From fa126f6f1a7e37dc01974b21848ba4ea108f2c4a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ga=C3=ABtan=20Maisse?= <gmaisse@solocal.com>
Date: Tue, 7 Jul 2020 08:31:29 +0200
Subject: [PATCH] fix(essentials): use `require.resolve` to ensure Yarn PnP
 compatibility

Files of various addons should be resolved in the context of `addon-essentials` and not in the one of SB user projects.
File to load can be `preset.js`, `register.js`, or the package entry point, so we need to check all these cases as it's done in `lib/core/src/server/presets.js`.
---
 addons/essentials/src/index.ts | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/addons/essentials/src/index.ts b/addons/essentials/src/index.ts
index 7cea28fe846..6eb7d03c154 100644
--- a/addons/essentials/src/index.ts
+++ b/addons/essentials/src/index.ts
@@ -1,4 +1,4 @@
-import path from 'path';
+import path, { join } from 'path';
 import { logger } from '@storybook/node-logger';
 
 interface PresetOptions {
@@ -33,8 +33,30 @@ export function addons(options: PresetOptions = {}) {
   };
 
   const main = requireMain(options.configDir);
-  return ['actions', 'docs', 'controls', 'backgrounds', 'viewport']
-    .filter((key) => (options as any)[key] !== false)
-    .map((key) => `@storybook/addon-${key}`)
-    .filter((addon) => !checkInstalled(addon, main));
+  return (
+    ['actions', 'docs', 'controls', 'backgrounds', 'viewport']
+      .filter((key) => (options as any)[key] !== false)
+      .map((key) => `@storybook/addon-${key}`)
+      .filter((addon) => !checkInstalled(addon, main))
+      // Use `require.resolve` to ensure Yarn PnP compatibility
+      // Files of various addons should be resolved in the context of `addon-essentials` as they are listed as deps here
+      // and not in `@storybook/core` nor in SB user projects. If `@storybook/core` make the require itself Yarn 2 will
+      // throw an error saying that the package to require must be added as a dependency. Doing `require.resolve` will
+      // allow `@storybook/core` to work with absolute path directly, no more require of dep no more issue.
+      // File to load can be `preset.js`, `register.js`, or the package entry point, so we need to check all these cases
+      // as it's done in `lib/core/src/server/presets.js`.
+      .map((addon) => {
+        try {
+          return require.resolve(join(addon, 'preset'));
+          // eslint-disable-next-line no-empty
+        } catch (err) {}
+
+        try {
+          return require.resolve(join(addon, 'register'));
+          // eslint-disable-next-line no-empty
+        } catch (err) {}
+
+        return require.resolve(addon);
+      })
+  );
 }