implement json5 parser strategy

src/main/java/de/marhali/easyi18n/io/parser/ParserStrategyType.java

@@ -1,6 +1,7 @@
 package de.marhali.easyi18n.io.parser;
 
 import de.marhali.easyi18n.io.parser.json.JsonParserStrategy;
+import de.marhali.easyi18n.io.parser.json5.Json5ParserStrategy;
 import de.marhali.easyi18n.io.parser.properties.PropertiesParserStrategy;
 import de.marhali.easyi18n.io.parser.yaml.YamlParserStrategy;
 
@@ -10,6 +11,7 @@ import de.marhali.easyi18n.io.parser.yaml.YamlParserStrategy;
  */
 public enum ParserStrategyType {
     JSON(JsonParserStrategy.class),
+    JSON5(Json5ParserStrategy.class),
     YAML(YamlParserStrategy.class),
     YML(YamlParserStrategy.class),
     PROPERTIES(PropertiesParserStrategy.class),

src/main/java/de/marhali/easyi18n/io/parser/json5/Json5ParserStrategy.java

@@ -0,0 +1,58 @@
+package de.marhali.easyi18n.io.parser.json5;
+
+import com.intellij.openapi.vfs.VirtualFile;
+
+import de.marhali.easyi18n.io.parser.ParserStrategy;
+import de.marhali.easyi18n.model.SettingsState;
+import de.marhali.easyi18n.model.TranslationData;
+import de.marhali.easyi18n.model.TranslationFile;
+import de.marhali.easyi18n.model.TranslationNode;
+import de.marhali.json5.Json5;
+import de.marhali.json5.Json5Element;
+import de.marhali.json5.Json5Object;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.Objects;
+
+/**
+ * Json5 file format parser strategy
+ * @author marhali
+ */
+public class Json5ParserStrategy extends ParserStrategy {
+
+    private static final Json5 JSON5 = Json5.builder(builder ->
+            builder.allowInvalidSurrogate().trailingComma().indentFactor(4).build());
+
+    public Json5ParserStrategy(@NotNull SettingsState settings) {
+        super(settings);
+    }
+
+    @Override
+    public void read(@NotNull TranslationFile file, @NotNull TranslationData data) throws Exception {
+        data.addLocale(file.getLocale());
+
+        VirtualFile vf = file.getVirtualFile();
+        TranslationNode targetNode = super.getOrCreateTargetNode(file, data);
+
+        try (Reader reader = new InputStreamReader(vf.getInputStream(), vf.getCharset())) {
+            Json5Element input = JSON5.parse(reader);
+            if(input != null && input.isJsonObject()) {
+                Json5Mapper.read(file.getLocale(), input.getAsJsonObject(), targetNode);
+            }
+        }
+    }
+
+    @Override
+    public void write(@NotNull TranslationData data, @NotNull TranslationFile file) throws Exception {
+        TranslationNode targetNode = super.getTargetNode(data, file);
+
+        Json5Object output = new Json5Object();
+        Json5Mapper.write(file.getLocale(), output, Objects.requireNonNull(targetNode));
+
+        VirtualFile vf = file.getVirtualFile();
+        vf.setBinaryContent(JSON5.serialize(output).getBytes(vf.getCharset()));
+    }
+}

src/main/resources/messages.properties

@@ -17,7 +17,7 @@ settings.path.text=Locales directory
 settings.strategy.title=Translation file structure
 settings.strategy.folder=Single Directory;Modularized: Locale / Namespace;Modularized: Namespace / Locale
 settings.strategy.folder.tooltip=What is the folder structure of your translation files?
-settings.strategy.parser=JSON;YAML;YML;Properties;ARB
+settings.strategy.parser=JSON;JSON5;YAML;YML;Properties;ARB
 settings.strategy.parser.tooltip=Which file parser should be used to process your translation files?
 settings.strategy.file-pattern.tooltip=Defines a wildcard matcher to filter relevant translation files. For example *.json, *.???.
 settings.preview=Preview locale