Core: Single story option in iframe view

lib/client-api/src/story_store.test.ts

@@ -1583,4 +1583,78 @@ describe('preview.story_store', () => {
       expect(onStorySpecified).not.toHaveBeenCalled();
     });
   });
+
+  describe('In Single Story mode', () => {
+    describe('when storySpecifier is story id', () => {
+      it('adds only one story specified in selection specifier when addStory is called', () => {
+        const store = new StoryStore({ channel });
+        store.setSelectionSpecifier({
+          storySpecifier: toId('kind-1', 'story-1.1'),
+          viewMode: 'story',
+          singleStory: true,
+        });
+
+        store.startConfiguring();
+        addStoryToStore(store, 'kind-1', 'story-1.1', () => 0);
+        addStoryToStore(store, 'kind-1', 'story-1.2', () => 0);
+        store.finishConfiguring();
+
+        expect(store.fromId(toId('kind-1', 'story-1.1'))).toBeTruthy();
+        expect(store.fromId(toId('kind-1', 'story-1.2'))).toBeFalsy();
+      });
+
+      it('adds only kind metadata specified in selection specifier when addKindMetadata is called', () => {
+        const store = new StoryStore({ channel });
+        store.setSelectionSpecifier({
+          storySpecifier: toId('kind-1', 'story-1.1'),
+          viewMode: 'story',
+          singleStory: true,
+        });
+
+        store.startConfiguring();
+        store.addKindMetadata('kind-1', {});
+        store.addKindMetadata('kind-2', {});
+        store.finishConfiguring();
+
+        expect(store._kinds['kind-1']).toBeDefined();
+        expect(store._kinds['kind-2']).not.toBeDefined();
+      });
+    });
+
+    describe('when storySpecifier is object', () => {
+      it('adds only one story specified in selection specifier when addStory is called', () => {
+        const store = new StoryStore({ channel });
+        store.setSelectionSpecifier({
+          storySpecifier: { kind: 'kind-1', name: 'story-1.1' },
+          viewMode: 'story',
+          singleStory: true,
+        });
+
+        store.startConfiguring();
+        addStoryToStore(store, 'kind-1', 'story-1.1', () => 0);
+        addStoryToStore(store, 'kind-1', 'story-1.2', () => 0);
+        store.finishConfiguring();
+
+        expect(store.fromId(toId('kind-1', 'story-1.1'))).toBeTruthy();
+        expect(store.fromId(toId('kind-1', 'story-1.2'))).toBeFalsy();
+      });
+
+      it('adds only kind metadata specified in selection specifier when addKindMetadata is called', () => {
+        const store = new StoryStore({ channel });
+        store.setSelectionSpecifier({
+          storySpecifier: { kind: 'kind-1', name: 'story-1.1' },
+          viewMode: 'story',
+          singleStory: true,
+        });
+
+        store.startConfiguring();
+        store.addKindMetadata('kind-1', {});
+        store.addKindMetadata('kind-2', {});
+        store.finishConfiguring();
+
+        expect(store._kinds['kind-1']).toBeDefined();
+        expect(store._kinds['kind-2']).not.toBeDefined();
+      });
+    });
+  });
 });

lib/client-api/src/story_store.ts

@@ -10,6 +10,7 @@ import deprecate from 'util-deprecate';
 import { Channel } from '@storybook/channels';
 import Events from '@storybook/core-events';
 import { logger } from '@storybook/client-logger';
+import { sanitize, toId } from '@storybook/csf';
 import {
   Comparator,
   Parameters,
@@ -32,6 +33,7 @@ import {
   ArgTypesEnhancer,
   StoreSelectionSpecifier,
   StoreSelection,
+  StorySpecifier,
 } from './types';
 import { combineArgs, mapArgsToTypes, validateOptions } from './args';
 import { HooksContext } from './hooks';
@@ -49,6 +51,22 @@ type KindMetadata = StoryMetadata & { order: number };
 
 const STORAGE_KEY = '@storybook/preview/store';
 
+function extractSanitizedKindNameFromStorySpecifier(storySpecifier: StorySpecifier): string {
+  if (typeof storySpecifier === 'string') {
+    return storySpecifier.split('--').shift();
+  }
+
+  return sanitize(storySpecifier.kind);
+}
+
+function extractIdFromStorySpecifier(storySpecifier: StorySpecifier): string {
+  if (typeof storySpecifier === 'string') {
+    return storySpecifier;
+  }
+
+  return toId(storySpecifier.kind, storySpecifier.name);
+}
+
 const isStoryDocsOnly = (parameters?: Parameters) => {
   return parameters && parameters.docsOnly;
 };
@@ -301,6 +319,10 @@ export default class StoryStore {
   }
 
   addKindMetadata(kind: string, { parameters = {}, decorators = [], loaders = [] }: StoryMetadata) {
+    if (this.shouldBlockAddingKindMetadata(kind)) {
+      return;
+    }
+
     this.ensureKind(kind);
     if (parameters) {
       checkGlobals(parameters);
@@ -328,6 +350,21 @@ export default class StoryStore {
     );
   }
 
+  shouldBlockAddingStory(id: string): boolean {
+    return (
+      this.isSingleStoryMode() &&
+      id !== extractIdFromStorySpecifier(this._selectionSpecifier.storySpecifier)
+    );
+  }
+
+  shouldBlockAddingKindMetadata(kind: string): boolean {
+    return (
+      this.isSingleStoryMode() &&
+      sanitize(kind) !==
+        extractSanitizedKindNameFromStorySpecifier(this._selectionSpecifier.storySpecifier)
+    );
+  }
+
   addStory(
     {
       id,
@@ -350,6 +387,10 @@ export default class StoryStore {
         'Cannot add a story when not configuring, see https://github.com/storybookjs/storybook/blob/next/MIGRATION.md#story-store-immutable-outside-of-configuration'
       );
 
+    if (this.shouldBlockAddingStory(id)) {
+      return;
+    }
+
     checkGlobals(storyParameters);
     checkStorySort(storyParameters);
 
@@ -658,6 +699,15 @@ export default class StoryStore {
     }
   }
 
+  isSingleStoryMode(): boolean {
+    if (!this._selectionSpecifier) {
+      return false;
+    }
+
+    const { singleStory, storySpecifier } = this._selectionSpecifier;
+    return storySpecifier && storySpecifier !== '*' && singleStory;
+  }
+
   getSelection = (): StoreSelection => this._selection;
 
   getDataForManager = () => {

lib/client-api/src/types.ts

@@ -31,11 +31,12 @@ export interface StoryMetadata {
 }
 export type ArgTypesEnhancer = (context: StoryContext) => ArgTypes;
 
-type StorySpecifier = StoryId | { name: StoryName; kind: StoryKind } | '*';
+export type StorySpecifier = StoryId | { name: StoryName; kind: StoryKind } | '*';
 
 export interface StoreSelectionSpecifier {
   storySpecifier: StorySpecifier;
   viewMode: ViewMode;
+  singleStory?: boolean;
   args?: Args;
 }
 

lib/core-client/src/preview/url.test.ts

@@ -73,29 +73,41 @@ describe('url', () => {
       expect(getSelectionSpecifierFromPath()).toEqual({
         storySpecifier: 'story--id',
         viewMode: 'story',
+        singleStory: false,
       });
     });
     it('should handle id queries with *', () => {
       document.location.search = '?id=*';
       expect(getSelectionSpecifierFromPath()).toEqual({
         storySpecifier: '*',
         viewMode: 'story',
+        singleStory: false,
       });
     });
     it('should redirect legacy queries', () => {
       document.location.search = '?selectedKind=kind&selectedStory=story';
       expect(getSelectionSpecifierFromPath()).toEqual({
         storySpecifier: { kind: 'kind', name: 'story' },
         viewMode: 'story',
+        singleStory: false,
       });
     });
     it('should parse args', () => {
       document.location.search = '?id=story--id&args=obj.key:val';
       expect(getSelectionSpecifierFromPath()).toEqual({
         storySpecifier: 'story--id',
         viewMode: 'story',
+        singleStory: false,
         args: { obj: { key: 'val' } },
       });
     });
+    it('should handle singleStory param', () => {
+      document.location.search = '?id=abc&singleStory=true';
+      expect(getSelectionSpecifierFromPath()).toEqual({
+        storySpecifier: 'abc',
+        viewMode: 'story',
+        singleStory: true,
+      });
+    });
   });
 });

lib/core-client/src/preview/url.ts

@@ -72,11 +72,12 @@ export const getSelectionSpecifierFromPath: () => StoreSelectionSpecifier = () =
     viewMode = 'story';
   }
 
+  const singleStory = getFirstString(query.singleStory) === 'true';
   const path = getFirstString(query.path);
   const storyId = path ? pathToId(path) : getFirstString(query.id);
 
   if (storyId) {
-    return { storySpecifier: storyId, args, viewMode };
+    return { storySpecifier: storyId, args, viewMode, singleStory };
   }
 
   // Legacy URL format
@@ -85,7 +86,7 @@ export const getSelectionSpecifierFromPath: () => StoreSelectionSpecifier = () =
 
   if (kind && name) {
     deprecatedLegacyQuery();
-    return { storySpecifier: { kind, name }, args, viewMode };
+    return { storySpecifier: { kind, name }, args, viewMode, singleStory };
   }
   return null;
 };