feat: explain command

Cargo.toml

@@ -20,5 +20,5 @@ nonempty = "0.9.0"
 pest = { version = "2.7.5", features = ["pretty-print"] }
 tracing = "0.1.40"
 tracing-subscriber = "0.3.18"
-wdl = { version = "0.2.0", features = ["ast", "core", "grammar"] }
+wdl = { version = "0.3.0", features = ["ast", "core", "grammar"] }
 walkdir = "2.4.0"

src/commands.rs

@@ -1 +1,2 @@
+pub mod explain;
 pub mod lint;

src/commands/explain.rs

@@ -0,0 +1,45 @@
+use clap::Parser;
+use wdl::ast::v1::lint as ast_lint;
+use wdl::grammar::v1::lint as grammar_lint;
+
+/// Arguments for the `explain` subcommand.
+#[derive(Parser, Debug)]
+#[command(author, version, about)]
+pub struct Args {
+    /// The rule name to explain.
+    #[arg(required = true)]
+    pub rule_name: String,
+}
+
+pub fn explain(args: Args) -> anyhow::Result<()> {
+    let name = args.rule_name;
+
+    let rules = grammar_lint::rules()
+        .iter()
+        .map(|rule| rule.name())
+        .chain(ast_lint::rules().iter().map(|rule| rule.name()))
+        .collect::<Vec<String>>();
+
+    if !rules.contains(&name) {
+        return Err(anyhow::anyhow!("Unknown rule: {}", name));
+    }
+
+    let rule = grammar_lint::rules()
+        .into_iter()
+        .find(|rule| rule.name() == name);
+
+    match rule {
+        Some(rule) => {
+            println!("{}", rule.body());
+        }
+        None => {
+            let rule = ast_lint::rules()
+                .into_iter()
+                .find(|rule| rule.name() == name)
+                .unwrap();
+            println!("{}", rule.body());
+        }
+    }
+
+    Ok(())
+}

src/main.rs

@@ -14,6 +14,9 @@ git_testament!(TESTAMENT);
 enum Commands {
     /// Lints Workflow Description Language files.
     Lint(commands::lint::Args),
+
+    /// Explains a lint warning.
+    Explain(commands::explain::Args),
 }
 
 #[derive(Parser)]
@@ -51,6 +54,7 @@ pub fn inner() -> anyhow::Result<()> {
 
     match cli.command {
         Commands::Lint(args) => commands::lint::lint(args),
+        Commands::Explain(args) => commands::explain::explain(args),
     }
 }
 

src/report.rs

@@ -42,9 +42,9 @@ impl<'a> Reporter<'a> {
             Concern::LintWarning(warning) => {
                 let mut diagnostic = Diagnostic::warning()
                     .with_code(format!(
-                        "{}::{}/{:?}",
+                        "{}::{}::{:?}",
                         warning.code(),
-                        warning.group(),
+                        warning.tags(),
                         warning.level()
                     ))
                     .with_message(warning.subject());
@@ -56,7 +56,7 @@ impl<'a> Reporter<'a> {
                     let byte_range = location.byte_range().unwrap();
 
                     diagnostic = diagnostic.with_labels(vec![
-                        Label::primary(handle, byte_range).with_message(warning.body()),
+                        Label::primary(handle, byte_range).with_message(warning.subject()),
                     ]);
                 }