From 3c16c0aa5abc7f2b1d48b2dd4731bc547cc811c5 Mon Sep 17 00:00:00 2001
From: Yacin Tmimi <yacintmimi@gmail.com>
Date: Mon, 7 Nov 2022 17:52:21 -0500
Subject: [PATCH] only dump defaults for stable configs when running stable
 rustfmt

Previously running rustfmt with `--print-config default` would always
return a list of all config options and their default values.

Now, when running the command on stable rustfmt we only return the
default options for configs that have been marked as stable.
---
 src/bin/main.rs           |  7 ++++++-
 src/config/config_type.rs | 16 ++++++++++++++++
 src/config/mod.rs         | 36 +++++++++++++++++++++++++++++++++++-
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/src/bin/main.rs b/src/bin/main.rs
index be64559e877..ad1ef7a0a37 100644
--- a/src/bin/main.rs
+++ b/src/bin/main.rs
@@ -214,7 +214,12 @@ fn execute(opts: &Options) -> Result<i32> {
             Ok(0)
         }
         Operation::ConfigOutputDefault { path } => {
-            let toml = Config::default().all_options().to_toml()?;
+            let toml = if is_nightly() {
+                Config::default().all_options().to_toml()?
+            } else {
+                Config::default().stable_options().to_toml()?
+            };
+
             if let Some(path) = path {
                 let mut file = File::create(path)?;
                 file.write_all(toml.as_bytes())?;
diff --git a/src/config/config_type.rs b/src/config/config_type.rs
index 90a67e12c5a..102db70ec95 100644
--- a/src/config/config_type.rs
+++ b/src/config/config_type.rs
@@ -237,6 +237,22 @@ macro_rules! create_config {
                 }
             }
 
+
+            #[allow(unreachable_pub)]
+            pub fn stable_options(&self) -> PartialConfig {
+                PartialConfig {
+                    $(
+                        $i: if $stb {
+                                Some(self.$i.2.clone())
+                            } else {
+                                None
+                            },
+                    )+
+                }
+            }
+
+
+
             #[allow(unreachable_pub)]
             pub fn override_value(&mut self, key: &str, val: &str)
             {
diff --git a/src/config/mod.rs b/src/config/mod.rs
index 14f27f3f8b6..22b8cfd699b 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -603,8 +603,9 @@ mod test {
         assert_eq!(s.contains(PRINT_DOCS_PARTIALLY_UNSTABLE_OPTION), true);
     }
 
+    #[nightly_only_test]
     #[test]
-    fn test_dump_default_config() {
+    fn test_dump_all_default_config() {
         let default_config = format!(
             r#"max_width = 100
 hard_tabs = false
@@ -690,6 +691,39 @@ make_backup = false
         assert_eq!(&toml, &default_config);
     }
 
+    #[stable_only_test]
+    #[test]
+    fn test_dump_stable_default_config() {
+        let default_config = r#"max_width = 100
+hard_tabs = false
+tab_spaces = 4
+newline_style = "Auto"
+use_small_heuristics = "Default"
+fn_call_width = 60
+attr_fn_like_width = 70
+struct_lit_width = 18
+struct_variant_width = 35
+array_width = 60
+chain_width = 60
+single_line_if_else_max_width = 50
+reorder_imports = true
+reorder_modules = true
+remove_nested_parens = true
+short_array_element_width_threshold = 10
+match_arm_leading_pipes = "Never"
+fn_params_layout = "Tall"
+match_block_trailing_comma = false
+edition = "2015"
+merge_derives = true
+use_try_shorthand = false
+use_field_init_shorthand = false
+force_explicit_abi = true
+disable_all_formatting = false
+"#;
+        let toml = Config::default().stable_options().to_toml().unwrap();
+        assert_eq!(&toml, &default_config);
+    }
+
     #[stable_only_test]
     #[test]
     fn test_as_not_nightly_channel() {