feat: allow configuring getModulesRunBeforeMainModule in Metro

.changeset/twenty-bears-sleep.md

@@ -0,0 +1,5 @@
+---
+'@rnef/plugin-metro': minor
+---
+
+Allow configuring `getModulesRunBeforeMainModule` through Metro config

packages/plugin-metro/src/lib/start/loadMetroConfig.ts

@@ -49,24 +49,41 @@ function getOverrideConfig(
   }
 
   const require = createRequire(import.meta.url);
+
+  // We can include multiple copies of InitializeCore here because metro will
+  // only add ones that are already part of the bundle
+  const initializeCorePaths = [
+    require.resolve(
+      path.join(ctx.reactNativePath, 'Libraries/Core/InitializeCore'),
+      { paths: [ctx.root] }
+    ),
+    ...outOfTreePlatforms.map((platform) =>
+      require.resolve(
+        // @ts-expect-error - TBD
+        `${ctx.platforms[platform].npmPackageName}/Libraries/Core/InitializeCore`,
+        { paths: [ctx.root] }
+      )
+    ),
+  ];
+
   return {
     resolver,
     serializer: {
-      // We can include multiple copies of InitializeCore here because metro will
-      // only add ones that are already part of the bundle
-      getModulesRunBeforeMainModule: () => [
-        require.resolve(
-          path.join(ctx.reactNativePath, 'Libraries/Core/InitializeCore'),
-          { paths: [ctx.root] }
-        ),
-        ...outOfTreePlatforms.map((platform) =>
-          require.resolve(
-            // @ts-expect-error - TBD
-            `${ctx.platforms[platform].npmPackageName}/Libraries/Core/InitializeCore`,
-            { paths: [ctx.root] }
-          )
-        ),
-      ],
+      getModulesRunBeforeMainModule: (entrypoint) => {
+        const originalBeforeMainModules =
+          config.serializer.getModulesRunBeforeMainModule(entrypoint);
+
+        // If the InitializeCore path is not specified in the original config,
+        // add it to the front of the list
+        const beforeMainModules = [];
+        for (const modulePath of initializeCorePaths) {
+          if (!originalBeforeMainModules.includes(modulePath)) {
+            beforeMainModules.push(modulePath);
+          }
+        }
+
+        return [...beforeMainModules, ...originalBeforeMainModules];
+      },
     },
   };
 }