Add option to substitute isWeb and shouldBeUseWeb in babel plugin. (

#5283)

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## Summary

This PR changes the Babel plugin to substitute `isWeb()` and
`shouldBeUseWeb()` calls with `true` so that Webpack is able to
recognize dead code.

## Test plan
Modify the NextExample/babel.config.js file:
```js
['react-native-reanimated/plugin', { omitNativeOnlyData: true, substituteWebPlatformChecks: true }]
```
Run yarn build in NextExample and verify that the difference between
reanimated and noreanimated is around 34KB.

__tests__/__snapshots__/plugin.test.ts.snap

@@ -1620,6 +1620,40 @@ function App() {
 }"
 `;
 
+exports[`babel plugin for web configuration doesn't substitute isWeb and shouldBeUseWeb in worklets 1`] = `
+"var _worklet_8641000714901_init_data = {
+  code: "function foo(){const{isWeb,shouldBeUseWeb}=this.__closure;const x=isWeb();const y=shouldBeUseWeb();}",
+  location: "/dev/null",
+  sourceMap: "\\"mock source map\\"",
+  version: "x.y.z"
+};
+var foo = function () {
+  var _e = [new global.Error(), -3, -27];
+  var foo = function foo() {
+    var x = true;
+    var y = true;
+  };
+  foo.__closure = {
+    isWeb: isWeb,
+    shouldBeUseWeb: shouldBeUseWeb
+  };
+  foo.__workletHash = 8641000714901;
+  foo.__initData = _worklet_8641000714901_init_data;
+  foo.__stackDetails = _e;
+  return foo;
+}();"
+`;
+
+exports[`babel plugin for web configuration doesn't substitute isWeb and shouldBeUseWeb with true when substituteWebPlatformChecks option is set to false 1`] = `
+"var x = isWeb();
+var y = shouldBeUseWeb();"
+`;
+
+exports[`babel plugin for web configuration doesn't substitute isWeb and shouldBeUseWeb with true when substituteWebPlatformChecks option is undefined 1`] = `
+"var x = isWeb();
+var y = shouldBeUseWeb();"
+`;
+
 exports[`babel plugin for web configuration includes initData when omitNativeOnlyData option is set to false 1`] = `
 "var _worklet_17472070642672_init_data = {
   code: "function foo(){var foo='bar';}",
@@ -1653,6 +1687,11 @@ exports[`babel plugin for web configuration skips initData when omitNativeOnlyDa
 }();"
 `;
 
+exports[`babel plugin for web configuration substitutes isWeb and shouldBeUseWeb with true when substituteWebPlatformChecks option is set to true 1`] = `
+"var x = true;
+var y = true;"
+`;
+
 exports[`babel plugin for worklet nesting doesn't process nested worklets when disabled 1`] = `
 "var _worklet_1678749606628_init_data = {
   code: "function foo(x){function bar(x){'worklet';return x+2;}return bar(x)+1;}",

__tests__/plugin.test.ts

@@ -1609,5 +1609,68 @@ describe('babel plugin', () => {
       expect(code).toHaveWorkletData(1);
       expect(code).toMatchSnapshot();
     });
+
+    it('substitutes isWeb and shouldBeUseWeb with true when substituteWebPlatformChecks option is set to true', () => {
+      const input = html`<script>
+        const x = isWeb();
+        const y = shouldBeUseWeb();
+      </script>`;
+
+      const { code } = runPlugin(
+        input,
+        {},
+        { substituteWebPlatformChecks: true }
+      );
+      expect(code).toContain('var x = true;');
+      expect(code).toContain('var y = true;');
+      expect(code).toMatchSnapshot();
+    });
+
+    it("doesn't substitute isWeb and shouldBeUseWeb with true when substituteWebPlatformChecks option is set to false", () => {
+      const input = html`<script>
+        const x = isWeb();
+        const y = shouldBeUseWeb();
+      </script>`;
+
+      const { code } = runPlugin(
+        input,
+        {},
+        { substituteWebPlatformChecks: false }
+      );
+      expect(code).toContain('var x = isWeb();');
+      expect(code).toContain('var y = shouldBeUseWeb();');
+      expect(code).toMatchSnapshot();
+    });
+
+    it("doesn't substitute isWeb and shouldBeUseWeb with true when substituteWebPlatformChecks option is undefined", () => {
+      const input = html`<script>
+        const x = isWeb();
+        const y = shouldBeUseWeb();
+      </script>`;
+
+      const { code } = runPlugin(input);
+      expect(code).toContain('var x = isWeb();');
+      expect(code).toContain('var y = shouldBeUseWeb();');
+      expect(code).toMatchSnapshot();
+    });
+
+    it("doesn't substitute isWeb and shouldBeUseWeb in worklets", () => {
+      const input = html`<script>
+        function foo() {
+          'worklet';
+          const x = isWeb();
+          const y = shouldBeUseWeb();
+        }
+      </script>`;
+
+      const { code } = runPlugin(
+        input,
+        {},
+        { substituteWebPlatformChecks: true }
+      );
+      expect(code).toContain('const x=isWeb();');
+      expect(code).toContain('const y=shouldBeUseWeb();');
+      expect(code).toMatchSnapshot();
+    });
   });
 });

plugin/src/plugin.ts

@@ -7,6 +7,7 @@ import { processInlineStylesWarning } from './processInlineStylesWarning';
 import { processIfCallback } from './processIfCallback';
 import { addCustomGlobals } from './addCustomGlobals';
 import { initializeGlobals } from './globals';
+import { substituteWebCallExpression } from './substituteWebCallExpression';
 
 module.exports = function (): PluginItem {
   function runWithTaggedExceptions(fun: () => void) {
@@ -27,7 +28,12 @@ module.exports = function (): PluginItem {
     visitor: {
       CallExpression: {
         enter(path: NodePath<CallExpression>, state: ReanimatedPluginPass) {
-          runWithTaggedExceptions(() => processForCalleesWorklets(path, state));
+          runWithTaggedExceptions(() => {
+            processForCalleesWorklets(path, state);
+            if (state.opts.substituteWebPlatformChecks) {
+              substituteWebCallExpression(path);
+            }
+          });
         },
       },
       'FunctionDeclaration|FunctionExpression|ArrowFunctionExpression': {

plugin/src/substituteWebCallExpression.ts

@@ -0,0 +1,13 @@
+import type { NodePath } from '@babel/core';
+import { booleanLiteral, isIdentifier } from '@babel/types';
+import type { CallExpression } from '@babel/types';
+
+export function substituteWebCallExpression(path: NodePath<CallExpression>) {
+  const callee = path.node.callee;
+  if (isIdentifier(callee)) {
+    const name = callee.name;
+    if (name === 'isWeb' || name === 'shouldBeUseWeb') {
+      path.replaceWith(booleanLiteral(true));
+    }
+  }
+}

plugin/src/types.ts

@@ -12,6 +12,7 @@ export interface ReanimatedPluginOptions {
   processNestedWorklets?: boolean;
   omitNativeOnlyData?: boolean;
   globals?: string[];
+  substituteWebPlatformChecks?: boolean;
 }
 
 export interface ReanimatedPluginPass {