feat(commit): implement questions 'filter' support with evaluations

Supported APIs: Common Python, commitizen.cz.utils.* functions

Example YAML configurations:
---
commitizen:
  name: cz_customize
  customize:
    questions:
      - ...
      - type: input
        name: scope
        message: 'Scope of the change :'
        filter: 'lambda text: commitizen.cz.utils.required_validator(text, msg="! Error: Scope is required")'
        default: ''
      - type: input
        name: subject
        message: 'Title of the commit (starting in lower case and without period) :'
        filter: 'lambda text: commitizen.cz.utils.required_validator(text.strip(".").strip(), msg="! Error: Title is required")'
        default: ''
      - type: input
        name: body
        message: 'Additional contextual message (Empty to skip) :'
        default: 'Issue: #...'
        filter: 'commitizen.cz.utils.multiple_line_breaker'
---

Signed-off-by: Adrian DC <radian.dc@gmail.com>

commitizen/commands/commit.py

@@ -8,7 +8,10 @@
 from commitizen import factory, git, out
 from commitizen.config import BaseConfig
 from commitizen.cz.exceptions import CzException
-from commitizen.cz.utils import get_backup_file_path
+from commitizen.cz.utils import (
+    get_backup_file_path,
+    multiple_line_breaker,
+)
 from commitizen.exceptions import (
     CommitError,
     CommitMessageLengthExceededError,
@@ -52,6 +55,19 @@ def prompt_commit_questions(self) -> str:
 
         for question in filter(lambda q: q["type"] == "list", questions):
             question["use_shortcuts"] = self.config.settings["use_shortcuts"]
+
+        # Import allowed modules for 'filter'
+        global commitizen
+        import commitizen.cz.utils
+
+        for question in filter(
+            lambda q: isinstance(q.get("filter", None), str), questions
+        ):
+            question_filter = [
+                multiple_line_breaker(question["filter"].replace("\\n", "\n"))
+            ]
+            question["filter"] = eval("\n".join(question_filter))
+
         try:
             answers = questionary.prompt(questions, style=cz.style)
         except ValueError as err:

docs/customization.md

@@ -175,7 +175,7 @@ commitizen:
 | `message` | `str`  | `None`  | Detail description for the question.                                                                                                                                                            |
 | `choices` | `list` | `None`  | (OPTIONAL) The choices when `type = list`. Either use a list of values or a list of dictionaries with `name` and `value` keys. Keyboard shortcuts can be defined via `key`. See examples above. |
 | `default` | `Any`  | `None`  | (OPTIONAL) The default value for this question.                                                                                                                                                 |
-| `filter`  | `str`  | `None`  | (Optional) Validator for user's answer. **(Work in Progress)**                                                                                                                                  |
+| `filter`  | `str`  | `None`  | (OPTIONAL) Validator for user's answer. The string is evaluated into a Python function, either use `commitizen.cz.utils.*` or lambda functions like `lambda text: text.strip(".").strip()`      |
 [different-question-types]: https://github.com/tmbo/questionary#different-question-types
 
 #### Shortcut keys

tests/test_cz_customize.py

@@ -1,7 +1,12 @@
+from types import LambdaType
+
 import pytest
+from pytest_mock import MockFixture
 
+from commitizen import cmd, commands
 from commitizen.config import BaseConfig, JsonConfig, TomlConfig, YAMLConfig
 from commitizen.cz.customize import CustomizeCommitsCz
+from commitizen.cz.utils import multiple_line_breaker
 from commitizen.exceptions import MissingCzCustomizeConfigError
 
 TOML_STR = r"""
@@ -36,10 +41,17 @@
     ]
     message = "Select the type of change you are committing"
 
+    [[tool.commitizen.customize.questions]]
+    type = "input"
+    name = "subject"
+    message = "Subject."
+    filter = "lambda text: commitizen.cz.utils.required_validator(text.strip(\".\").strip(), msg=\"! Error: Subject is required\")"
+
     [[tool.commitizen.customize.questions]]
     type = "input"
     name = "message"
     message = "Body."
+    filter = "commitizen.cz.utils.multiple_line_breaker"
 
     [[tool.commitizen.customize.questions]]
     type = "confirm"
@@ -89,10 +101,17 @@
                         ],
                         "message": "Select the type of change you are committing"
                     },
+                    {
+                        "type": "input",
+                        "name": "subject",
+                        "message": "Subject.",
+                        "filter": "lambda text: commitizen.cz.utils.required_validator(text.strip(\".\").strip(), msg=\"! Error: Subject is required\")"
+                    },
                     {
                         "type": "input",
                         "name": "message",
-                        "message": "Body."
+                        "message": "Body.",
+                        "filter": "commitizen.cz.utils.multiple_line_breaker"
                     },
                     {
                         "type": "confirm",
@@ -139,9 +158,14 @@
       - value: bug fix
         name: 'bug fix: A bug fix.'
       message: Select the type of change you are committing
+    - type: input
+      name: subject
+      message: Subject.
+      filter: 'lambda text: commitizen.cz.utils.required_validator(text.strip(".").strip(), msg="! Error: Subject is required")'
     - type: input
       name: message
       message: Body.
+      filter: 'commitizen.cz.utils.multiple_line_breaker'
     - type: confirm
       name: show_message
       message: Do you want to add body message in commit?
@@ -330,6 +354,13 @@
 """
 
 
+@pytest.fixture
+def staging_is_clean(mocker: MockFixture, tmp_git_project):
+    is_staging_clean_mock = mocker.patch("commitizen.git.is_staging_clean")
+    is_staging_clean_mock.return_value = False
+    return tmp_git_project
+
+
 @pytest.fixture(
     params=[
         TomlConfig(data=TOML_STR, path="not_exist.toml"),
@@ -437,7 +468,7 @@ def test_change_type_order_unicode(config_with_unicode):
     ]
 
 
-def test_questions(config):
+def test_questions_default(config):
     cz = CustomizeCommitsCz(config)
     questions = cz.questions()
     expected_questions = [
@@ -450,7 +481,18 @@ def test_questions(config):
             ],
             "message": "Select the type of change you are committing",
         },
-        {"type": "input", "name": "message", "message": "Body."},
+        {
+            "type": "input",
+            "name": "subject",
+            "message": "Subject.",
+            "filter": 'lambda text: commitizen.cz.utils.required_validator(text.strip(".").strip(), msg="! Error: Subject is required")',
+        },
+        {
+            "type": "input",
+            "name": "message",
+            "message": "Body.",
+            "filter": "commitizen.cz.utils.multiple_line_breaker",
+        },
         {
             "type": "confirm",
             "name": "show_message",
@@ -460,6 +502,38 @@ def test_questions(config):
     assert list(questions) == expected_questions
 
 
+@pytest.mark.usefixtures("staging_is_clean")
+def test_questions_filter(config, mocker: MockFixture):
+    is_staging_clean_mock = mocker.patch("commitizen.git.is_staging_clean")
+    is_staging_clean_mock.return_value = False
+
+    prompt_mock = mocker.patch("questionary.prompt")
+    prompt_mock.return_value = {
+        "change_type": "feature",
+        "subject": "user created",
+        "message": "body of the commit",
+        "show_message": True,
+    }
+
+    commit_mock = mocker.patch("commitizen.git.commit")
+    commit_mock.return_value = cmd.Command("success", "", b"", b"", 0)
+
+    commands.Commit(config, {})()
+
+    prompts_questions = prompt_mock.call_args[0][0]
+    assert prompts_questions[0]["type"] == "list"
+    assert prompts_questions[0]["name"] == "change_type"
+    assert prompts_questions[0]["use_shortcuts"] is False
+    assert prompts_questions[1]["type"] == "input"
+    assert prompts_questions[1]["name"] == "subject"
+    assert type(prompts_questions[1]["filter"]) is LambdaType
+    assert prompts_questions[2]["type"] == "input"
+    assert prompts_questions[2]["name"] == "message"
+    assert prompts_questions[2]["filter"] == multiple_line_breaker
+    assert prompts_questions[3]["type"] == "confirm"
+    assert prompts_questions[3]["name"] == "show_message"
+
+
 def test_questions_unicode(config_with_unicode):
     cz = CustomizeCommitsCz(config_with_unicode)
     questions = cz.questions()