From 4a383a0b0f1e2861a4d0884f40ae2c1d83ad156a Mon Sep 17 00:00:00 2001
From: Shoyu Vanilla <modulo641@gmail.com>
Date: Tue, 21 Oct 2025 00:40:12 +0900
Subject: [PATCH] fix: strip ANSI escape codes from flycheck messages

---
 Cargo.lock                           | 19 +++++++++++++++
 Cargo.toml                           |  1 +
 crates/rust-analyzer/Cargo.toml      |  1 +
 crates/rust-analyzer/src/flycheck.rs | 35 +++++++++++++++++++++-------
 4 files changed, 47 insertions(+), 9 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ea8d1a781dcc..4cbfb705322e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2048,6 +2048,7 @@ dependencies = [
  "serde_derive",
  "serde_json",
  "stdx",
+ "strip-ansi-escapes",
  "syntax",
  "syntax-bridge",
  "tenthash",
@@ -2379,6 +2380,15 @@ dependencies = [
  "windows-sys 0.60.2",
 ]
 
+[[package]]
+name = "strip-ansi-escapes"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a8f8038e7e7969abb3f1b7c2a811225e9296da208539e0f79c5251d6cac0025"
+dependencies = [
+ "vte",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.106"
@@ -2840,6 +2850,15 @@ dependencies = [
  "walkdir",
 ]
 
+[[package]]
+name = "vte"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "231fdcd7ef3037e8330d8e17e61011a2c244126acc0a982f4040ac3f9f0bc077"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "walkdir"
 version = "2.5.0"
diff --git a/Cargo.toml b/Cargo.toml
index 8a108974681a..336ae6a77501 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -144,6 +144,7 @@ semver = "1.0.26"
 serde = { version = "1.0.219" }
 serde_derive = { version = "1.0.219" }
 serde_json = "1.0.140"
+strip-ansi-escapes = "0.2.1"
 rustc-hash = "2.1.1"
 rustc-literal-escaper = "0.0.4"
 smallvec = { version = "1.15.1", features = [
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index c746f848b6a0..408f9d3a129e 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -53,6 +53,7 @@ semver.workspace = true
 memchr = "2.7.5"
 cargo_metadata.workspace = true
 process-wrap.workspace = true
+strip-ansi-escapes.workspace = true
 
 cfg.workspace = true
 hir-def.workspace = true
diff --git a/crates/rust-analyzer/src/flycheck.rs b/crates/rust-analyzer/src/flycheck.rs
index 73a51bba3d9a..5962beff1f29 100644
--- a/crates/rust-analyzer/src/flycheck.rs
+++ b/crates/rust-analyzer/src/flycheck.rs
@@ -421,11 +421,16 @@ impl FlycheckActor {
 
                     let formatted_command = format!("{command:?}");
 
+                    let strip_ansi_color_codes = !matches!(
+                        self.config,
+                        FlycheckConfig::CargoCommand { ansi_color_output: false, .. }
+                    );
+
                     tracing::debug!(?command, "will restart flycheck");
                     let (sender, receiver) = unbounded();
                     match CommandHandle::spawn(
                         command,
-                        CargoCheckParser,
+                        CargoCheckParser { strip_ansi_color_codes },
                         sender,
                         match &self.config {
                             FlycheckConfig::CargoCommand { options, .. } => Some(
@@ -655,11 +660,12 @@ impl FlycheckActor {
                     };
                 }
 
-                cmd.arg(if *ansi_color_output {
-                    "--message-format=json-diagnostic-rendered-ansi"
+                if *ansi_color_output {
+                    cmd.arg("--message-format=json-diagnostic-rendered-ansi");
                 } else {
-                    "--message-format=json"
-                });
+                    cmd.arg("--message-format=json");
+                    cmd.arg("--color=never");
+                }
 
                 if let Some(manifest_path) = &self.manifest_path {
                     cmd.arg("--manifest-path");
@@ -725,7 +731,9 @@ enum CargoCheckMessage {
     Diagnostic { diagnostic: Diagnostic, package_id: Option<Arc<PackageId>> },
 }
 
-struct CargoCheckParser;
+struct CargoCheckParser {
+    strip_ansi_color_codes: bool,
+}
 
 impl CargoParser<CargoCheckMessage> for CargoCheckParser {
     fn from_line(&self, line: &str, error: &mut String) -> Option<CargoCheckMessage> {
@@ -739,15 +747,24 @@ impl CargoParser<CargoCheckMessage> for CargoCheckParser {
                         Some(CargoCheckMessage::CompilerArtifact(artifact))
                     }
                     cargo_metadata::Message::CompilerMessage(msg) => {
+                        let mut diagnostic = msg.message;
+                        if self.strip_ansi_color_codes {
+                            diagnostic.rendered =
+                                diagnostic.rendered.map(strip_ansi_escapes::strip_str);
+                        }
                         Some(CargoCheckMessage::Diagnostic {
-                            diagnostic: msg.message,
+                            diagnostic,
                             package_id: Some(Arc::new(msg.package_id)),
                         })
                     }
                     _ => None,
                 },
-                JsonMessage::Rustc(message) => {
-                    Some(CargoCheckMessage::Diagnostic { diagnostic: message, package_id: None })
+                JsonMessage::Rustc(mut diagnostic) => {
+                    if self.strip_ansi_color_codes {
+                        diagnostic.rendered =
+                            diagnostic.rendered.map(strip_ansi_escapes::strip_str);
+                    }
+                    Some(CargoCheckMessage::Diagnostic { diagnostic, package_id: None })
                 }
             };
         }