Improve discoverability of dev commands (#621)

.cargo/config.toml

@@ -0,0 +1,2 @@
+[alias]
+dev = "run --package ruff_dev --bin ruff_dev"

CONTRIBUTING.md

@@ -58,8 +58,9 @@ pattern implemented therein.
 
 To trigger the rule, you'll likely want to augment the logic in `src/check_ast.rs`, which defines
 the Python AST visitor, responsible for iterating over the abstract syntax tree and collecting
-lint-rule violations as it goes. Grep for the `Check::new` invocations to understand how other,
-similar rules are implemented.
+lint-rule violations as it goes. If you need to inspect the AST, you can run `cargo dev print-ast`
+with a python file. Grep for the `Check::new` invocations to understand how other, similar rules
+are implemented.
 
 To add a test fixture, create a file under `resources/test/fixtures`, named to match the `CheckCode`
 you defined earlier (e.g., `E402.py`). This file should contain a variety of violations and

README.md

@@ -300,7 +300,7 @@ By default, Ruff enables all `E` and `F` error codes, which correspond to those
 
 The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` command-line option.
 
-<!-- Sections automatically generated by examples/generate_rules_table.rs. -->
+<!-- Sections automatically generated by `cargo dev generate-rules-table`. -->
 <!-- Begin auto-generated sections. -->
 
 ### Pyflakes

ruff_dev/src/generate_rules_table.rs

@@ -3,13 +3,13 @@
 use std::fs;
 use std::fs::OpenOptions;
 use std::io::Write;
+use std::path::PathBuf;
 
 use anyhow::Result;
 use clap::Args;
 use ruff::checks::{CheckCategory, CheckCode};
 use strum::IntoEnumIterator;
 
-const FILE: &str = "../README.md";
 const BEGIN_PRAGMA: &str = "<!-- Begin auto-generated sections. -->";
 const END_PRAGMA: &str = "<!-- End auto-generated sections. -->";
 
@@ -64,7 +64,11 @@ pub fn main(cli: &Cli) -> Result<()> {
         print!("{}", output);
     } else {
         // Read the existing file.
-        let existing = fs::read_to_string(FILE)?;
+        let file = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+            .parent()
+            .expect("Failed to find root directory")
+            .join("README.md");
+        let existing = fs::read_to_string(&file)?;
 
         // Extract the prefix.
         let index = existing
@@ -79,7 +83,7 @@ pub fn main(cli: &Cli) -> Result<()> {
         let suffix = &existing[index..];
 
         // Write the prefix, new contents, and suffix.
-        let mut f = OpenOptions::new().write(true).truncate(true).open(FILE)?;
+        let mut f = OpenOptions::new().write(true).truncate(true).open(&file)?;
         write!(f, "{}\n\n", prefix)?;
         write!(f, "{}", output)?;
         write!(f, "{}", suffix)?;