use a .toml file to list the crates we want to check

Also sort lint results alphabetically.

clippy_dev/Cargo.toml

@@ -11,8 +11,10 @@ flate2 = "1.0.19"
 itertools = "0.9"
 opener = "0.4"
 regex = "1"
+serde = {version = "1.0", features = ["derive"]}
 shell-escape = "0.1"
 tar = "0.4.30"
+toml = "0.5"
 ureq = "2.0.0-rc3"
 walkdir = "2"
 

clippy_dev/crater_crates.toml

@@ -0,0 +1,20 @@
+[crates]
+# some of these are from cargotest
+cargo = '0.49.0'
+iron = '0.6.1'
+ripgrep = '12.1.1'
+xsv = '0.13.0'
+#tokei = '12.0.4'
+rayon = '1.5.0'
+serde = '1.0.118'
+# top 10 crates.io dls
+bitflags = '1.2.1'
+libc = '0.2.81'
+log = '0.4.11'
+proc-macro2 = '1.0.24'
+quote = '1.0.7'
+rand = '0.7.3'
+rand_core = '0.6.0'
+regex = '1.3.2'
+syn = '1.0.54'
+unicode-xid = '0.2.1'

clippy_dev/src/crater.rs

@@ -1,16 +1,24 @@
 #![allow(clippy::filter_map)]
 
 use crate::clippy_project_root;
-use std::path::PathBuf;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
 use std::process::Command;
+use std::{fs::write, path::PathBuf};
 
 // represents an archive we download from crates.io
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize, Eq, Hash, PartialEq)]
 struct KrateSource {
     version: String,
     name: String,
 }
 
+// use this to store the crates when interacting with the crates.toml file
+#[derive(Debug, Serialize, Deserialize)]
+struct CrateList {
+    crates: HashMap<String, String>,
+}
+
 // represents the extracted sourcecode of a crate
 #[derive(Debug)]
 struct Krate {
@@ -129,33 +137,25 @@ fn build_clippy() {
         .expect("Failed to build clippy!");
 }
 
+// get a list of KrateSources we want to check from a "crater_crates.toml" file.
+fn read_crates() -> Vec<KrateSource> {
+    let toml_path = PathBuf::from("clippy_dev/crater_crates.toml");
+    let toml_content: String =
+        std::fs::read_to_string(&toml_path).unwrap_or_else(|_| panic!("Failed to read {}", toml_path.display()));
+    let crate_list: CrateList =
+        toml::from_str(&toml_content).unwrap_or_else(|e| panic!("Failed to parse {}: \n{}", toml_path.display(), e));
+    // parse the hashmap of the toml file into a list of crates
+    crate_list
+        .crates
+        .iter()
+        .map(|(name, version)| KrateSource::new(&name, &version))
+        .collect()
+}
+
 // the main fn
 pub fn run() {
     let cargo_clippy_path: PathBuf = PathBuf::from("target/debug/cargo-clippy");
 
-    // crates we want to check:
-    let krates: Vec<KrateSource> = vec![
-        // some of these are form cargotest
-        KrateSource::new("cargo", "0.49.0"),
-        KrateSource::new("iron", "0.6.1"),
-        KrateSource::new("ripgrep", "12.1.1"),
-        //KrateSource::new("tokei", "12.0.4"),
-        KrateSource::new("xsv", "0.13.0"),
-        KrateSource::new("serde", "1.0.118"),
-        KrateSource::new("rayon", "1.5.0"),
-        // top 10 crates.io dls
-        KrateSource::new("rand", "0.7.3"),
-        KrateSource::new("syn", "1.0.54"),
-        KrateSource::new("libc", "0.2.81"),
-        KrateSource::new("quote", "1.0.7"),
-        KrateSource::new("rand_core", "0.6.0"),
-        KrateSource::new("unicode-xid", "0.2.1"),
-        KrateSource::new("proc-macro2", "1.0.24"),
-        KrateSource::new("bitflags", "1.2.1"),
-        KrateSource::new("log", "0.4.11"),
-        KrateSource::new("regex", "1.4.2"),
-    ];
-
     println!("Compiling clippy...");
     build_clippy();
     println!("Done compiling");
@@ -168,15 +168,17 @@ pub fn run() {
     );
 
     // download and extract the crates, then run clippy on them and collect clippys warnings
-    let clippy_lint_results: Vec<Vec<String>> = krates
+
+    let clippy_lint_results: Vec<Vec<String>> = read_crates()
         .into_iter()
         .map(|krate| krate.download_and_extract())
         .map(|krate| krate.run_clippy_lints(&cargo_clippy_path))
         .collect();
 
-    let all_warnings: Vec<String> = clippy_lint_results.into_iter().flatten().collect();
+    let mut all_warnings: Vec<String> = clippy_lint_results.into_iter().flatten().collect();
+    all_warnings.sort();
 
     // save the text into mini-crater/logs.txt
     let text = all_warnings.join("");
-    std::fs::write("mini-crater/logs.txt", text).unwrap();
+    write("mini-crater/logs.txt", text).unwrap();
 }