Refactor settings/tabs/TabsJsonHelper.java#getTabsFromJson to recieve

not null arguments

Author: Yevhen Babiichuk (DustDFG)

app/src/main/java/org/schabi/newpipe/settings/tabs/TabsJsonHelper.java

@@ -1,5 +1,6 @@
 package org.schabi.newpipe.settings.tabs;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 import com.grack.nanojson.JsonArray;
@@ -39,9 +40,9 @@ private TabsJsonHelper() { }
      * @return a list of {@link Tab tabs}.
      * @throws InvalidJsonException if the JSON string is not valid
      */
-    public static List<Tab> getTabsFromJson(@Nullable final String tabsJson)
+    public static List<Tab> getTabsFromJson(@NonNull final String tabsJson)
             throws InvalidJsonException {
-        if (tabsJson == null || tabsJson.isEmpty()) {
+        if (tabsJson.isEmpty()) {
             return getDefaultTabs();
         }
 

app/src/main/java/org/schabi/newpipe/settings/tabs/TabsManager.java

@@ -28,7 +28,7 @@ public static TabsManager getManager(final Context context) {
     }
 
     public List<Tab> getTabs() {
-        final String savedJson = sharedPreferences.getString(savedTabsKey, null);
+        final String savedJson = sharedPreferences.getString(savedTabsKey, "");
         try {
             return TabsJsonHelper.getTabsFromJson(savedJson);
         } catch (final TabsJsonHelper.InvalidJsonException e) {

app/src/test/java/org/schabi/newpipe/settings/tabs/TabsJsonHelperTest.java

@@ -21,15 +21,11 @@ public class TabsJsonHelperTest {
     private static final String JSON_TAB_ID_KEY = "tab_id";
 
     @Test
-    public void testEmptyAndNullRead() throws TabsJsonHelper.InvalidJsonException {
+    public void testEmptyRead() throws TabsJsonHelper.InvalidJsonException {
         final List<Tab> defaultTabs = TabsJsonHelper.getDefaultTabs();
 
         final String emptyTabsJson = "{\"" + JSON_TABS_ARRAY_KEY + "\":[]}";
-        List<Tab> items = TabsJsonHelper.getTabsFromJson(emptyTabsJson);
-        assertEquals(items, defaultTabs);
-
-        final String nullSource = null;
-        items = TabsJsonHelper.getTabsFromJson(nullSource);
+        final List<Tab> items = TabsJsonHelper.getTabsFromJson(emptyTabsJson);
         assertEquals(items, defaultTabs);
     }