From 9887582497cc07be6f5028ba82d63339188a2209 Mon Sep 17 00:00:00 2001
From: Casey Rodarmor <casey@rodarmor.com>
Date: Tue, 20 Dec 2022 20:57:58 -0800
Subject: [PATCH] Suppress --fmt --check diff if --quiet is passed (#1457)

---
 src/subcommand.rs | 32 +++++++++++++++++---------------
 tests/fmt.rs      |  8 ++++++++
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/src/subcommand.rs b/src/subcommand.rs
index 449f100976..be36912b56 100644
--- a/src/subcommand.rs
+++ b/src/subcommand.rs
@@ -374,21 +374,23 @@ impl Subcommand {
       return if formatted == src {
         Ok(())
       } else {
-        use similar::{ChangeTag, TextDiff};
-
-        let diff = TextDiff::configure()
-          .algorithm(similar::Algorithm::Patience)
-          .diff_lines(src, &formatted);
-
-        for op in diff.ops() {
-          for change in diff.iter_changes(op) {
-            let (symbol, color) = match change.tag() {
-              ChangeTag::Delete => ("-", config.color.stderr().diff_deleted()),
-              ChangeTag::Equal => (" ", config.color.stderr()),
-              ChangeTag::Insert => ("+", config.color.stderr().diff_added()),
-            };
-
-            eprint!("{}{symbol}{change}{}", color.prefix(), color.suffix());
+        if !config.verbosity.quiet() {
+          use similar::{ChangeTag, TextDiff};
+
+          let diff = TextDiff::configure()
+            .algorithm(similar::Algorithm::Patience)
+            .diff_lines(src, &formatted);
+
+          for op in diff.ops() {
+            for change in diff.iter_changes(op) {
+              let (symbol, color) = match change.tag() {
+                ChangeTag::Delete => ("-", config.color.stderr().diff_deleted()),
+                ChangeTag::Equal => (" ", config.color.stderr()),
+                ChangeTag::Insert => ("+", config.color.stderr().diff_added()),
+              };
+
+              eprint!("{}{symbol}{change}{}", color.prefix(), color.suffix());
+            }
           }
         }
 
diff --git a/tests/fmt.rs b/tests/fmt.rs
index 348cb27fab..3c972eda80 100644
--- a/tests/fmt.rs
+++ b/tests/fmt.rs
@@ -53,6 +53,14 @@ test! {
   status: EXIT_FAILURE,
 }
 
+test! {
+  name: check_found_diff_quiet,
+  justfile: "x:=``\n",
+  args: ("--unstable", "--fmt", "--check", "--quiet"),
+  stderr: "",
+  status: EXIT_FAILURE,
+}
+
 test! {
   name: check_diff_color,
   justfile: "x:=``\n",