feat(formatter): added option to add blank line before tags

closes #307

docs/src/_data/configuration.json

@@ -143,6 +143,24 @@
       }
     ]
   },
+  {
+    "name": "blank_line_before_tag",
+    "description": {
+      "en": "Add an additional blank line before `{% <tag> ... %}` tag groups. Blank lines will never be added to start of file or between similar tags.",
+      "ru": "Добавляет дополнительную пустую строку перед группами тегов `{% <tag> ... %}`. Пустые строки никогда не будут добавлены в начало файла или между похожими тегами.",
+      "fr": "Ajoute une ligne blanche supplémentaire avant les groupes de balises `{% <tag> ... %}`. Les lignes vides ne seront jamais ajoutées au début du fichier ou entre des balises similaires."
+    },
+    "usage": [
+      {
+        "name": "pyproject.toml",
+        "value": "blank_line_before_tag=\"load,extends,include\""
+      },
+      {
+        "name": ".djlintrc",
+        "value": "\"blank_line_before_tag\": \"load,extends,include\""
+      }
+    ]
+  },
   {
     "name": "profile",
     "description": {

src/djlint/formatter/condense.py

@@ -70,24 +70,43 @@ def condense_html(html: str, config: Config) -> str:
             )
         return True
 
+    def if_blank_line_before_match(config: Config, html: str) -> bool:
+        """Check if there should be a blank line before."""
+        if config.blank_line_before_tag:
+            return not any(
+                re.findall(
+                    re.compile(
+                        rf"((?:{{%\s*?{tag}[^}}]+?%}}\n?)+)",
+                        re.IGNORECASE | re.MULTILINE | re.DOTALL,
+                    ),
+                    html,
+                )
+                for tag in [x.strip() for x in config.blank_line_before_tag.split(",")]
+            )
+        return True
+
     def condense_line(config: Config, match: re.Match) -> str:
         """Put contents on a single line if below max line length."""
         if (
-            len(match.group(1) + match.group(3) + match.group(4))
-            < config.max_line_length
-        ) and if_blank_line_after_match(config, match.group(3)):
+            (
+                len(match.group(1) + match.group(3) + match.group(4))
+                < config.max_line_length
+            )
+            and if_blank_line_after_match(config, match.group(3))
+            and if_blank_line_before_match(config, match.group(3))
+        ):
             return match.group(1) + match.group(3) + match.group(4)
 
         return match.group()
 
-    def add_blank_line(config: Config, html: str, match: re.Match) -> str:
+    def add_blank_line_after(config: Config, html: str, match: re.Match) -> str:
         """Add break after if not in ignored block."""
         if inside_ignored_block(config, html, match):
             return match.group()
 
         return match.group() + "\n"
 
-    func = partial(add_blank_line, config, html)
+    func = partial(add_blank_line_after, config, html)
 
     # should we add blank lines after load tags?
     if config.blank_line_after_tag:
@@ -101,6 +120,27 @@ def condense_html(html: str, config: Config) -> str:
                 html,
             )
 
+    def add_blank_line_before(config: Config, html: str, match: re.Match) -> str:
+        """Add break before if not in ignored block and not first line in file."""
+        if inside_ignored_block(config, html, match) or match.start() == 0:
+            return match.group()
+
+        return "\n" + match.group()
+
+    func = partial(add_blank_line_before, config, html)
+
+    # should we add blank lines before load tags?
+    if config.blank_line_before_tag:
+        for tag in [x.strip() for x in config.blank_line_before_tag.split(",")]:
+            html = re.sub(
+                re.compile(
+                    rf"(?<!^\n$)((?:{{%\s*?{tag}\b[^}}]+?%}}\n?)+)",
+                    re.IGNORECASE | re.MULTILINE | re.DOTALL,
+                ),
+                func,
+                html,
+            )
+
     func = partial(condense_line, config)
 
     # put short single line tags on one line

src/djlint/settings.py

@@ -334,6 +334,11 @@ class Config:
             "blank_line_after_tag", None
         )
 
+        # add blank line before load tags
+        self.blank_line_before_tag: Optional[str] = djlint_settings.get(
+            "blank_line_before_tag", None
+        )
+
         # contents of tags will not be formatted
         self.ignored_block_opening: str = r"""
               <style

tests/test_config/test_blank_lines_before_tag/html.html

@@ -0,0 +1 @@
+{% extends "nothing.html" %}{% load stuff %}{% load stuff 2 %}{% include "html_two.html" %}<div></div>

tests/test_config/test_blank_lines_before_tag/html_eight.html

@@ -0,0 +1,3 @@
+{% extends nothing %}
+
+<div></div>

tests/test_config/test_blank_lines_before_tag/html_five.html

@@ -0,0 +1,6 @@
+<tr>
+    <td rowspan="{{ quality.row_span }}">
+
+        {% include "common/pdfs/partials/display_quality_improvements.html" %}
+    </td>
+</tr>

tests/test_config/test_blank_lines_before_tag/html_four.html

@@ -0,0 +1,3 @@
+{% block this %}
+{% load i18n %}
+{% endblock this %}

tests/test_config/test_blank_lines_before_tag/html_seven.html

@@ -0,0 +1,6 @@
+{% blocktrans %}my words{% endblocktrans %}
+{% block body %}
+    <div></div>
+
+{% endblock body %}
+{% block js %}{% endblock %}

tests/test_config/test_blank_lines_before_tag/html_six.html

@@ -0,0 +1,4 @@
+{% block include %}
+    {#    {% include 'common/sticky-topbar-hidden-nav.html' %}#}
+
+{% endblock %}

tests/test_config/test_blank_lines_before_tag/html_three.html

@@ -0,0 +1,8 @@
+<div class="tab-cnt">
+    <div class="tab-dta active" id="details">
+        <div class="em-grid">
+
+            {% include "pages/task/details_source.html.j2" %}
+        </div>
+    </div>
+</div>

tests/test_config/test_blank_lines_before_tag/html_two.html

@@ -0,0 +1,2 @@
+{% load stuff %}
+<div></div>

tests/test_config/test_blank_lines_before_tag/pyproject.toml

@@ -0,0 +1,3 @@
+[tool]
+[tool.djlint]
+blank_line_before_tag = "load, extends,     include     ,endblock "

tests/test_config/test_blank_lines_before_tag/test_config.py

@@ -0,0 +1,101 @@
+"""Djlint tests specific to pyproject.toml configuration.
+
+run::
+
+   pytest tests/test_config/test_blank_lines_before_tag/test_config.py --cov=src/djlint --cov-branch \
+          --cov-report xml:coverage.xml --cov-report term-missing
+
+for a single test, run::
+
+   pytest tests/test_config.py::test_custom_html --cov=src/djlint \
+     --cov-branch --cov-report xml:coverage.xml --cov-report term-missing
+
+"""
+# pylint: disable=C0116
+
+from click.testing import CliRunner
+
+from src.djlint import main as djlint
+
+
+def test_blank_lines_before_tag(runner: CliRunner) -> None:
+    result = runner.invoke(
+        djlint, ["tests/test_config/test_blank_lines_before_tag/html.html", "--check"]
+    )
+
+    assert (
+        """+{% extends "nothing.html" %}
++
++{% load stuff %}
++{% load stuff 2 %}
++
++{% include "html_two.html" %}
++<div></div>"""
+        in result.output
+    )
+    assert """1 file would be updated.""" in result.output
+    assert result.exit_code == 1
+
+    result = runner.invoke(
+        djlint,
+        ["tests/test_config/test_blank_lines_before_tag/html_two.html", "--check"],
+    )
+    assert result.exit_code == 0
+
+    # check blocks that do not start on a newline - they should be left as is.
+    result = runner.invoke(
+        djlint,
+        ["tests/test_config/test_blank_lines_before_tag/html_three.html", "--check"],
+    )
+
+    assert """0 files would be updated.""" in result.output
+    assert result.exit_code == 0
+
+    result = runner.invoke(
+        djlint,
+        ["tests/test_config/test_blank_lines_before_tag/html_four.html", "--check"],
+    )
+
+    assert result.exit_code == 1
+    assert (
+        """ {% block this %}
+-{% load i18n %}
++
++    {% load i18n %}
++
+ {% endblock this %}
+"""
+        in result.output
+    )
+
+    # something perfect should stay perfect :)
+    result = runner.invoke(
+        djlint,
+        ["tests/test_config/test_blank_lines_before_tag/html_five.html", "--check"],
+    )
+    assert result.exit_code == 0
+
+    # something perfect should stay perfect :)
+    result = runner.invoke(
+        djlint,
+        ["tests/test_config/test_blank_lines_before_tag/html_six.html", "--check"],
+    )
+    assert result.exit_code == 0
+
+    # make sure endblock doesn't pick up endblocktrans :)
+    result = runner.invoke(
+        djlint,
+        ["tests/test_config/test_blank_lines_before_tag/html_seven.html", "--check"],
+    )
+    assert result.exit_code == 0
+
+    # check that multiple blank lines are not added
+    result = runner.invoke(
+        djlint,
+        [
+            "tests/test_config/test_blank_lines_before_tag/html_eight.html",
+            "--preserve-blank-lines",
+            "--check",
+        ],
+    )
+    assert result.exit_code == 0