Infer docsOnly from component stories shape

lib/api/src/lib/stories.ts

@@ -2,6 +2,7 @@ import React from 'react';
 import deprecate from 'util-deprecate';
 import dedent from 'ts-dedent';
 import mapValues from 'lodash/mapValues';
+import countBy from 'lodash/countBy';
 import {
   StoryId,
   ComponentTitle,
@@ -173,12 +174,14 @@ export const transformStoryIndexToStoriesHash = (
   index: StoryIndex,
   { provider }: { provider: Provider }
 ): StoriesHash => {
+  const countByTitle = countBy(Object.values(index.stories), 'title');
   const input = Object.entries(index.stories).reduce((acc, [id, { title, name, importPath }]) => {
+    const docsOnly = name === 'Page' && countByTitle[title] === 1;
     acc[id] = {
       id,
       kind: title,
       name,
-      parameters: { fileName: importPath, options: {} },
+      parameters: { fileName: importPath, options: {}, docsOnly },
     };
     return acc;
   }, {} as StoriesRaw);

lib/api/src/tests/stories.test.js

@@ -914,6 +914,59 @@ describe('stories API', () => {
       });
       expect(storedStoriesHash['component-a--story-1'].args).toBeUndefined();
     });
+
+    it('infers docs only if there is only one story and it has the name "Page"', async () => {
+      mockStories.mockReset().mockReturnValue({
+        'component-a--page': {
+          title: 'Component A',
+          name: 'Page', // Called "Page" but not only story
+          importPath: './path/to/component-a.ts',
+        },
+        'component-a--story-2': {
+          title: 'Component A',
+          name: 'Story 2',
+          importPath: './path/to/component-a.ts',
+        },
+        'component-b--page': {
+          title: 'Component B',
+          name: 'Page', // Page and only story
+          importPath: './path/to/component-b.ts',
+        },
+        'component-c--story-4': {
+          title: 'Component c',
+          name: 'Story 4', // Only story but not page
+          importPath: './path/to/component-c.ts',
+        },
+      });
+
+      const navigate = jest.fn();
+      const store = createMockStore();
+      const fullAPI = Object.assign(new EventEmitter(), {
+        setStories: jest.fn(),
+      });
+
+      const { api, init } = initStories({ store, navigate, provider, fullAPI });
+      Object.assign(fullAPI, api);
+
+      await init();
+
+      const { storiesHash: storedStoriesHash } = store.getState();
+
+      // We need exact key ordering, even if in theory JS doesn't guarantee it
+      expect(Object.keys(storedStoriesHash)).toEqual([
+        'component-a',
+        'component-a--page',
+        'component-a--story-2',
+        'component-b',
+        'component-b--page',
+        'component-c',
+        'component-c--story-4',
+      ]);
+      expect(storedStoriesHash['component-a--page'].parameters.docsOnly).toBe(false);
+      expect(storedStoriesHash['component-a--story-2'].parameters.docsOnly).toBe(false);
+      expect(storedStoriesHash['component-b--page'].parameters.docsOnly).toBe(true);
+      expect(storedStoriesHash['component-c--story-4'].parameters.docsOnly).toBe(false);
+    });
   });
 
   describe('STORY_PREPARED', () => {