Remove location property in worklets for production builds (#4695)

## Summary

Currently we inject `location` property in worklets - which is there for
debugging purposes - even in production build. This PR corrects this.

Fixes: #4689

## Test plan

Added a new test suite in plugin. Also ran production android Example
just to be sure.

__tests__/__snapshots__/plugin.test.ts.snap

@@ -27,6 +27,24 @@ var f = function () {
 }();"
 `;
 
+exports[`babel plugin does inject location for worklets in dev builds 1`] = `
+"var _worklet_1852213185147_init_data = {
+  code: "function anonymous(){const x=1;}",
+  location: "/dev/null"
+};
+var foo = useAnimatedStyle(function () {
+  var _e = [new global.Error(), 1, -27];
+  var _f = function _f() {
+    var x = 1;
+  };
+  _f._closure = {};
+  _f.__initData = _worklet_1852213185147_init_data;
+  _f.__workletHash = 1852213185147;
+  _f.__stackDetails = _e;
+  return _f;
+}());"
+`;
+
 exports[`babel plugin doesn't bother other Directive Literals 1`] = `
 "function foo() {
   'foobar';
@@ -53,6 +71,21 @@ var f = function () {
 }();"
 `;
 
+exports[`babel plugin doesn't inject location for worklets in production builds 1`] = `
+"var _worklet_1852213185147_init_data = {
+  code: "function anonymous(){const x=1;}"
+};
+var foo = useAnimatedStyle(function () {
+  var _f = function _f() {
+    var x = 1;
+  };
+  _f._closure = {};
+  _f.__initData = _worklet_1852213185147_init_data;
+  _f.__workletHash = 1852213185147;
+  return _f;
+}());"
+`;
+
 exports[`babel plugin doesn't nest worklets for other threads 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

@@ -6,12 +6,14 @@ import { strict as assert } from 'assert';
 import '../plugin/jestUtils';
 import { version as packageVersion } from '../package.json';
 
+const MOCK_LOCATION = '/dev/null';
+
 function runPlugin(input: string, opts = {}) {
   const transformed = transform(input.replace(/<\/?script[^>]*>/g, ''), {
     // Our babel presets require us to specify a filename here
     // but it is never used so we put in '/dev/null'
     // as a safe fallback.
-    filename: '/dev/null',
+    filename: MOCK_LOCATION,
     compact: false,
     plugins: [plugin],
     ...opts,
@@ -1125,4 +1127,33 @@ describe('babel plugin', () => {
     </script>`;
     expect(resultIsIdempotent(input9)).toBe(true);
   });
+
+  // location
+  it('does inject location for worklets in dev builds', () => {
+    const input = html`<script>
+      const foo = useAnimatedStyle(() => {
+        const x = 1;
+      });
+    </script>`;
+
+    const { code } = runPlugin(input);
+    expect(code).toHaveLocation(MOCK_LOCATION);
+    expect(code).toMatchSnapshot();
+  });
+
+  it("doesn't inject location for worklets in production builds", () => {
+    const input = html`<script>
+      const foo = useAnimatedStyle(() => {
+        const x = 1;
+      });
+    </script>`;
+
+    const current = process.env.BABEL_ENV;
+    process.env.BABEL_ENV = 'production';
+    const { code } = runPlugin(input, {});
+    process.env.BABEL_ENV = current;
+
+    expect(code).not.toHaveLocation(MOCK_LOCATION);
+    expect(code).toMatchSnapshot();
+  });
 });

plugin/jestUtils.ts

@@ -6,6 +6,7 @@ declare global {
     interface Matchers<R> {
       toHaveWorkletData(times?: number): R;
       toHaveInlineStyleWarning(times?: number): R;
+      toHaveLocation(location: string): R;
     }
   }
 }
@@ -21,7 +22,7 @@ expect.extend({
     if (receivedMatchCount === expectedMatchCount) {
       return {
         message: () =>
-          `Reanimated: expected code to have worklet data ${expectedMatchCount} times`,
+          `Reanimated: found worklet data ${expectedMatchCount} times`,
         pass: true,
       };
     }
@@ -31,9 +32,6 @@ expect.extend({
       pass: false,
     };
   },
-});
-
-expect.extend({
   toHaveInlineStyleWarning(received: string, expectedMatchCount = 1) {
     const receivedMatchCount = received.match(
       INLINE_STYLE_WARNING_REGEX
@@ -42,7 +40,7 @@ expect.extend({
     if (receivedMatchCount === expectedMatchCount) {
       return {
         message: () =>
-          `Reanimated: expected to have inline style warning ${expectedMatchCount} times`,
+          `Reanimated: found inline style warning ${expectedMatchCount} times`,
         pass: true,
       };
     }
@@ -52,4 +50,19 @@ expect.extend({
       pass: false,
     };
   },
+  toHaveLocation(received: string, expectedLocation: string) {
+    const expectedString = `location: "${expectedLocation}"`;
+    const hasLocation = received.includes(expectedLocation);
+    if (hasLocation) {
+      return {
+        message: () => `Reanimated: found location ${expectedString}`,
+        pass: true,
+      };
+    }
+    return {
+      message: () =>
+        `Reanimated: expected to have location ${expectedString}, but it's not present`,
+      pass: false,
+    };
+  },
 });

plugin/src/makeWorklet.ts

@@ -127,11 +127,6 @@ export function makeWorklet(
   assert(funString, "'funString' is undefined");
   const workletHash = hash(funString);
 
-  let location = state.file.opts.filename;
-  if (state.opts.relativeSourceLocation) {
-    location = relative(state.cwd, location);
-  }
-
   let lineOffset = 1;
   if (variables.length > 0) {
     // When worklet captures some variables, we append closure destructing at
@@ -158,9 +153,23 @@ export function makeWorklet(
 
   const initDataObjectExpression = objectExpression([
     objectProperty(identifier('code'), stringLiteral(funString)),
-    objectProperty(identifier('location'), stringLiteral(location)),
   ]);
 
+  // When testing with jest I noticed that environment variables are set later
+  // than some functions are evaluated. E.g. this cannot be above this function
+  // because it would always evaluate to true.
+  const shouldInjectLocation = !isRelease();
+  if (shouldInjectLocation) {
+    let location = state.file.opts.filename;
+    if (state.opts.relativeSourceLocation) {
+      location = relative(state.cwd, location);
+    }
+
+    initDataObjectExpression.properties.push(
+      objectProperty(identifier('location'), stringLiteral(location))
+    );
+  }
+
   if (sourceMapString) {
     initDataObjectExpression.properties.push(
       objectProperty(identifier('sourceMap'), stringLiteral(sourceMapString))