add support for arb files (flutter)

Resolves #64

CHANGELOG.md

@@ -3,13 +3,16 @@
 # easy-i18n Changelog
 
 ## [Unreleased]
-### Fixed
-- NullPointerException on key completion
-- Changelog handling in release flow
+### Added
+- Support for json based arb files (flutter)
 
 ### Changed
 - Updated plugin dependencies
 
+### Fixed
+- NullPointerException on key completion
+- Changelog handling in release flow
+
 ## [1.6.0]
 ### Added
 - The search function now supports full-text-search

src/main/java/de/marhali/easyi18n/DataStore.java

@@ -29,7 +29,8 @@ import java.util.function.Consumer;
 public class DataStore {
 
     private static final Set<IOStrategy> STRATEGIES = new LinkedHashSet<>(Arrays.asList(
-       new JsonIOStrategy(), new ModularizedJsonIOStrategy(),
+       new JsonIOStrategy("json"), new ModularizedJsonIOStrategy("json"),
+            new JsonIOStrategy("arb"), new ModularizedJsonIOStrategy("arb"),
        new YamlIOStrategy("yaml"), new YamlIOStrategy("yml"),
        new PropertiesIOStrategy()
     ));

src/main/java/de/marhali/easyi18n/io/json/JsonIOStrategy.java

@@ -27,10 +27,14 @@ import java.util.function.Consumer;
  * @author marhali
  */
 public class JsonIOStrategy implements IOStrategy {
-
-    private static final String FILE_EXTENSION = "json";
     private static final Gson GSON = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();
 
+    private final String FILE_EXTENSION;
+
+    public JsonIOStrategy(@NotNull String fileExtension) {
+        this.FILE_EXTENSION = fileExtension;
+    }
+
     @Override
     public boolean canUse(@NotNull Project project, @NotNull String localesPath, @NotNull SettingsState state) {
         VirtualFile directory = LocalFileSystem.getInstance().findFileByIoFile(new File(localesPath));

src/main/java/de/marhali/easyi18n/io/json/ModularizedJsonIOStrategy.java

@@ -33,9 +33,14 @@ import java.util.function.Consumer;
  */
 public class ModularizedJsonIOStrategy implements IOStrategy {
 
-    private static final String FILE_EXTENSION = "json";
     private static final Gson GSON = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();
 
+    private final String FILE_EXTENSION;
+
+    public ModularizedJsonIOStrategy(@NotNull String fileExtension) {
+        this.FILE_EXTENSION = fileExtension;
+    }
+
     @Override
     public boolean canUse(@NotNull Project project, @NotNull String localesPath, @NotNull SettingsState state) {
         VirtualFile directory = LocalFileSystem.getInstance().findFileByIoFile(new File(localesPath));