One class per javascript file.

static/plugin_dbui/src/form/field/Dict.js

-/**
- * Extend the default type for Ext.grid.column in order to render JSON object.
- *
- * @since 0.4.15.0
- *
- */
-Ext.define('Ext.grid.JsonColumn', {
-
-    extend: 'Ext.grid.column.Column',
-    alias: 'widget.jsoncolumn',
-
-    constructor: function () {
-
-        this.renderer = JSON.stringify;
-        this.callParent(arguments);
-    }
-});
-
 /**
  * The Dict widget is an Ext.grid.PropertyGrid which is associated
  * to a JSON database field. It can be embedded in Ext.form.Panel.

static/plugin_dbui/src/grid/JsonColumn.js

+/**
+ * Extend the default type for Ext.grid.column in order to render JSON object.
+ *
+ * @since 0.4.15.0
+ *
+ */
+Ext.define('Ext.grid.JsonColumn', {
+
+    extend: 'Ext.grid.column.Column',
+    alias: 'widget.jsoncolumn',
+
+    constructor: function () {
+
+        this.renderer = JSON.stringify;
+        this.callParent(arguments);
+    }
+});