From 6e01447c20d6b4a68ff44515aff0dfcff5928a39 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 2 Oct 2021 15:20:11 -0500
Subject: [PATCH 01/13] add test args for makefile

---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 2be0397..454483d 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ install-localdev:  ## install library for local development; pip install -e .
 	flit install --symlink
 
 test: ## run tests
-	pytest
+	pytest $(args)
 
 test-cov: ## run tests with coverage
 	pytest --cov finite_state_machine/ --cov examples/

From b5fc95851f7d71ac96ef2450fb3b241a8a6030c1 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 2 Oct 2021 15:20:32 -0500
Subject: [PATCH 02/13] add pytest asyncio as dev requirement

---
 requirements_dev.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/requirements_dev.txt b/requirements_dev.txt
index 482c17e..e4a0c63 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -3,6 +3,7 @@
 # testing
 pytest==6.2.5
 pytest-cov==2.10.1
+pytest-asyncio==0.15.1
 
 # package management
 flit==3.0.0

From 9b502daedff982d32bb2cc18afe1e13073a2f117 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 2 Oct 2021 15:21:03 -0500
Subject: [PATCH 03/13] add code and tests

---
 examples/async_turnstile.py                 |  17 +++
 finite_state_machine/state_machine.py       | 120 +++++++++++++-------
 tests/examples/test_async_state_machinne.py |  40 +++++++
 3 files changed, 139 insertions(+), 38 deletions(-)
 create mode 100644 examples/async_turnstile.py
 create mode 100644 tests/examples/test_async_state_machinne.py

diff --git a/examples/async_turnstile.py b/examples/async_turnstile.py
new file mode 100644
index 0000000..f206140
--- /dev/null
+++ b/examples/async_turnstile.py
@@ -0,0 +1,17 @@
+from finite_state_machine import StateMachine, transition
+
+
+class Turnstile(StateMachine):
+    initial_state = "close"
+
+    def __init__(self):
+        self.state = self.initial_state
+        super().__init__()
+
+    @transition(source=["close", "open"], target="open")
+    async def insert_coin(self):
+        return "inserted coin"
+
+    @transition(source="open", target="close")
+    async def pass_thru(self):
+        return "passed thru"
diff --git a/finite_state_machine/state_machine.py b/finite_state_machine/state_machine.py
index 399b59d..9d1cad9 100644
--- a/finite_state_machine/state_machine.py
+++ b/finite_state_machine/state_machine.py
@@ -1,3 +1,4 @@
+import asyncio
 from enum import Enum
 import functools
 import types
@@ -51,43 +52,86 @@ def transition(source, target, conditions=None, on_error=None):
     def transition_decorator(func):
         func.__fsm = Transition(func.__name__, source, target, conditions, on_error)
 
-        @functools.wraps(func)
-        def _wrapper(*args, **kwargs):
-            try:
-                self, rest = args
-            except ValueError:
-                self = args[0]
-
-            if self.state not in source:
-                exception_message = (
-                    f"Current state is {self.state}. "
-                    f"{func.__name__} allows transitions from {source}."
-                )
-                raise InvalidStartState(exception_message)
-
-            conditions_not_met = []
-            for condition in conditions:
-                if not condition(*args, **kwargs):
-                    conditions_not_met.append(condition)
-            if conditions_not_met:
-                raise ConditionsNotMet(conditions_not_met)
-
-            if not on_error:
-                result = func(*args, **kwargs)
-                self.state = target
-                return result
-
-            try:
-                result = func(*args, **kwargs)
-                self.state = target
-                return result
-            except Exception:
-                # TODO should we log this somewhere?
-                # logger.error? maybe have an optional parameter to set this up
-                # how to libraries log?
-                self.state = on_error
-                return
-
-        return _wrapper
+        synchronous_execution = not asyncio.iscoroutinefunction(func)
+        if synchronous_execution:
+
+            @functools.wraps(func)
+            def _wrapper(*args, **kwargs):
+                try:
+                    self, rest = args
+                except ValueError:
+                    self = args[0]
+
+                if self.state not in source:
+                    exception_message = (
+                        f"Current state is {self.state}. "
+                        f"{func.__name__} allows transitions from {source}."
+                    )
+                    raise InvalidStartState(exception_message)
+
+                conditions_not_met = []
+                for condition in conditions:
+                    if not condition(*args, **kwargs):
+                        conditions_not_met.append(condition)
+                if conditions_not_met:
+                    raise ConditionsNotMet(conditions_not_met)
+
+                if not on_error:
+                    result = func(*args, **kwargs)
+                    self.state = target
+                    return result
+
+                try:
+                    result = func(*args, **kwargs)
+                    self.state = target
+                    return result
+                except Exception:
+                    # TODO should we log this somewhere?
+                    # logger.error? maybe have an optional parameter to set this up
+                    # how to libraries log?
+                    self.state = on_error
+                    return
+
+            return _wrapper
+        else:
+
+            @functools.wraps(func)
+            async def _wrapper(*args, **kwargs):
+                try:
+                    self, rest = args
+                except ValueError:
+                    self = args[0]
+
+                if self.state not in source:
+                    exception_message = (
+                        f"Current state is {self.state}. "
+                        f"{func.__name__} allows transitions from {source}."
+                    )
+                    raise InvalidStartState(exception_message)
+
+                conditions_not_met = []
+                for condition in conditions:
+                    if not condition(*args, **kwargs):
+                        conditions_not_met.append(condition)
+                if conditions_not_met:
+                    raise ConditionsNotMet(conditions_not_met)
+
+                if not on_error:
+                    result = await func(*args, **kwargs)
+                    self.state = target
+                    return result
+
+                try:
+                    result = await func(*args, **kwargs)
+                    self.state = target
+                    return result
+                except Exception:
+                    # TODO should we log this somewhere?
+                    # logger.error? maybe have an optional parameter to set this up
+                    # how to libraries log?
+                    self.state = on_error
+                    return
+
+            return _wrapper
 
     return transition_decorator
diff --git a/tests/examples/test_async_state_machinne.py b/tests/examples/test_async_state_machinne.py
new file mode 100644
index 0000000..09b8eb8
--- /dev/null
+++ b/tests/examples/test_async_state_machinne.py
@@ -0,0 +1,40 @@
+import warnings
+
+import pytest
+
+from finite_state_machine.exceptions import InvalidStartState
+from examples.async_turnstile import Turnstile
+
+
+@pytest.mark.asyncio
+async def test_async_turnstile_does_not_raise_coroutine_not_awaited_warnings():
+    with warnings.catch_warnings(record=True) as caught_warnings:
+        t = Turnstile()
+        assert t.state == "close"
+
+        result = await t.insert_coin()
+        assert t.state == "open"
+        assert result == "inserted coin"
+
+        result = await t.insert_coin()
+        assert t.state == "open"
+        assert result == "inserted coin"
+
+        result = await t.pass_thru()
+        assert t.state == "close"
+        assert result == "passed thru"
+
+    assert len(caught_warnings) == 0
+
+
+@pytest.mark.asyncio
+async def test_async_turnstile__cannot_pass_thru_closed_turnstile():
+    t = Turnstile()
+    assert t.state == "close"
+
+    with pytest.raises(
+        InvalidStartState, match="Current state is close"
+    ), warnings.catch_warnings(record=True) as caught_warnings:
+        await t.pass_thru()
+
+    assert len(caught_warnings) == 0

From 1074487014fe928a7216528682750f550ff82fdf Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 2 Oct 2021 15:37:36 -0500
Subject: [PATCH 04/13] async transition function goes to error state

---
 examples/async_turnstile.py                 |  4 ++++
 tests/examples/test_async_state_machinne.py | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/examples/async_turnstile.py b/examples/async_turnstile.py
index f206140..4801a0d 100644
--- a/examples/async_turnstile.py
+++ b/examples/async_turnstile.py
@@ -15,3 +15,7 @@ async def insert_coin(self):
     @transition(source="open", target="close")
     async def pass_thru(self):
         return "passed thru"
+
+    @transition(source="close", target="close", on_error="error_state")
+    async def error_function(self):
+        raise ValueError
diff --git a/tests/examples/test_async_state_machinne.py b/tests/examples/test_async_state_machinne.py
index 09b8eb8..1b0b4e8 100644
--- a/tests/examples/test_async_state_machinne.py
+++ b/tests/examples/test_async_state_machinne.py
@@ -38,3 +38,15 @@ async def test_async_turnstile__cannot_pass_thru_closed_turnstile():
         await t.pass_thru()
 
     assert len(caught_warnings) == 0
+
+
+@pytest.mark.asyncio
+async def test_async_turnstile__goes_into_error_state():
+    t = Turnstile()
+    assert t.state == "close"
+
+    with warnings.catch_warnings(record=True) as caught_warnings:
+        await t.error_function()
+
+    assert t.state == "error_state"
+    assert len(caught_warnings) == 0

From a9ae3f9cc44e179182dc2e1e3965350ef213d14d Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 2 Oct 2021 15:40:58 -0500
Subject: [PATCH 05/13] improve code cov

---
 examples/async_turnstile.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/async_turnstile.py b/examples/async_turnstile.py
index 4801a0d..1bf45f9 100644
--- a/examples/async_turnstile.py
+++ b/examples/async_turnstile.py
@@ -8,7 +8,7 @@ def __init__(self):
         self.state = self.initial_state
         super().__init__()
 
-    @transition(source=["close", "open"], target="open")
+    @transition(source=["close", "open"], target="open", on_error="error_state")
     async def insert_coin(self):
         return "inserted coin"
 

From 8ff48d37de7c1595d28d525d760bfa723a982c44 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 9 Oct 2021 15:07:52 -0500
Subject: [PATCH 06/13] Allow for asynchronous condition functions (#33)

---
 .pre-commit-config.yaml                       |  2 +-
 README.md                                     | 14 ++++
 examples/async_github_pull_request.py         | 46 +++++++++++
 finite_state_machine/state_machine.py         |  8 +-
 .../test_async_github_pull_request.py         | 78 +++++++++++++++++++
 5 files changed, 145 insertions(+), 3 deletions(-)
 create mode 100644 examples/async_github_pull_request.py
 create mode 100644 tests/examples/test_async_github_pull_request.py

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 23ea442..1fb63f8 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
 -   repo: https://github.com/ambv/black
-    rev: stable
+    rev: 21.9b0
     hooks:
     - id: black
 -   repo: https://gitlab.com/pycqa/flake8
diff --git a/README.md b/README.md
index 6308f23..ac61355 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,7 @@ Lightweight, decorator-based Python implementation of a [Finite State Machine](h
 - [Installation](#installation)
 - [Usage](#usage)
 - [Example](#example)
+- [Async Support](#async-support)
 - [State Diagram](#state-diagram)
 - [Contributing](#contributing)
 - [Inspiration](#inspiration)
@@ -134,6 +135,19 @@ InvalidStartState:
 
 The [examples](/examples) folder contains additional workflows.
 
+## Async Support
+
+This library supports asynchronous state machines
+through the use of async `@transition` decorator and async condition functions.
+
+See the following matrix on how synchronous and asynchronous functions
+can be combined to build state machines:
+
+||Sync `@transition` decorator|Async `@transition` decorator|
+|---|:---:|:---:|
+|Sync condition function|✅|❌|
+|Async condition function|✅|✅|
+
 ## State Diagram
 
 State Machine workflows can be visualized using a
diff --git a/examples/async_github_pull_request.py b/examples/async_github_pull_request.py
new file mode 100644
index 0000000..411040b
--- /dev/null
+++ b/examples/async_github_pull_request.py
@@ -0,0 +1,46 @@
+from finite_state_machine import StateMachine, transition
+
+
+async def async_is_approved_or_is_admin(machine, user):
+    return machine.num_approvals >= 1 or user.is_admin
+
+
+def sync_is_approved_or_is_admin(machine, user):
+    return machine.num_approvals >= 1 or user.is_admin
+
+
+class GitHubPullRequest(StateMachine):
+    """State Machine to represent a GitHub Pull Request workflow"""
+
+    def __init__(self):
+        self.state = "opened"
+        self.num_approvals = 0
+        self.changes_request = False
+
+    @transition(source="opened", target="opened")
+    async def approve(self):
+        self.num_approvals += 1
+
+    @transition(source="opened", target="opened")
+    async def request_changes(self):
+        self.changes_request = True
+
+    @transition(source="opened", target="closed")
+    async def close_pull_request(self):
+        pass
+
+    @transition(
+        source="opened",
+        target="merged",
+        conditions=[async_is_approved_or_is_admin],
+    )
+    async def fully_async_merge_pull_request(self, user):
+        pass
+
+    @transition(
+        source="opened",
+        target="merged",
+        conditions=[sync_is_approved_or_is_admin],
+    )
+    async def async_merge_pull_request_with_sync_condition(self, user):
+        pass
diff --git a/finite_state_machine/state_machine.py b/finite_state_machine/state_machine.py
index 9d1cad9..c5f9548 100644
--- a/finite_state_machine/state_machine.py
+++ b/finite_state_machine/state_machine.py
@@ -71,7 +71,7 @@ def _wrapper(*args, **kwargs):
 
                 conditions_not_met = []
                 for condition in conditions:
-                    if not condition(*args, **kwargs):
+                    if condition(*args, **kwargs) is not True:
                         conditions_not_met.append(condition)
                 if conditions_not_met:
                     raise ConditionsNotMet(conditions_not_met)
@@ -111,7 +111,11 @@ async def _wrapper(*args, **kwargs):
 
                 conditions_not_met = []
                 for condition in conditions:
-                    if not condition(*args, **kwargs):
+                    if asyncio.iscoroutinefunction(condition):
+                        condition_result = await condition(*args, **kwargs)
+                    else:
+                        condition_result = condition(*args, **kwargs)
+                    if condition_result is not True:
                         conditions_not_met.append(condition)
                 if conditions_not_met:
                     raise ConditionsNotMet(conditions_not_met)
diff --git a/tests/examples/test_async_github_pull_request.py b/tests/examples/test_async_github_pull_request.py
new file mode 100644
index 0000000..0a6cee0
--- /dev/null
+++ b/tests/examples/test_async_github_pull_request.py
@@ -0,0 +1,78 @@
+from collections import namedtuple
+
+import pytest
+
+from examples.async_github_pull_request import GitHubPullRequest
+
+User = namedtuple("User", "name github_id is_admin")
+
+
+@pytest.mark.asyncio
+async def test_approved_pr_can_be_merged__with_sync_condition_function():
+    # Arrange
+    github_pr = GitHubPullRequest()
+    await github_pr.approve()
+    assert github_pr.state == "opened"
+    user = User(name="Aly Sivji", github_id="alysivji", is_admin=False)
+
+    # Act
+    await github_pr.async_merge_pull_request_with_sync_condition(user)
+
+    # Assert
+    assert github_pr.state == "merged"
+
+
+@pytest.mark.asyncio
+async def test_approved_pr_can_be_merged__fully_async():
+    # Arrange
+    github_pr = GitHubPullRequest()
+    await github_pr.approve()
+    assert github_pr.state == "opened"
+    user = User(name="Aly Sivji", github_id="alysivji", is_admin=False)
+
+    # Act
+    await github_pr.fully_async_merge_pull_request(user)
+
+    # Assert
+    assert github_pr.state == "merged"
+
+
+@pytest.mark.asyncio
+async def test_pr_with_no_approvals_can_be_merged_by_admin():
+    # Arrange
+    github_pr = GitHubPullRequest()
+    assert github_pr.state == "opened"
+    user = User(name="Aly Sivji", github_id="alysivji", is_admin=True)
+
+    # Act
+    await github_pr.fully_async_merge_pull_request(user)
+
+    # Assert
+    assert github_pr.state == "merged"
+
+
+@pytest.mark.asyncio
+async def test_request_approval():
+    # Arrange
+    github_pr = GitHubPullRequest()
+    assert github_pr.state == "opened"
+
+    # Act
+    await github_pr.request_changes()
+
+    # Assert
+    assert github_pr.state == "opened"
+    assert github_pr.changes_request is True
+
+
+@pytest.mark.asyncio
+async def test_close_pull_request():
+    # Arrange
+    github_pr = GitHubPullRequest()
+    assert github_pr.state == "opened"
+
+    # Act
+    await github_pr.close_pull_request()
+
+    # Assert
+    assert github_pr.state == "closed"

From 50ce62dd21c76cb2921e99c24b5c9e46e9322fa2 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 9 Oct 2021 15:16:49 -0500
Subject: [PATCH 07/13] improve codecov

---
 tests/examples/test_async_github_pull_request.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tests/examples/test_async_github_pull_request.py b/tests/examples/test_async_github_pull_request.py
index 0a6cee0..a0d4070 100644
--- a/tests/examples/test_async_github_pull_request.py
+++ b/tests/examples/test_async_github_pull_request.py
@@ -2,6 +2,7 @@
 
 import pytest
 
+from finite_state_machine.exceptions import ConditionsNotMet
 from examples.async_github_pull_request import GitHubPullRequest
 
 User = namedtuple("User", "name github_id is_admin")
@@ -37,6 +38,18 @@ async def test_approved_pr_can_be_merged__fully_async():
     assert github_pr.state == "merged"
 
 
+@pytest.mark.asyncio
+async def test_pr_with_no_approvals_cannot_be_merged():
+    # Arrange
+    github_pr = GitHubPullRequest()
+    assert github_pr.state == "opened"
+    user = User(name="Aly Sivji", github_id="alysivji", is_admin=False)
+
+    # Act
+    with pytest.raises(ConditionsNotMet):
+        await github_pr.fully_async_merge_pull_request(user)
+
+
 @pytest.mark.asyncio
 async def test_pr_with_no_approvals_can_be_merged_by_admin():
     # Arrange

From 3e9fb7cda7e7145e4986bf8cfad22c2e8160a6f9 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 9 Oct 2021 16:53:55 -0500
Subject: [PATCH 08/13] make decorator a callable class

---
 finite_state_machine/state_machine.py | 238 ++++++++++++++------------
 1 file changed, 124 insertions(+), 114 deletions(-)

diff --git a/finite_state_machine/state_machine.py b/finite_state_machine/state_machine.py
index c5f9548..a855726 100644
--- a/finite_state_machine/state_machine.py
+++ b/finite_state_machine/state_machine.py
@@ -23,119 +23,129 @@ class Transition(NamedTuple):
     on_error: Union[bool, int, str]
 
 
-def transition(source, target, conditions=None, on_error=None):
-    allowed_types = (str, bool, int, Enum)
-
-    if isinstance(source, allowed_types):
-        source = [source]
-    if not isinstance(source, list):
-        raise ValueError("Source can be a bool, int, string, Enum, or list")
-    for item in source:
-        if not isinstance(item, allowed_types):
-            raise ValueError("Source can be a bool, int, string, Enum, or list")
+class transition:
+    _fsm_transition_mapping = {}
 
-    if not isinstance(target, allowed_types):
-        raise ValueError("Target needs to be a bool, int or string")
-
-    if not conditions:
-        conditions = []
-    if not isinstance(conditions, list):
-        raise ValueError("conditions must be a list")
-    for condition in conditions:
-        if not isinstance(condition, types.FunctionType):
-            raise ValueError("conditions list must contain functions")
-
-    if on_error:
-        if not isinstance(on_error, allowed_types):
-            raise ValueError("on_error needs to be a bool, int or string")
-
-    def transition_decorator(func):
-        func.__fsm = Transition(func.__name__, source, target, conditions, on_error)
-
-        synchronous_execution = not asyncio.iscoroutinefunction(func)
-        if synchronous_execution:
-
-            @functools.wraps(func)
-            def _wrapper(*args, **kwargs):
-                try:
-                    self, rest = args
-                except ValueError:
-                    self = args[0]
-
-                if self.state not in source:
-                    exception_message = (
-                        f"Current state is {self.state}. "
-                        f"{func.__name__} allows transitions from {source}."
-                    )
-                    raise InvalidStartState(exception_message)
-
-                conditions_not_met = []
-                for condition in conditions:
-                    if condition(*args, **kwargs) is not True:
-                        conditions_not_met.append(condition)
-                if conditions_not_met:
-                    raise ConditionsNotMet(conditions_not_met)
-
-                if not on_error:
-                    result = func(*args, **kwargs)
-                    self.state = target
-                    return result
-
-                try:
-                    result = func(*args, **kwargs)
-                    self.state = target
-                    return result
-                except Exception:
-                    # TODO should we log this somewhere?
-                    # logger.error? maybe have an optional parameter to set this up
-                    # how to libraries log?
-                    self.state = on_error
-                    return
-
-            return _wrapper
-        else:
+    def __init__(self, source, target, conditions=None, on_error=None):
+        allowed_types = (str, bool, int, Enum)
 
-            @functools.wraps(func)
-            async def _wrapper(*args, **kwargs):
-                try:
-                    self, rest = args
-                except ValueError:
-                    self = args[0]
-
-                if self.state not in source:
-                    exception_message = (
-                        f"Current state is {self.state}. "
-                        f"{func.__name__} allows transitions from {source}."
-                    )
-                    raise InvalidStartState(exception_message)
-
-                conditions_not_met = []
-                for condition in conditions:
-                    if asyncio.iscoroutinefunction(condition):
-                        condition_result = await condition(*args, **kwargs)
-                    else:
-                        condition_result = condition(*args, **kwargs)
-                    if condition_result is not True:
-                        conditions_not_met.append(condition)
-                if conditions_not_met:
-                    raise ConditionsNotMet(conditions_not_met)
-
-                if not on_error:
-                    result = await func(*args, **kwargs)
-                    self.state = target
-                    return result
-
-                try:
-                    result = await func(*args, **kwargs)
-                    self.state = target
-                    return result
-                except Exception:
-                    # TODO should we log this somewhere?
-                    # logger.error? maybe have an optional parameter to set this up
-                    # how to libraries log?
-                    self.state = on_error
-                    return
-
-            return _wrapper
-
-    return transition_decorator
+        if isinstance(source, allowed_types):
+            source = [source]
+        if not isinstance(source, list):
+            raise ValueError("Source can be a bool, int, string, Enum, or list")
+        for item in source:
+            if not isinstance(item, allowed_types):
+                raise ValueError("Source can be a bool, int, string, Enum, or list")
+        self.source = source
+
+        if not isinstance(target, allowed_types):
+            raise ValueError("Target needs to be a bool, int or string")
+        self.target = target
+
+        if not conditions:
+            conditions = []
+        if not isinstance(conditions, list):
+            raise ValueError("conditions must be a list")
+        for condition in conditions:
+            if not isinstance(condition, types.FunctionType):
+                raise ValueError("conditions list must contain functions")
+        self.conditions = conditions
+
+        if on_error:
+            if not isinstance(on_error, allowed_types):
+                raise ValueError("on_error needs to be a bool, int or string")
+        self.on_error = on_error
+
+    def __call__(self, func):
+        func.__fsm = Transition(
+            func.__name__,
+            self.source,
+            self.target,
+            self.conditions,
+            self.on_error,
+        )
+        # TODO update on class transition mapping
+        self.__class__._fsm_transition_mapping[func.__qualname__] = func
+
+        @functools.wraps(func)
+        def callable(*args, **kwargs):
+            try:
+                state_machine, rest = args
+            except ValueError:
+                state_machine = args[0]
+
+            if state_machine.state not in self.source:
+                exception_message = (
+                    f"Current state is {state_machine.state}. "
+                    f"{func.__name__} allows transitions from {self.source}."
+                )
+                raise InvalidStartState(exception_message)
+
+            conditions_not_met = []
+            for condition in self.conditions:
+                if condition(*args, **kwargs) is not True:
+                    conditions_not_met.append(condition)
+            if conditions_not_met:
+                raise ConditionsNotMet(conditions_not_met)
+
+            if not self.on_error:
+                result = func(*args, **kwargs)
+                state_machine.state = self.target
+                return result
+
+            try:
+                result = func(*args, **kwargs)
+                state_machine.state = self.target
+                return result
+            except Exception:
+                # TODO should we log this somewhere?
+                # logger.error? maybe have an optional parameter to set this up
+                # how to libraries log?
+                state_machine.state = self.on_error
+                return
+
+        @functools.wraps(func)
+        async def async_callable(*args, **kwargs):
+            try:
+                state_machine, rest = args
+            except ValueError:
+                state_machine = args[0]
+
+            if state_machine.state not in self.source:
+                exception_message = (
+                    f"Current state is {state_machine.state}. "
+                    f"{func.__name__} allows transitions from {self.source}."
+                )
+                raise InvalidStartState(exception_message)
+
+            conditions_not_met = []
+            for condition in self.conditions:
+                if asyncio.iscoroutinefunction(condition):
+                    condition_result = await condition(*args, **kwargs)
+                else:
+                    condition_result = condition(*args, **kwargs)
+                if condition_result is not True:
+                    conditions_not_met.append(condition)
+            if conditions_not_met:
+                raise ConditionsNotMet(conditions_not_met)
+
+            if not self.on_error:
+                result = await func(*args, **kwargs)
+                state_machine.state = self.target
+                return result
+
+            try:
+                result = await func(*args, **kwargs)
+                state_machine.state = self.target
+                return result
+            except Exception:
+                # TODO should we log this somewhere?
+                # logger.error? maybe have an optional parameter to set this up
+                # how to libraries log?
+                state_machine.state = self.on_error
+                return
+
+        if asyncio.iscoroutinefunction(func):
+            return async_callable
+        else:
+            return callable

From 13ccb6db2e9b00728c9bdbbf15ed1fa095329404 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 9 Oct 2021 16:55:04 -0500
Subject: [PATCH 09/13] get draw fsm tests to pass

---
 finite_state_machine/draw_state_diagram.py | 2 +-
 finite_state_machine/state_machine.py      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/finite_state_machine/draw_state_diagram.py b/finite_state_machine/draw_state_diagram.py
index 0d12c19..176fecf 100644
--- a/finite_state_machine/draw_state_diagram.py
+++ b/finite_state_machine/draw_state_diagram.py
@@ -29,7 +29,7 @@ def generate_state_diagram_markdown(cls, initial_state):
 
     class_fns = inspect.getmembers(cls, predicate=inspect.isfunction)
     state_transitions: List[Transition] = [
-        func.__fsm for name, func in class_fns if hasattr(func, "__fsm")
+        func._fsm for name, func in class_fns if hasattr(func, "_fsm")
     ]
 
     transition_template = "    {source} --> {target} : {name}\n"
diff --git a/finite_state_machine/state_machine.py b/finite_state_machine/state_machine.py
index a855726..236f8dc 100644
--- a/finite_state_machine/state_machine.py
+++ b/finite_state_machine/state_machine.py
@@ -57,7 +57,7 @@ def __init__(self, source, target, conditions=None, on_error=None):
         self.on_error = on_error
 
     def __call__(self, func):
-        func.__fsm = Transition(
+        func._fsm = Transition(
             func.__name__,
             self.source,
             self.target,

From 19b31aba9d02d345b0192b5858a4eae96a3a2216 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 9 Oct 2021 16:56:08 -0500
Subject: [PATCH 10/13] improve name

---
 finite_state_machine/state_machine.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/finite_state_machine/state_machine.py b/finite_state_machine/state_machine.py
index 236f8dc..5479e3f 100644
--- a/finite_state_machine/state_machine.py
+++ b/finite_state_machine/state_machine.py
@@ -68,7 +68,7 @@ def __call__(self, func):
         self.__class__._fsm_transition_mapping[func.__qualname__] = func
 
         @functools.wraps(func)
-        def callable(*args, **kwargs):
+        def sync_callable(*args, **kwargs):
             try:
                 state_machine, rest = args
             except ValueError:
@@ -148,4 +148,4 @@ async def async_callable(*args, **kwargs):
         if asyncio.iscoroutinefunction(func):
             return async_callable
         else:
-            return callable
+            return sync_callable

From 90e0e8cdb6551fa11b4b4588615b80c41e00a8d1 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sat, 9 Oct 2021 17:11:36 -0500
Subject: [PATCH 11/13] add comment

---
 finite_state_machine/state_machine.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/finite_state_machine/state_machine.py b/finite_state_machine/state_machine.py
index 5479e3f..8ff670c 100644
--- a/finite_state_machine/state_machine.py
+++ b/finite_state_machine/state_machine.py
@@ -24,6 +24,7 @@ class Transition(NamedTuple):
 
 
 class transition:
+    # TODO remove from part 1 PR
     _fsm_transition_mapping = {}
 
     def __init__(self, source, target, conditions=None, on_error=None):

From 29b65cddf4007a0c480774b1b9e2896c45a54958 Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sun, 10 Oct 2021 16:04:50 -0500
Subject: [PATCH 12/13] remove todo

---
 finite_state_machine/state_machine.py | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/finite_state_machine/state_machine.py b/finite_state_machine/state_machine.py
index 8ff670c..0f24a1c 100644
--- a/finite_state_machine/state_machine.py
+++ b/finite_state_machine/state_machine.py
@@ -24,9 +24,6 @@ class Transition(NamedTuple):
 
 
 class transition:
-    # TODO remove from part 1 PR
-    _fsm_transition_mapping = {}
-
     def __init__(self, source, target, conditions=None, on_error=None):
         allowed_types = (str, bool, int, Enum)
 
@@ -65,8 +62,6 @@ def __call__(self, func):
             self.conditions,
             self.on_error,
         )
-        # TODO update on class transition mapping
-        self.__class__._fsm_transition_mapping[func.__qualname__] = func
 
         @functools.wraps(func)
         def sync_callable(*args, **kwargs):

From ef3cba9b0a579ed698a3ae4f27b6f758e2e30c9e Mon Sep 17 00:00:00 2001
From: Aly Sivji <alysivji@gmail.com>
Date: Sun, 10 Oct 2021 16:05:57 -0500
Subject: [PATCH 13/13] improve name of dto

---
 finite_state_machine/draw_state_diagram.py | 4 ++--
 finite_state_machine/state_machine.py      | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/finite_state_machine/draw_state_diagram.py b/finite_state_machine/draw_state_diagram.py
index 176fecf..0018a52 100644
--- a/finite_state_machine/draw_state_diagram.py
+++ b/finite_state_machine/draw_state_diagram.py
@@ -5,7 +5,7 @@
 import sys
 from typing import List
 
-from finite_state_machine.state_machine import Transition
+from finite_state_machine.state_machine import TransitionDetails
 
 
 def import_state_machine_class(path):  # pragma: no cover
@@ -28,7 +28,7 @@ def generate_state_diagram_markdown(cls, initial_state):
     """
 
     class_fns = inspect.getmembers(cls, predicate=inspect.isfunction)
-    state_transitions: List[Transition] = [
+    state_transitions: List[TransitionDetails] = [
         func._fsm for name, func in class_fns if hasattr(func, "_fsm")
     ]
 
diff --git a/finite_state_machine/state_machine.py b/finite_state_machine/state_machine.py
index 0f24a1c..ca5b9f6 100644
--- a/finite_state_machine/state_machine.py
+++ b/finite_state_machine/state_machine.py
@@ -15,7 +15,7 @@ def __init__(self):
             raise ValueError("Need to set a state instance variable")
 
 
-class Transition(NamedTuple):
+class TransitionDetails(NamedTuple):
     name: str
     source: Union[list, bool, int, str]
     target: Union[bool, int, str]
@@ -55,7 +55,7 @@ def __init__(self, source, target, conditions=None, on_error=None):
         self.on_error = on_error
 
     def __call__(self, func):
-        func._fsm = Transition(
+        func._fsm = TransitionDetails(
             func.__name__,
             self.source,
             self.target,