Merge pull request #8 from joshuajaco/add-scopes

Enable scoped sharing of workspaces

Author: joshuajaco

docs/rules/no-cross-imports.md

@@ -8,15 +8,15 @@ This rule takes one argument:
 
 ```
 ...
-"workspaces/no-cross-imports": ["error", { allow: ["@project/A", "@project/B"] }]
+"workspaces/no-cross-imports": ["error", { allow: ["@project/A", "@project/B"], scopes: { enable: true, folderName: 'shared' } }]
 ...
 ```
 
 ### allow
 
 Takes a single or a list of package names to exclude from this rule.
 
-## Example
+#### Example
 
 These examples have the following project structure:
 
@@ -46,3 +46,91 @@ import bar from '../B/bar';
 // inside "project/index.js"
 import foo from './packages/B/foo';
 ```
+
+### scopes
+
+Takes either a boolean or an options object. Defaults to `false`.
+
+Scopes are a way to partially allow imports across workspace boundaries.
+In larger monorepos, you might run into a situation where you want to group code
+across _some_ packages, but not all of them. A natural way to do this would be
+to create folder structure that visualizes this. So your structure might look
+like this:
+
+```
+project
+└─── packages
+     └─── shared-components/
+          └─── package.json
+     └─── welcome-page/
+          └─── package.json
+     └─── user-management/
+          └─── registration/
+               └─── package.json
+          └─── login/
+               └─── package.json
+```
+                                                                         
+Now, we may want to share code across the packages in the `user-management`
+section (e.g. fetching the user object, user form components etc.). With scopes,
+i am always allowed to import from a package with a **special folder name**
+(see below) given that it shares a common folder parent. So for
+the above case, I would be able to do this:
+
+```
+project
+└─── packages
+     └─── shared-components/
+          └─── package.json
+     └─── welcome-page/
+          └─── package.json
+     └─── user-management/
+          └─── shared/
+               └─── package.json
+          └─── registration/
+               └─── package.json
+          └─── login/
+               └─── package.json
+```
+
+When passing a boolean, the default folder name `shared` will be used. If you
+want to configure this, pass another string via the `folderName` key.
+
+#### Example
+
+These examples have the following project structure:
+
+```
+project
+└─── packages
+     └─── shared-components/
+          └─── package.json
+     └─── welcome-page/
+          └─── package.json
+     └─── user-management/
+          └─── shared/
+               └─── package.json
+          └─── registration/
+               └─── package.json
+          └─── login/
+               └─── package.json
+```
+
+Examples of **incorrect** code for this rule:
+
+```js
+// inside "project/packages/welcome-page/index.js"
+// configuration: [{ allow: "@project/user-management-shared", scopes: true }]
+import foo from '@project/user-management-shared';
+```
+
+Examples of **correct** code for this rule:
+
+```js
+// inside "project/packages/user-management/registration/index.js"
+// configuration: [{ allow: "@project/user-management-shared", scopes: true }]
+import foo from '@project/user-management-shared';
+
+// inside "project/index.js"
+import foo from './packages/user-management/registration';
+```

lib/rules/no-cross-imports.js

@@ -26,31 +26,70 @@ module.exports.meta = {
             },
           ],
         },
+        scopes: {
+          anyOf: [
+            { type: 'boolean', additionalProperties: false },
+            {
+              type: 'object',
+              additionalProperties: false,
+              properties: {
+                enable: { type: 'boolean' },
+                folderName: { type: 'string' },
+              },
+            },
+          ],
+        },
       },
     },
   ],
 };
 
+const filterSharedPackagesInCurrentScope = (
+  { location: currentLocation },
+  scopedEnabled,
+  scopedSharingFolderName,
+) => ({ location }) => {
+  if (!scopedEnabled) return true;
+  const locationArray = location.split('/');
+  const forbiddenPackageParent = locationArray.slice(0, -1).join('/');
+  if (!isSubPath(forbiddenPackageParent, currentLocation)) {
+    return true;
+  }
+
+  return locationArray[locationArray.length - 1] !== scopedSharingFolderName;
+};
+
 module.exports.create = (context) => {
   const {
-    options: [{ allow = [] } = {}],
+    options: [{ allow = [], scopes = { enable: false } } = {}],
   } = context;
 
   const allowed = typeof allow === 'string' ? [allow] : allow;
+  const scopedEnabled = scopes === true || !!scopes.enable;
+  const scopedSharingFolderName = scopes.folderName || 'shared';
+
   const forbidden = packages.filter(({ name }) => !allowed.includes(name));
 
   return getImport(context, ({ node, value, path, currentPackage }) => {
-    forbidden.forEach(({ name, location }) => {
-      if (
-        name !== currentPackage.name &&
-        (isSubPath(name, value) || isSubPath(location, path))
-      ) {
-        context.report({
-          node,
-          message: 'Import from package "{{name}}" is not allowed',
-          data: { name },
-        });
-      }
-    });
+    forbidden
+      .filter(
+        filterSharedPackagesInCurrentScope(
+          currentPackage,
+          scopedEnabled,
+          scopedSharingFolderName,
+        ),
+      )
+      .forEach(({ name, location }) => {
+        if (
+          name !== currentPackage.name &&
+          (isSubPath(name, value) || isSubPath(location, path))
+        ) {
+          context.report({
+            node,
+            message: 'Import from package "{{name}}" is not allowed',
+            data: { name },
+          });
+        }
+      });
   });
 };

tests/rules/no-cross-imports.js

@@ -38,6 +38,21 @@ ruleTester.run('no-cross-imports', rule, {
       filename: '/some/file.js',
       code: "import '@test/workspace';",
     },
+    {
+      options: [{ scopes: true }],
+      filename: '/test/scope/workspace/file.js',
+      code: "import '@test/shared-in-scope';",
+    },
+    {
+      options: [{ scopes: { enable: true } }],
+      filename: '/test/scope/workspace/file.js',
+      code: "import '@test/shared-in-scope';",
+    },
+    {
+      options: [{ scopes: { enable: true, folderName: 'shared' } }],
+      filename: '/test/scope/workspace/file.js',
+      code: "import '@test/shared-in-scope';",
+    },
   ],
 
   invalid: [
@@ -184,5 +199,35 @@ ruleTester.run('no-cross-imports', rule, {
         },
       ],
     },
+    {
+      options: [{ scopes: true }],
+      filename: '/test/scope/workspace/file.js',
+      code: "import '@test/shared-outside-scope';",
+      errors: [
+        {
+          message:
+            'Import from package "@test/shared-outside-scope" is not allowed',
+        },
+      ],
+    },
+    {
+      filename: '/test/scope/workspace/file.js',
+      code: "import '@test/shared-in-scope';",
+      errors: [
+        {
+          message: 'Import from package "@test/shared-in-scope" is not allowed',
+        },
+      ],
+    },
+    {
+      options: [{ scopes: { enable: true, folderName: 'something-else' } }],
+      filename: '/test/scope/workspace/file.js',
+      code: "import '@test/shared-in-scope';",
+      errors: [
+        {
+          message: 'Import from package "@test/shared-in-scope" is not allowed',
+        },
+      ],
+    },
   ],
 });

tests/setup.js

@@ -22,4 +22,22 @@ mock('get-monorepo-packages', () => [
       name: '@test/third-workspace',
     },
   },
+  {
+    location: '/test/scope/shared',
+    package: {
+      name: '@test/shared-in-scope',
+    },
+  },
+  {
+    location: '/test/other-scope/shared',
+    package: {
+      name: '@test/shared-outside-scope',
+    },
+  },
+  {
+    location: '/test/scope/workspace',
+    package: {
+      name: '@test/scoped-workspace',
+    },
+  },
 ]);