reposList = awaitSuccessful(github.listRepos(userName))
       showRepos(reposList)
 
       progressBar.isIndeterminate = false
       reposList.forEachIndexed { i, repo ->
          txtStatus.text = "Loading info for ${repo.name}..."
          progressBar.progress = i * 100 / reposList.size
-         val repoDetails = await(github.repoDetails(userName, repo.name))
+         val repoDetails = awaitSuccessful(github.repoDetails(userName, repo.name))
          repo.stars = repoDetails.stargazers_count
          showRepos(reposList)
       }
 
+      hideLoadingUi()
+   }.onError {
       progressBar.visibility = View.INVISIBLE
       btnGetRepos.isEnabled = true
-      txtStatus.text = "Done."
-   }.onError {
+
+      val errorMessage = getErrorMessage(it)
+
+      txtStatus.text = errorMessage
+      Log.e(TAG, errorMessage, it)
+   }
+
+   private fun showLoadingUi() {
+      txtRepos.text = ""
+      progressBar.isIndeterminate = true
+      progressBar.visibility = View.VISIBLE
+      btnGetRepos.isEnabled = false
+      txtStatus.text = "Loading repos list..."
+   }
+
+   private fun hideLoadingUi() {
       progressBar.visibility = View.INVISIBLE
       btnGetRepos.isEnabled = true
+      txtStatus.text = "Done."
+   }
 
-      val errorMessage = if (it is RetrofitHttpException) {
+   private fun getErrorMessage(it: Exception): String {
+      return if (it is RetrofitHttpError) {
          val httpErrorCode = it.errorResponse.code()
          val errorResponse = Gson().fromJson(it.errorResponse.errorBody().string(), GithubErrorResponse::class.java)
          "[$httpErrorCode] ${errorResponse.message}"
       } else {
          "Couldn't load repos (${it.message})"
       }
-
-      txtStatus.text = errorMessage
-      Log.e(TAG, errorMessage, it)
    }
 
    private fun showRepos(reposResponse: List<Repo>) {

asyncawait/build.gradle

@@ -21,6 +21,7 @@ android {
 
     defaultConfig {
         minSdkVersion 15
+        //noinspection OldTargetApi
         targetSdkVersion 23
         versionCode 1
         versionName "1"
@@ -38,6 +39,7 @@ android {
 
 dependencies {
     compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
+    compile 'com.squareup.retrofit2:retrofit:2.1.0'
     testCompile "org.jetbrains.kotlin:kotlin-test-junit:$kotlin_version"
     testCompile 'junit:junit:4.12'
     testCompile "org.robolectric:robolectric:3.1.2"

asyncawait/src/main/kotlin/co/metalab/asyncawait/RetrofitExtensions.kt

@@ -0,0 +1,21 @@
+package co.metalab.asyncawait
+
+import retrofit2.Call
+import retrofit2.Response
+
+suspend fun <V> AsyncController.await(call: Call<V>, machine: Continuation<Response<V>>) {
+   this.await({ call.execute() }, machine)
+}
+
+suspend fun <V> AsyncController.awaitSuccessful(call: Call<V>, machine: Continuation<V>) {
+   this.await({
+      val response = call.execute()
+      if (response.isSuccessful) {
+         response.body()
+      } else {
+         throw RetrofitHttpError(response)
+      }
+   }, machine)
+}
+
+class RetrofitHttpError(val errorResponse: Response<*>) : RuntimeException("${errorResponse.code()}")