From 53e38a960d62c80a74d29e44f66d9b96465a5471 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 20:08:49 +0000
Subject: [PATCH 1/6] Initial plan


From ff0ed7a6267485657e7d295e13d3f7a0b1708b08 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 20:12:33 +0000
Subject: [PATCH 2/6] Add async function extensions (then and catch) for
 coroutines

Co-authored-by: neriyaco <42520786+neriyaco@users.noreply.github.com>
---
 README.md                                     |  49 ++++++--
 pyproject.toml                                |   2 +-
 .../builtin_extensions/coroutine_ext.py       |  90 +++++++++++++++
 src/extype/builtin_extensions/extend_all.py   |   2 +
 src/extype/builtin_extensions/meson.build     |   3 +-
 tests/test_builtin_extensions.py              | 106 ++++++++++++++++++
 6 files changed, 241 insertions(+), 11 deletions(-)
 create mode 100644 src/extype/builtin_extensions/coroutine_ext.py

diff --git a/README.md b/README.md
index 4978476..fb97f34 100644
--- a/README.md
+++ b/README.md
@@ -47,15 +47,16 @@ list_ext.extend()
 Currently, we provide the following extensions:
 
 
-|       file      |           extended types           |
-|:---------------:|:----------------------------------:|
-|   dict_ext.py   | dict_keys, dict_values, dict_items |
-|   float_ext.py  | float |
-| function_ext.py | FunctionType, LambdaType  |
-|    int_ext.py   | int |
-|   list_ext.py   | list |
-|    seq_ext.py   | map, filter, range, zip |
-|    str_ext.py   | str |
+|       file       |           extended types           |
+|:----------------:|:----------------------------------:|
+| coroutine_ext.py | coroutine (async functions)       |
+|   dict_ext.py    | dict_keys, dict_values, dict_items |
+|   float_ext.py   | float |
+| function_ext.py  | FunctionType, LambdaType  |
+|    int_ext.py    | int |
+|   list_ext.py    | list |
+|    seq_ext.py    | map, filter, range, zip |
+|    str_ext.py    | str |
 
 
 
@@ -214,6 +215,36 @@ list.last(self: List[T]) -> T, raise IndexError
 ```
 Returns the last element in the list, or raises `IndexError` if the list is empty.
 
+```py
+coroutine.then(self: Awaitable[T], fn: Callable[[T], Awaitable[U] | U]) -> Awaitable[U]
+```
+Maps the result of the awaitable via an optionally async function. If the function is async, it is awaited in the context of the wrapped awaitable.
+
+Example:
+```py
+async def get_value():
+    return 10
+
+result = await get_value().then(lambda x: x * 2)  # result is 20
+```
+
+```py
+coroutine.catch(self: Awaitable[T], fn: Callable[[E], Awaitable[U] | U], *, exception: type[E] = Exception) -> Awaitable[T | U]
+```
+Catches an exception of the given type and calls the passed function with the caught exception.
+
+If no exception was raised inside the wrapped awaitable, the function will not be called.
+The passed function can optionally return a value to be returned in case of an error.
+The passed function can be either sync or async. If it's async, it is awaited in the context of the wrapped awaitable.
+
+Example:
+```py
+async def might_fail():
+    raise ValueError("error")
+
+result = await might_fail().catch(lambda e: "default", exception=ValueError)  # result is "default"
+```
+
 ```py
 float.round(self: float) -> int
 ```
diff --git a/pyproject.toml b/pyproject.toml
index d806e6f..2b98ab4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,4 +23,4 @@ dev = [
     "meson-python>=0.17.1",
     "ninja>=1.11.1.4",
 ]
-test = ["pytest>=7.4.4", "typing-extensions>=4.7.1"]
+test = ["pytest>=7.4.4", "pytest-asyncio>=0.21.0", "typing-extensions>=4.7.1"]
diff --git a/src/extype/builtin_extensions/coroutine_ext.py b/src/extype/builtin_extensions/coroutine_ext.py
new file mode 100644
index 0000000..293ff1c
--- /dev/null
+++ b/src/extype/builtin_extensions/coroutine_ext.py
@@ -0,0 +1,90 @@
+from inspect import iscoroutinefunction
+from typing import Awaitable, Callable, TypeVar
+
+from ..extension_utils import extend_type_with, extension
+
+
+__all__ = [
+    "extend",
+    "CoroutineExtension"
+]
+
+
+_T = TypeVar("_T")
+_U = TypeVar("_U")
+_E = TypeVar("_E", bound=BaseException)
+
+
+class CoroutineExtension:
+    """
+    A class that contains methods to extend coroutine objects (async functions).
+    """
+
+    @extension
+    def then(self: Awaitable[_T], fn: Callable[[_T], Awaitable[_U] | _U]) -> Awaitable[_U]:
+        """
+        Maps the result of the awaitable via an optionally async function.
+        
+        If the function is async, it is awaited in the context of the wrapped awaitable.
+        
+        Args:
+            fn: A function that takes the result of the awaitable and returns a value or awaitable.
+            
+        Returns:
+            An awaitable that resolves to the result of the function.
+        """
+        async def _then():
+            result = fn(await self)
+            if iscoroutinefunction(fn):
+                return await result
+            return result
+        
+        return _then()
+
+    @extension
+    def catch(
+        self: Awaitable[_T],
+        fn: Callable[[_E], Awaitable[_U] | _U],
+        *,
+        exception: type[_E] = Exception
+    ) -> Awaitable[_T | _U]:
+        """
+        Catches an exception of the given type and calls the passed function with the caught exception.
+        
+        If no exception was raised inside the wrapped awaitable, the function will not be called.
+        The passed function can optionally return a value to be returned in case of an error.
+        The passed function can be either sync or async. If it's async, it is awaited.
+        
+        Args:
+            fn: A function that takes the exception and returns a value or awaitable.
+            exception: The type of exception to catch (default: Exception).
+            
+        Returns:
+            An awaitable that resolves to the original result or the result of the error handler.
+        """
+        async def _catch():
+            try:
+                return await self
+            except exception as e:
+                result = fn(e)
+                if iscoroutinefunction(fn):
+                    return await result
+                return result
+        
+        return _catch()
+
+
+def extend():
+    """
+    Applies the coroutine extensions to coroutine objects.
+    """
+    # Get the coroutine type by creating a coroutine and getting its type
+    async def _dummy():
+        pass
+    
+    coro = _dummy()
+    coroutine_type = type(coro)
+    extend_type_with(coroutine_type, CoroutineExtension)
+    
+    # Close the coroutine to avoid warnings
+    coro.close()
diff --git a/src/extype/builtin_extensions/extend_all.py b/src/extype/builtin_extensions/extend_all.py
index 59a4651..95176fe 100644
--- a/src/extype/builtin_extensions/extend_all.py
+++ b/src/extype/builtin_extensions/extend_all.py
@@ -6,6 +6,7 @@
     function_ext,
     dict_ext,
     str_ext,
+    coroutine_ext,
 )
 
 for ext in [
@@ -16,5 +17,6 @@
     function_ext,
     dict_ext,
     str_ext,
+    coroutine_ext,
 ]:
     ext.extend()
diff --git a/src/extype/builtin_extensions/meson.build b/src/extype/builtin_extensions/meson.build
index 5c68d17..ef6032a 100644
--- a/src/extype/builtin_extensions/meson.build
+++ b/src/extype/builtin_extensions/meson.build
@@ -7,7 +7,8 @@ python_sources = [
     'int_ext.py',
     'list_ext.py',
     'seq_ext.py',
-    'str_ext.py'
+    'str_ext.py',
+    'coroutine_ext.py'
 ]
 
 
diff --git a/tests/test_builtin_extensions.py b/tests/test_builtin_extensions.py
index ee7ede0..62c21b2 100644
--- a/tests/test_builtin_extensions.py
+++ b/tests/test_builtin_extensions.py
@@ -322,3 +322,109 @@ def test_str_to_float():
 
 ###################################################
 
+
+# coroutine extensions tests
+
+
+@pytest.mark.asyncio
+async def test_coroutine_then_sync():
+    async def foo():
+        return 10
+    
+    result = await foo().then(lambda x: x + 5)
+    assert result == 15
+
+
+@pytest.mark.asyncio
+async def test_coroutine_then_async():
+    async def foo():
+        return 10
+    
+    async def add_five(x):
+        return x + 5
+    
+    result = await foo().then(add_five)
+    assert result == 15
+
+
+@pytest.mark.asyncio
+async def test_coroutine_then_chaining():
+    async def foo():
+        return 10
+    
+    async def add_five(x):
+        return x + 5
+    
+    result = await foo().then(lambda x: x * 2).then(add_five).then(lambda x: x - 3)
+    assert result == 22  # (10 * 2) + 5 - 3 = 22
+
+
+@pytest.mark.asyncio
+async def test_coroutine_catch_no_exception():
+    async def foo():
+        return 42
+    
+    result = await foo().catch(lambda e: 0)
+    assert result == 42
+
+
+@pytest.mark.asyncio
+async def test_coroutine_catch_with_exception():
+    async def foo():
+        raise ValueError("test error")
+    
+    result = await foo().catch(lambda e: 100, exception=ValueError)
+    assert result == 100
+
+
+@pytest.mark.asyncio
+async def test_coroutine_catch_async_handler():
+    async def foo():
+        raise ValueError("test error")
+    
+    async def handle_error(e):
+        return 200
+    
+    result = await foo().catch(handle_error, exception=ValueError)
+    assert result == 200
+
+
+@pytest.mark.asyncio
+async def test_coroutine_catch_wrong_exception_type():
+    async def foo():
+        raise ValueError("test error")
+    
+    with pytest.raises(ValueError):
+        await foo().catch(lambda e: 0, exception=TypeError)
+
+
+@pytest.mark.asyncio
+async def test_coroutine_catch_default_exception():
+    async def foo():
+        raise RuntimeError("test error")
+    
+    result = await foo().catch(lambda e: 300)
+    assert result == 300
+
+
+@pytest.mark.asyncio
+async def test_coroutine_then_and_catch_combined():
+    async def foo():
+        return 10
+    
+    result = await foo().then(lambda x: x * 2).catch(lambda e: 0)
+    assert result == 20
+
+
+@pytest.mark.asyncio
+async def test_coroutine_catch_and_then_combined():
+    async def foo():
+        raise ValueError("error")
+    
+    result = await foo().catch(lambda e: 50, exception=ValueError).then(lambda x: x + 10)
+    assert result == 60
+
+
+###################################################
+
+

From f79f0628f6099a4112a3b2f20ed5fc772dc32a9e Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 20:14:07 +0000
Subject: [PATCH 3/6] Fix linting issues (trailing whitespace)

Co-authored-by: neriyaco <42520786+neriyaco@users.noreply.github.com>
---
 .../builtin_extensions/coroutine_ext.py       | 20 ++++++-------
 tests/test_builtin_extensions.py              | 30 +++++++++----------
 2 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/src/extype/builtin_extensions/coroutine_ext.py b/src/extype/builtin_extensions/coroutine_ext.py
index 293ff1c..8bfa7be 100644
--- a/src/extype/builtin_extensions/coroutine_ext.py
+++ b/src/extype/builtin_extensions/coroutine_ext.py
@@ -24,12 +24,12 @@ class CoroutineExtension:
     def then(self: Awaitable[_T], fn: Callable[[_T], Awaitable[_U] | _U]) -> Awaitable[_U]:
         """
         Maps the result of the awaitable via an optionally async function.
-        
+
         If the function is async, it is awaited in the context of the wrapped awaitable.
-        
+
         Args:
             fn: A function that takes the result of the awaitable and returns a value or awaitable.
-            
+
         Returns:
             An awaitable that resolves to the result of the function.
         """
@@ -38,7 +38,7 @@ async def _then():
             if iscoroutinefunction(fn):
                 return await result
             return result
-        
+
         return _then()
 
     @extension
@@ -50,15 +50,15 @@ def catch(
     ) -> Awaitable[_T | _U]:
         """
         Catches an exception of the given type and calls the passed function with the caught exception.
-        
+
         If no exception was raised inside the wrapped awaitable, the function will not be called.
         The passed function can optionally return a value to be returned in case of an error.
         The passed function can be either sync or async. If it's async, it is awaited.
-        
+
         Args:
             fn: A function that takes the exception and returns a value or awaitable.
             exception: The type of exception to catch (default: Exception).
-            
+
         Returns:
             An awaitable that resolves to the original result or the result of the error handler.
         """
@@ -70,7 +70,7 @@ async def _catch():
                 if iscoroutinefunction(fn):
                     return await result
                 return result
-        
+
         return _catch()
 
 
@@ -81,10 +81,10 @@ def extend():
     # Get the coroutine type by creating a coroutine and getting its type
     async def _dummy():
         pass
-    
+
     coro = _dummy()
     coroutine_type = type(coro)
     extend_type_with(coroutine_type, CoroutineExtension)
-    
+
     # Close the coroutine to avoid warnings
     coro.close()
diff --git a/tests/test_builtin_extensions.py b/tests/test_builtin_extensions.py
index 62c21b2..ed2aea3 100644
--- a/tests/test_builtin_extensions.py
+++ b/tests/test_builtin_extensions.py
@@ -1,5 +1,5 @@
 import pytest
-from extype.builtin_extensions import extend_all
+from extype.builtin_extensions import extend_all  # noqa: F401
 
 
 # dict keys extension tests
@@ -330,7 +330,7 @@ def test_str_to_float():
 async def test_coroutine_then_sync():
     async def foo():
         return 10
-    
+
     result = await foo().then(lambda x: x + 5)
     assert result == 15
 
@@ -339,10 +339,10 @@ async def foo():
 async def test_coroutine_then_async():
     async def foo():
         return 10
-    
+
     async def add_five(x):
         return x + 5
-    
+
     result = await foo().then(add_five)
     assert result == 15
 
@@ -351,10 +351,10 @@ async def add_five(x):
 async def test_coroutine_then_chaining():
     async def foo():
         return 10
-    
+
     async def add_five(x):
         return x + 5
-    
+
     result = await foo().then(lambda x: x * 2).then(add_five).then(lambda x: x - 3)
     assert result == 22  # (10 * 2) + 5 - 3 = 22
 
@@ -363,7 +363,7 @@ async def add_five(x):
 async def test_coroutine_catch_no_exception():
     async def foo():
         return 42
-    
+
     result = await foo().catch(lambda e: 0)
     assert result == 42
 
@@ -372,7 +372,7 @@ async def foo():
 async def test_coroutine_catch_with_exception():
     async def foo():
         raise ValueError("test error")
-    
+
     result = await foo().catch(lambda e: 100, exception=ValueError)
     assert result == 100
 
@@ -381,10 +381,10 @@ async def foo():
 async def test_coroutine_catch_async_handler():
     async def foo():
         raise ValueError("test error")
-    
+
     async def handle_error(e):
         return 200
-    
+
     result = await foo().catch(handle_error, exception=ValueError)
     assert result == 200
 
@@ -393,7 +393,7 @@ async def handle_error(e):
 async def test_coroutine_catch_wrong_exception_type():
     async def foo():
         raise ValueError("test error")
-    
+
     with pytest.raises(ValueError):
         await foo().catch(lambda e: 0, exception=TypeError)
 
@@ -402,7 +402,7 @@ async def foo():
 async def test_coroutine_catch_default_exception():
     async def foo():
         raise RuntimeError("test error")
-    
+
     result = await foo().catch(lambda e: 300)
     assert result == 300
 
@@ -411,7 +411,7 @@ async def foo():
 async def test_coroutine_then_and_catch_combined():
     async def foo():
         return 10
-    
+
     result = await foo().then(lambda x: x * 2).catch(lambda e: 0)
     assert result == 20
 
@@ -420,11 +420,9 @@ async def foo():
 async def test_coroutine_catch_and_then_combined():
     async def foo():
         raise ValueError("error")
-    
+
     result = await foo().catch(lambda e: 50, exception=ValueError).then(lambda x: x + 10)
     assert result == 60
 
 
 ###################################################
-
-

From 14145769bb26564961107caceb075273b0264acb Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 20:15:08 +0000
Subject: [PATCH 4/6] Fix code review issue: use iscoroutine instead of
 iscoroutinefunction

Co-authored-by: neriyaco <42520786+neriyaco@users.noreply.github.com>
---
 src/extype/builtin_extensions/coroutine_ext.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/extype/builtin_extensions/coroutine_ext.py b/src/extype/builtin_extensions/coroutine_ext.py
index 8bfa7be..6525def 100644
--- a/src/extype/builtin_extensions/coroutine_ext.py
+++ b/src/extype/builtin_extensions/coroutine_ext.py
@@ -1,4 +1,4 @@
-from inspect import iscoroutinefunction
+from inspect import iscoroutine
 from typing import Awaitable, Callable, TypeVar
 
 from ..extension_utils import extend_type_with, extension
@@ -35,7 +35,7 @@ def then(self: Awaitable[_T], fn: Callable[[_T], Awaitable[_U] | _U]) -> Awaitab
         """
         async def _then():
             result = fn(await self)
-            if iscoroutinefunction(fn):
+            if iscoroutine(result):
                 return await result
             return result
 
@@ -67,7 +67,7 @@ async def _catch():
                 return await self
             except exception as e:
                 result = fn(e)
-                if iscoroutinefunction(fn):
+                if iscoroutine(result):
                     return await result
                 return result
 

From b545dd14d90b0ddb703cd92bf59e0e19afde46d5 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 10 Feb 2026 10:31:37 +0000
Subject: [PATCH 5/6] Fix CI: install pytest-asyncio in all workflow test steps

Co-authored-by: binyamin555 <42520501+binyamin555@users.noreply.github.com>
---
 .github/workflows/python-test-linux.yml   | 4 ++--
 .github/workflows/python-test-macos.yml   | 4 ++--
 .github/workflows/python-test-windows.yml | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/python-test-linux.yml b/.github/workflows/python-test-linux.yml
index bc1c9c5..55f47c8 100644
--- a/.github/workflows/python-test-linux.yml
+++ b/.github/workflows/python-test-linux.yml
@@ -39,7 +39,7 @@ jobs:
         pip install dist/*.whl
     - name: Test with pytest
       run: |
-        python -m pip install typing-extensions
+        python -m pip install typing-extensions pytest-asyncio
         pytest
 
   build:
@@ -71,6 +71,6 @@ jobs:
         pip install dist/*.whl
     - name: Test with pytest
       run: |
-        python -m pip install typing-extensions
+        python -m pip install typing-extensions pytest-asyncio
         pytest
 
diff --git a/.github/workflows/python-test-macos.yml b/.github/workflows/python-test-macos.yml
index 55d5488..6a0d1c6 100644
--- a/.github/workflows/python-test-macos.yml
+++ b/.github/workflows/python-test-macos.yml
@@ -39,7 +39,7 @@ jobs:
         pip install dist/*.whl
     - name: Test with pytest
       run: |
-        python -m pip install typing-extensions
+        python -m pip install typing-extensions pytest-asyncio
         pytest
 
   build:
@@ -71,6 +71,6 @@ jobs:
         pip install dist/*.whl
     - name: Test with pytest
       run: |
-        python -m pip install typing-extensions
+        python -m pip install typing-extensions pytest-asyncio
         pytest
 
diff --git a/.github/workflows/python-test-windows.yml b/.github/workflows/python-test-windows.yml
index eb3545b..7674e42 100644
--- a/.github/workflows/python-test-windows.yml
+++ b/.github/workflows/python-test-windows.yml
@@ -46,6 +46,6 @@ jobs:
         }
     - name: Test with pytest
       run: |
-        python -m pip install typing-extensions
+        python -m pip install typing-extensions pytest-asyncio
         pytest
 

From 2e969bd239e8c44f8917c3d5cf23d3ca6042a330 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 10 Feb 2026 10:41:00 +0000
Subject: [PATCH 6/6] Fix Python 3.7+ compatibility: use Union and Type instead
 of | and type

Co-authored-by: binyamin555 <42520501+binyamin555@users.noreply.github.com>
---
 src/extype/builtin_extensions/coroutine_ext.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/extype/builtin_extensions/coroutine_ext.py b/src/extype/builtin_extensions/coroutine_ext.py
index 6525def..44c0bf8 100644
--- a/src/extype/builtin_extensions/coroutine_ext.py
+++ b/src/extype/builtin_extensions/coroutine_ext.py
@@ -1,5 +1,5 @@
 from inspect import iscoroutine
-from typing import Awaitable, Callable, TypeVar
+from typing import Awaitable, Callable, Type, TypeVar, Union
 
 from ..extension_utils import extend_type_with, extension
 
@@ -21,7 +21,7 @@ class CoroutineExtension:
     """
 
     @extension
-    def then(self: Awaitable[_T], fn: Callable[[_T], Awaitable[_U] | _U]) -> Awaitable[_U]:
+    def then(self: Awaitable[_T], fn: Callable[[_T], Union[Awaitable[_U], _U]]) -> Awaitable[_U]:
         """
         Maps the result of the awaitable via an optionally async function.
 
@@ -44,10 +44,10 @@ async def _then():
     @extension
     def catch(
         self: Awaitable[_T],
-        fn: Callable[[_E], Awaitable[_U] | _U],
+        fn: Callable[[_E], Union[Awaitable[_U], _U]],
         *,
-        exception: type[_E] = Exception
-    ) -> Awaitable[_T | _U]:
+        exception: Type[_E] = Exception
+    ) -> Awaitable[Union[_T, _U]]:
         """
         Catches an exception of the given type and calls the passed function with the caught exception.