⚡ Improve the detection of headings

Closes #27.

Author: davep

ChangeLog.md

@@ -10,6 +10,8 @@
   ([#24](https://github.com/davep/rogallo/pull/24))
 - Improved the detection of links.
   ([#26](https://github.com/davep/rogallo/pull/26))
+- Improved the detection of headings.
+  ([#29](https://github.com/davep/rogallo/pull/29))
 
 ## v0.1.0
 

src/rogallo/gemtext/parser.py

@@ -4,6 +4,7 @@
 # Python imports.
 from collections.abc import Iterator
 from functools import cached_property
+from typing import Final
 
 
 ##############################################################################
@@ -90,6 +91,17 @@ def uri(self) -> str:
         return self._uri
 
 
+##############################################################################
+_LINK: Final[str] = "=>"
+"""Marker for a link in Gemtext."""
+_H1: Final[str] = "#"
+"""Marker for a level 1 heading in Gemtext."""
+_H2: Final[str] = "##"
+"""Marker for a level 2 heading in Gemtext."""
+_H3: Final[str] = "###"
+"""Marker for a level 3 heading in Gemtext."""
+
+
 ##############################################################################
 class Gemtext:
     """A Gemtext parser."""
@@ -118,14 +130,17 @@ def _parse(self) -> Iterator[Line]:
                     preformat_content = []
             elif in_preformat:
                 preformat_content.append(line)
-            elif line.startswith("=>"):
-                parts = line.removeprefix("=>").strip().split(maxsplit=1)
+            elif line.startswith(_LINK):
+                parts = line.removeprefix(_LINK).strip().split(maxsplit=1)
                 yield Link(parts[0], parts[1] if len(parts) > 1 else "")
             elif line.startswith("> "):
                 yield Quote(line.removeprefix("> ").strip())
-            elif line.startswith(("# ", "## ", "### ")):
-                marker, _, heading_text = line.partition(" ")
-                yield Heading(heading_text.strip(), len(marker.strip()))
+            elif line.startswith(_H3):
+                yield Heading(line.removeprefix(_H3).strip(), 3)
+            elif line.startswith(_H2):
+                yield Heading(line.removeprefix(_H2).strip(), 2)
+            elif line.startswith(_H1):
+                yield Heading(line.removeprefix(_H1).strip(), 1)
             elif line.startswith("* "):
                 yield ListItem(line.removeprefix("* ").strip())
             else:

tests/unit/test_gemtext.py

@@ -42,10 +42,6 @@ def test_str_gemtext() -> None:
         (">Not a quote", ">Not a quote"),
         (">> Not a quote", ">> Not a quote"),
         (" # Not a header", " # Not a header"),
-        ("#Not a header", "#Not a header"),
-        ("##Not a header", "##Not a header"),
-        ("###Not a header", "###Not a header"),
-        ("#### Header 4", "#### Header 4"),
         ("*Not a list item", "*Not a list item"),
         ("** Not a list item", "** Not a list item"),
         (" * Not a list item", " * Not a list item"),
@@ -70,9 +66,17 @@ def test_parse_paragraph(gemtext: str, expected_text: str) -> None:
         ("#  Header 1", 1, "Header 1"),
         ("##  Header 2", 2, "Header 2"),
         ("###  Header 3", 3, "Header 3"),
+        ("#\tHeader 1", 1, "Header 1"),
+        ("##\tHeader 2", 2, "Header 2"),
+        ("###\tHeader 3", 3, "Header 3"),
+        ("# \tHeader 1", 1, "Header 1"),
+        ("## \tHeader 2", 2, "Header 2"),
+        ("### \tHeader 3", 3, "Header 3"),
         ("# # Header 1", 1, "# Header 1"),
         ("## ## Header 2", 2, "## Header 2"),
         ("### ### Header 3", 3, "### Header 3"),
+        ("#### Header 3", 3, "# Header 3"),
+        ("####Header 3", 3, "#Header 3"),
     ],
 )
 def test_parse_header(gemtext: str, expected_level: int, expected_content: str) -> None: