Support setting GKs in RecoilEnv

This change adds a new property to RecoilEnv, RECOIL_GKS_ENABLED, which
can be used to enable certain GKs at runtime. We update the OSS gkx()
implementation to refer to this property directly, and as a result we
have to move the RecoilEnv to the shared package (which also
conveniently ensures that RecoilEnv properties and gkx() are initialized
together).

packages/recoil/Recoil_index.js

@@ -44,7 +44,7 @@ export type {
 
 const {RecoilLoadable} = require('./adt/Recoil_Loadable');
 const {DefaultValue} = require('./core/Recoil_Node');
-const RecoilEnv = require('./core/Recoil_RecoilEnv');
+const RecoilEnv = require('recoil-shared/util/Recoil_RecoilEnv');
 const {RecoilRoot, useRecoilStoreID} = require('./core/Recoil_RecoilRoot');
 const {isRecoilValue} = require('./core/Recoil_RecoilValue');
 const {retentionZone} = require('./core/Recoil_RetentionZone');

packages/recoil/core/Recoil_Node.js

@@ -17,7 +17,7 @@ import type {RetainedBy} from './Recoil_RetainedBy';
 import type {AtomWrites, NodeKey, Store, TreeState} from './Recoil_State';
 
 const {isFastRefreshEnabled} = require('./Recoil_ReactMode');
-const RecoilEnv = require('./Recoil_RecoilEnv');
+const RecoilEnv = require('recoil-shared/util/Recoil_RecoilEnv');
 const RecoilValueClasses = require('./Recoil_RecoilValue');
 const expectationViolation = require('recoil-shared/util/Recoil_expectationViolation');
 const gkx = require('recoil-shared/util/Recoil_gkx');

packages/recoil/recoil_values/__tests__/Recoil_atom-test.js

@@ -57,7 +57,7 @@ const testRecoil = getRecoilTestFn(() => {
 
   ({DEFAULT_VALUE, DefaultValue} = require('../../core/Recoil_Node'));
   ({RecoilRoot, useRecoilStoreID} = require('../../core/Recoil_RecoilRoot'));
-  RecoilEnv = require('../../core/Recoil_RecoilEnv');
+  RecoilEnv = require('recoil-shared/util/Recoil_RecoilEnv');
   ({isRecoilValue} = require('../../core/Recoil_RecoilValue'));
   ({RecoilLoadable, isLoadable} = require('../../adt/Recoil_Loadable'));
   ({

packages/recoil/core/Recoil_RecoilEnv.js → packages/shared/util/Recoil_RecoilEnv.js

@@ -11,16 +11,50 @@
 
 'use strict';
 
-const err = require('recoil-shared/util/Recoil_err');
+const err = require('./Recoil_err');
 
 export type RecoilEnv = {
   RECOIL_DUPLICATE_ATOM_KEY_CHECKING_ENABLED: boolean,
+  RECOIL_GKS_ENABLED: Set<string>,
 };
 
 const env: RecoilEnv = {
   RECOIL_DUPLICATE_ATOM_KEY_CHECKING_ENABLED: true,
+  RECOIL_GKS_ENABLED: new Set([
+    'recoil_hamt_2020',
+    'recoil_sync_external_store',
+    'recoil_suppress_rerender_in_callback',
+    'recoil_memory_managament_2020',
+  ]),
 };
 
+function readProcessEnvBooleanFlag(name: string, set: boolean => void) {
+  const sanitizedValue = process.env[name]?.toLowerCase()?.trim();
+
+  if (sanitizedValue == null || sanitizedValue === '') {
+    return;
+  }
+
+  const allowedValues = ['true', 'false'];
+  if (!allowedValues.includes(sanitizedValue)) {
+    throw err(
+      `process.env.${name} value must be 'true', 'false', or empty: ${sanitizedValue}`,
+    );
+  }
+
+  set(sanitizedValue === 'true');
+}
+
+function readProcessEnvStringArrayFlag(name: string, set: (string[]) => void) {
+  const sanitizedValue = process.env[name]?.trim();
+
+  if (sanitizedValue == null || sanitizedValue === '') {
+    return;
+  }
+
+  set(sanitizedValue.split(/\s*,\s*|\s+/));
+}
+
 /**
  * Allow NodeJS/NextJS/etc to set the initial state through process.env variable
  * Note:  we don't assume 'process' is available in all runtime environments
@@ -38,21 +72,17 @@ function applyProcessEnvFlagOverrides() {
     return;
   }
 
-  const sanitizedValue =
-    process.env.RECOIL_DUPLICATE_ATOM_KEY_CHECKING_ENABLED?.toLowerCase()?.trim();
-
-  if (sanitizedValue == null || sanitizedValue === '') {
-    return;
-  }
-
-  const allowedValues = ['true', 'false'];
-  if (!allowedValues.includes(sanitizedValue)) {
-    throw err(
-      `process.env.RECOIL_DUPLICATE_ATOM_KEY_CHECKING_ENABLED value must be 'true', 'false', or empty: ${sanitizedValue}`,
-    );
-  }
-
-  env.RECOIL_DUPLICATE_ATOM_KEY_CHECKING_ENABLED = sanitizedValue === 'true';
+  readProcessEnvBooleanFlag(
+    'RECOIL_DUPLICATE_ATOM_KEY_CHECKING_ENABLED',
+    value => {
+      env.RECOIL_DUPLICATE_ATOM_KEY_CHECKING_ENABLED = value;
+    },
+  );
+  readProcessEnvStringArrayFlag('RECOIL_GKS_ENABLED', value => {
+    value.forEach(gk => {
+      env.RECOIL_GKS_ENABLED.add(gk);
+    });
+  });
 }
 
 applyProcessEnvFlagOverrides();

packages/shared/util/Recoil_gkx.js

@@ -10,26 +10,22 @@
  */
 'use strict';
 
-const gks = new Map()
-  .set('recoil_hamt_2020', true)
-  .set('recoil_sync_external_store', true)
-  .set('recoil_suppress_rerender_in_callback', true)
-  .set('recoil_memory_managament_2020', true);
+const RecoilEnv = require('./Recoil_RecoilEnv');
 
 function Recoil_gkx_OSS(gk: string): boolean {
-  return gks.get(gk) ?? false;
+  return RecoilEnv.RECOIL_GKS_ENABLED.has(gk);
 }
 
 Recoil_gkx_OSS.setPass = (gk: string): void => {
-  gks.set(gk, true);
+  RecoilEnv.RECOIL_GKS_ENABLED.add(gk);
 };
 
 Recoil_gkx_OSS.setFail = (gk: string): void => {
-  gks.set(gk, false);
+  RecoilEnv.RECOIL_GKS_ENABLED.delete(gk);
 };
 
 Recoil_gkx_OSS.clear = (): void => {
-  gks.clear();
+  RecoilEnv.RECOIL_GKS_ENABLED.clear();
 };
 
 module.exports = Recoil_gkx_OSS; // @oss-only

packages/shared/util/__tests__/Recoil_RecoilEnv-test.js

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ * @oncall recoil
+ */
+'use strict';
+
+describe('RecoilEnv', () => {
+  test('environment propagates GKs', () => {
+    const RecoilEnv = require('../Recoil_RecoilEnv');
+    const gkx = require('../Recoil_gkx');
+
+    expect(gkx('recoil_test_gk')).toBe(false);
+    RecoilEnv.RECOIL_GKS_ENABLED.add('recoil_test_gk');
+    expect(gkx('recoil_test_gk')).toBe(true);
+  });
+
+  describe('support for process.env.RECOIL_GKS_ENABLED', () => {
+    const originalProcessEnv = process.env;
+    beforeEach(() => {
+      process.env = {...originalProcessEnv};
+      process.env.RECOIL_GKS_ENABLED =
+        'recoil_test_gk1,recoil_test_gk2 recoil_test_gk3';
+      jest.resetModules();
+    });
+
+    afterEach(() => {
+      process.env = originalProcessEnv;
+    });
+
+    test('environment propagates GKs', () => {
+      const gkx = require('../Recoil_gkx');
+
+      expect(gkx('recoil_test_gk1')).toBe(true);
+      expect(gkx('recoil_test_gk2')).toBe(true);
+      expect(gkx('recoil_test_gk3')).toBe(true);
+    });
+  });
+});

typescript/recoil.d.ts

@@ -38,6 +38,7 @@
 // recoilEnv.d.ts
 export interface RecoilEnv {
   RECOIL_DUPLICATE_ATOM_KEY_CHECKING_ENABLED: boolean;
+  RECOIL_GKS_ENABLED: Set<string>;
 }
 
 export const RecoilEnv: RecoilEnv;