refactor: add normal and reverse task grouping functions

Author: ilandikov

src/Query/Filter/Field.ts

@@ -364,4 +364,24 @@ export abstract class Field {
 
         return new RegExp(`^group by ${this.fieldNameSingularEscaped()}( reverse)?$`);
     }
+
+    /**
+     * Create a {@link Grouper} object for grouping tasks by this field's value,
+     * in the standard/normal group order for this field.
+     *
+     * @see {@link createReverseGrouper}
+     */
+    public createNormalGrouper(): Grouper {
+        return this.createGrouper(false);
+    }
+
+    /**
+     * Create a {@link Grouper} object for grouping tasks by this field's value,
+     * in the reverse of the standard/normal group order for this field.
+     *
+     * @see {@link createNormalGrouper}
+     */
+    public createReverseGrouper(): Grouper {
+        return this.createGrouper(true);
+    }
 }

tests/TaskGroups.test.ts

@@ -246,7 +246,10 @@ describe('Grouping tasks', () => {
         });
         const tasks = [t1, t2, t3];
 
-        const grouping: Grouper[] = [new FolderField().createGrouper(true), new FilenameField().createGrouper()];
+        const grouping: Grouper[] = [
+            new FolderField().createReverseGrouper(),
+            new FilenameField().createNormalGrouper(),
+        ];
 
         // Act
         const groups = new TaskGroups(grouping, tasks);