--show-settings displays active settings in a far more readable format

crates/ruff_cli/src/commands/show_settings.rs

@@ -35,7 +35,7 @@ pub(crate) fn show_settings(
     if let Some(settings_path) = pyproject_config.path.as_ref() {
         writeln!(writer, "Settings path: {settings_path:?}")?;
     }
-    writeln!(writer, "{settings:#?}")?;
+    writeln!(writer, "{settings}")?;
 
     Ok(())
 }

crates/ruff_formatter/src/lib.rs

@@ -35,6 +35,7 @@ mod source_code;
 use crate::formatter::Formatter;
 use crate::group_id::UniqueGroupIdBuilder;
 use crate::prelude::TagKind;
+use std::fmt;
 use std::fmt::{Debug, Display};
 use std::marker::PhantomData;
 use std::num::{NonZeroU16, NonZeroU8, TryFromIntError};
@@ -113,6 +114,12 @@ impl Default for IndentWidth {
     }
 }
 
+impl fmt::Display for IndentWidth {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        std::write!(f, "{}", self.0)
+    }
+}
+
 impl TryFrom<u8> for IndentWidth {
     type Error = TryFromIntError;
 
@@ -146,6 +153,12 @@ impl Default for LineWidth {
     }
 }
 
+impl Display for LineWidth {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        std::write!(f, "{}", self.0)
+    }
+}
+
 impl TryFrom<u16> for LineWidth {
     type Error = TryFromIntError;
 

crates/ruff_linter/src/line_width.rs

@@ -1,4 +1,5 @@
 use std::error::Error;
+use std::fmt;
 use std::hash::Hasher;
 use std::num::{NonZeroU16, NonZeroU8, ParseIntError};
 use std::str::FromStr;
@@ -39,6 +40,12 @@ impl Default for LineLength {
     }
 }
 
+impl fmt::Display for LineLength {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
 impl CacheKey for LineLength {
     fn cache_key(&self, state: &mut CacheKeyHasher) {
         state.write_u16(self.0.get());
@@ -248,6 +255,12 @@ impl Default for IndentWidth {
     }
 }
 
+impl fmt::Display for IndentWidth {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
 impl From<NonZeroU8> for IndentWidth {
     fn from(tab_size: NonZeroU8) -> Self {
         Self(tab_size)

crates/ruff_linter/src/registry/rule_set.rs

@@ -1,6 +1,7 @@
 use crate::registry::Rule;
+use itertools::Itertools;
 use ruff_macros::CacheKey;
-use std::fmt::{Debug, Formatter};
+use std::fmt::{Debug, Display, Formatter};
 use std::iter::FusedIterator;
 
 const RULESET_SIZE: usize = 13;
@@ -269,6 +270,22 @@ impl Debug for RuleSet {
     }
 }
 
+impl Display for RuleSet {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        if self.is_empty() {
+            write!(f, "[]")
+        } else {
+            write!(
+                f,
+                "[\n\t{}\n]",
+                self.iter()
+                    .map(|rule| format!("\"{rule:?}\""))
+                    .join(",\n\t")
+            )
+        }
+    }
+}
+
 impl FromIterator<Rule> for RuleSet {
     fn from_iter<T: IntoIterator<Item = Rule>>(iter: T) -> Self {
         let mut set = RuleSet::empty();

crates/ruff_linter/src/rules/flake8_annotations/settings.rs

@@ -1,6 +1,8 @@
 //! Settings for the `flake-annotations` plugin.
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
+use std::fmt::{Display, Formatter};
 
 #[derive(Debug, Default, CacheKey)]
 #[allow(clippy::struct_excessive_bools)]
@@ -11,3 +13,20 @@ pub struct Settings {
     pub allow_star_arg_any: bool,
     pub ignore_fully_untyped: bool,
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_annotations.",
+            fields = [
+                self.mypy_init_return,
+                self.suppress_dummy_args,
+                self.suppress_none_returning,
+                self.allow_star_arg_any,
+                self.ignore_fully_untyped
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_bandit/settings.rs

@@ -1,6 +1,8 @@
 //! Settings for the `flake8-bandit` plugin.
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
+use std::fmt::{Display, Formatter};
 
 pub fn default_tmp_dirs() -> Vec<String> {
     ["/tmp", "/var/tmp", "/dev/shm"]
@@ -22,3 +24,17 @@ impl Default for Settings {
         }
     }
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_bandit.",
+            fields = [
+                self.hardcoded_tmp_directory | debug,
+                self.check_typed_exception
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_bugbear/settings.rs

@@ -1,8 +1,23 @@
 //! Settings for the `flake8-bugbear` plugin.
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
+use std::fmt::{Display, Formatter};
 
 #[derive(Debug, Default, CacheKey)]
 pub struct Settings {
     pub extend_immutable_calls: Vec<String>,
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_bugbear.",
+            fields = [
+                self.extend_immutable_calls | debug
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_builtins/settings.rs

@@ -1,8 +1,23 @@
 //! Settings for the `flake8-builtins` plugin.
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
+use std::fmt::{Display, Formatter};
 
 #[derive(Debug, Default, CacheKey)]
 pub struct Settings {
     pub builtins_ignorelist: Vec<String>,
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_builtins.",
+            fields = [
+                self.builtins_ignorelist | debug
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_comprehensions/settings.rs

@@ -1,8 +1,23 @@
 //! Settings for the `flake8-comprehensions` plugin.
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
+use std::fmt::{Display, Formatter};
 
 #[derive(Debug, Default, CacheKey)]
 pub struct Settings {
     pub allow_dict_calls_with_keyword_arguments: bool,
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_comprehensions.",
+            fields = [
+                self.allow_dict_calls_with_keyword_arguments
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_copyright/settings.rs

@@ -2,7 +2,9 @@
 
 use once_cell::sync::Lazy;
 use regex::Regex;
+use std::fmt::{Display, Formatter};
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
 
 #[derive(Debug, CacheKey)]
@@ -24,3 +26,19 @@ impl Default for Settings {
         }
     }
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_copyright",
+            fields = [
+                self.notice_rgx,
+                // TODO(jane): remove debug
+                self.author | debug,
+                self.min_file_size,
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_errmsg/settings.rs

@@ -1,8 +1,23 @@
 //! Settings for the `flake8-errmsg` plugin.
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
+use std::fmt::{Display, Formatter};
 
 #[derive(Debug, Default, CacheKey)]
 pub struct Settings {
     pub max_string_length: usize,
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_errmsg.",
+            fields = [
+                self.max_string_length
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_gettext/settings.rs

@@ -1,4 +1,6 @@
+use crate::display_settings;
 use ruff_macros::CacheKey;
+use std::fmt::{Display, Formatter};
 
 #[derive(Debug, CacheKey)]
 pub struct Settings {
@@ -20,3 +22,16 @@ impl Default for Settings {
         }
     }
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_gettext.",
+            fields = [
+                self.functions_names | debug
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_implicit_str_concat/settings.rs

@@ -1,6 +1,8 @@
 //! Settings for the `flake8-implicit-str-concat` plugin.
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
+use std::fmt::{Display, Formatter};
 
 #[derive(Debug, CacheKey)]
 pub struct Settings {
@@ -14,3 +16,16 @@ impl Default for Settings {
         }
     }
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_implicit_str_concat.",
+            fields = [
+                self.allow_multiline
+            ]
+        }
+        Ok(())
+    }
+}

crates/ruff_linter/src/rules/flake8_import_conventions/settings.rs

@@ -1,7 +1,9 @@
 //! Settings for import conventions.
 
 use rustc_hash::{FxHashMap, FxHashSet};
+use std::fmt::{Display, Formatter};
 
+use crate::display_settings;
 use ruff_macros::CacheKey;
 
 const CONVENTIONAL_ALIASES: &[(&str, &str)] = &[
@@ -44,3 +46,18 @@ impl Default for Settings {
         }
     }
 }
+
+impl Display for Settings {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        display_settings! {
+            formatter = f,
+            namespace = "linter.flake8_import_conventions",
+            fields = [
+                self.aliases | debug,
+                self.banned_aliases | debug,
+                self.banned_from | debug,
+            ]
+        }
+        Ok(())
+    }
+}