rumdl_lib/rules/

md037_spaces_around_emphasis.rs

/// Rule MD037: No spaces around emphasis markers
///
/// See [docs/md037.md](../../docs/md037.md) for full documentation, configuration, and examples.
use crate::config::MarkdownFlavor;
use crate::rule::{FixCapability, LintError, LintResult, LintWarning, Rule, RuleCategory, Severity};
use crate::utils::emphasis_utils::{
    EmphasisEdges, EmphasisMarker, find_emphasis_edges, find_emphasis_markers, find_valid_emphasis_ranges,
    has_doc_patterns, replace_inline_code_cow, replace_inline_math_cow,
};
use crate::utils::kramdown_utils::has_span_ial;
use crate::utils::range_utils::byte_to_char_count;
use crate::utils::regex_cache::UNORDERED_LIST_MARKER_REGEX;
use crate::utils::skip_context::{is_in_inline_html_code, is_in_math_context, is_in_mkdocs_markup};
use crate::utils::table_utils::TableUtils;
use std::ops::Range;

/// Check if an emphasis span has spacing issues that should be flagged
#[inline]
fn has_spacing_issues(span: &EmphasisEdges) -> bool {
    span.has_leading_space || span.has_trailing_space
}

/// Byte ranges of the cells in a table row.
///
/// A row is split on pipes that are neither escaped nor inside a code span, and
/// every cell is parsed as its own inline context, so a marker in one cell can
/// never pair with a marker in the next. Scanning cells separately gives the
/// line-level emphasis finder the boundaries the parser already uses.
fn table_cell_ranges(line: &str, flavor: MarkdownFlavor) -> Vec<Range<usize>> {
    // Only an escape or a code span can hide a pipe from the split, so a row
    // containing neither is scanned as it stands. Masking copies the row.
    let masked;
    let scan = if line.contains('\\') || line.contains('`') {
        let escaped = TableUtils::mask_escaped_pipes(line, flavor);
        masked = TableUtils::mask_pipes_in_inline_code(&escaped);
        debug_assert_eq!(
            masked.len(),
            line.len(),
            "pipe masking must preserve byte offsets for cell slicing"
        );
        masked.as_str()
    } else {
        line
    };

    let mut ranges = Vec::new();
    let mut start = 0;
    for (pipe_pos, _) in scan.match_indices('|') {
        ranges.push(start..pipe_pos);
        start = pipe_pos + 1;
    }
    ranges.push(start..line.len());
    ranges
}

/// Truncate long text for display in warning messages
/// Shows first ~30 and last ~30 chars with ellipsis in middle for readability
#[inline]
fn truncate_for_display(text: &str, max_len: usize) -> String {
    if text.len() <= max_len {
        return text.to_string();
    }

    let prefix_len = max_len / 2 - 2; // -2 for "..."
    let suffix_len = max_len / 2 - 2;

    // Use floor_char_boundary to safely find UTF-8 character boundaries
    let prefix_end = text.floor_char_boundary(prefix_len.min(text.len()));
    let suffix_start = text.floor_char_boundary(text.len().saturating_sub(suffix_len));

    format!("{}...{}", &text[..prefix_end], &text[suffix_start..])
}

/// Rule MD037: Spaces inside emphasis markers
#[derive(Clone)]
pub struct MD037NoSpaceInEmphasis;

impl Default for MD037NoSpaceInEmphasis {
    fn default() -> Self {
        Self
    }
}

impl MD037NoSpaceInEmphasis {
    /// Check if a byte position is within a link (inline links, reference links, or reference definitions)
    fn is_in_link(&self, ctx: &crate::lint_context::LintContext, byte_pos: usize) -> bool {
        if ctx.is_range_in_rendered_link(&(byte_pos..byte_pos + 1))
            || ctx
                .images()
                .iter()
                .any(|image| image.byte_offset <= byte_pos && byte_pos < image.byte_end)
        {
            return true;
        }

        // Check reference definitions [ref]: url "title" using pre-computed data (O(1) vs O(n))
        ctx.is_in_reference_def(byte_pos)
    }

    /// Where each emphasis span ends, ascending, paired with where it began.
    ///
    /// Ordering by end position is what keeps [`Self::closes_earlier_emphasis`]
    /// logarithmic: a run only has to consider the spans that close inside it,
    /// which is a handful, rather than every span in the document.
    fn emphasis_span_ends(ctx: &crate::lint_context::LintContext) -> Vec<(usize, usize)> {
        let mut ends: Vec<(usize, usize)> = ctx
            .source_emphasis_spans()
            .iter()
            .map(|span| (span.byte_end, span.byte_offset))
            .collect();
        ends.sort_unstable();
        ends
    }

    /// Check whether a flagged run only looks spaced because its opening marker
    /// is really the closing delimiter of emphasis that began further up.
    ///
    /// Markers are paired one line at a time, so on a line that continues a span
    /// the first marker reads as an opener and every marker after it pairs one
    /// position off, putting ordinary words between what look like delimiters.
    /// The document-level parse settles it: a marker already spent closing a
    /// span cannot also open one.
    ///
    /// A span that both starts and ends inside the run is a different thing, and
    /// stays reported: `* _real_ *` really is emphasis with spaces in it.
    fn closes_earlier_emphasis(span_ends: &[(usize, usize)], start: usize, end: usize) -> bool {
        let first_after_start = span_ends.partition_point(|(span_end, _)| *span_end <= start);
        span_ends[first_after_start..]
            .iter()
            .take_while(|(span_end, _)| *span_end < end)
            .any(|(_, span_start)| *span_start <= start)
    }
}

impl Rule for MD037NoSpaceInEmphasis {
    fn name(&self) -> &'static str {
        "MD037"
    }

    fn description(&self) -> &'static str {
        "Spaces inside emphasis markers"
    }

    fn check(&self, ctx: &crate::lint_context::LintContext) -> LintResult {
        let _timer = crate::profiling::ScopedTimer::new("MD037_check");
        let has_html = ctx.has_char('<');

        // Early return: if no emphasis markers at all, skip processing
        if !ctx.has_char('*') && !ctx.has_char('_') {
            return Ok(vec![]);
        }

        // Source-location queries preserve correct offsets across all line ending types.

        let mut warnings = Vec::new();

        // Process content lines, automatically skipping front matter, code blocks, math blocks,
        // and Obsidian comments (when in Obsidian flavor)
        // Math blocks contain LaTeX syntax where _ and * have special meaning
        for syntax in ctx.lexical_emphasis() {
            let line_num = syntax.line_num;
            let line_content = syntax.source();
            if ctx.lines[line_num - 1].in_table_block {
                // Each table cell is its own inline context, so scan cells separately.
                // A marker in one cell can never pair with a marker in the next, and a
                // cell holds inline content only (never a list item), so the line-level
                // list-marker handling does not apply here.
                for cell in table_cell_ranges(line_content, ctx.flavor) {
                    let Some(cell_content) = line_content.get(cell.clone()) else {
                        continue;
                    };
                    if !cell_content.contains('*') && !cell_content.contains('_') {
                        continue;
                    }
                    if has_doc_patterns(cell_content) {
                        continue;
                    }
                    self.check_line_content_for_emphasis_fast(cell_content, line_num, cell.start, &mut warnings);
                }
                continue;
            }

            // Check for emphasis issues on the original line
            self.check_line_for_emphasis_issues_fast(syntax, &mut warnings);
        }

        // Filter out warnings for emphasis markers that are inside links, HTML comments, math, or MkDocs markup
        let mut filtered_warnings = Vec::new();
        let lines = ctx.raw_lines();
        let span_ends = if warnings.is_empty() {
            Vec::new()
        } else {
            Self::emphasis_span_ends(ctx)
        };

        for warning in &warnings {
            let line_num = warning.line;
            let Some(line) = line_num.checked_sub(1).and_then(|index| lines.get(index)) else {
                continue;
            };
            let line_start_pos = ctx.line_start_byte(line_num).unwrap_or(0);
            // `warning.column` is a byte offset within the line at this stage.
            // Derive the byte position (for byte-based skip checks) and the
            // character column (for char-based checks and the emitted warning).
            let byte_pos = line_start_pos + (warning.column - 1);
            // Calculate byte position within the line (0-indexed)
            let line_pos = warning.column - 1;
            let char_col = byte_to_char_count(line, warning.column - 1);

            // Skip if inside links, HTML comments, math contexts, code spans, MDX constructs, or MkDocs markup
            // Note: is_in_code_span uses pulldown-cmark and correctly handles multi-line spans
            // Pandoc bracketed spans `[text]{.class}` may contain spaced
            // emphasis markers as literal content; suppress MD037 there.
            // Subscripts/superscripts cannot contain whitespace per the
            // detector grammar, so MD037's spaced-emphasis warnings can
            // never land inside one.
            // A shortcode tag is an argument list read by a template, so
            // `*` and `_` in it are literal characters the template sees;
            // closing the spaces around them changes what it receives.
            let in_pandoc_construct = ctx.flavor.is_pandoc_compatible() && ctx.is_in_bracketed_span(byte_pos);
            let byte_end = line_start_pos + (warning.end_column - 1);
            let closing_pos = byte_end.saturating_sub(1);
            let marker_in_html = has_html
                && [byte_pos, closing_pos].into_iter().any(|pos| {
                    ctx.is_in_html_comment(pos) || ctx.is_in_html_tag(pos) || ctx.is_in_jsx_component_tag(pos)
                });
            if !in_pandoc_construct
                && !marker_in_html
                && !ctx.is_in_jinja_string(byte_pos)
                && !ctx.is_in_jinja_string(closing_pos)
                && !Self::closes_earlier_emphasis(&span_ends, byte_pos, byte_end)
                && !self.is_in_link(ctx, byte_pos)
                && !ctx.is_in_shortcode(byte_pos)
                && !ctx.is_in_shortcode(closing_pos)
                && !is_in_math_context(ctx, byte_pos)
                && !ctx.is_in_code_span(line_num, char_col)
                // A marker on the opening line of a multiline code span
                // can appear to close emphasis that started outside code.
                && !ctx.is_in_code_span_byte(closing_pos)
                && !is_in_inline_html_code(line, line_pos)
                && !ctx.overlaps_mdx_inline_code(byte_pos, byte_end)
                && !is_in_mkdocs_markup(line, line_pos, ctx.flavor)
                && !ctx.is_position_in_obsidian_comment(line_num, char_col)
            {
                let mut adjusted_warning = warning.clone();
                // Emit character-based columns (byte-based skip checks done above).
                adjusted_warning.column = char_col;
                adjusted_warning.end_column = byte_to_char_count(line, warning.end_column - 1);
                filtered_warnings.push(adjusted_warning);
            }
        }

        Ok(filtered_warnings)
    }

    fn fix(&self, ctx: &crate::lint_context::LintContext) -> Result<String, LintError> {
        Ok(ctx.content.to_string())
    }

    fn fix_capability(&self) -> FixCapability {
        // Spaced delimiter pairs are literal text under CommonMark. Removing
        // their whitespace creates emphasis and can change the author's meaning.
        FixCapability::Unfixable
    }

    /// Get the category of this rule for selective processing
    fn category(&self) -> RuleCategory {
        RuleCategory::Emphasis
    }

    /// Check if this rule should be skipped
    fn should_skip(&self, ctx: &crate::lint_context::LintContext) -> bool {
        ctx.content.is_empty() || !ctx.likely_has_emphasis()
    }

    fn as_any(&self) -> &dyn std::any::Any {
        self
    }

    fn from_config(_config: &crate::config::Config) -> Box<dyn Rule>
    where
        Self: Sized,
    {
        Box::new(MD037NoSpaceInEmphasis)
    }
}

impl MD037NoSpaceInEmphasis {
    /// Optimized line checking for emphasis spacing issues
    #[inline]
    fn check_line_for_emphasis_issues_fast(
        &self,
        syntax: crate::lint_context::EmphasisLine<'_>,
        warnings: &mut Vec<LintWarning>,
    ) {
        let line = syntax.source();
        let line_num = syntax.line_num;
        // Quick documentation pattern checks
        if has_doc_patterns(line) {
            return;
        }

        // Optimized list detection with fast path
        // When a list marker is detected, ALWAYS check only the content after the marker,
        // never the full line. This prevents the list marker (* + -) from being mistaken
        // for emphasis markers.
        if (line.starts_with(' ') || line.starts_with('*') || line.starts_with('+') || line.starts_with('-'))
            && UNORDERED_LIST_MARKER_REGEX.is_match(line)
        {
            if let Some(caps) = UNORDERED_LIST_MARKER_REGEX.captures(line)
                && let Some(full_match) = caps.get(0)
            {
                let list_marker_end = full_match.end();
                if list_marker_end < line.len() {
                    let remaining_content = &line[list_marker_end..];

                    // Always check just the remaining content (after the list marker).
                    // The list marker itself is never emphasis.
                    self.check_line_content_for_emphasis_fast(remaining_content, line_num, list_marker_end, warnings);
                }
            }
            return;
        }

        // Reuse the code mask and delimiter scan shared with MD049. Math is
        // intentionally MD037-specific; rescan only when it changes the text.
        let processed = replace_inline_math_cow(syntax.without_code());
        let fresh_markers;
        let markers = if matches!(processed, std::borrow::Cow::Borrowed(_)) {
            syntax.markers
        } else {
            fresh_markers = find_emphasis_markers(&processed);
            &fresh_markers
        };
        self.check_prepared_content(line, &processed, markers, line_num, 0, warnings);
    }

    /// Optimized line content checking for emphasis issues
    fn check_line_content_for_emphasis_fast(
        &self,
        content: &str,
        line_num: usize,
        offset: usize,
        warnings: &mut Vec<LintWarning>,
    ) {
        // Replace inline code and inline math to avoid false positives
        // with emphasis markers inside backticks or dollar signs
        let code_masked = replace_inline_code_cow(content);
        let processed_content = replace_inline_math_cow(&code_masked);
        let markers = find_emphasis_markers(&processed_content);
        self.check_prepared_content(content, &processed_content, &markers, line_num, offset, warnings);
    }

    fn check_prepared_content(
        &self,
        content: &str,
        processed_content: &str,
        markers: &[EmphasisMarker],
        line_num: usize,
        offset: usize,
        warnings: &mut Vec<LintWarning>,
    ) {
        if markers.is_empty() {
            return;
        }

        // Find valid emphasis spans
        let spans = find_emphasis_edges(processed_content, markers);

        // Byte ranges that are genuine CommonMark emphasis. A spaced span that
        // falls entirely inside one of these is not "spaces inside emphasis
        // markers" but the interior of valid emphasis containing a literal
        // marker (e.g. `*foo * bar*`), which the greedy finder above mispairs.
        let valid_ranges = find_valid_emphasis_ranges(processed_content, markers);

        // Check each span for spacing issues
        for span in spans {
            if has_spacing_issues(&span) {
                let full_start = span.opening.start_pos;
                let full_end = span.closing.end_pos();

                // Suppress when the spaced run is contained in valid emphasis.
                if valid_ranges
                    .iter()
                    .any(|&(start, end)| start <= full_start && full_end <= end)
                {
                    continue;
                }

                let full_text = &content[full_start..full_end];

                // Skip if this emphasis has a Kramdown span IAL immediately after it
                // (no space between emphasis and IAL)
                if full_end < content.len() {
                    let remaining = &content[full_end..];
                    // Check if IAL starts immediately after the emphasis (no whitespace)
                    if remaining.starts_with('{') && has_span_ial(remaining.split_whitespace().next().unwrap_or("")) {
                        continue;
                    }
                }

                // Truncate long emphasis spans for readable warning messages
                let display_text = truncate_for_display(full_text, 60);

                let warning = LintWarning {
                    rule_name: Some(self.name().to_string()),
                    message: format!("Spaces inside emphasis markers: {display_text:?}"),
                    // Byte-based columns within the line. The filter pass below relies
                    // on `column` being a byte offset for its skip checks, then converts
                    // the emitted columns to character offsets.
                    line: line_num,
                    column: offset + full_start + 1,
                    end_line: line_num,
                    end_column: offset + full_end + 1,
                    severity: Severity::Warning,
                    fix: None,
                };

                warnings.push(warning);
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::lint_context::LintContext;
    use crate::utils::emphasis_utils::find_emphasis_spans;

    #[test]
    fn test_marker_inside_shortcode_cannot_close_spaced_emphasis() {
        let rule = MD037NoSpaceInEmphasis;
        let source = "Before * text {{< note title=\"*\" >}}\n\nBefore * visible *\n";
        let ctx = LintContext::new(source, crate::config::MarkdownFlavor::Hugo, None);
        assert_eq!(rule.check(&ctx).unwrap().len(), 1);
        assert_eq!(rule.fix(&ctx).unwrap(), source);
    }

    #[test]
    fn test_myst_comment_contents_are_not_linted() {
        let rule = MD037NoSpaceInEmphasis;
        for prefix in ["% ", "%", "  %\t", "   % "] {
            let source = format!("{prefix}* literal *\n\nBefore * visible *\n");
            let ctx = crate::lint_context::LintContext::new(&source, crate::config::MarkdownFlavor::MyST, None);
            let warnings = rule.check(&ctx).unwrap();
            assert_eq!(warnings.len(), 1, "comments are not visible prose: {source}");
            assert_eq!(warnings[0].line, 3);
            assert_eq!(rule.fix(&ctx).unwrap(), source);
        }
    }

    #[test]
    fn test_jinja_quoted_spaced_markers_are_literal() {
        let rule = MD037NoSpaceInEmphasis;
        for template in [
            r#"{{ "* literal *" }}"#,
            "{% set text = '_ 内容 _' %}",
            "{{\n  \"** literal **\"\n}}",
            r#"{{ {"text": "* literal *"} }}"#,
            r#"* text {{ "*" }}"#,
        ] {
            let source = format!("Before {template}\n\nBefore * visible *\n");
            let ctx = LintContext::new(&source, crate::config::MarkdownFlavor::Standard, None);
            assert_eq!(
                rule.check(&ctx).unwrap().len(),
                1,
                "quoted markers are literal: {source}"
            );
            assert_eq!(rule.fix(&ctx).unwrap(), source);
        }
    }

    #[test]
    fn test_mdx_module_spaced_markers_are_literal() {
        let rule = MD037NoSpaceInEmphasis;
        for module in [
            "export const text = \"* literal *\"",
            "export const data = {\n  text: \"_ 内容 _\"\n}",
            "import text from \"./* literal *.js\"",
        ] {
            let source = format!("{module}\n\nBefore * visible *\n");
            let ctx = LintContext::new(&source, crate::config::MarkdownFlavor::MDX, None);
            let warnings = rule.check(&ctx).unwrap();
            assert_eq!(warnings.len(), 1, "module strings must stay literal: {source}");
            assert!(warnings[0].line > module.lines().count());
            assert_eq!(rule.fix(&ctx).unwrap(), source);
        }
    }

    #[test]
    fn test_spaced_markers_in_html_attributes_or_closing_in_comments_are_ignored() {
        let rule = MD037NoSpaceInEmphasis;
        for source in [
            "Before <span title=\"* literal *\">visible</span>\n",
            "Before <span\n title=\"_ literal _\">visible</span>\n",
            "日本語 <span title=\"** 内容 **\">表示</span>\n",
            "Before * text <!-- * -->\n",
            "Before ** text <span title=\"**\">visible</span>\n",
        ] {
            let ctx = LintContext::new(source, crate::config::MarkdownFlavor::Standard, None);
            assert!(
                rule.check(&ctx).unwrap().is_empty(),
                "HTML markers are literal: {source}"
            );
            assert_eq!(rule.fix(&ctx).unwrap(), source);
        }
    }

    #[test]
    fn test_spaced_emphasis_beside_html_attributes_still_reported() {
        let rule = MD037NoSpaceInEmphasis;
        let source = "Before <span title=\"* literal *\">* visible *</span> <!-- * hidden * -->\n";
        let expected = "Before <span title=\"* literal *\">*visible*</span> <!-- * hidden * -->\n";
        let ctx = LintContext::new(source, crate::config::MarkdownFlavor::Standard, None);
        assert_eq!(rule.check(&ctx).unwrap().len(), 1);
        assert_eq!(rule.fix(&ctx).unwrap(), source);
        let fixed_ctx = LintContext::new(expected, crate::config::MarkdownFlavor::Standard, None);
        assert!(rule.check(&fixed_ctx).unwrap().is_empty());
    }

    #[test]
    fn test_spaced_marker_pair_ending_inside_multiline_code_is_ignored() {
        let rule = MD037NoSpaceInEmphasis;
        for content in [
            "Before * text `code *\nend`\n",
            "_ text `code _\nend`\n",
            "** text `code **\nend`\n",
            "__ text ``code `tick` __\nend``\n",
            "日本語 * 内容 `コード *\n終了`\n",
        ] {
            let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
            assert!(
                rule.check(&ctx).unwrap().is_empty(),
                "closing marker is code: {content}"
            );
            assert_eq!(rule.fix(&ctx).unwrap(), content);
        }
    }

    #[test]
    fn test_spaced_emphasis_beside_multiline_code_requires_manual_correction() {
        let rule = MD037NoSpaceInEmphasis;
        let source = "Before ** text `code **\nend` and * real *\n";
        let expected = "Before ** text `code **\nend` and *real*\n";
        let ctx = LintContext::new(source, crate::config::MarkdownFlavor::Standard, None);
        let warnings = rule.check(&ctx).unwrap();
        assert_eq!(warnings.len(), 1);
        assert_eq!(warnings[0].line, 2);
        assert_eq!(rule.fix(&ctx).unwrap(), source);
        let fixed_ctx = LintContext::new(expected, crate::config::MarkdownFlavor::Standard, None);
        assert!(rule.check(&fixed_ctx).unwrap().is_empty());
        assert_eq!(rule.fix(&fixed_ctx).unwrap(), expected);
        let code_values = |content: &str| {
            pulldown_cmark::Parser::new(content)
                .filter_map(|event| match event {
                    pulldown_cmark::Event::Code(value) => Some(value.into_string()),
                    _ => None,
                })
                .collect::<Vec<_>>()
        };
        assert_eq!(code_values(source), vec!["code ** end"]);
        assert_eq!(code_values(source), code_values(expected));
    }

    #[test]
    fn table_cell_ranges_unmasked_scan_matches_masked_scan() {
        // Rows without an escape or a code span skip the masking copy. Both
        // paths must split a row into the same cells.
        fn always_masked(line: &str, flavor: MarkdownFlavor) -> Vec<Range<usize>> {
            let escaped = TableUtils::mask_escaped_pipes(line, flavor);
            let masked = TableUtils::mask_pipes_in_inline_code(&escaped);
            let mut ranges = Vec::new();
            let mut start = 0;
            for (pipe_pos, _) in masked.match_indices('|') {
                ranges.push(start..pipe_pos);
                start = pipe_pos + 1;
            }
            ranges.push(start..line.len());
            ranges
        }

        for line in [
            "| a | b |",
            "| a * x * | b |",
            "a | b",
            "no pipes at all",
            "",
            "|||",
            "| naïve ünïcode | 日本語 |",
            r"| a \| b | c |",
            "| `a | b` | c |",
            r"| `a \| b` | c |",
            r"| a \\ | b |",
            r"| a \\| b | c |",
            "> | a * x * | b |",
        ] {
            for flavor in [MarkdownFlavor::Standard, MarkdownFlavor::MkDocs] {
                assert_eq!(
                    table_cell_ranges(line, flavor),
                    always_masked(line, flavor),
                    "line: {line:?} flavor: {flavor:?}"
                );
            }
        }
    }

    #[test]
    fn test_emphasis_marker_parsing() {
        let markers = find_emphasis_markers("This has *single* and **double** emphasis");
        assert_eq!(markers.len(), 4); // *, *, **, **

        let markers = find_emphasis_markers("*start* and *end*");
        assert_eq!(markers.len(), 4); // *, *, *, *
    }

    #[test]
    fn test_emphasis_span_detection() {
        let markers = find_emphasis_markers("This has *valid* emphasis");
        let spans = find_emphasis_spans("This has *valid* emphasis", &markers);
        assert_eq!(spans.len(), 1);
        assert_eq!(spans[0].content, "valid");
        assert!(!spans[0].has_leading_space);
        assert!(!spans[0].has_trailing_space);

        let markers = find_emphasis_markers("This has * invalid * emphasis");
        let spans = find_emphasis_spans("This has * invalid * emphasis", &markers);
        assert_eq!(spans.len(), 1);
        assert_eq!(spans[0].content, " invalid ");
        assert!(spans[0].has_leading_space);
        assert!(spans[0].has_trailing_space);
    }

    #[test]
    fn test_with_document_structure() {
        let rule = MD037NoSpaceInEmphasis;

        // Test with no spaces inside emphasis - should pass
        let content = "This is *correct* emphasis and **strong emphasis**";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(result.is_empty(), "No warnings expected for correct emphasis");

        // Test with actual spaces inside emphasis - use content that should warn
        let content = "This is * text with spaces * and more content";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(!result.is_empty(), "Expected warnings for spaces in emphasis");

        // Test with code blocks - emphasis in code should be ignored
        let content = "This is *correct* emphasis\n```\n* incorrect * in code block\n```\nOutside block with * spaces in emphasis *";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            !result.is_empty(),
            "Expected warnings for spaces in emphasis outside code block"
        );
    }

    #[test]
    fn test_spaced_literal_markers_preserve_embedded_inline_code() {
        // Ambiguous spacing must remain literal, including embedded inline code.
        let rule = MD037NoSpaceInEmphasis;
        let content = "Set * the `id` field * below.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let fixed = rule.fix(&ctx).unwrap();
        assert_eq!(fixed, content);
    }

    #[test]
    fn unresolved_spaced_reference_still_warns_while_rendered_links_do_not() {
        let rule = MD037NoSpaceInEmphasis;
        for (source, expected) in [
            ("[ * spaced * ][unknown]\n", 1),
            ("[ * spaced * ](url)\n", 0),
            ("![ * spaced * ](url)\n", 0),
        ] {
            let ctx = LintContext::new(source, crate::config::MarkdownFlavor::Standard, None);
            assert_eq!(rule.check(&ctx).unwrap().len(), expected, "{source:?}");
        }
    }

    #[test]
    fn test_emphasis_in_links_not_flagged() {
        let rule = MD037NoSpaceInEmphasis;
        let content = r#"Check this [* spaced asterisk *](https://example.com/*test*) link.

This has * real spaced emphasis * that should be flagged."#;
        let ctx = crate::lint_context::LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();

        // Test passed - emphasis inside links are filtered out correctly

        // Only the real emphasis outside links should be flagged
        assert_eq!(
            result.len(),
            1,
            "Expected exactly 1 warning, but got: {:?}",
            result.len()
        );
        assert!(result[0].message.contains("Spaces inside emphasis markers"));
        // Should flag "* real spaced emphasis *" but not emphasis patterns inside links
        assert!(result[0].line == 3); // Line with "* real spaced emphasis *"
    }

    #[test]
    fn test_emphasis_in_links_vs_outside_links() {
        let rule = MD037NoSpaceInEmphasis;
        let content = r#"Check [* spaced *](https://example.com/*test*) and inline * real spaced * text.

[* link *]: https://example.com/*path*"#;
        let ctx = crate::lint_context::LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();

        // Only the actual emphasis outside links should be flagged
        assert_eq!(result.len(), 1);
        assert!(result[0].message.contains("Spaces inside emphasis markers"));
        // Should be the "* real spaced *" text on line 1
        assert!(result[0].line == 1);
    }

    #[test]
    fn test_issue_49_asterisk_in_inline_code() {
        // Test for issue #49 - Asterisk within backticks identified as for emphasis
        let rule = MD037NoSpaceInEmphasis;

        // Test case from issue #49
        let content = "The `__mul__` method is needed for left-hand multiplication (`vector * 3`) and `__rmul__` is needed for right-hand multiplication (`3 * vector`).";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag asterisks inside inline code as emphasis (issue #49). Got: {result:?}"
        );
    }

    #[test]
    fn test_issue_28_inline_code_in_emphasis() {
        // Test for issue #28 - MD037 should not flag inline code inside emphasis as spaces
        let rule = MD037NoSpaceInEmphasis;

        // Test case 1: inline code with single backticks inside bold emphasis
        let content = "Though, we often call this an **inline `if`** because it looks sort of like an `if`-`else` statement all in *one line* of code.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag inline code inside emphasis as spaces (issue #28). Got: {result:?}"
        );

        // Test case 2: multiple inline code snippets inside emphasis
        let content2 = "The **`foo` and `bar`** methods are important.";
        let ctx2 = LintContext::new(content2, crate::config::MarkdownFlavor::Standard, None);
        let result2 = rule.check(&ctx2).unwrap();
        assert!(
            result2.is_empty(),
            "Should not flag multiple inline code snippets inside emphasis. Got: {result2:?}"
        );

        // Test case 3: inline code with underscores for emphasis
        let content3 = "This is __inline `code`__ with underscores.";
        let ctx3 = LintContext::new(content3, crate::config::MarkdownFlavor::Standard, None);
        let result3 = rule.check(&ctx3).unwrap();
        assert!(
            result3.is_empty(),
            "Should not flag inline code with underscore emphasis. Got: {result3:?}"
        );

        // Test case 4: single asterisk emphasis with inline code
        let content4 = "This is *inline `test`* with single asterisks.";
        let ctx4 = LintContext::new(content4, crate::config::MarkdownFlavor::Standard, None);
        let result4 = rule.check(&ctx4).unwrap();
        assert!(
            result4.is_empty(),
            "Should not flag inline code with single asterisk emphasis. Got: {result4:?}"
        );

        // Test case 5: actual spaces that should be flagged
        let content5 = "This has * real spaces * that should be flagged.";
        let ctx5 = LintContext::new(content5, crate::config::MarkdownFlavor::Standard, None);
        let result5 = rule.check(&ctx5).unwrap();
        assert!(!result5.is_empty(), "Should still flag actual spaces in emphasis");
        assert!(result5[0].message.contains("Spaces inside emphasis markers"));
    }

    #[test]
    fn test_multibyte_utf8_no_panic() {
        // Regression test: ensure multi-byte UTF-8 characters don't cause panics
        // in the truncate_for_display function when handling long emphasis spans.
        // These test cases include various scripts that could trigger boundary issues.
        let rule = MD037NoSpaceInEmphasis;

        // Greek text with emphasis
        let greek = "Αυτό είναι ένα * τεστ με ελληνικά * και πολύ μεγάλο κείμενο που θα πρέπει να περικοπεί σωστά.";
        let ctx = LintContext::new(greek, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx);
        assert!(result.is_ok(), "Greek text should not panic");

        // Chinese text with emphasis
        let chinese = "这是一个 * 测试文本 * 包含中文字符，需要正确处理多字节边界。";
        let ctx = LintContext::new(chinese, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx);
        assert!(result.is_ok(), "Chinese text should not panic");

        // Cyrillic/Russian text with emphasis
        let cyrillic = "Это * тест с кириллицей * и очень длинным текстом для проверки обрезки.";
        let ctx = LintContext::new(cyrillic, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx);
        assert!(result.is_ok(), "Cyrillic text should not panic");

        // Mixed multi-byte characters in a long emphasis span that triggers truncation
        let mixed =
            "日本語と * 中文と한국어が混在する非常に長いテキストでtruncate_for_displayの境界処理をテスト * します。";
        let ctx = LintContext::new(mixed, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx);
        assert!(result.is_ok(), "Mixed CJK text should not panic");

        // Arabic text (right-to-left) with emphasis
        let arabic = "هذا * اختبار بالعربية * مع نص طويل جداً لاختبار معالجة حدود الأحرف.";
        let ctx = LintContext::new(arabic, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx);
        assert!(result.is_ok(), "Arabic text should not panic");

        // Emoji with emphasis
        let emoji = "This has * 🎉 party 🎊 celebration 🥳 emojis * that use multi-byte sequences.";
        let ctx = LintContext::new(emoji, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx);
        assert!(result.is_ok(), "Emoji text should not panic");
    }

    #[test]
    fn test_template_shortcode_syntax_not_flagged() {
        // Test for FastAPI/MkDocs style template syntax {* ... *}
        // These should NOT be flagged as emphasis with spaces
        let rule = MD037NoSpaceInEmphasis;

        // FastAPI style code inclusion
        let content = "{* ../../docs_src/cookie_param_models/tutorial001.py hl[9:12,16] *}";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Template shortcode syntax should not be flagged. Got: {result:?}"
        );

        // Another FastAPI example
        let content = "{* ../../docs_src/conditional_openapi/tutorial001.py hl[6,11] *}";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Template shortcode syntax should not be flagged. Got: {result:?}"
        );

        // Multiple shortcodes on different lines
        let content = "# Header\n\n{* file1.py *}\n\nSome text.\n\n{* file2.py hl[1-5] *}";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Multiple template shortcodes should not be flagged. Got: {result:?}"
        );

        // But actual emphasis with spaces should still be flagged
        let content = "This has * real spaced emphasis * here.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(!result.is_empty(), "Real spaced emphasis should still be flagged");
    }

    #[test]
    fn test_multiline_code_span_not_flagged() {
        // Test for multi-line code spans - asterisks inside should not be flagged
        // This tests the case where a code span starts on one line and ends on another
        let rule = MD037NoSpaceInEmphasis;

        // Code span spanning multiple lines with asterisks inside
        let content = "# Test\n\naffects the structure. `1 + 0 + 0` is parsed as `(1 + 0) +\n0` while `1 + 0 * 0` is parsed as `1 + (0 * 0)`. Since the pattern";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag asterisks inside multi-line code spans. Got: {result:?}"
        );

        // Another multi-line code span case
        let content2 = "Text with `code that\nspans * multiple * lines` here.";
        let ctx2 = LintContext::new(content2, crate::config::MarkdownFlavor::Standard, None);
        let result2 = rule.check(&ctx2).unwrap();
        assert!(
            result2.is_empty(),
            "Should not flag asterisks inside multi-line code spans. Got: {result2:?}"
        );
    }

    #[test]
    fn test_html_block_asterisks_not_flagged() {
        let rule = MD037NoSpaceInEmphasis;

        // Asterisks used as multiplication inside HTML <code> tags within an HTML table
        let content = r#"<table>
<tr><td>Format</td><td>Size</td></tr>
<tr><td>BC1</td><td><code>floor((width + 3) / 4) * floor((height + 3) / 4) * 8</code></td></tr>
<tr><td>BC2</td><td><code>floor((width + 3) / 4) * floor((height + 3) / 4) * 16</code></td></tr>
</table>"#;
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag asterisks inside HTML blocks. Got: {result:?}"
        );

        // Standalone HTML block with emphasis-like patterns
        let content2 = "<div>\n<p>Value is * something * here</p>\n</div>";
        let ctx2 = LintContext::new(content2, crate::config::MarkdownFlavor::Standard, None);
        let result2 = rule.check(&ctx2).unwrap();
        assert!(
            result2.is_empty(),
            "Should not flag emphasis-like patterns inside HTML div blocks. Got: {result2:?}"
        );

        // Regular markdown with spaced emphasis should still be flagged
        let content3 = "Regular * spaced emphasis * text\n\n<div>* not emphasis *</div>";
        let ctx3 = LintContext::new(content3, crate::config::MarkdownFlavor::Standard, None);
        let result3 = rule.check(&ctx3).unwrap();
        assert_eq!(
            result3.len(),
            1,
            "Should flag spaced emphasis in regular markdown but not inside HTML blocks. Got: {result3:?}"
        );
        assert_eq!(result3[0].line, 1, "Warning should be on line 1 (regular markdown)");
    }

    #[test]
    fn test_mkdocs_icon_shortcode_not_flagged() {
        // Test that MkDocs icon shortcodes with asterisks inside are not flagged
        let rule = MD037NoSpaceInEmphasis;

        // Icon shortcode syntax like :material-star: should not trigger MD037
        // because it's valid MkDocs Material syntax
        let content = "Click :material-check: to confirm and :fontawesome-solid-star: for favorites.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::MkDocs, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag MkDocs icon shortcodes. Got: {result:?}"
        );

        // Actual emphasis with spaces should still be flagged even in MkDocs mode
        let content2 = "This has * real spaced emphasis * but also :material-check: icon.";
        let ctx2 = LintContext::new(content2, crate::config::MarkdownFlavor::MkDocs, None);
        let result2 = rule.check(&ctx2).unwrap();
        assert!(
            !result2.is_empty(),
            "Should still flag real spaced emphasis in MkDocs mode"
        );
    }

    #[test]
    fn test_mkdocs_pymdown_markup_not_flagged() {
        // Test that PyMdown extension markup is not flagged as emphasis issues
        let rule = MD037NoSpaceInEmphasis;

        // Keys notation (++ctrl+alt+delete++)
        let content = "Press ++ctrl+c++ to copy.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::MkDocs, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag PyMdown Keys notation. Got: {result:?}"
        );

        // Mark notation (==highlighted==)
        let content2 = "This is ==highlighted text== for emphasis.";
        let ctx2 = LintContext::new(content2, crate::config::MarkdownFlavor::MkDocs, None);
        let result2 = rule.check(&ctx2).unwrap();
        assert!(
            result2.is_empty(),
            "Should not flag PyMdown Mark notation. Got: {result2:?}"
        );

        // Insert notation (^^inserted^^)
        let content3 = "This is ^^inserted text^^ here.";
        let ctx3 = LintContext::new(content3, crate::config::MarkdownFlavor::MkDocs, None);
        let result3 = rule.check(&ctx3).unwrap();
        assert!(
            result3.is_empty(),
            "Should not flag PyMdown Insert notation. Got: {result3:?}"
        );

        // Mixed content with real emphasis issue and PyMdown markup
        let content4 = "Press ++ctrl++ then * spaced emphasis * here.";
        let ctx4 = LintContext::new(content4, crate::config::MarkdownFlavor::MkDocs, None);
        let result4 = rule.check(&ctx4).unwrap();
        assert!(
            !result4.is_empty(),
            "Should still flag real spaced emphasis alongside PyMdown markup"
        );
    }

    // ==================== Obsidian highlight tests ====================

    #[test]
    fn test_obsidian_highlight_not_flagged() {
        // Test that Obsidian highlight syntax (==text==) is not flagged as emphasis
        let rule = MD037NoSpaceInEmphasis;

        // Simple highlight
        let content = "This is ==highlighted text== here.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag Obsidian highlight syntax. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_multiple_on_line() {
        // Multiple highlights on one line
        let rule = MD037NoSpaceInEmphasis;

        let content = "Both ==one== and ==two== are highlighted.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag multiple Obsidian highlights. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_entire_paragraph() {
        // Entire paragraph highlighted
        let rule = MD037NoSpaceInEmphasis;

        let content = "==Entire paragraph highlighted==";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag entire highlighted paragraph. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_with_emphasis() {
        // Highlights nested with other emphasis
        let rule = MD037NoSpaceInEmphasis;

        // Bold highlight
        let content = "**==bold highlight==**";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag bold highlight combination. Got: {result:?}"
        );

        // Italic highlight
        let content2 = "*==italic highlight==*";
        let ctx2 = LintContext::new(content2, crate::config::MarkdownFlavor::Obsidian, None);
        let result2 = rule.check(&ctx2).unwrap();
        assert!(
            result2.is_empty(),
            "Should not flag italic highlight combination. Got: {result2:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_in_lists() {
        // Highlights in list items
        let rule = MD037NoSpaceInEmphasis;

        let content = "- Item with ==highlight== text\n- Another ==highlighted== item";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag highlights in list items. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_in_blockquote() {
        // Highlights in blockquotes
        let rule = MD037NoSpaceInEmphasis;

        let content = "> This quote has ==highlighted== text.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag highlights in blockquotes. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_in_tables() {
        // Highlights in tables
        let rule = MD037NoSpaceInEmphasis;

        let content = "| Header | Column |\n|--------|--------|\n| ==highlighted== | text |";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag highlights in tables. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_in_code_blocks_ignored() {
        // Highlights inside code blocks should be ignored (they're in code)
        let rule = MD037NoSpaceInEmphasis;

        let content = "```\n==not highlight in code==\n```";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should ignore highlights in code blocks. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_edge_case_three_equals() {
        // Three equals signs (===) should not be treated as highlight
        let rule = MD037NoSpaceInEmphasis;

        // This is not valid highlight syntax
        let content = "Test === something === here";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        // This may or may not generate warnings depending on if it looks like emphasis
        // The key is it shouldn't crash and should be handled gracefully
        let _ = result;
    }

    #[test]
    fn test_obsidian_highlight_edge_case_four_equals() {
        // Four equals signs (====) - empty highlight
        let rule = MD037NoSpaceInEmphasis;

        let content = "Test ==== here";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        // Empty highlights should not match as valid highlights
        let _ = result;
    }

    #[test]
    fn test_obsidian_highlight_adjacent() {
        // Adjacent highlights
        let rule = MD037NoSpaceInEmphasis;

        let content = "==one====two==";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        // Should handle adjacent highlights gracefully
        let _ = result;
    }

    #[test]
    fn test_obsidian_highlight_with_special_chars() {
        // Highlights with special characters inside
        let rule = MD037NoSpaceInEmphasis;

        // Highlight with backtick inside
        let content = "Test ==code: `test`== here";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        // Should handle gracefully
        let _ = result;
    }

    #[test]
    fn test_obsidian_highlight_unclosed() {
        // Unclosed highlight should not cause issues
        let rule = MD037NoSpaceInEmphasis;

        let content = "This ==starts but never ends";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        // Unclosed highlight should not match anything special
        let _ = result;
    }

    #[test]
    fn test_obsidian_highlight_still_flags_real_emphasis_issues() {
        // Real emphasis issues should still be flagged in Obsidian mode
        let rule = MD037NoSpaceInEmphasis;

        let content = "This has * spaced emphasis * and ==valid highlight==";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            !result.is_empty(),
            "Should still flag real spaced emphasis in Obsidian mode"
        );
        assert!(
            result.len() == 1,
            "Should flag exactly one issue (the spaced emphasis). Got: {result:?}"
        );
    }

    #[test]
    fn test_standard_flavor_does_not_recognize_highlight() {
        // Standard flavor should NOT recognize ==highlight== as special
        // It may or may not flag it as emphasis depending on context
        let rule = MD037NoSpaceInEmphasis;

        let content = "This is ==highlighted text== here.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        // In standard flavor, == is not recognized as highlight syntax
        // It won't be flagged as "spaces in emphasis" because == is not * or _
        // The key is that standard flavor doesn't give special treatment to ==
        let _ = result; // Just ensure it runs without error
    }

    #[test]
    fn test_obsidian_highlight_mixed_with_regular_emphasis() {
        // Mix of highlights and regular emphasis
        let rule = MD037NoSpaceInEmphasis;

        let content = "==highlighted== and *italic* and **bold** text";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag valid highlight and emphasis. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_unicode() {
        // Highlights with Unicode content
        let rule = MD037NoSpaceInEmphasis;

        let content = "Text ==日本語 highlighted== here";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should handle Unicode in highlights. Got: {result:?}"
        );
    }

    #[test]
    fn test_obsidian_highlight_with_html() {
        // Highlights inside HTML should be handled
        let rule = MD037NoSpaceInEmphasis;

        let content = "<!-- ==not highlight in comment== --> ==actual highlight==";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();
        // The highlight in HTML comment should be ignored, only the actual highlight is processed
        let _ = result;
    }

    #[test]
    fn test_obsidian_inline_comment_emphasis_ignored() {
        // Emphasis inside Obsidian comments should be ignored
        let rule = MD037NoSpaceInEmphasis;

        let content = "Visible %%* spaced emphasis *%% still visible.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Obsidian, None);
        let result = rule.check(&ctx).unwrap();

        assert!(
            result.is_empty(),
            "Should ignore emphasis inside Obsidian comments. Got: {result:?}"
        );
    }

    #[test]
    fn test_inline_html_code_not_flagged() {
        let rule = MD037NoSpaceInEmphasis;

        // Asterisks used as multiplication inside inline <code> tags
        let content = "The formula is <code>a * b * c</code> in math.";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "Should not flag asterisks inside inline <code> tags. Got: {result:?}"
        );

        // Multiple inline code-like tags on the same line
        let content2 = "Use <kbd>Ctrl * A</kbd> and <samp>x * y</samp> here.";
        let ctx2 = LintContext::new(content2, crate::config::MarkdownFlavor::Standard, None);
        let result2 = rule.check(&ctx2).unwrap();
        assert!(
            result2.is_empty(),
            "Should not flag asterisks inside inline <kbd> and <samp> tags. Got: {result2:?}"
        );

        // Code tag with attributes
        let content3 = r#"Result: <code class="math">a * b</code> done."#;
        let ctx3 = LintContext::new(content3, crate::config::MarkdownFlavor::Standard, None);
        let result3 = rule.check(&ctx3).unwrap();
        assert!(
            result3.is_empty(),
            "Should not flag asterisks inside <code> with attributes. Got: {result3:?}"
        );

        // Real emphasis on the same line as inline code should still be flagged
        let content4 = "Text * spaced * and <code>a * b</code>.";
        let ctx4 = LintContext::new(content4, crate::config::MarkdownFlavor::Standard, None);
        let result4 = rule.check(&ctx4).unwrap();
        assert_eq!(
            result4.len(),
            1,
            "Should flag real spaced emphasis but not code content. Got: {result4:?}"
        );
        assert_eq!(result4[0].column, 6);
    }

    /// Emphasis with spaces inside Pandoc bracketed spans should be suppressed under Pandoc,
    /// but regular emphasis-with-spaces outside bracketed spans must still be flagged.
    #[test]
    fn test_pandoc_bracketed_span_guard() {
        use crate::config::MarkdownFlavor;
        let rule = MD037NoSpaceInEmphasis;
        // Emphasis-like pattern inside a bracketed span (Pandoc construct)
        let content = "See [* important *]{.highlight} for details.\n";
        let ctx = LintContext::new(content, MarkdownFlavor::Pandoc, None);
        let result = rule.check(&ctx).unwrap();
        assert!(
            result.is_empty(),
            "MD037 should not flag emphasis-like patterns inside Pandoc bracketed spans: {result:?}"
        );

        // Outside Pandoc flavor, the same text should still be flagged
        let ctx_std = LintContext::new(content, MarkdownFlavor::Standard, None);
        let result_std = rule.check(&ctx_std).unwrap();
        assert!(
            !result_std.is_empty(),
            "MD037 should still flag spaces in emphasis under Standard flavor: {result_std:?}"
        );
    }

    #[test]
    fn test_spaced_bold_metadata_pattern_detected() {
        let rule = MD037NoSpaceInEmphasis;

        // Broken bold metadata — leading space after opening **
        let content = "# Test\n\n** Explicit Import**: Convert markdownlint configs to rumdl format:";
        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard, None);
        let result = rule.check(&ctx).unwrap();
        assert_eq!(
            result.len(),
            1,
            "Should flag '** Explicit Import**' as spaced emphasis. Got: {result:?}"
        );
        assert_eq!(result[0].line, 3);

        // Trailing space before closing **
        let content2 = "# Test\n\n**trailing only **: some text";
        let ctx2 = LintContext::new(content2, crate::config::MarkdownFlavor::Standard, None);
        let result2 = rule.check(&ctx2).unwrap();
        assert_eq!(
            result2.len(),
            1,
            "Should flag '**trailing only **' as spaced emphasis. Got: {result2:?}"
        );

        // Both leading and trailing spaces with colon
        let content3 = "# Test\n\n** both spaces **: some text";
        let ctx3 = LintContext::new(content3, crate::config::MarkdownFlavor::Standard, None);
        let result3 = rule.check(&ctx3).unwrap();
        assert_eq!(
            result3.len(),
            1,
            "Should flag '** both spaces **' as spaced emphasis. Got: {result3:?}"
        );

        // Valid bold metadata — should NOT be flagged
        let content4 = "# Test\n\n**Key**: value";
        let ctx4 = LintContext::new(content4, crate::config::MarkdownFlavor::Standard, None);
        let result4 = rule.check(&ctx4).unwrap();
        assert!(
            result4.is_empty(),
            "Should not flag valid bold metadata '**Key**: value'. Got: {result4:?}"
        );
    }
}

#[cfg(test)]
mod mdx_adjacent_prose_tests {
    use super::*;
    #[test]
    fn md037_mdx_code_does_not_hide_adjacent_prose() {
        let rule = MD037NoSpaceInEmphasis;
        for code in [
            "{value}",
            "{/* * literal * */}",
            "{\"* literal *\"}",
            "<Card onClick={() => null} title='* literal *'>text</Card>",
        ] {
            for ending in ["\n", "\r\n"] {
                let source = format!("内容 Before {code} after * visible *{ending}");
                let ctx = crate::lint_context::LintContext::new(&source, crate::config::MarkdownFlavor::MDX, None);
                assert_eq!(rule.check(&ctx).unwrap().len(), 1, "{source}");
                assert_eq!(rule.fix(&ctx).unwrap(), source);
            }
        }
    }
    #[test]
    fn md037_mdx_code_cannot_supply_the_other_emphasis_marker() {
        let rule = MD037NoSpaceInEmphasis;
        for source in ["Before * text {\"*\"} after\n", "Before * text {/* * */} after\n"] {
            let ctx = crate::lint_context::LintContext::new(source, crate::config::MarkdownFlavor::MDX, None);
            assert!(rule.check(&ctx).unwrap().is_empty(), "{source}");
            assert_eq!(rule.fix(&ctx).unwrap(), source);
        }
    }
}