From a94aac607cbae80984db04e9e4fd1439ef0003e4 Mon Sep 17 00:00:00 2001
From: Martin Fischer <martin@push-f.com>
Date: Fri, 16 Jun 2023 11:51:17 +0200
Subject: [PATCH 1/2] Refactor to make following commit pass single_match_else
 lint

---
 clippy_lints/src/lib.rs | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index b254c05d48b..cd1b63bdba2 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -497,24 +497,23 @@ pub(crate) struct LintInfo {
 
 pub fn explain(name: &str) {
     let target = format!("clippy::{}", name.to_ascii_uppercase());
-    match declared_lints::LINTS.iter().find(|info| info.lint.name == target) {
-        Some(info) => {
-            println!("{}", info.explanation);
-            // Check if the lint has configuration
-            let mdconf = get_configuration_metadata();
-            if let Some(config_vec_positions) = mdconf
-                .iter()
-                .find_all(|cconf| cconf.lints.contains(&info.lint.name_lower()[8..].to_owned()))
-            {
-                // If it has, print it
-                println!("### Configuration for {}:\n", info.lint.name_lower());
-                for position in config_vec_positions {
-                    let conf = &mdconf[position];
-                    println!("  - {}: {} (default: {})", conf.name, conf.doc, conf.default);
-                }
+    if let Some(info) = declared_lints::LINTS.iter().find(|info| info.lint.name == target) {
+        println!("{}", info.explanation);
+        // Check if the lint has configuration
+        let mdconf = get_configuration_metadata();
+        if let Some(config_vec_positions) = mdconf
+            .iter()
+            .find_all(|cconf| cconf.lints.contains(&info.lint.name_lower()[8..].to_owned()))
+        {
+            // If it has, print it
+            println!("### Configuration for {}:\n", info.lint.name_lower());
+            for position in config_vec_positions {
+                let conf = &mdconf[position];
+                println!("  - {}: {} (default: {})", conf.name, conf.doc, conf.default);
             }
-        },
-        None => println!("unknown lint: {name}"),
+        }
+    } else {
+        println!("unknown lint: {name}");
     }
 }
 

From 894d5dafac8cb087a353047f33b4330c2a78cf2d Mon Sep 17 00:00:00 2001
From: Martin Fischer <martin@push-f.com>
Date: Fri, 16 Jun 2023 11:11:20 +0200
Subject: [PATCH 2/2] Make `--explain` subcommand return 1 for missing lints

---
 clippy_lints/src/lib.rs | 4 +++-
 src/main.rs             | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index cd1b63bdba2..f0a873b91eb 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -495,7 +495,7 @@ pub(crate) struct LintInfo {
     explanation: &'static str,
 }
 
-pub fn explain(name: &str) {
+pub fn explain(name: &str) -> i32 {
     let target = format!("clippy::{}", name.to_ascii_uppercase());
     if let Some(info) = declared_lints::LINTS.iter().find(|info| info.lint.name == target) {
         println!("{}", info.explanation);
@@ -512,8 +512,10 @@ pub fn explain(name: &str) {
                 println!("  - {}: {} (default: {})", conf.name, conf.doc, conf.default);
             }
         }
+        0
     } else {
         println!("unknown lint: {name}");
+        1
     }
 }
 
diff --git a/src/main.rs b/src/main.rs
index 188ff87abfc..300c84a1442 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -57,7 +57,9 @@ pub fn main() {
     if let Some(pos) = env::args().position(|a| a == "--explain") {
         if let Some(mut lint) = env::args().nth(pos + 1) {
             lint.make_ascii_lowercase();
-            clippy_lints::explain(&lint.strip_prefix("clippy::").unwrap_or(&lint).replace('-', "_"));
+            process::exit(clippy_lints::explain(
+                &lint.strip_prefix("clippy::").unwrap_or(&lint).replace('-', "_"),
+            ));
         } else {
             show_help();
         }