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>

Author: AdrianDC

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,
@@ -49,8 +52,20 @@ def prompt_commit_questions(self) -> str:
         # Prompt user for the commit message
         cz = self.cz
         questions = cz.questions()
+
         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

@@ -32,6 +32,7 @@
     type = "input"
     name = "message"
     message = "Body."
+    filter = "commitizen.cz.utils.multiple_line_breaker"
 
     [[tool.commitizen.customize.questions]]
     type = "confirm"
@@ -84,7 +85,8 @@
                     {
                         "type": "input",
                         "name": "message",
-                        "message": "Body."
+                        "message": "Body.",
+                        "filter": "commitizen.cz.utils.multiple_line_breaker"
                     },
                     {
                         "type": "confirm",
@@ -134,6 +136,7 @@
     - 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?
@@ -442,7 +445,40 @@ def test_questions(config):
             ],
             "message": "Select the type of change you are committing",
         },
-        {"type": "input", "name": "message", "message": "Body."},
+        {
+            "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?",
+        },
+    ]
+    assert list(questions) == expected_questions
+
+
+def test_questions_filter(config):
+    cz = CustomizeCommitsCz(config)
+    questions = cz.questions()
+    expected_questions = [
+        {
+            "type": "list",
+            "name": "change_type",
+            "choices": [
+                {"value": "feature", "name": "feature: A new feature."},
+                {"value": "bug fix", "name": "bug fix: A bug fix."},
+            ],
+            "message": "Select the type of change you are committing",
+        },
+        {
+            "type": "input",
+            "name": "message",
+            "message": "Body.",
+            "filter": "commitizen.cz.utils.multiple_line_breaker",
+        },
         {
             "type": "confirm",
             "name": "show_message",