44 Make regex capture groups from patterns available in jinja (#70)

Author: award28

CHANGELOG.md

@@ -14,6 +14,11 @@ The [Changelogger tool](https://pypi.org/project/changelogged) is used for autom
 <!-- BEGIN RELEASE NOTES -->
 ### [Unreleased]
 
+### [0.11.0] - 2023-03-05
+
+#### Added
+- Jinja templates now have access to the `match` variable. This allows access to match groups.
+
 ### [0.10.2] - 2023-03-05
 
 #### Changed
@@ -132,7 +137,8 @@ The [Changelogger tool](https://pypi.org/project/changelogged) is used for autom
 - `unreleased add`, which allows inline or prompted adding of unreleased changes.
 <!-- END RELEASE NOTES -->
 <!-- BEGIN LINKS -->
-[Unreleased]: https://github.com/award28/changelogger/compare/0.10.2...HEAD
+[Unreleased]: https://github.com/award28/changelogger/compare/0.11.0...HEAD
+[0.11.0]: https://github.com/award28/changelogger/compare/0.10.2...0.11.0
 [0.10.2]: https://github.com/award28/changelogger/compare/0.10.1...0.10.2
 [0.10.1]: https://github.com/award28/changelogger/compare/0.10.0...0.10.1
 [0.10.0]: https://github.com/award28/changelogger/compare/0.9.1...0.10.0

changelogger/templating.py

@@ -1,4 +1,6 @@
 from datetime import date
+from functools import partial
+from re import Match
 from typing import Any
 
 from jinja2 import BaseLoader, Environment, Template
@@ -20,11 +22,16 @@ def update(
         assert file.jinja_rel_path, "No valid jinja template found."
         replacement_str = file.jinja_rel_path.read_text()
 
-    variables = _get_variables(file, update)
-    pattern = render_jinja(file.pattern, variables)
-    replacement = render_jinja(replacement_str, variables)
+    var_getter = partial(_get_variables, file, update)
+    pattern = render_jinja(file.pattern, var_getter())
 
-    return cached_compile(pattern).sub(replacement, content)
+    # re.sub can take a callable as the replacement argument rather than a
+    # string. This callable accepts a match and returns a string. For each
+    # match which is found, re.sub will call repl with the match, and
+    # replace the found pattern with the output string of the user supplied
+    # repl function.
+    repl = lambda m: render_jinja(replacement_str, var_getter(m))
+    return cached_compile(pattern).sub(repl, content)
 
 
 def render_pattern(
@@ -47,11 +54,13 @@ def _tmpl(jinja: str) -> Template:
 def _get_variables(
     versioned_file: VersionedFile,
     update: ChangelogUpdate,
+    match: Match | None = None,
 ) -> dict[str, Any]:
     return dict(
         new_version=update.new_version,
         old_version=update.old_version,
         today=date.today(),
         sections=update.release_notes.dict(),
         context=versioned_file.context,
+        match=match,
     )

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "changelogged"
-version = "0.10.2"
+version = "0.11.0"
 description = "Automated management of your changelog and other versioned files, following the principles of Keep a Changelog and Semantic Versioning."
 license = "MIT"
 authors = ["award28 <austin.ward@klaviyo.com>"]

tests/test_templating.py

@@ -99,6 +99,35 @@ def test_render_pattern(
         )
         mock_render_jinja.assert_called_once()
 
+    def test_update(
+        self,
+    ) -> None:
+        file = MagicMock()
+        file.pattern = r"# This (?P<word>\w+)(?P<rest>.*)"
+        file.jinja = r"# This {{ match.rest | reverse }}{{ match.word }}"
+        file.context = {}
+        file.jinja_rel_path = None
+
+        content = """
+        # This is a test
+        # Not being tested
+        # This should be tested
+        """
+
+        expected = """
+        # This tset a is
+        # Not being tested
+        # This detset eb should
+        """
+
+        update = MagicMock()
+        actual = templating.update(
+            file,
+            update,
+            content,
+        )
+        assert actual == expected
+
     def test_update_neither_jinja_raises(
         self,
     ):
@@ -134,20 +163,15 @@ def test_update_from_jinja_string(
             [
                 call(file.pattern),
                 call().render(),
-                call(file.jinja),
-                call().render(),
             ]
         )
 
         mock_tmpl().render.assert_has_calls(
-            [call(**mock_get_variables())] * 2,
+            [call(**mock_get_variables())],
         )
 
         mock_cached_compile.assert_called_once_with(mock_tmpl().render())
-        mock_cached_compile().sub.assert_called_once_with(
-            mock_tmpl().render(),
-            content,
-        )
+        mock_cached_compile().sub.assert_called_once()
 
     def test_update_from_jinja_file(
         self,
@@ -171,17 +195,12 @@ def test_update_from_jinja_file(
             [
                 call(file.pattern),
                 call().render(),
-                call(file.jinja_rel_path.read_text()),
-                call().render(),
             ]
         )
 
         mock_tmpl().render.assert_has_calls(
-            [call(**mock_get_variables())] * 2,
+            [call(**mock_get_variables())],
         )
 
         mock_cached_compile.assert_called_once_with(mock_tmpl().render())
-        mock_cached_compile().sub.assert_called_once_with(
-            mock_tmpl().render(),
-            content,
-        )
+        mock_cached_compile().sub.assert_called_once()