feat(formatter): added max-blank-lines flag to consolidate blank lines

closes #675

docs/src/_data/configuration.json

@@ -1,4 +1,27 @@
 [
+  {
+    "name": "max_blank_lines",
+    "description": {
+      "en": "Consolidate blank lines down to x lines. Default is 0 meaning blank lines will be removed.",
+      "ru": "Объедините пустые строки до х строк. По умолчанию 0, что означает, что пустые строки будут удалены.",
+      "fr": "Consolider les lignes vierges en les ramenant à x lignes. La valeur par défaut est 0, ce qui signifie que les lignes vierges seront supprimées."
+    },
+    "usage": [
+      {
+        "name": "pyproject.toml",
+        "value": "max_blank_lines=5"
+      },
+      {
+        "name": ".djlintrc",
+        "value": "\"max_blank_lines\": 5"
+      },
+      {
+        "name": "cli",
+        "value": "--max_blank_lines 5"
+      }
+    ],
+    "tags": ["formatter"]
+  },
   {
     "name": "no_set_formatting",
     "description": {

docs/src/_includes/cli.md

@@ -57,6 +57,7 @@ Options:
                                   matter.
   --no-function-formatting        Do not attempt to format function contents.
   --no-set-formatting             Do not attempt to format set contents.
+  --max-blank-lines INTEGER       Consolidate blank lines down to x lines. [default: 0]
   -h, --help                      Show this message and exit.
 ```
 

docs/src/docs/linter.md

@@ -67,7 +67,7 @@ This can also be done through the [{{ "configuration" | i18n }}]({{ "lang_code_u
 | H033 | Extra whitespace found in form action.                                                       | ✔️      |
 | J004 | (Jinja) Static urls should follow {% raw %}`{{ url_for('static'..) }}`{% endraw %} pattern.  | ✔️      |
 | J018 | (Jinja) Internal links should use the {% raw %}`{% url ... %}`{% endraw %} pattern.          | ✔️      |
-| T001 | Variables should be wrapped in a single whitespace. Ex: {% raw %}`{{ this }}`{% endraw %}    | ✔️      |
+| T001 | Variables should be wrapped in whitespace. Ex: {% raw %}`{{ this }}`{% endraw %}             | ✔️      |
 | T002 | Double quotes should be used in tags. Ex {% raw %}`{% extends "this.html" %}`{% endraw %}    | ✔️      |
 | T003 | Endblock should have name. Ex: {% raw %}`{% endblock body %}`{% endraw %}.                   | ✔️      |
 | T027 | Unclosed string found in template syntax.                                                    | ✔️      |

docs/src/fr/docs/linter.md

@@ -67,7 +67,7 @@ Cela peut également se faire par l'intermédiaire de l'option [{{ "configuratio
 | H033 | Espace supplémentaire dans l'action du formulaire.                                                                        | ✔️     |
 | J004 | (Jinja) Les urls statiques doivent suivre le modèle {% raw %}`{ url_for('static'..) }}`{% endraw %}.                      | ✔️     |
 | J018 | (Jinja) Les liens internes doivent utiliser le modèle {% raw %}`{% url ... %}`{% endraw %}.                               | ✔️     |
-| T001 | Les variables doivent être entourées d'un seul espace. Ex : {% raw %}`{{ this }}`{% endraw %}                             | ✔️     |
+| T001 | Les variables doivent être entourées d'un espace. Ex : {% raw %}`{{ this }}`{% endraw %}                                  | ✔️     |
 | T002 | Les doubles quotes doivent être utilisées dans les balises. Ex : {% raw %}`{% extends "this.html" %}`{% endraw %}         | ✔️     |
 | T003 | Le bloc de fin doit avoir un nom. Ex : {% raw %}`{% endblock body %}`{% endraw %}.                                        | ✔️     |
 | T027 | Chaîne non fermée trouvée dans la syntaxe du modèle.                                                                      | ✔️     |

docs/src/ru/docs/linter.md

@@ -67,7 +67,7 @@ djlint . --lint --include=H017,H035 --ignore=H013,H015
 | H033 | В действии формы обнаружен лишний пробел.                                                                                 | ✔️           |
 | J004 | (Jinja) Статические урлы должны следовать шаблону {% raw %}`{{ url_for('static'...)}}`{% endraw %}.                       | ✔️           |
 | J018 | (Jinja) Внутренние ссылки должны использовать шаблон {% raw %}`{% url ... %}`{% endraw %}.                                | ✔️           |
-| T001 | Переменные должны быть заключены в один пробел. Например: {% raw %}`{{ this }}`{% endraw %}                               | ✔️           |
+| T001 | Переменные должны быть заключены в пробел. Например: {% raw %}`{{ this }}`{% endraw %}                                    | ✔️           |
 | T002 | В тегах следует использовать двойные кавычки. Ex {% raw %}`{% extends "this.html" %}`{% endraw %}                         | ✔️           |
 | T003 | Конечный блок должен иметь имя. Например: {% raw %}`{% endblock body %}`{% endraw %}.                                     | ✔️           |
 | T027 | В синтаксисе шаблона найдена незакрытая строка.                                                                           | ✔️           |

src/djlint/__init__.py

@@ -247,6 +247,12 @@
     is_flag=True,
     help="Do not attempt to format set contents.",
 )
+@click.option(
+    "--max-blank-lines",
+    type=int,
+    help="Consolidate blank lines down to x lines. [default: 0]",
+    show_default=False,
+)
 @colorama_text(autoreset=True)
 def main(
     src: List[str],
@@ -288,6 +294,7 @@ def main(
     no_line_after_yaml: bool,
     no_function_formatting: bool,
     no_set_formatting: bool,
+    max_blank_lines: Optional[int],
 ) -> None:
     """djLint · HTML template linter and formatter."""
     config = Config(
@@ -330,6 +337,7 @@ def main(
         no_line_after_yaml=no_line_after_yaml,
         no_function_formatting=no_function_formatting,
         no_set_formatting=no_set_formatting,
+        max_blank_lines=max_blank_lines,
     )
 
     temp_file = None

src/djlint/formatter/condense.py

@@ -36,7 +36,16 @@ def strip_space(config: Config, html: str, match: re.Match) -> str:
         if inside_protected_trans_block(config, html[: match.end()], match):
             return match.group().rstrip()
 
-        return match.group(1)
+        lines = len(
+            re.findall(
+                r"\n",
+                match.group(2),
+            )
+        )
+        blank_lines = "\n" * lines
+        if lines > config.max_blank_lines:
+            blank_lines = "\n" * max(config.max_blank_lines, 0)
+        return match.group(1) + blank_lines
 
     func = partial(strip_space, config, html)
 
@@ -50,7 +59,7 @@ def strip_space(config: Config, html: str, match: re.Match) -> str:
     if not config.preserve_leading_space:
         # remove any leading/trailing space
         html = re.sub(
-            re.compile(rf"^[ \t]*{line_contents}[{trailing_contents}]*$", re.M),
+            re.compile(rf"^[ \t]*{line_contents}([{trailing_contents}]*)$", re.M),
             func,
             html,
         )
@@ -59,12 +68,12 @@ def strip_space(config: Config, html: str, match: re.Match) -> str:
         # only remove leading space in front of tags
         # <, {%
         html = re.sub(
-            re.compile(rf"^[ \t]*((?:<|{{%).*?)[{trailing_contents}]*$", re.M),
+            re.compile(rf"^[ \t]*((?:<|{{%).*?)([{trailing_contents}]*)$", re.M),
             func,
             html,
         )
         html = re.sub(
-            re.compile(rf"^{line_contents}[{trailing_contents}]*$", re.M), func, html
+            re.compile(rf"^{line_contents}([{trailing_contents}]*)$", re.M), func, html
         )
 
     def add_blank_line_after(config: Config, html: str, match: re.Match) -> str:

src/djlint/settings.py

@@ -254,6 +254,7 @@ def __init__(
         no_line_after_yaml: bool = False,
         no_function_formatting: bool = False,
         no_set_formatting: bool = False,
+        max_blank_lines: Optional[int] = None,
     ):
         self.reformat = reformat
         self.check = check
@@ -405,6 +406,17 @@ def __init__(
         self.indent_size = indent
         self.indent: str = int(indent) * " "
 
+        try:
+            self.max_blank_lines = int(
+                djlint_settings.get("max_blank_lines", max_blank_lines or 0)
+            )
+        except ValueError:
+            echo(
+                Fore.RED
+                + f"Error: Invalid pyproject.toml indent value {djlint_settings['max_blank_lines']}"
+            )
+            self.max_blank_lines = max_blank_lines or 0
+
         default_exclude: str = r"""
             \.venv
             | venv/

tests/test_config/test_max_blank_lines.py

@@ -0,0 +1,55 @@
+"""Test for max blank lines.
+
+poetry run pytest tests/test_config/test_max_blank_lines.py
+"""
+import pytest
+
+from src.djlint.reformat import formatter
+from tests.conftest import config_builder, printer
+
+test_data = [
+    pytest.param(
+        ("<img>\n\n\n\n\n\n\n\n\n\n<meta>"),
+        ("<img>\n" "<meta>\n"),
+        ({}),
+        id="default",
+    ),
+    pytest.param(
+        ("<img>\n\n\n\n\n\n\n\n\n\n<meta>"),
+        ("<img>\n\n\n\n\n\n" "<meta>\n"),
+        ({"max_blank_lines": 5}),
+        id="5",
+    ),
+    pytest.param(
+        ("<img>\n\n\n\n\n\n\n\n\n\n<meta>"),
+        ("<img>\n\n" "<meta>\n"),
+        ({"max_blank_lines": 1}),
+        id="1",
+    ),
+    pytest.param(
+        ("<img>\n\n\n\n\n\n\n\n\n\n<meta>"),
+        ("<img>\n" "<meta>\n"),
+        ({"max_blank_lines": -1}),
+        id="-1",
+    ),
+    pytest.param(
+        ("<img>\n\n\n\n\n\n\n\n\n\n<meta>"),
+        ("<img>\n\n\n\n\n\n\n\n\n\n" "<meta>\n"),
+        ({"max_blank_lines": 30}),
+        id="30",
+    ),
+    pytest.param(
+        ("<img>\n\n<div>\n\n<p>\n\n</p>\n\n</div>\n\n<meta>"),
+        ("<img>\n" "\n" "<div>\n" "\n" "    <p></p>\n" "\n" "</div>\n" "\n" "<meta>\n"),
+        ({"max_blank_lines": 30}),
+        id="div",
+    ),
+]
+
+
+@pytest.mark.parametrize(("source", "expected", "args"), test_data)
+def test_base(source, expected, args):
+    output = formatter(config_builder(args), source)
+
+    printer(expected, source, output)
+    assert expected == output