Support `.jinja` for theme static templates (#11916)

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

CHANGES.rst

@@ -13,6 +13,12 @@ Deprecated
 Features added
 --------------
 
+* #11165: Support the `officially recommended`_ ``.jinja`` suffix for template
+  files.
+  Patch by James Addison and Adam Turner
+
+  .. _officially recommended: https://jinja.palletsprojects.com/en/latest/templates/#template-file-extension
+
 Bugs fixed
 ----------
 

doc/development/theming.rst

@@ -247,12 +247,28 @@ template static files as well as HTML files.  Therefore, Sphinx supports
 so-called "static templates", like this:
 
 If the name of a file in the ``static/`` directory of a theme (or in the user's
-static path, for that matter) ends with ``_t``, it will be processed by the
-template engine.  The ``_t`` will be left from the final file name.  For
-example, the *classic* theme has a file ``static/classic.css_t`` which uses
-templating to put the color options into the stylesheet.  When a documentation
-project is built with the classic theme, the output directory will contain a
-``_static/classic.css`` file where all template tags have been processed.
+static path) ends with ``.jinja`` or ``_t``, it will be processed by the
+template engine.  The suffix will be removed from the final file name.
+
+For example, a theme with a ``static/theme_styles.css.jinja`` file could use
+templating to put options into the stylesheet.
+When a documentation project is built with that theme,
+the output directory will contain a ``_static/theme_styles.css`` file
+where all template tags have been processed.
+
+.. versionchanged:: 7.4
+
+   The preferred suffix for static templates is now ``.jinja``, in line with
+   the Jinja project's `recommended file extension`_.
+
+   The ``_t`` file suffix for static templates is now considered 'legacy', and
+   support may eventually be removed.
+
+   If a static template with either a ``_t`` suffix or a ``.jinja`` suffix is
+   detected, it will be processed by the template engine, with the suffix
+   removed from the final file name.
+
+  .. _recommended file extension: https://jinja.palletsprojects.com/en/latest/templates/#template-file-extension
 
 
 Use custom page metadata in HTML templates

doc/latex.rst

@@ -1826,16 +1826,21 @@ Miscellany
 .. hint::
 
    As an experimental feature, Sphinx can use user-defined template file for
-   LaTeX source if you have a file named ``_templates/latex.tex_t`` in your
+   LaTeX source if you have a file named ``_templates/latex.tex.jinja`` in your
    project.
 
-   Additional files ``longtable.tex_t``, ``tabulary.tex_t`` and
-   ``tabular.tex_t`` can be added to ``_templates/`` to configure some aspects
-   of table rendering (such as the caption position).
+   Additional files ``longtable.tex.jinja``, ``tabulary.tex.jinja`` and
+   ``tabular.tex.jinja`` can be added to ``_templates/`` to configure some
+   aspects of table rendering (such as the caption position).
 
    .. versionadded:: 1.6
       currently all template variables are unstable and undocumented.
 
+   .. versionchanged:: 7.4
+      Added support for the ``.jinja`` file extension, which is preferred.
+      The old file names remain supported.
+      (``latex.tex_t``, ``longtable.tex_t``, ``tabulary.tex_t``, and ``tabular.tex_t``)
+
 .. raw:: latex
 
    \endgroup

sphinx/util/fileutil.py

@@ -15,6 +15,19 @@ if TYPE_CHECKING:
     from sphinx.util.typing import PathMatcher
 
 
+def _template_basename(filename: str | os.PathLike[str]) -> str | None:
+    """Given an input filename:
+    If the input looks like a template, then return the filename output should
+    be written to.  Otherwise, return no result (None).
+    """
+    basename = os.path.basename(filename)
+    if basename.lower().endswith('_t'):
+        return str(filename)[:-2]
+    elif basename.lower().endswith('.jinja'):
+        return str(filename)[:-6]
+    return None
+
+
 def copy_asset_file(source: str | os.PathLike[str], destination: str | os.PathLike[str],
                     context: dict[str, Any] | None = None,
                     renderer: BaseRenderer | None = None) -> None:
@@ -37,14 +50,13 @@ def copy_asset_file(source: str | os.PathLike[str], destination: str | os.PathLi
     else:
         destination = str(destination)
 
-    if os.path.basename(source).endswith(('_t', '_T')) and context is not None:
+    if _template_basename(source) and context is not None:
         if renderer is None:
             from sphinx.util.template import SphinxRenderer
             renderer = SphinxRenderer()
 
         with open(source, encoding='utf-8') as fsrc:
-            if destination.endswith(('_t', '_T')):
-                destination = destination[:-2]
+            destination = _template_basename(destination) or destination
             with open(destination, 'w', encoding='utf-8') as fdst:
                 fdst.write(renderer.render_string(fsrc.read(), context))
     else:

tests/roots/test-latex-table/_mytemplates/latex/tabulary.tex_t

@@ -0,0 +1 @@
+AU REVOIR, KANIGGETS

tests/roots/test-theming/test_theme/staticfiles/static/legacytmpl.html_t

@@ -0,0 +1,2 @@
+<!-- testing legacy _t static templates -->
+<html><project>{{ project | lower | escape }}</project></html>

tests/test_builders/test_build_latex.py

@@ -1391,6 +1391,7 @@ def test_latex_table_custom_template_caseA(app, status, warning):
     app.build(force_all=True)
     result = (app.outdir / 'python.tex').read_text(encoding='utf8')
     assert 'SALUT LES COPAINS' in result
+    assert 'AU REVOIR, KANIGGETS' in result
 
 
 @pytest.mark.sphinx('latex', testroot='latex-table',

tests/test_theming/test_theming.py

@@ -109,6 +109,11 @@ def test_nested_zipped_theme(app, status, warning):
 @pytest.mark.sphinx(testroot='theming', confoverrides={'html_theme': 'staticfiles'})
 def test_staticfiles(app, status, warning):
     app.build()
+    assert (app.outdir / '_static' / 'legacytmpl.html').exists()
+    assert (app.outdir / '_static' / 'legacytmpl.html').read_text(encoding='utf8') == (
+        '<!-- testing legacy _t static templates -->\n'
+        '<html><project>python</project></html>'
+    )
     assert (app.outdir / '_static' / 'staticimg.png').exists()
     assert (app.outdir / '_static' / 'statictmpl.html').exists()
     assert (app.outdir / '_static' / 'statictmpl.html').read_text(encoding='utf8') == (

tests/test_util/test_util_fileutil.py

@@ -3,7 +3,7 @@
 from unittest import mock
 
 from sphinx.jinja2glue import BuiltinTemplateLoader
-from sphinx.util.fileutil import copy_asset, copy_asset_file
+from sphinx.util.fileutil import _template_basename, copy_asset, copy_asset_file
 
 
 class DummyTemplateLoader(BuiltinTemplateLoader):
@@ -101,3 +101,13 @@ def test_copy_asset(tmp_path):
     assert not (destdir / '_static' / 'basic.css').exists()
     assert (destdir / '_templates' / 'layout.html').exists()
     assert not (destdir / '_templates' / 'sidebar.html').exists()
+
+
+def test_template_basename():
+    assert _template_basename('asset.txt') is None
+    assert _template_basename('asset.txt.jinja') == 'asset.txt'
+    assert _template_basename('sidebar.html.jinja') == 'sidebar.html'
+
+
+def test_legacy_template_basename():
+    assert _template_basename('asset.txt_t') == 'asset.txt'

utils/babel_runner.py

@@ -42,7 +42,9 @@ METHOD_MAP = [
     # Extraction from Python source files
     ('**.py', extract_python),
     # Extraction from Jinja2 template files
+    ('**/templates/latex/**.tex.jinja', extract_jinja2),
     ('**/templates/latex/**.tex_t', extract_jinja2),
+    ('**/templates/latex/**.sty.jinja', extract_jinja2),
     ('**/templates/latex/**.sty_t', extract_jinja2),
     # Extraction from Jinja2 HTML templates
     ('**/themes/**.html', extract_jinja2),
@@ -50,6 +52,7 @@ METHOD_MAP = [
     ('**/themes/**.xml', extract_jinja2),
     # Extraction from JavaScript files
     ('**.js', extract_javascript),
+    ('**.js.jinja', extract_javascript),
     ('**.js_t', extract_javascript),
 ]
 OPTIONS_MAP = {
@@ -58,7 +61,9 @@ OPTIONS_MAP = {
         'encoding': 'utf-8',
     },
     # Extraction from Jinja2 template files
+    '**/templates/latex/**.tex.jinja': TEX_DELIMITERS.copy(),
     '**/templates/latex/**.tex_t': TEX_DELIMITERS.copy(),
+    '**/templates/latex/**.sty.jinja': TEX_DELIMITERS.copy(),
     '**/templates/latex/**.sty_t': TEX_DELIMITERS.copy(),
     # Extraction from Jinja2 HTML templates
     '**/themes/**.html': {