From 9d23bcb441f006d4e30b585e67ca773255fca930 Mon Sep 17 00:00:00 2001
From: Mike Duminy <mike@getwala.com>
Date: Wed, 22 Aug 2018 12:53:23 +0200
Subject: [PATCH 1/2] allow replacing of stories

fixes #4056

remove try catch in test
---
 lib/core/src/client/preview/client_api.js     |  2 +-
 .../src/client/preview/client_api.test.js     | 36 +++++++++++++++++++
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/lib/core/src/client/preview/client_api.js b/lib/core/src/client/preview/client_api.js
index b7d0c8c3ef3a..d7faf8f8091d 100644
--- a/lib/core/src/client/preview/client_api.js
+++ b/lib/core/src/client/preview/client_api.js
@@ -95,7 +95,7 @@ export default class ClientApi {
       }
 
       if (this._storyStore.hasStory(kind, storyName)) {
-        throw new Error(`Story of "${kind}" named "${storyName}" already exists`);
+        logger.warn(`Story of "${kind}" named "${storyName}" already exists`);
       }
 
       // Wrap the getStory function with each decorator. The first
diff --git a/lib/core/src/client/preview/client_api.test.js b/lib/core/src/client/preview/client_api.test.js
index 1a451da4cdeb..ccbb36d65366 100644
--- a/lib/core/src/client/preview/client_api.test.js
+++ b/lib/core/src/client/preview/client_api.test.js
@@ -344,4 +344,40 @@ describe('preview.client_api', () => {
       });
     });
   });
+
+  describe('storiesOf', () => {
+    class MockModule {
+      filename = 'mock';
+    }
+
+    describe('add', () => {
+      it('should replace stories when adding the same story', () => {
+        const module = new MockModule();
+        const stories = [jest.fn(), jest.fn()];
+        const warn = jest.spyOn(global.console, 'warn').mockImplementationOnce(jest.fn());
+
+        const api = new ClientAPI();
+        expect(api.getStorybook()).toEqual([]);
+
+        api.storiesOf('kind', module).add('story', stories[0]);
+        expect(api.getStorybook()).toEqual([
+          {
+            fileName: 'mock',
+            kind: 'kind',
+            stories: [{ name: 'story', render: stories[0] }],
+          },
+        ]);
+
+        api.storiesOf('kind', module).add('story', stories[1]);
+        expect(warn).toHaveBeenCalled();
+        expect(api.getStorybook()).toEqual([
+          {
+            fileName: 'mock',
+            kind: 'kind',
+            stories: [{ name: 'story', render: stories[1] }],
+          },
+        ]);
+      });
+    });
+  });
 });

From 8041d150f90481119c37af7126a80b15d33f8a94 Mon Sep 17 00:00:00 2001
From: Mike Duminy <mike@getwala.com>
Date: Thu, 23 Aug 2018 13:52:21 +0200
Subject: [PATCH 2/2] story replacement test to work with v3 and v4

fixes #4056
---
 .../src/client/preview/client_api.test.js     | 56 +++++++++++--------
 1 file changed, 34 insertions(+), 22 deletions(-)

diff --git a/lib/core/src/client/preview/client_api.test.js b/lib/core/src/client/preview/client_api.test.js
index ccbb36d65366..b83284ffccc2 100644
--- a/lib/core/src/client/preview/client_api.test.js
+++ b/lib/core/src/client/preview/client_api.test.js
@@ -346,37 +346,49 @@ describe('preview.client_api', () => {
   });
 
   describe('storiesOf', () => {
-    class MockModule {
-      filename = 'mock';
-    }
-
     describe('add', () => {
       it('should replace stories when adding the same story', () => {
-        const module = new MockModule();
-        const stories = [jest.fn(), jest.fn()];
-        const warn = jest.spyOn(global.console, 'warn').mockImplementationOnce(jest.fn());
-
+        const stories = [jest.fn().mockReturnValue('story1'), jest.fn().mockReturnValue('story2')];
         const api = new ClientAPI();
         expect(api.getStorybook()).toEqual([]);
 
         api.storiesOf('kind', module).add('story', stories[0]);
-        expect(api.getStorybook()).toEqual([
-          {
-            fileName: 'mock',
-            kind: 'kind',
-            stories: [{ name: 'story', render: stories[0] }],
-          },
-        ]);
+        {
+          const book = api.getStorybook();
+          expect(book).toHaveLength(1);
+
+          const entry = book[0];
+          expect(entry.kind).toMatch('kind');
+          expect(entry.stories).toHaveLength(1);
+          expect(entry.stories[0].name).toBe('story');
+
+          // v3 returns the same function we passed in
+          if (jest.isMockFunction(entry.stories[0].render)) {
+            expect(entry.stories[0].render).toBe(stories[0]);
+          } else {
+            expect(entry.stories[0].render()).toBe('story1');
+          }
+        }
 
+        const warn = jest.spyOn(global.console, 'warn').mockImplementationOnce(jest.fn());
         api.storiesOf('kind', module).add('story', stories[1]);
         expect(warn).toHaveBeenCalled();
-        expect(api.getStorybook()).toEqual([
-          {
-            fileName: 'mock',
-            kind: 'kind',
-            stories: [{ name: 'story', render: stories[1] }],
-          },
-        ]);
+        {
+          const book = api.getStorybook();
+          expect(book).toHaveLength(1);
+
+          const entry = book[0];
+          expect(entry.kind).toMatch('kind');
+          expect(entry.stories).toHaveLength(1);
+          expect(entry.stories[0].name).toBe('story');
+
+          // v3 returns the same function we passed in
+          if (jest.isMockFunction(entry.stories[0].render)) {
+            expect(entry.stories[0].render).toBe(stories[0]);
+          } else {
+            expect(entry.stories[0].render()).toBe('story2');
+          }
+        }
       });
     });
   });