fix: show caret for top-level $refs

fixes https://github.com/stoplightio/platform-internal/issues/1568

Author: P0lip

src/components/SchemaRow.tsx

@@ -1,10 +1,11 @@
-import { IRowRendererOptions, Tree } from '@stoplight/tree-list';
+import { IRowRendererOptions, isParentNode, Tree } from '@stoplight/tree-list';
 import cn from 'classnames';
 import * as React from 'react';
 
 import { getNodeMetadata, getSchemaNodeMetadata } from '../tree/metadata';
 import { GoToRefHandler, SchemaKind, SchemaTreeListNode } from '../types';
 import { getPrimaryType } from '../utils/getPrimaryType';
+import { isRefNode } from '../utils/guards';
 import { Caret, Description, Divider, Property, Validations } from './shared';
 
 export interface ISchemaRow {
@@ -48,17 +49,23 @@ export const SchemaPropertyRow: typeof SchemaRow = ({ node, onGoToRef, rowOption
 
   return (
     <>
-      {'children' in node && Tree.getLevel(node) > 0 && (
+      {isRefNode(schemaNode) || (isParentNode(node) && Tree.getLevel(node) > 0) ? (
         <Caret
           isExpanded={!!rowOptions.isExpanded}
           style={{
-            left: ICON_DIMENSION * -1 + ROW_OFFSET / -2,
             width: ICON_DIMENSION,
             height: ICON_DIMENSION,
+            ...(isRefNode(schemaNode)
+              ? {
+                  position: 'relative',
+                }
+              : {
+                  left: ICON_DIMENSION * -1 + ROW_OFFSET / -2,
+                }),
           }}
           size={ICON_SIZE}
         />
-      )}
+      ) : null}
 
       {node.parent !== null &&
         node.parent.children.length > 0 &&

src/components/__tests__/SchemaRow.spec.tsx

@@ -8,6 +8,7 @@ import { SchemaTree } from '../../tree';
 import { metadataStore } from '../../tree/metadata';
 import { SchemaKind, SchemaTreeListNode } from '../../types';
 import { SchemaErrorRow, SchemaPropertyRow, SchemaRow } from '../SchemaRow';
+import { Caret } from '../shared';
 import { Validations } from '../shared/Validations';
 
 describe('SchemaRow component', () => {
@@ -51,6 +52,36 @@ describe('SchemaRow component', () => {
     expect(wrapper).toHaveText('enum:null,0,false');
   });
 
+  test('should render caret for top-level $ref', () => {
+    const schema: JSONSchema4 = {
+      $ref: '#/definitions/foo',
+      definitions: {
+        foo: {
+          type: 'string',
+        },
+      },
+    };
+
+    const tree = new SchemaTree(schema, new TreeState(), {
+      expandedDepth: Infinity,
+      mergeAllOf: false,
+      resolveRef: void 0,
+    });
+
+    tree.populate();
+
+    const wrapper = shallow(<SchemaRow node={tree.itemAt(0)!} rowOptions={{}} />)
+      .find(SchemaPropertyRow)
+      .shallow();
+
+    expect(wrapper.find(Caret)).toExist();
+    expect(wrapper.find(Caret)).toHaveProp('style', {
+      height: 20,
+      position: 'relative',
+      width: 20,
+    });
+  });
+
   describe('expanding errors', () => {
     describe('$refs', () => {
       let tree: SchemaTree;