From 735cbfdc1e1ca7f12928393acdb98e295ed6133e Mon Sep 17 00:00:00 2001
From: Oleksandr Fediashov <olfedias@microsoft.com>
Date: Wed, 7 Dec 2022 12:14:28 +0100
Subject: [PATCH] fix: use global constants (#290)

* fix: use global constants

* PR review
---
 ...-cb8022d0-7662-4724-a582-c6536e4413fc.json |  7 ++++
 packages/core/src/constants.test.ts           | 14 ++++++++
 packages/core/src/constants.ts                | 32 +++++++++++++++----
 3 files changed, 47 insertions(+), 6 deletions(-)
 create mode 100644 change/@griffel-core-cb8022d0-7662-4724-a582-c6536e4413fc.json
 create mode 100644 packages/core/src/constants.test.ts

diff --git a/change/@griffel-core-cb8022d0-7662-4724-a582-c6536e4413fc.json b/change/@griffel-core-cb8022d0-7662-4724-a582-c6536e4413fc.json
new file mode 100644
index 000000000..8b789f076
--- /dev/null
+++ b/change/@griffel-core-cb8022d0-7662-4724-a582-c6536e4413fc.json
@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "fix: use global constants",
+  "packageName": "@griffel/core",
+  "email": "olfedias@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/packages/core/src/constants.test.ts b/packages/core/src/constants.test.ts
new file mode 100644
index 000000000..8f16899fb
--- /dev/null
+++ b/packages/core/src/constants.test.ts
@@ -0,0 +1,14 @@
+it('hosts global constants', async () => {
+  const importA = await import('./constants');
+
+  // We are reloading a module, so instances that are created inside a module will be different
+  // https://jestjs.io/docs/jest-object#jestresetmodules
+  jest.resetModules();
+  const importB = await import('./constants');
+
+  expect(importA.DEFINITION_LOOKUP_TABLE).toBe(importA.DEFINITION_LOOKUP_TABLE);
+  expect(importA.DEBUG_RESET_CLASSES).toBe(importA.DEBUG_RESET_CLASSES);
+
+  // This constant is not global, expected to be different
+  expect(importA.UNSUPPORTED_CSS_PROPERTIES).not.toBe(importB.UNSUPPORTED_CSS_PROPERTIES);
+});
diff --git a/packages/core/src/constants.ts b/packages/core/src/constants.ts
index 87f6e4af0..c5989304e 100644
--- a/packages/core/src/constants.ts
+++ b/packages/core/src/constants.ts
@@ -1,5 +1,31 @@
 import { GriffelStylesUnsupportedCSSProperties, LookupItem, SequenceHash } from './types';
 
+// ----
+
+// Heads up!
+// These constants are global and will be shared between Griffel instances.
+// Any change in them should happen only in a MAJOR version. If it happens,
+// please change "__NAMESPACE_PREFIX__" to include a version.
+
+const __GLOBAL__: any = typeof window === 'undefined' ? global : window;
+const __NAMESPACE_PREFIX__ = '@griffel/';
+
+function getGlobalVar<T>(name: string, defaultValue: T): T {
+  if (!__GLOBAL__[Symbol.for(__NAMESPACE_PREFIX__ + name)]) {
+    __GLOBAL__[Symbol.for(__NAMESPACE_PREFIX__ + name)] = defaultValue;
+  }
+
+  return __GLOBAL__[Symbol.for(__NAMESPACE_PREFIX__ + name)];
+}
+
+/** @internal */
+export const DEBUG_RESET_CLASSES = getGlobalVar<Record<string, 1>>('DEBUG_RESET_CLASSES', {});
+
+/** @internal */
+export const DEFINITION_LOOKUP_TABLE = getGlobalVar<Record<SequenceHash, LookupItem>>('DEFINITION_LOOKUP_TABLE', {});
+
+// ----
+
 /** @internal */
 export const DATA_BUCKET_ATTR = 'data-make-styles-bucket';
 
@@ -24,12 +50,6 @@ export const SEQUENCE_SIZE =
     ? SEQUENCE_PREFIX.length + SEQUENCE_HASH_LENGTH
     : SEQUENCE_PREFIX.length + SEQUENCE_HASH_LENGTH + DEBUG_SEQUENCE_SEPARATOR.length + SEQUENCE_HASH_LENGTH;
 
-/** @internal */
-export const DEBUG_RESET_CLASSES: Record<string, 1> = {};
-
-/** @internal */
-export const DEFINITION_LOOKUP_TABLE: Record<SequenceHash, LookupItem> = {};
-
 // indexes for values in LookupItem tuple
 
 /** @internal */