feat(commands/commit): apply prepare-commit-msg hook

add --commit-msg-file argument

Author: saygox

.pre-commit-hooks.yaml

@@ -6,3 +6,11 @@
   language_version: python3
   require_serial: true
   minimum_pre_commit_version: "0.15.4"
+- id: commitizen-prepare-commit-msg
+  name: commitizen prepare commit msg
+  description: "prepare commit message"
+  entry: cz commit --commit-msg-file
+  language: python
+  language_version: python3
+  require_serial: true
+  minimum_pre_commit_version: "0.15.4"

commitizen/cli.py

@@ -48,6 +48,14 @@
                         "action": "store_true",
                         "help": "show output to stdout, no commit, no modified files",
                     },
+                    {
+                        "name": "--commit-msg-file",
+                        "help": (
+                            "ask for the name of the temporal file that contains "
+                            "the commit message. "
+                            "Using it in a git hook script: MSG_FILE=$1"
+                        ),
+                    },
                 ],
             },
             {

commitizen/commands/commit.py

@@ -1,5 +1,6 @@
 import contextlib
 import os
+import sys
 import tempfile
 
 import questionary
@@ -18,6 +19,21 @@
 )
 
 
+class WrapStdin:
+    def __init__(self):
+        fd = os.open("/dev/tty", os.O_RDWR | os.O_NOCTTY)
+        tty = open(fd, "wb+", buffering=0)
+        self.tty = tty
+
+    def __getattr__(self, key):
+        if key == "encoding":
+            return "UTF-8"
+        return getattr(self.tty, key)
+
+    def __del__(self):
+        self.tty.close()
+
+
 class Commit:
     """Show prompt for the user to create a guided commit."""
 
@@ -58,6 +74,15 @@ def prompt_commit_questions(self) -> str:
     def __call__(self):
         dry_run: bool = self.arguments.get("dry_run")
 
+        commit_msg_file: str = self.arguments.get("commit_msg_file")
+        if commit_msg_file:
+            old_stdin = sys.stdin
+            old_stdout = sys.stdout
+            old_stderr = sys.stderr
+            sys.stdin = WrapStdin()
+            sys.stdout = open("/dev/tty", "w")
+            sys.stderr = open("/dev/tty", "w")
+
         if git.is_staging_clean() and not dry_run:
             raise NothingToCommitError("No files added to staging!")
 
@@ -73,6 +98,22 @@ def __call__(self):
         if dry_run:
             raise DryRunExit()
 
+        if commit_msg_file:
+            sys.stdin.close()
+            sys.stdout.close()
+            sys.stderr.close()
+            sys.stdin = old_stdin
+            sys.stdout = old_stdout
+            sys.stderr = old_stderr
+            defaultmesaage = ""
+            with open(commit_msg_file) as f:
+                defaultmesaage = f.read()
+            with open(commit_msg_file, "w") as f:
+                f.write(m)
+                f.write(defaultmesaage)
+                out.success("Commit message is successful!")
+                return
+
         c = git.commit(m)
 
         if c.return_code != 0:

docs/README.md

@@ -79,7 +79,7 @@ cz c
 ```
 
 ### Integrating with Pre-commit
-Commitizen can lint your commit message for you with `cz check`.
+Commitizen can lint your commit message for you with `cz check` and `cz commit`.
 You can integrate this in your [pre-commit](https://pre-commit.com/) config with:
 
 ```yaml
@@ -90,6 +90,8 @@ repos:
     hooks:
       - id: commitizen
         stages: [commit-msg]
+      - id: commitizen-prepare-commit-msg
+        stages: [prepare-commit-msg]
 ```
 
 After the configuration is added, you'll need to run

tests/commands/test_commit_command.py

@@ -1,8 +1,9 @@
 import os
+import sys
 
 import pytest
 
-from commitizen import cmd, commands
+from commitizen import cli, cmd, commands
 from commitizen.cz.exceptions import CzException
 from commitizen.exceptions import (
     CommitError,
@@ -158,3 +159,41 @@ def test_commit_in_non_git_project(tmpdir, config):
     with tmpdir.as_cwd():
         with pytest.raises(NotAGitProjectError):
             commands.Commit(config, {})
+
+
+def test_commit_from_pre_commit_msg_hook(config, mocker, capsys):
+    testargs = ["cz", "commit", "--commit-msg-file", "some_file"]
+    mocker.patch.object(sys, "argv", testargs)
+
+    prompt_mock = mocker.patch("questionary.prompt")
+    prompt_mock.return_value = {
+        "prefix": "feat",
+        "subject": "user created",
+        "scope": "",
+        "is_breaking_change": False,
+        "body": "",
+        "footer": "",
+    }
+
+    commit_mock = mocker.patch("commitizen.git.commit")
+    mocker.patch("commitizen.commands.commit.WrapStdin")
+    mocker.patch("os.open")
+    reader_mock = mocker.mock_open(read_data="\n\n#test\n")
+    mocker.patch("builtins.open", reader_mock, create=True)
+
+    cli.main()
+
+    out, _ = capsys.readouterr()
+    assert "Commit message is successful!" in out
+    commit_mock.assert_not_called()
+
+
+def test_WrapStdin(mocker):
+    mocker.patch("os.open")
+    reader_mock = mocker.mock_open(read_data="data")
+    mocker.patch("builtins.open", reader_mock, create=True)
+
+    wrap_stdin = commands.commit.WrapStdin()
+
+    assert wrap_stdin.encoding == "UTF-8"
+    assert wrap_stdin.read() == "data"