From a91c4a48251ee7841b7cfc2ac24096ccc574ca09 Mon Sep 17 00:00:00 2001
From: Hong Minhee <hong@minhee.org>
Date: Tue, 7 May 2024 12:09:45 +0900
Subject: [PATCH] Fix bug causing multiple instances of LogTape to import
 separate Logger instances

---
 CHANGES.md        |  4 ++++
 logtape/logger.ts | 16 ++++++++++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index 1c75c9c..93cb33c 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -8,6 +8,10 @@ Version 0.1.2
 
 To be released.
 
+ -  Fixed a bug where two or more versions of LogTape were imported in the same
+    runtime, the `Logger` instances would not be shared between them.  This was
+    caused by the `Logger` instances being stored in a module-level variable.
+
 
 Version 0.1.1
 -------------
diff --git a/logtape/logger.ts b/logtape/logger.ts
index 68995cc..d686017 100644
--- a/logtape/logger.ts
+++ b/logtape/logger.ts
@@ -356,9 +356,16 @@ export function getLogger(category: string | readonly string[] = []): Logger {
 }
 
 /**
- * The root logger.
+ * The symbol for the global root logger.
  */
-let rootLogger: LoggerImpl | null = null;
+const globalRootLoggerSymbol = Symbol.for("logtape.rootLogger");
+
+/**
+ * The global root logger registry.
+ */
+interface GlobalRootLoggerRegistry {
+  [globalRootLoggerSymbol]?: LoggerImpl;
+}
 
 /**
  * A logger implementation.  Do not use this directly; use {@link getLogger}
@@ -372,8 +379,13 @@ export class LoggerImpl implements Logger {
   readonly filters: Filter[];
 
   static getLogger(category: string | readonly string[] = []): LoggerImpl {
+    let rootLogger: LoggerImpl | null = globalRootLoggerSymbol in globalThis
+      ? (globalThis as GlobalRootLoggerRegistry)[globalRootLoggerSymbol] ?? null
+      : null;
     if (rootLogger == null) {
       rootLogger = new LoggerImpl(null, []);
+      (globalThis as GlobalRootLoggerRegistry)[globalRootLoggerSymbol] =
+        rootLogger;
     }
     if (typeof category === "string") return rootLogger.getChild(category);
     if (category.length === 0) return rootLogger;