added tests for FakeValuesService, added exception handling

pom.xml

@@ -64,6 +64,12 @@
             <version>0.9.9-RC1</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-all</artifactId>
+            <version>1.9.5</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <build>
 		<pluginManagement>

src/main/java/com/github/javafaker/service/FakeValuesService.java

@@ -22,7 +22,11 @@ public class FakeValuesService {
         logger.info("Using locale " + locale);
 
         String languageCode = locale.getLanguage();
-        Map valuesMap = (Map) new Yaml().load(findStream(languageCode + ".yml"));
+        final InputStream stream = findStream(languageCode + ".yml");
+        if (stream == null) {
+            throw new LocaleDoesNotExistException(String.format("%s could not be found, does not have a corresponding yaml file", locale));
+        }
+        Map valuesMap = (Map) new Yaml().load(stream);
         valuesMap = (Map) valuesMap.get(languageCode);
         fakeValuesMap = (Map<String, Object>) valuesMap.get("faker");
         this.randomService = randomService;
@@ -36,7 +40,6 @@ public class FakeValuesService {
         return getClass().getClassLoader().getResourceAsStream(filename);
     }
 
-
     /**
      * Fetch a random value from an array item specified by the key
      *

src/main/java/com/github/javafaker/service/LocaleDoesNotExistException.java

@@ -0,0 +1,7 @@
+package com.github.javafaker.service;
+
+public class LocaleDoesNotExistException extends RuntimeException {
+    public LocaleDoesNotExistException(String message) {
+        super(message);
+    }
+}

src/test/java/com/github/javafaker/service/FakeValuesServiceTest.java

@@ -0,0 +1,41 @@
+package com.github.javafaker.service;
+
+import java.util.Locale;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Mockito.when;
+
+public class FakeValuesServiceTest {
+
+    @Mock
+    private RandomService randomService;
+
+    @Before
+    public void before() {
+        MockitoAnnotations.initMocks(this);
+        when(randomService.nextInt(anyInt())).thenReturn(0);
+    }
+
+    @Test
+    public void localeShouldLoadWhenItExists() {
+        new FakeValuesService(new Locale("test"), randomService);
+    }
+
+    @Test(expected = LocaleDoesNotExistException.class)
+    public void localeShouldThrowException() {
+        new FakeValuesService(new Locale("Does not exist"), randomService);
+    }
+
+    @Test
+    public void fetchStringShouldReturnValue() {
+        final FakeValuesService fakeValueService = new FakeValuesService(new Locale("test"), randomService);
+        assertThat(fakeValueService.fetchString("property.dummy"), is("x"));
+    }
+}

src/test/resources/test.yml

@@ -1,4 +1,4 @@
-en:
+test:
   faker:
-    abc:
-	  def: [x, y, z]
+    property:
+       dummy: [x, y, z]