From 434dc956a40b9d7659830a88dcf1e2eb0e193a71 Mon Sep 17 00:00:00 2001
From: Aditya Pillai <29032680+pilleye@users.noreply.github.com>
Date: Sat, 1 Jun 2024 19:49:11 -0700
Subject: [PATCH] fix displaying non-printable characters

---
 crates/ruff_linter/src/lib.rs          |  1 +
 crates/ruff_linter/src/message/diff.rs | 12 ++++++++++--
 crates/ruff_linter/src/message/text.rs |  5 ++++-
 crates/ruff_linter/src/source_kind.rs  | 21 ++++++++++++++++-----
 crates/ruff_linter/src/text_helpers.rs | 23 +++++++++++++++++++++++
 5 files changed, 54 insertions(+), 8 deletions(-)
 create mode 100644 crates/ruff_linter/src/text_helpers.rs

diff --git a/crates/ruff_linter/src/lib.rs b/crates/ruff_linter/src/lib.rs
index 7ce0bdd15a6117..e01601ed2581e4 100644
--- a/crates/ruff_linter/src/lib.rs
+++ b/crates/ruff_linter/src/lib.rs
@@ -39,6 +39,7 @@ pub mod rule_selector;
 pub mod rules;
 pub mod settings;
 pub mod source_kind;
+mod text_helpers;
 pub mod upstream_categories;
 
 #[cfg(any(test, fuzzing))]
diff --git a/crates/ruff_linter/src/message/diff.rs b/crates/ruff_linter/src/message/diff.rs
index 2ba3f24ee24df4..4c47677c28da5c 100644
--- a/crates/ruff_linter/src/message/diff.rs
+++ b/crates/ruff_linter/src/message/diff.rs
@@ -10,6 +10,7 @@ use ruff_diagnostics::{Applicability, Fix};
 use ruff_source_file::{OneIndexed, SourceFile};
 
 use crate::message::Message;
+use crate::text_helpers::ShowNonprinting;
 
 /// Renders a diff that shows the code fixes.
 ///
@@ -102,9 +103,16 @@ impl Display for Diff<'_> {
 
                     for (emphasized, value) in change.iter_strings_lossy() {
                         if emphasized {
-                            write!(f, "{}", line_style.apply_to(&value).underline().on_black())?;
+                            write!(
+                                f,
+                                "{}",
+                                line_style
+                                    .apply_to(&value.show_nonprinting())
+                                    .underline()
+                                    .on_black()
+                            )?;
                         } else {
-                            write!(f, "{}", line_style.apply_to(&value))?;
+                            write!(f, "{}", line_style.apply_to(&value.show_nonprinting()))?;
                         }
                     }
                     if change.missing_newline() {
diff --git a/crates/ruff_linter/src/message/text.rs b/crates/ruff_linter/src/message/text.rs
index 833deab46c8182..6e104e49af2a50 100644
--- a/crates/ruff_linter/src/message/text.rs
+++ b/crates/ruff_linter/src/message/text.rs
@@ -17,6 +17,7 @@ use crate::message::diff::Diff;
 use crate::message::{Emitter, EmitterContext, Message};
 use crate::registry::AsRule;
 use crate::settings::types::UnsafeFixes;
+use crate::text_helpers::ShowNonprinting;
 
 bitflags! {
     #[derive(Default)]
@@ -251,6 +252,8 @@ impl Display for MessageCodeFrame<'_> {
             range - start_offset,
         );
 
+        let source_text = source.text.show_nonprinting();
+
         let start_char = source.text[TextRange::up_to(source.annotation_range.start())]
             .chars()
             .count();
@@ -262,7 +265,7 @@ impl Display for MessageCodeFrame<'_> {
         let snippet = Snippet {
             title: None,
             slices: vec![Slice {
-                source: &source.text,
+                source: &source_text,
                 line_start: self.notebook_index.map_or_else(
                     || start_index.get(),
                     |notebook_index| {
diff --git a/crates/ruff_linter/src/source_kind.rs b/crates/ruff_linter/src/source_kind.rs
index da27457348a1b1..f3392864ff1bec 100644
--- a/crates/ruff_linter/src/source_kind.rs
+++ b/crates/ruff_linter/src/source_kind.rs
@@ -14,6 +14,7 @@ use ruff_python_ast::PySourceType;
 use colored::Colorize;
 
 use crate::fs;
+use crate::text_helpers::ShowNonprinting;
 
 #[derive(Clone, Debug, PartialEq, is_macro::Is)]
 pub enum SourceKind {
@@ -220,8 +221,8 @@ impl<'a> CodeDiff<'a> {
 impl std::fmt::Display for CodeDiff<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         if let Some((original, modified)) = self.header {
-            writeln!(f, "--- {}", original.red())?;
-            writeln!(f, "+++ {}", modified.green())?;
+            writeln!(f, "--- {}", original.show_nonprinting().red())?;
+            writeln!(f, "+++ {}", modified.show_nonprinting().green())?;
         }
 
         let mut unified = self.diff.unified_diff();
@@ -234,9 +235,19 @@ impl std::fmt::Display for CodeDiff<'_> {
             // individual lines
             for change in hunk.iter_changes() {
                 match change.tag() {
-                    ChangeTag::Equal => write!(f, " {}", change.value())?,
-                    ChangeTag::Delete => write!(f, "{}{}", "-".red(), change.value().red())?,
-                    ChangeTag::Insert => write!(f, "{}{}", "+".green(), change.value().green())?,
+                    ChangeTag::Equal => write!(f, " {}", change.value().show_nonprinting())?,
+                    ChangeTag::Delete => write!(
+                        f,
+                        "{}{}",
+                        "-".red(),
+                        change.value().show_nonprinting().red()
+                    )?,
+                    ChangeTag::Insert => write!(
+                        f,
+                        "{}{}",
+                        "+".green(),
+                        change.value().show_nonprinting().green()
+                    )?,
                 }
 
                 if !self.diff.newline_terminated() {
diff --git a/crates/ruff_linter/src/text_helpers.rs b/crates/ruff_linter/src/text_helpers.rs
new file mode 100644
index 00000000000000..422cf170b163c8
--- /dev/null
+++ b/crates/ruff_linter/src/text_helpers.rs
@@ -0,0 +1,23 @@
+use std::borrow::Cow;
+
+pub(crate) trait ShowNonprinting {
+    fn show_nonprinting(&self) -> Cow<'_, str>;
+}
+
+macro_rules! impl_show_nonprinting {
+    ($(($from:expr, $to:expr)),+) => {
+        impl ShowNonprinting for str {
+            fn show_nonprinting(&self) -> Cow<'_, str> {
+                if self.find(&[$($from),*][..]).is_some() {
+                    Cow::Owned(
+                        self.$(replace($from, $to)).*
+                    )
+                } else {
+                    Cow::Borrowed(self)
+                }
+            }
+        }
+    };
+}
+
+impl_show_nonprinting!(('\x07', "␇"), ('\x08', "␈"), ('\x1b', "␛"), ('\x7f', "␡"));