diff --git a/tests/test_counter.py b/tests/test_counter.py
index 1753b104..96973d53 100644
--- a/tests/test_counter.py
+++ b/tests/test_counter.py
@@ -1,7 +1,176 @@
+import asyncio
 import pytest
 from a_sync.primitives import CounterLock
 
 
 @pytest.mark.asyncio_cooperative
 async def test_counter_lock():
-    assert await CounterLock().wait_for(0)
+    counter = CounterLock(name='test')
+    assert await counter.wait_for(0)
+    assert counter._name == "test"
+
+@pytest.mark.asyncio_cooperative
+async def test_counterlock_initialization():
+    counter = CounterLock(start_value=5)
+    assert counter.value == 5
+
+@pytest.mark.asyncio_cooperative
+async def test_counterlock_set():
+    counter = CounterLock(start_value=0)
+    counter.set(10)
+    assert counter.value == 10
+
+@pytest.mark.asyncio_cooperative
+async def test_counterlock_wait_for():
+    counter = CounterLock(start_value=0)
+
+    async def waiter():
+        await counter.wait_for(5)
+        return 'done'
+
+    waiter_task = asyncio.create_task(waiter())
+    await asyncio.sleep(0.1)
+    counter.set(5)
+    result = await waiter_task
+    assert result == 'done'
+
+@pytest.mark.asyncio_cooperative
+async def test_counterlock_concurrent_waiters():
+    counter = CounterLock(start_value=0)
+    results = []
+
+    async def waiter(index):
+        await counter.wait_for(5)
+        results.append(index)
+
+    tasks = [asyncio.create_task(waiter(i)) for i in range(3)]
+    await asyncio.sleep(0.1)
+    counter.set(5)
+    await asyncio.gather(*tasks)
+    assert results == [0, 1, 2]
+
+@pytest.mark.asyncio_cooperative
+async def test_counterlock_increment_only():
+    counter = CounterLock(start_value=5)
+    with pytest.raises(ValueError):
+        counter.set(3)
+
+@pytest.mark.asyncio_cooperative
+async def test_counterlock_large_value():
+    counter = CounterLock(start_value=0)
+    large_value = 10**6
+    counter.set(large_value)
+    assert counter.value == large_value
+
+@pytest.mark.asyncio_cooperative
+async def test_counterlock_zero_value():
+    counter = CounterLock(start_value=0)
+    assert counter.value == 0
+
+@pytest.mark.asyncio_cooperative
+async def test_counterlock_exception_handling():
+    counter = CounterLock(start_value=0)
+
+    async def waiter():
+        try:
+            await counter.wait_for(5)
+            raise ValueError("Intentional error")
+        except ValueError as e:
+            return str(e)
+
+    counter.set(5)
+    result = await waiter()
+    assert result == "Intentional error"
+
+@pytest.mark.asyncio_cooperative
+async def test_simultaneous_set_and_wait():
+    counter = CounterLock(start_value=0)
+    results = []
+
+    async def waiter(index):
+        await counter.wait_for(5)
+        results.append(index)
+
+    tasks = [asyncio.create_task(waiter(i)) for i in range(5)]
+    counter.set(5)
+    await asyncio.gather(*tasks)
+    assert results == [0, 1, 2, 3, 4]
+
+@pytest.mark.asyncio_cooperative
+async def test_reentrant_set():
+    counter = CounterLock(start_value=0)
+    counter.set(5)
+    counter.set(10)  # Reentrant set
+    assert counter.value == 10
+
+def test_counterlock_negative_start_value():
+    with pytest.raises(ValueError):
+        CounterLock(start_value=-1)
+
+@pytest.mark.asyncio_cooperative
+async def test_immediate_set_and_wait():
+    counter = CounterLock(start_value=5)
+
+    async def waiter():
+        return await counter.wait_for(5)
+
+    result = await waiter()
+    assert result is True
+
+@pytest.mark.asyncio_cooperative
+async def test_delayed_set():
+    counter = CounterLock(start_value=0)
+
+    async def waiter():
+        await counter.wait_for(5)
+        return 'done'
+
+    waiter_task = asyncio.create_task(waiter())
+    await asyncio.sleep(0.5)  # Delay before setting the counter
+    counter.set(5)
+    result = await waiter_task
+    assert result == 'done'
+
+@pytest.mark.asyncio_cooperative
+async def test_multiple_sets():
+    counter = CounterLock(start_value=0)
+    results = []
+
+    async def waiter(index):
+        await counter.wait_for(10)
+        results.append(index)
+
+    tasks = [asyncio.create_task(waiter(i)) for i in range(3)]
+    counter.set(5)
+    counter.set(10)
+    await asyncio.gather(*tasks)
+    assert results == [0, 1, 2]
+
+@pytest.mark.asyncio_cooperative
+async def test_custom_error_handling():
+    counter = CounterLock(start_value=0)
+
+    async def waiter():
+        try:
+            await counter.wait_for(5)
+            raise RuntimeError("Custom error")
+        except RuntimeError as e:
+            return str(e)
+
+    counter.set(5)
+    result = await waiter()
+    assert result == "Custom error"
+
+@pytest.mark.asyncio_cooperative
+async def test_external_interruptions():
+    counter = CounterLock(start_value=0)
+
+    async def waiter():
+        await counter.wait_for(5)
+        return 'done'
+
+    waiter_task = asyncio.create_task(waiter())
+    await asyncio.sleep(0.1)
+    waiter_task.cancel()
+    await asyncio.sleep(0.1)
+    assert counter.value == 0
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