Added some tests

Author: davidbilik

library/build.gradle

@@ -13,6 +13,9 @@ android {
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
 
     }
+    testOptions {
+        unitTests.returnDefaultValues = true
+    }
     buildTypes {
         release {
             minifyEnabled false
@@ -25,4 +28,5 @@ dependencies {
     testCompile 'junit:junit:4.12'
     compile 'io.reactivex:rxjava:1.2.5'
     compile 'io.reactivex:rxandroid:0.24.0'
+    testCompile 'com.android.support.test:runner:0.5'
 }

library/src/androidTest/java/com/ackee/versioupdatehandler/ExampleInstrumentedTest.java

@@ -0,0 +1,80 @@
+package com.ackee.versioupdatehandler;
+
+
+import com.ackee.versioupdatehandler.model.BasicVersionsConfiguration;
+import com.ackee.versioupdatehandler.model.VersionFetchError;
+import com.ackee.versioupdatehandler.model.VersionStatus;
+import com.ackee.versioupdatehandler.model.VersionsConfiguration;
+
+import org.junit.Test;
+
+import rx.Single;
+import rx.functions.Func1;
+import rx.observers.TestSubscriber;
+
+/**
+ * Tests for {@link VersionStatusResolver}
+ *
+ * @author David Bilik [[email protected]]
+ * @since 06/02/2017
+ **/
+public class VersionStatusResolverTest {
+
+    public static final BasicVersionsConfiguration BASIC_VERSIONS_CONFIGURATION = new BasicVersionsConfiguration(10, 15);
+
+    @Test
+    public void should_fire_error() {
+        //any error should map to VersionFetchError
+        VersionStatusResolver resolver = new VersionStatusResolver(new VersionFetcher() {
+            @Override
+            public Single<VersionsConfiguration> fetch() {
+                return Single.error(new VersionFetchError());
+            }
+        });
+        TestSubscriber<VersionStatus> testSubscriber = TestSubscriber.create();
+        resolver.checkVersionStatus(0)
+                .subscribe(testSubscriber);
+        testSubscriber.assertError(VersionFetchError.class);
+        testSubscriber.assertNoValues();
+        testSubscriber.assertTerminalEvent();
+    }
+
+    @Test
+    public void should_be_up_to_date_greater_than_last() {
+        checkSuccess(15, VersionStatus.UP_TO_DATE);
+    }
+
+    @Test
+    public void should_be_up_to_date_same_as_last() {
+        checkSuccess(20, VersionStatus.UP_TO_DATE);
+    }
+
+    @Test
+    public void should_be_mandatory_update() {
+        checkSuccess(8, VersionStatus.UPDATE_REQUIRED);
+    }
+
+    @Test
+    public void should_be_not_mandatory_update() {
+        checkSuccess(13, VersionStatus.UPDATE_AVAILABLE);
+    }
+
+    private void checkSuccess(int actualVersion, VersionStatus expectedResult) {
+        VersionStatusResolver resolver = new VersionStatusResolver(new VersionFetcher() {
+            @Override
+            public Single<VersionsConfiguration> fetch() {
+                return Single.just(BASIC_VERSIONS_CONFIGURATION).map(new Func1<BasicVersionsConfiguration, VersionsConfiguration>() {
+                    @Override
+                    public VersionsConfiguration call(BasicVersionsConfiguration basicVersionsConfiguration) {
+                        return basicVersionsConfiguration;
+                    }
+                });
+            }
+        });
+        TestSubscriber<VersionStatus> testSubscriber = TestSubscriber.create();
+        resolver.checkVersionStatus(actualVersion)
+                .subscribe(testSubscriber);
+        testSubscriber.assertValue(expectedResult);
+        testSubscriber.assertNoErrors();
+    }
+}

library/src/test/java/com/ackee/versioupdatehandler/ExampleUnitTest.java

@@ -29,7 +29,7 @@ public class RestVersionFetcher implements VersionFetcher {
     private ApiDescription api = null;
 
     interface ApiDescription {
-        @GET("/app_version")
+        @GET("app_version")
         public Single<BasicVersionsConfiguration> getVersions();
     }
 
@@ -41,7 +41,8 @@ public RestVersionFetcher(String baseUrl) {
 
     @Override
     public Single<VersionsConfiguration> fetch() {
-        return getApi().getVersions()
+        return getApi()
+                .getVersions()
                 // Single<BasicVersionsConfiguration> is not subtype of Single<VersionsConfiguration> :(
                 .map(new Func1<BasicVersionsConfiguration, VersionsConfiguration>() {
                     @Override