From aa14660c2ac8665c66274398cec37cfec79e0056 Mon Sep 17 00:00:00 2001
From: "Maheiah (AI Assistant)" <7+mahseiah_ai@noreply.localhost>
Date: Wed, 6 May 2026 17:41:00 -0400
Subject: [PATCH] feat: add buffer max to buffer appender

---
 package.json                     |  2 +-
 src/buffer-log-appender.ts       | 11 ++++++++++-
 test/buffer-log-appender.test.ts | 30 ++++++++++++++++++++++++++++++
 tsconfig.json                    |  1 +
 4 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/package.json b/package.json
index 603eafe..02d4965 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@jdbernard/logging",
-  "version": "2.3.3",
+  "version": "2.4.0",
   "description": "Simple Javascript logging service.",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
diff --git a/src/buffer-log-appender.ts b/src/buffer-log-appender.ts
index c802722..0313db0 100644
--- a/src/buffer-log-appender.ts
+++ b/src/buffer-log-appender.ts
@@ -4,6 +4,7 @@ import { LogLevel, type LogMessage } from './log-message'
 export class BufferLogAppender implements LogAppender {
   public threshold: LogLevel
   public buffer: LogMessage[]
+  public bufferMax?: number
 
   constructor(buffer?: LogMessage[], threshold?: LogLevel) {
     this.buffer = buffer ?? []
@@ -12,7 +13,15 @@ export class BufferLogAppender implements LogAppender {
 
   public appendMessage(msg: LogMessage): void {
     if (this.threshold && msg.level < this.threshold) return
-    else this.buffer.push(msg)
+
+    this.buffer.push(msg)
+
+    if (this.bufferMax !== undefined) {
+      const max = Math.max(0, this.bufferMax)
+      while (this.buffer.length > max) {
+        this.buffer.shift()
+      }
+    }
   }
 
   public clearBuffer(): void {
diff --git a/test/buffer-log-appender.test.ts b/test/buffer-log-appender.test.ts
index ad1feea..f6a7a22 100644
--- a/test/buffer-log-appender.test.ts
+++ b/test/buffer-log-appender.test.ts
@@ -39,6 +39,36 @@ describe("BufferLogAppender", () => {
     expect(appender.buffer[1].msg).toBe("second");
   });
 
+  test("defaults to an unbounded buffer", () => {
+    const appender = new BufferLogAppender();
+
+    appender.appendMessage(makeMsg({ msg: "first" }));
+    appender.appendMessage(makeMsg({ msg: "second" }));
+    appender.appendMessage(makeMsg({ msg: "third" }));
+
+    expect(appender.buffer.length).toBe(3);
+    expect(appender.buffer.map((message) => message.msg)).toEqual([
+      "first",
+      "second",
+      "third",
+    ]);
+  });
+
+  test("trims oldest messages when bufferMax is exceeded", () => {
+    const appender = new BufferLogAppender();
+    appender.bufferMax = 2;
+
+    appender.appendMessage(makeMsg({ msg: "first" }));
+    appender.appendMessage(makeMsg({ msg: "second" }));
+    appender.appendMessage(makeMsg({ msg: "third" }));
+
+    expect(appender.buffer.length).toBe(2);
+    expect(appender.buffer.map((message) => message.msg)).toEqual([
+      "second",
+      "third",
+    ]);
+  });
+
   test("respects threshold", () => {
     const appender = new BufferLogAppender(undefined, LogLevel.WARN);
 
diff --git a/tsconfig.json b/tsconfig.json
index 68a7856..65d9ee4 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -3,6 +3,7 @@
     "module": "commonjs",
     "target": "es2016",
     "declaration": true,
+    "rootDir": "./src",
     "outDir": "./dist",
     "strict": true,
     "skipLibCheck": true