From ac9c382e2681dbb874d412fcdb0cab83c1c6e212 Mon Sep 17 00:00:00 2001
From: Alberto Gasparin <agasparin@atlassian.com>
Date: Wed, 23 Oct 2024 15:11:05 +1100
Subject: [PATCH] Allow injection of whitelisted globals

---
 README.md                        | 20 +++++++++++++++++---
 src/babel/__tests__/unit.test.js | 30 ++++++++++++++++++++++++++++++
 src/babel/index.js               | 16 ++++++++++++++--
 src/babel/processor-di.js        |  3 ++-
 4 files changed, 63 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 8c6323e..0aa1f05 100644
--- a/README.md
+++ b/README.md
@@ -156,7 +156,20 @@ When you have the same dependency replaced multiple times, there are two behavio
 
 #### Allowing globals (variables) replacement
 
-Currently the library does not enable automatic replacement of globals. To do that, you need to manually "tag" a global for replacement with `di(myGlobal)` in the function scope. For instance:
+The library does not enable automatic replacement of all globals. To do that, you either need to need add a `globals` whitelist in babel config:
+
+```js
+// In your .babelrc / babel.config.js
+// ... other stuff like presets
+  plugins: [
+    // ... other plugins
+    ['react-magnetic-di/babel-plugin', {
+      globals: ['window', 'document', 'fetch'],
+    }],
+  ],
+```
+
+Or manually "tag" a global for replacement with `di(myGlobal)` in the function scope. For instance:
 
 ```js
 import { di } from 'react-magnetic-di';
@@ -169,7 +182,7 @@ export async function myApiFetcher() {
 }
 ```
 
-Alternatively, you can create a "getter" so that the library will pick it up:
+Alternatively, the recommended approach is to create a "getter" so it becomes explicit:
 
 ```js
 export const fetchApi = (...args) => fetch(...args);
@@ -236,7 +249,8 @@ The plugin provides a couple of options to explicitly disable auto injection for
       exclude: ['mocks', /test\.tsx?/],
       // List of Babel or Node environment names where the plugin should be enabled
       enabledEnvs: ['development', 'test'],
-
+      // Allow auto injection of some globals by default
+      globals: ['window', 'document', 'fetch'],
     }],
   ],
 ```
diff --git a/src/babel/__tests__/unit.test.js b/src/babel/__tests__/unit.test.js
index f749142..f177f83 100644
--- a/src/babel/__tests__/unit.test.js
+++ b/src/babel/__tests__/unit.test.js
@@ -655,6 +655,36 @@ describe('babel plugin', () => {
     `);
   });
 
+  it('should di globals defined in Babel settings', () => {
+    const input = `
+      const useDocument = () => {
+        return window.document;
+      };
+      const useBody = () => {
+        const window = {};
+        return () => {
+          window && document.body;
+        };
+      }
+    `;
+    const options = { globals: ['window', 'document'] };
+    expect(babel(input, { options })).toMatchInlineSnapshot(`
+      "import { di as _di } from "react-magnetic-di";
+      const useDocument = () => {
+        const [_window] = _di([window], useDocument);
+        return _window.document;
+      };
+      const useBody = () => {
+        const [_document] = _di([document], useBody);
+        const window = {};
+        return () => {
+          const [_document2] = _di([_document], null);
+          window && _document2.body;
+        };
+      };"
+    `);
+  });
+
   it('should not di component itself class', () => {
     const input = `
       export default class MyComponent {
diff --git a/src/babel/index.js b/src/babel/index.js
index c789c46..1821e90 100644
--- a/src/babel/index.js
+++ b/src/babel/index.js
@@ -144,8 +144,20 @@ module.exports = function (babel) {
           state.addDependency(p)
         );
 
-        // TODO
-        // Should we add collection of globals to di via path.scope.globals?
+        // Collect globals reference paths
+        if (opts.globals) {
+          path.traverse({
+            ReferencedIdentifier(idnt) {
+              if (
+                path.scope.globals[idnt.node.name] &&
+                opts.globals.includes(idnt.node.name) &&
+                !idnt.scope.hasBinding(idnt)
+              ) {
+                state.addDependency(idnt);
+              }
+            },
+          });
+        }
 
         stateCache.set(file, state);
       },
diff --git a/src/babel/processor-di.js b/src/babel/processor-di.js
index 5bd8533..c96a331 100644
--- a/src/babel/processor-di.js
+++ b/src/babel/processor-di.js
@@ -26,7 +26,8 @@ function processReference(t, path, locationValue, state) {
     if (!name || !n.parentPath) return;
     // Some babel plugins might rename imports (eg emotion) and references break
     // For now we skip, but ideally we would refresh the reference
-    if (!bodyPath.scope.getBinding(name)) return;
+    if (!bodyPath.scope.getBinding(name) && !bodyPath.scope.hasGlobal(name))
+      return;
     // Ensure we do not di() self name
     if (name === self?.name) {
       shadowsOwnName = true;