Pull request #13: feat: render units with non-breaking space

Merge in FRAG/50ohm.de from feature/unit-html-renderer to main

* commit '4c82c9fb146332bd3abe8e2d1d0308aafbdc54d4':
  refactor: improve code readability
  feat: improve tests for unit rendering
  refactor: use helper to format unit
  refactor: create module
  feat: render units with non-breaking space

renderer/__main__.py

@@ -1,8 +0,0 @@
-import sys
-
-import mistletoe
-from fifty_ohm_html_renderer import FiftyOhmHtmlRenderer
-
-if __name__ == "__main__":
-    with open(sys.argv[1]) as fin, open(sys.argv[2], "w") as fout:
-        fout.write(mistletoe.markdown(fin, FiftyOhmHtmlRenderer))

renderer/fifty_ohm_html_renderer.py

@@ -10,6 +10,7 @@ from renderer.quote import Quote
 from renderer.references import References
 from renderer.tag import Tag
 from renderer.underline import Underline
+from renderer.unit import Unit
 
 
 class FiftyOhmHtmlRenderer(HtmlRenderer):
@@ -24,6 +25,7 @@ class FiftyOhmHtmlRenderer(HtmlRenderer):
             BlockComment,
             SpanComment,
             Quote,
+            Unit,
             Underline,
             Tag,
             HalfwidthSpaces,
@@ -50,6 +52,31 @@ class FiftyOhmHtmlRenderer(HtmlRenderer):
     def render_underline(self, token):
         return f"<u>{self.render_inner(token)}</u>"
 
+    @classmethod
+    def render_unit(cls, token: Unit):
+        unit = token.prefix + cls.convert_unit_helper(token.unit)
+        if token.unit in ["°", "%"]:
+            # Special cases with no space between value and unit.
+            return f"{token.value}{unit}"
+        else:
+            # Default case is rendered with a narrow no-break space.
+            return f"{token.value}&#8239;{unit}"
+
+    units = {
+        "Ohm": "Ω",
+    }
+
+    @classmethod
+    def convert_unit_helper(cls, unit: str) -> str:
+        """Converts human-typable units to their preferred representation.
+
+        :param str unit: The unit to convert
+        """
+        if unit in cls.units.keys():
+            return cls.units[unit]
+        else:
+            return unit
+
     def render_thematic_break(self, token):
         self.margin_anchor_id += 1
         return f'<a id="margin_{self.margin_anchor_id}"></a>'

renderer/unit.py

@@ -0,0 +1,55 @@
+import re
+
+from mistletoe.span_token import SpanToken
+
+
+class Unit(SpanToken):
+    units = [
+        "A",
+        "Ah",
+        "A/mm²",
+        "baud",
+        "Bit",
+        "Bit/s",
+        "dB",
+        "dBi",
+        "dBm",
+        "dBW",
+        "F",
+        "J",
+        "Hz",
+        "H",
+        "cm",
+        "m",
+        "m²",
+        "Ohm",
+        "ppm",
+        "pps",
+        "s",
+        "V",
+        "W",
+        "Wh",
+        "°",
+        "%",
+    ]
+    prefixes = ["p", "n", "μ", "m", "k", "M", "G"]
+
+    pattern = re.compile(
+        r"(?P<value>[0-9,]+) ?(?P<prefix>"
+        # Group all prefixes together in a capture group
+        # Empty string at end of list is required so the group always exists in the resulting match
+        + "|".join(prefixes + [""])
+        + ")(?P<unit>"
+        # Group all units together in a capture group.
+        + "|".join(units)
+        + r")(?!\w)"
+    )
+
+    value: str
+    prefix: str
+    unit: str
+
+    def __init__(self, match: re.Match):
+        self.value = match.group("value")
+        self.prefix = match.group("prefix") or ""
+        self.unit = match.group("unit")

test/test_unit.py

@@ -0,0 +1,45 @@
+import mistletoe
+import pytest
+
+from renderer.fifty_ohm_html_renderer import FiftyOhmHtmlRenderer
+
+from .util import paragraph
+
+
+@pytest.mark.html
+def test_basic_units_html():
+    """Test basic units: Insert non-breaking, smaller space."""
+    assertions = {
+        "1 V": "1 V",
+        "0,12 V": "0,12 V",
+        "0,75 kW": "0,75 kW",
+        "33 A": "33 A",
+        "1 Ah": "1 Ah",  # Ah can be a tricky case if the RegEx is wrong, as A might match before Ah, thus rendering the output with an "A" unit
+    }
+
+    for input, output in assertions.items():
+        assert mistletoe.markdown(input, FiftyOhmHtmlRenderer) == paragraph(output)
+
+
+@pytest.mark.html
+def test_translated_units_html():
+    """Test translated units: Replace Ohm with Ω."""
+    assertions = {
+        "50 Ohm": "50 Ω",
+        "100 mOhm": "100 mΩ",
+    }
+
+    for input, output in assertions.items():
+        assert mistletoe.markdown(input, FiftyOhmHtmlRenderer) == paragraph(output)
+
+
+@pytest.mark.html
+def test_special_units_html():
+    """Test special units: Don't put space before ° and %."""
+    assertions = {
+        "100%": "100%",
+        "42,24°": "42,24°",
+    }
+
+    for input, output in assertions.items():
+        assert mistletoe.markdown(input, FiftyOhmHtmlRenderer) == paragraph(output)

test/util.py

@@ -1,2 +1,2 @@
-def paragraph(text) :
-    return f'<p>{text}</p>\n'
+def paragraph(text):
+    return f"<p>{text}</p>\n"