fix: some minor fixes

- Rename rule id's: QM... -> MD...
- Print linting violations in STDERR instead of STDOUT
- Return proper exit code

src/main.rs

@@ -1,8 +1,9 @@
 use anyhow::Context;
 use clap::Parser;
+use quickmark::linter::RuleViolationSeverity::Error;
 use quickmark::linter::{MultiRuleLinter, Settings};
-use std::{fs, path::PathBuf};
-
+use std::cmp::min;
+use std::{fs, path::PathBuf, process::exit};
 #[derive(Parser, Debug)]
 #[command(version, about = "Quickmark: An extremely fast CommonMark linter")]
 struct Cli {
@@ -17,17 +18,29 @@ fn main() -> anyhow::Result<()> {
     let file_content = fs::read_to_string(&file_path)
         .context(format!("Can't read file {}", &file_path.to_string_lossy()))?;
 
-    let rules = vec![quickmark::rules::qm001::QM001];
+    let rules = vec![quickmark::rules::md001::MD001];
 
     let context = quickmark::linter::Context {
         file_path: file_path.clone(),
         settings: Settings {},
     };
 
     let mut linter = MultiRuleLinter::new(&rules, context);
-    linter
+
+    let (warns, errs) = linter
         .lint(&file_content)
         .iter()
-        .for_each(|v| print!("{}", v));
-    Ok(())
+        .fold((0, 0), |(warns, errs), v| {
+            eprint!("{}", v);
+            match &v.severity {
+                Error => (warns, errs + 1),
+                _ => (warns + 1, errs),
+            }
+        });
+
+    println!("\n\nErrors: {}", errs);
+    println!("Warnings: {}", warns);
+
+    let exit_code = min(errs, 1);
+    exit(exit_code);
 }

src/rules/qm001.rs → src/rules/md001.rs

@@ -4,12 +4,12 @@ use crate::{
 };
 use comrak::nodes::{Ast, NodeHeading, NodeValue};
 
-pub(crate) struct QM001Linter {
+pub(crate) struct MD001Linter {
     context: Context,
     current_heading_level: u8,
 }
 
-impl QM001Linter {
+impl MD001Linter {
     pub fn new(context: Context) -> Self {
         Self {
             context,
@@ -18,13 +18,13 @@ impl QM001Linter {
     }
 }
 
-impl RuleLinter for QM001Linter {
+impl RuleLinter for MD001Linter {
     fn feed(&mut self, node: &Ast) -> Option<RuleViolation> {
         if let NodeValue::Heading(NodeHeading { level, setext: _ }) = node.value {
             if self.current_heading_level > 0 && level as i8 - self.current_heading_level as i8 > 1
             {
                 return Option::Some(RuleViolation::new(
-                    &QM001,
+                    &MD001,
                     RuleViolationSeverity::Error,
                     self.context.file_path.clone(),
                     &(node.sourcepos),
@@ -36,12 +36,12 @@ impl RuleLinter for QM001Linter {
     }
 }
 
-pub const QM001: Rule = Rule {
-    id: "QM001",
+pub const MD001: Rule = Rule {
+    id: "MD001",
     alias: "heading-increment",
     tags: &["headings"],
     description: "Heading levels should only increment by one level at a time",
-    new_linter: |context| Box::new(QM001Linter::new(context)),
+    new_linter: |context| Box::new(MD001Linter::new(context)),
 };
 
 #[cfg(test)]
@@ -54,7 +54,7 @@ mod test {
     use crate::rules::Context;
 
     use super::super::RuleLinter;
-    use super::QM001;
+    use super::MD001;
 
     fn lint_content(input: &str, linter: &mut Box<dyn RuleLinter>) -> Vec<RuleViolation> {
         parse_document(&Arena::new(), input, &Options::default())
@@ -83,7 +83,7 @@ foobar
 ### Heading level 3
 ";
 
-        let violations = lint_content(input, &mut (QM001.new_linter)(test_context()));
+        let violations = lint_content(input, &mut (MD001.new_linter)(test_context()));
         assert_eq!(2, violations.len());
         let mut iter = violations.iter();
         let range1 = &iter.next().unwrap().location.range;
@@ -113,7 +113,7 @@ foobar
 ###### Heading level 6
 ";
 
-        let violations = lint_content(input, &mut (QM001.new_linter)(test_context()));
+        let violations = lint_content(input, &mut (MD001.new_linter)(test_context()));
         assert_eq!(0, violations.len());
     }
 
@@ -131,7 +131,7 @@ foobar
 # level 1
 ";
 
-        let violations = lint_content(input, &mut (QM001.new_linter)(test_context()));
+        let violations = lint_content(input, &mut (MD001.new_linter)(test_context()));
         assert_eq!(0, violations.len());
     }
 }

src/rules/mod.rs

@@ -1,6 +1,6 @@
 use crate::linter::{Context, RuleLinter};
 
-pub mod qm001;
+pub mod md001;
 
 #[derive(Debug)]
 pub struct Rule {