refactor: add editor module (#31)

Author: mtth

src/git_draft/__main__.py

@@ -6,14 +6,9 @@
 import sys
 
 from .bots import Operation, load_bot
-from .common import (
-    Config,
-    PROGRAM,
-    UnreachableError,
-    ensure_state_home,
-    open_editor,
-)
+from .common import Config, PROGRAM, UnreachableError, ensure_state_home
 from .drafter import Drafter
+from .editor import open_editor
 from .prompt import TemplatedPrompt
 from .store import Store
 

src/git_draft/common.py

@@ -2,14 +2,9 @@
 
 import dataclasses
 import logging
-import os
 from pathlib import Path
 import random
-import shutil
-import subprocess
 import string
-import sys
-import tempfile
 import tomllib
 from typing import Any, Mapping, Self, Sequence
 import xdg_base_dirs
@@ -67,44 +62,6 @@ class BotConfig:
     pythonpath: str | None = None
 
 
-_default_editors = ["vim", "emacs", "nano"]
-
-
-def _guess_editor_binpath() -> str:
-    editor = os.environ.get("EDITOR")
-    if editor:
-        return shutil.which(editor) or ""
-    for editor in _default_editors:
-        binpath = shutil.which(editor)
-        if binpath:
-            return binpath
-    return ""
-
-
-def _get_tty_filename():
-    return "CON:" if sys.platform == "win32" else "/dev/tty"
-
-
-def open_editor(placeholder="") -> str:
-    with tempfile.NamedTemporaryFile(delete_on_close=False) as temp:
-        binpath = _guess_editor_binpath()
-        if not binpath:
-            raise ValueError("Editor unavailable")
-
-        if placeholder:
-            with open(temp.name, "w") as writer:
-                writer.write(placeholder)
-
-        stdout = open(_get_tty_filename(), "wb")
-        proc = subprocess.Popen(
-            [binpath, temp.name], close_fds=True, stdout=stdout
-        )
-        proc.communicate()
-
-        with open(temp.name, mode="r") as reader:
-            return reader.read()
-
-
 _random = random.Random()
 _alphabet = string.ascii_lowercase + string.digits
 

src/git_draft/editor.py

@@ -0,0 +1,43 @@
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+_default_editors = ["vim", "emacs", "nano"]
+
+
+def _guess_editor_binpath() -> str:
+    editor = os.environ.get("EDITOR")
+    if editor:
+        return shutil.which(editor) or ""
+    for editor in _default_editors:
+        binpath = shutil.which(editor)
+        if binpath:
+            return binpath
+    return ""
+
+
+def _get_tty_filename():
+    return "CON:" if sys.platform == "win32" else "/dev/tty"
+
+
+def open_editor(placeholder="", *, _open_tty=open) -> str:
+    with tempfile.NamedTemporaryFile(delete_on_close=False) as temp:
+        binpath = _guess_editor_binpath()
+        if not binpath:
+            raise ValueError("Editor unavailable")
+
+        if placeholder:
+            with open(temp.name, "w") as writer:
+                writer.write(placeholder)
+
+        stdout = _open_tty(_get_tty_filename(), "wb")
+        proc = subprocess.Popen(
+            [binpath, temp.name], close_fds=True, stdout=stdout
+        )
+        proc.communicate()
+
+        with open(temp.name, mode="r") as reader:
+            return reader.read()

tests/git_draft/editor_test.py

@@ -0,0 +1,74 @@
+import pytest
+import shutil
+import subprocess
+
+import git_draft.editor as sut
+
+
+class TestGuessEditorBinPath:
+    def test_from_env_ok(self, monkeypatch) -> None:
+        def which(editor):
+            assert editor == "foo"
+            return "/bin/bar"
+
+        monkeypatch.setattr(shutil, "which", which)
+        monkeypatch.setenv("EDITOR", "foo")
+
+        assert sut._guess_editor_binpath() == "/bin/bar"
+
+    def test_from_env_missing(self, monkeypatch) -> None:
+        def which(_editor):
+            return ""
+
+        monkeypatch.setattr(shutil, "which", which)
+        monkeypatch.setenv("EDITOR", "foo")
+
+        assert sut._guess_editor_binpath() == ""
+
+    def test_from_default_ok(self, monkeypatch) -> None:
+        def which(editor):
+            return "/bin/nano" if editor == "nano" else ""
+
+        monkeypatch.setattr(shutil, "which", which)
+        monkeypatch.setenv("EDITOR", "")
+
+        assert sut._guess_editor_binpath() == "/bin/nano"
+
+    def test_from_default_missing(self, monkeypatch) -> None:
+        def which(_editor):
+            return ""
+
+        monkeypatch.setattr(shutil, "which", which)
+        monkeypatch.setenv("EDITOR", "")
+
+        assert sut._guess_editor_binpath() == ""
+
+
+class TestOpenEditor:
+    def test_no_binpath(self, monkeypatch) -> None:
+        def which(_editor):
+            return ""
+
+        monkeypatch.setattr(shutil, "which", which)
+
+        with pytest.raises(ValueError):
+            sut.open_editor()
+
+    def test_ok(self, monkeypatch) -> None:
+        def which(editor):
+            return f"/bin/{editor}"
+
+        def open_tty(*_args):
+            return None
+
+        class Popen:
+            def __init__(self, *_args, **_kwargs):
+                pass
+
+            def communicate(self):
+                pass
+
+        monkeypatch.setattr(shutil, "which", which)
+        monkeypatch.setattr(subprocess, "Popen", Popen)
+
+        assert sut.open_editor("hello", _open_tty=open_tty) == "hello"