Merge pull request #58 from daemontus/dir-existence-check

Add checks for cache dir validity. Closes #57

core/src/main/java/io/rx_cache/internal/Locale.java

@@ -21,6 +21,8 @@ public interface Locale {
   String NOT_DATA_RETURN_WHEN_CALLING_OBSERVABLE_LOADER =
       "The Loader provided did not return any data and there is not data to load from the Cache";
   String REPOSITORY_DISK_ADAPTER_CAN_NOT_BE_NULL = "File cache directory can not be null";
+  String REPOSITORY_DISK_ADAPTER_DOES_NOT_EXIST = "File cache directory does not exist";
+  String REPOSITORY_DISK_ADAPTER_IS_NOT_WRITABLE = "File cache directory is not writable";
   String JSON_CONVERTER_CAN_NOT_BE_NULL = "JsonConverter can not be null";
   String NOT_OBSERVABLE_LOADER_FOUND = " requires an instance of type observable";
   String JUST_ONE_INSTANCE = " requires just one instance of type ";

runtime/src/main/java/io/rx_cache/internal/RxCache.java

@@ -85,6 +85,12 @@ public RxCache persistence(File cacheDirectory, JolyglotGenerics jolyglot) {
       if (cacheDirectory == null) {
         throw new InvalidParameterException(Locale.REPOSITORY_DISK_ADAPTER_CAN_NOT_BE_NULL);
       }
+      if (!cacheDirectory.exists()) {
+        throw new InvalidParameterException(Locale.REPOSITORY_DISK_ADAPTER_DOES_NOT_EXIST);
+      }
+      if (!cacheDirectory.canWrite()) {
+        throw new InvalidParameterException(Locale.REPOSITORY_DISK_ADAPTER_IS_NOT_WRITABLE);
+      }
 
       if (jolyglot == null) {
         throw new InvalidParameterException(Locale.JSON_CONVERTER_CAN_NOT_BE_NULL);

runtime/src/test/java/io/rx_cache/internal/RxCacheBuilderValidationTest.java

@@ -0,0 +1,49 @@
+package io.rx_cache.internal;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+import java.security.InvalidParameterException;
+
+/**
+ * Created by daemontus on 02/09/16.
+ */
+public class RxCacheBuilderValidationTest {
+
+    @Rule
+    public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+    @Test(expected = InvalidParameterException.class)
+    public void Cache_Directory_Null() {
+        new RxCache.Builder()
+            .persistence(null, Jolyglot$.newInstance());
+    }
+
+    @Test(expected = InvalidParameterException.class)
+    public void Jolyglot_Null() {
+        new RxCache.Builder()
+                .persistence(temporaryFolder.getRoot(), null);
+    }
+
+    @Test(expected = InvalidParameterException.class)
+    public void Cache_Directory_Not_Exist() {
+        File cacheDir = new File(temporaryFolder.getRoot(), "non_existent_folder");
+        new RxCache.Builder()
+                .persistence(cacheDir, Jolyglot$.newInstance());
+    }
+
+    @Test(expected = InvalidParameterException.class)
+    public void Cache_Directory_Not_Writable() {
+        File cacheDir = new File(temporaryFolder.getRoot(), "non_existent_folder");
+        if (!cacheDir.mkdirs()) {
+            throw new IllegalStateException("Cannot create temporary directory");
+        }
+        if (!cacheDir.setWritable(false, false)) {
+            throw new IllegalStateException("Cannot modify permissions");
+        }
+        new RxCache.Builder()
+                .persistence(cacheDir, Jolyglot$.newInstance());
+    }
+}