From 8c5252986e547a43937c1cbc5b8ef9cfa615811e Mon Sep 17 00:00:00 2001
From: robonen <robonenandrew@gmail.com>
Date: Sun, 23 Feb 2025 00:44:14 +0700
Subject: [PATCH] feat(packages/stdlib): add SyncMutex

---
 packages/stdlib/src/index.ts                 |  1 +
 packages/stdlib/src/sync/index.ts            |  1 +
 packages/stdlib/src/sync/mutex/index.test.ts | 45 ++++++++++++++++++++
 packages/stdlib/src/sync/mutex/index.ts      | 29 +++++++++++++
 4 files changed, 76 insertions(+)
 create mode 100644 packages/stdlib/src/sync/index.ts
 create mode 100644 packages/stdlib/src/sync/mutex/index.test.ts
 create mode 100644 packages/stdlib/src/sync/mutex/index.ts

diff --git a/packages/stdlib/src/index.ts b/packages/stdlib/src/index.ts
index 9e936f1..62ebea0 100644
--- a/packages/stdlib/src/index.ts
+++ b/packages/stdlib/src/index.ts
@@ -5,6 +5,7 @@ export * from './math';
 export * from './objects';
 export * from './patterns';
 export * from './structs';
+export * from './sync';
 export * from './text';
 export * from './types';
 export * from './utils'
diff --git a/packages/stdlib/src/sync/index.ts b/packages/stdlib/src/sync/index.ts
new file mode 100644
index 0000000..b1ad937
--- /dev/null
+++ b/packages/stdlib/src/sync/index.ts
@@ -0,0 +1 @@
+export * from './mutex';
diff --git a/packages/stdlib/src/sync/mutex/index.test.ts b/packages/stdlib/src/sync/mutex/index.test.ts
new file mode 100644
index 0000000..c50ae0b
--- /dev/null
+++ b/packages/stdlib/src/sync/mutex/index.test.ts
@@ -0,0 +1,45 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { SyncMutex } from '.';
+
+describe('SyncMutex', () => {
+  let mutex: SyncMutex;
+
+  beforeEach(() => {
+    mutex = new SyncMutex();
+  });
+
+  it('unlocked by default', () => {
+    expect(mutex.isLocked).toBe(false);
+  });
+
+  it('lock the mutex', () => {
+    mutex.lock();
+    expect(mutex.isLocked).toBe(true);
+  });
+
+  it('remain locked when locked multiple times', () => {
+    mutex.lock();
+    mutex.lock();
+    expect(mutex.isLocked).toBe(true);
+  });
+
+  it('unlock a locked mutex', () => {
+    mutex.lock();
+    mutex.unlock();
+    expect(mutex.isLocked).toBe(false);
+  });
+
+  it('remain unlocked when unlocked multiple times', () => {
+    mutex.unlock();
+    mutex.unlock();
+    expect(mutex.isLocked).toBe(false);
+  });
+
+  it('reflect the current lock state', () => {
+    expect(mutex.isLocked).toBe(false);
+    mutex.lock();
+    expect(mutex.isLocked).toBe(true);
+    mutex.unlock();
+    expect(mutex.isLocked).toBe(false);
+  });
+});
diff --git a/packages/stdlib/src/sync/mutex/index.ts b/packages/stdlib/src/sync/mutex/index.ts
new file mode 100644
index 0000000..acb1610
--- /dev/null
+++ b/packages/stdlib/src/sync/mutex/index.ts
@@ -0,0 +1,29 @@
+/**
+ * @name SyncMutex
+ * @category Utils
+ * @description A simple synchronous mutex to provide more readable locking and unlocking of code blocks
+ * 
+ * @example
+ * const mutex = new SyncMutex();
+ * 
+ * mutex.lock();
+ *
+ * mutex.unlock();
+ * 
+ * @since 0.0.5
+ */
+export class SyncMutex {
+  private state: boolean = false;
+
+  public get isLocked() {
+    return this.state;
+  }
+
+  public lock() {
+    this.state = true;
+  }
+
+  public unlock() {
+    this.state = false;
+  }
+}