use crate::rule::{Fix, LintError, LintResult, LintWarning, Rule};
use regex::Regex;
use lazy_static::lazy_static;
lazy_static! {
static ref CLOSED_ATX_MULTIPLE_SPACE_PATTERN: Regex = Regex::new(r"^(\s*)(#+)(\s+)(.*?)(\s+)(#+)\s*$").unwrap();
static ref CODE_BLOCK_PATTERN: Regex = Regex::new(r"^(\s*)```").unwrap();
}
#[derive(Debug, Default)]
pub struct MD021NoMultipleSpaceClosedAtx;
impl MD021NoMultipleSpaceClosedAtx {
pub fn new() -> Self {
Self::default()
}
fn is_closed_atx_heading_with_multiple_spaces(&self, line: &str) -> bool {
if let Some(captures) = CLOSED_ATX_MULTIPLE_SPACE_PATTERN.captures(line) {
let start_spaces = captures.get(3).unwrap().as_str().len();
let end_spaces = captures.get(5).unwrap().as_str().len();
start_spaces > 1 || end_spaces > 1
} else {
false
}
}
fn fix_closed_atx_heading(&self, line: &str) -> String {
if let Some(captures) = CLOSED_ATX_MULTIPLE_SPACE_PATTERN.captures(line) {
let indentation = &captures[1];
let opening_hashes = &captures[2];
let content = &captures[4];
let closing_hashes = &captures[6];
format!("{}{} {} {}", indentation, opening_hashes, content.trim(), closing_hashes)
} else {
line.to_string()
}
}
fn count_spaces(&self, line: &str) -> (usize, usize) {
if let Some(captures) = CLOSED_ATX_MULTIPLE_SPACE_PATTERN.captures(line) {
let start_spaces = captures.get(3).unwrap().as_str().len();
let end_spaces = captures.get(5).unwrap().as_str().len();
(start_spaces, end_spaces)
} else {
(0, 0)
}
}
}
impl Rule for MD021NoMultipleSpaceClosedAtx {
fn name(&self) -> &'static str {
"MD021"
}
fn description(&self) -> &'static str {
"Multiple spaces inside hashes on closed ATX style heading"
}
fn check(&self, content: &str) -> LintResult {
let mut warnings = Vec::new();
let mut in_code_block = false;
for (line_num, line) in content.lines().enumerate() {
if CODE_BLOCK_PATTERN.is_match(line) {
in_code_block = !in_code_block;
continue;
}
if !in_code_block && self.is_closed_atx_heading_with_multiple_spaces(line) {
let captures = CLOSED_ATX_MULTIPLE_SPACE_PATTERN.captures(line).unwrap();
let indentation = captures.get(1).unwrap();
let opening_hashes = captures.get(2).unwrap();
let (start_spaces, end_spaces) = self.count_spaces(line);
let message = if start_spaces > 1 && end_spaces > 1 {
format!(
"Multiple spaces ({} at start, {} at end) inside hashes on closed ATX style heading with {} hashes",
start_spaces,
end_spaces,
opening_hashes.as_str().len()
)
} else if start_spaces > 1 {
format!(
"Multiple spaces ({}) after opening hashes on closed ATX style heading with {} hashes",
start_spaces,
opening_hashes.as_str().len()
)
} else {
format!(
"Multiple spaces ({}) before closing hashes on closed ATX style heading with {} hashes",
end_spaces,
opening_hashes.as_str().len()
)
};
warnings.push(LintWarning {
message,
line: line_num + 1,
column: indentation.end() + 1,
fix: Some(Fix {
line: line_num + 1,
column: 1,
replacement: self.fix_closed_atx_heading(line),
}),
});
}
}
Ok(warnings)
}
fn fix(&self, content: &str) -> Result<String, LintError> {
let mut result = String::new();
let mut in_code_block = false;
for line in content.lines() {
if CODE_BLOCK_PATTERN.is_match(line) {
in_code_block = !in_code_block;
result.push_str(line);
} else if !in_code_block && self.is_closed_atx_heading_with_multiple_spaces(line) {
result.push_str(&self.fix_closed_atx_heading(line));
} else {
result.push_str(line);
}
result.push('\n');
}
if !content.ends_with('\n') {
result.pop();
}
Ok(result)
}
}