use std::fmt::Write as FmtWrite;
use std::path::Path;
use std::process::Command;
use tree_sitter::{Node, Parser};
pub fn syntax_warning(path: &Path, content: &str) -> Option<String> {
let ext = path.extension().and_then(|ext| ext.to_str()).unwrap_or_default();
let file_name = path.file_name().and_then(|name| name.to_str()).unwrap_or_default();
match ext {
"json" => serde_json::from_str::<serde_json::Value>(content)
.err()
.map(|error| format!("Syntax warning: JSON parser reported: {error}")),
"toml" => toml::from_str::<toml::Value>(content)
.err()
.map(|error| format!("Syntax warning: TOML parser reported: {error}")),
"rs" => {
let language = tree_sitter_rust::LANGUAGE.into();
tree_sitter_warning(content, &language, "Rust")
}
"js" | "mjs" | "cjs" | "jsx" => {
let language = tree_sitter_javascript::LANGUAGE.into();
tree_sitter_warning(content, &language, "JavaScript")
}
"ts" => {
let language = tree_sitter_typescript::LANGUAGE_TYPESCRIPT.into();
tree_sitter_warning(content, &language, "TypeScript")
}
"tsx" => {
let language = tree_sitter_typescript::LANGUAGE_TSX.into();
tree_sitter_warning(content, &language, "TSX")
}
"sh" | "bash" | "zsh" => {
let language = tree_sitter_bash::LANGUAGE.into();
tree_sitter_warning(content, &language, "shell")
}
"go" => {
let language = tree_sitter_go::LANGUAGE.into();
tree_sitter_warning(content, &language, "Go")
}
"c" => {
let language = tree_sitter_c::LANGUAGE.into();
tree_sitter_warning(content, &language, "C")
}
"cpp" | "cc" | "cxx" | "hpp" | "hh" | "hxx" | "h" => {
let language = tree_sitter_cpp::LANGUAGE.into();
tree_sitter_warning(content, &language, "C++")
}
"java" => {
let language = tree_sitter_java::LANGUAGE.into();
tree_sitter_warning(content, &language, "Java")
}
"rb" => {
let language = tree_sitter_ruby::LANGUAGE.into();
tree_sitter_warning(content, &language, "Ruby")
}
"css" => {
let language = tree_sitter_css::LANGUAGE.into();
tree_sitter_warning(content, &language, "CSS")
}
"html" | "htm" => {
let language = tree_sitter_html::LANGUAGE.into();
tree_sitter_warning(content, &language, "HTML")
}
"php" => {
let language = tree_sitter_php::LANGUAGE_PHP.into();
tree_sitter_warning(content, &language, "PHP")
}
"cs" => {
let language = tree_sitter_c_sharp::LANGUAGE.into();
tree_sitter_warning(content, &language, "C#")
}
"lua" => {
let language = tree_sitter_lua::LANGUAGE.into();
tree_sitter_warning(content, &language, "Lua")
}
"py" | "pyi" => python_warning(path),
_ if matches!(file_name, "Dockerfile" | "Makefile") => None,
_ => None,
}
}
fn tree_sitter_warning(
content: &str,
language: &tree_sitter::Language,
language_name: &str,
) -> Option<String> {
let mut parser = Parser::new();
if let Err(error) = parser.set_language(language) {
return Some(format!("Syntax warning: failed to load {language_name} parser: {error}"));
}
let tree = parser.parse(content, None)?;
let root = tree.root_node();
if !root.has_error() {
return None;
}
let mut message =
format!("Syntax warning: tree-sitter reported {language_name} syntax errors.");
if let Some(row) = first_error_row(root) {
let _ = write!(message, "\n{}", error_context(content, row));
}
Some(message)
}
fn first_error_row(node: Node<'_>) -> Option<usize> {
if node.is_error() || node.is_missing() {
return Some(node.start_position().row);
}
if !node.has_error() {
return None;
}
let mut cursor = node.walk();
for child in node.children(&mut cursor) {
if let Some(row) = first_error_row(child) {
return Some(row);
}
}
None
}
fn error_context(content: &str, error_row: usize) -> String {
let lines: Vec<&str> = content.lines().collect();
if lines.is_empty() {
return String::new();
}
let start = error_row.saturating_sub(10);
let end = (error_row + 11).min(lines.len());
let mut out = String::from("<snippet>\n");
for (offset, line) in lines[start..end].iter().enumerate() {
let line_no = start + offset + 1;
let marker = if start + offset == error_row { '>' } else { ' ' };
let _ = writeln!(out, "{marker}{line_no} {line}");
}
out.push_str("</snippet>");
out
}
fn python_warning(path: &Path) -> Option<String> {
let python = if Command::new("python3").arg("--version").output().is_ok() {
"python3"
} else if Command::new("python").arg("--version").output().is_ok() {
"python"
} else {
return None;
};
let output = Command::new(python).args(["-m", "py_compile"]).arg(path).output().ok()?;
(!output.status.success()).then(|| {
let stderr = String::from_utf8_lossy(&output.stderr);
format!("Syntax warning: Python parser reported:\n{}", stderr.trim())
})
}
#[cfg(test)]
mod tests {
use super::syntax_warning;
use std::path::Path;
#[test]
fn reports_invalid_json() {
assert!(syntax_warning(Path::new("bad.json"), "{").is_some());
}
#[test]
fn accepts_valid_rust() {
assert!(syntax_warning(Path::new("lib.rs"), "fn main() {}\n").is_none());
}
#[test]
fn reports_invalid_bash() {
assert!(syntax_warning(Path::new("script.sh"), "if true; then\n").is_some());
}
#[test]
fn reports_invalid_zsh() {
assert!(syntax_warning(Path::new("script.zsh"), "if true; then\n").is_some());
}
#[test]
fn error_warning_includes_snippet() {
let warning = syntax_warning(Path::new("lib.rs"), "fn main() {\n").unwrap_or_default();
assert!(warning.contains("<snippet>"), "expected snippet, got: {warning}");
}
#[test]
fn checks_go() {
assert!(syntax_warning(Path::new("main.go"), "package main\nfunc main() {}\n").is_none());
assert!(syntax_warning(Path::new("main.go"), "package main\nfunc main( {\n").is_some());
}
#[test]
fn checks_php() {
assert!(syntax_warning(Path::new("a.php"), "<?php echo 1; ?>\n").is_none());
assert!(syntax_warning(Path::new("a.php"), "<?php echo (1; ?>\n").is_some());
}
}