🐛 Fix code span padding around non-space whitespace

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+* 🐛 Fix code span padding to strip one surrounding space when the content consists of tabs or other non-space whitespace.
 * ✨ Add `--enable-tables` to the CLI for file, standard input and interactive parsing in [#422](https://github.com/executablebooks/markdown-it-py/pull/422)
 * 🐛 Fix CLI interactive mode joining input lines with an extra newline, which split every line into its own paragraph and broke hard line breaks, in [#172](https://github.com/executablebooks/markdown-it-py/issues/172)
 * 🐛 Fix trimming and splitting with the Python whitespace set instead of the CommonMark one, which dropped U+001C–U+001F and U+0085 from paragraphs, headings, table cells and fence info strings and let distinct reference labels resolve each other, in [#418](https://github.com/executablebooks/markdown-it-py/pull/418), thanks to [@Nexory](https://github.com/Nexory)

markdown_it/rules_inline/backticks.py

@@ -54,7 +54,7 @@ def backtick(state: StateInline, silent: bool) -> bool:
                 if (
                     token.content.startswith(" ")
                     and token.content.endswith(" ")
-                    and len(token.content.strip()) > 0
+                    and len(token.content.strip(" ")) > 0
                 ):
                     token.content = token.content[1:-1]
             state.pos = matchEnd

tests/test_port/test_backticks.py

@@ -0,0 +1,51 @@
+"""Code span padding uses U+0020 spaces, not Python's whitespace set."""
+
+import pytest
+
+from markdown_it import MarkdownIt
+
+
+@pytest.mark.parametrize("marker", ["`", "``"])
+@pytest.mark.parametrize(
+    "content,expected",
+    [
+        pytest.param(" \t ", "\t", id="tab"),
+        pytest.param(" \v ", "\v", id="vertical-tab"),
+        pytest.param(" \f ", "\f", id="form-feed"),
+        pytest.param(" \x1c ", "\x1c", id="file-separator"),
+        pytest.param(" \x85 ", "\x85", id="next-line"),
+        pytest.param(" \xa0 ", "\xa0", id="no-break-space"),
+        pytest.param(" \u2003 ", "\u2003", id="em-space"),
+        pytest.param(" \u2028 ", "\u2028", id="line-separator"),
+        pytest.param(" \u3000 ", "\u3000", id="ideographic-space"),
+        pytest.param(" \t\xa0 ", "\t\xa0", id="mixed-whitespace"),
+        pytest.param("  \t  ", " \t ", id="one-space-per-side"),
+        pytest.param(" ", " ", id="one-space"),
+        pytest.param("  ", "  ", id="two-spaces"),
+        pytest.param("   ", "   ", id="three-spaces"),
+        pytest.param("\t", "\t", id="bare-tab"),
+        pytest.param("\xa0", "\xa0", id="bare-no-break-space"),
+        pytest.param(" \t", " \t", id="leading-space-only"),
+        pytest.param("\t ", "\t ", id="trailing-space-only"),
+        pytest.param("\t text \t", "\t text \t", id="non-space-edges"),
+        pytest.param(" text ", "text", id="text-padding"),
+        pytest.param("a \t b", "a \t b", id="internal-whitespace"),
+        pytest.param("\n", " ", id="newline-only"),
+        pytest.param(" \n ", "   ", id="spaces-and-newline"),
+        pytest.param("\n\t\n", "\t", id="newline-padding"),
+        pytest.param("\r\t\r", "\t", id="carriage-return-padding"),
+        pytest.param("\r\n\t\r\n", "\t", id="crlf-padding"),
+    ],
+)
+def test_code_span_space_padding(marker, content, expected):
+    """Strip one surrounding space unless the normalized content is all spaces."""
+    md = MarkdownIt("commonmark")
+    source = f"{marker}{content}{marker}"
+
+    assert md.renderInline(source) == f"<code>{expected}</code>"
+    children = md.parseInline(source)[0].children
+    assert children is not None
+    assert len(children) == 1
+    assert children[0].type == "code_inline"
+    assert children[0].markup == marker
+    assert children[0].content == expected