From d90f606fd55685bca4763f3bbbde1e6e2f9b3d8f Mon Sep 17 00:00:00 2001
From: bing <bingcicle@proton.me>
Date: Tue, 14 Mar 2023 21:01:59 +0000
Subject: [PATCH] fix(fmt): do not add extra spaces in empty parameter list
 when formatting (#4269)

## Description

Closes #4250

Moves the indent/unindent logic within the `LineStyle::Multiline` match
branch, and add an additional check for empty args before trying to
indent/unindent.

## Checklist

- [ ] I have linked to any relevant issues.
- [ ] I have commented my code, particularly in hard-to-understand
areas.
- [ ] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] I have added tests that prove my fix is effective or that my
feature works.
- [ ] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [ ] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [ ] I have requested a review from the relevant team or maintainers.

---------

Co-authored-by: Mohammad Fawaz <mohammadfawaz89@gmail.com>
---
 swayfmt/src/items/item_fn/mod.rs     | 49 ++++++++++++----------------
 swayfmt/src/items/item_impl/tests.rs | 16 +++++++++
 2 files changed, 36 insertions(+), 29 deletions(-)

diff --git a/swayfmt/src/items/item_fn/mod.rs b/swayfmt/src/items/item_fn/mod.rs
index 3f8859da2d5..0c69453bd39 100644
--- a/swayfmt/src/items/item_fn/mod.rs
+++ b/swayfmt/src/items/item_fn/mod.rs
@@ -201,9 +201,21 @@ fn format_fn_args(
     formatter: &mut Formatter,
 ) -> Result<(), FormatterError> {
     match fn_args {
-        FnArgs::Static(args) => {
-            args.format(formatted_code, formatter)?;
-        }
+        FnArgs::Static(args) => match formatter.shape.code_line.line_style {
+            LineStyle::Multiline => {
+                if !args.value_separator_pairs.is_empty() || args.final_value_opt.is_some() {
+                    formatter.shape.block_indent(&formatter.config);
+                    args.format(formatted_code, formatter)?;
+                    formatter.shape.block_unindent(&formatter.config);
+                    write!(
+                        formatted_code,
+                        "{}",
+                        formatter.shape.indent.to_string(&formatter.config)?
+                    )?;
+                }
+            }
+            _ => args.format(formatted_code, formatter)?,
+        },
         FnArgs::NonStatic {
             self_token,
             ref_self,
@@ -212,6 +224,7 @@ fn format_fn_args(
         } => {
             match formatter.shape.code_line.line_style {
                 LineStyle::Multiline => {
+                    formatter.shape.block_indent(&formatter.config);
                     write!(
                         formatted_code,
                         "\n{}",
@@ -266,39 +279,17 @@ fn format_self(
 impl Parenthesis for FnSignature {
     fn open_parenthesis(
         line: &mut FormattedCode,
-        formatter: &mut Formatter,
+        _formatter: &mut Formatter,
     ) -> Result<(), FormatterError> {
-        let open_paren = Delimiter::Parenthesis.as_open_char();
-        match formatter.shape.code_line.line_style {
-            LineStyle::Multiline => {
-                formatter.shape.block_indent(&formatter.config);
-                write!(line, "{open_paren}")?;
-            }
-            _ => {
-                write!(line, "{open_paren}")?;
-            }
-        }
+        write!(line, "{}", Delimiter::Parenthesis.as_open_char())?;
 
         Ok(())
     }
     fn close_parenthesis(
         line: &mut FormattedCode,
-        formatter: &mut Formatter,
+        _formatter: &mut Formatter,
     ) -> Result<(), FormatterError> {
-        let close_paren = Delimiter::Parenthesis.as_close_char();
-        match formatter.shape.code_line.line_style {
-            LineStyle::Multiline => {
-                formatter.shape.block_unindent(&formatter.config);
-                write!(
-                    line,
-                    "{}{close_paren}",
-                    formatter.shape.indent.to_string(&formatter.config)?
-                )?;
-            }
-            _ => {
-                write!(line, "{close_paren}")?;
-            }
-        }
+        write!(line, "{}", Delimiter::Parenthesis.as_close_char())?;
 
         Ok(())
     }
diff --git a/swayfmt/src/items/item_impl/tests.rs b/swayfmt/src/items/item_impl/tests.rs
index 0d74ef527dd..4d71d5092b7 100644
--- a/swayfmt/src/items/item_impl/tests.rs
+++ b/swayfmt/src/items/item_impl/tests.rs
@@ -74,3 +74,19 @@ fmt_test_item!(  normal_with_generics
                 }
             }"
 );
+
+fmt_test_item!(    impl_empty_fn_args
+"impl TestContract for Contract {
+    fn return_configurables() -> (u8, bool, [u32; 3], str[4], StructWithGeneric<u8>, EnumWithGeneric<bool>) {
+        (U8, BOOL, ARRAY, STR_4, STRUCT, ENUM)
+    }
+}",
+            intermediate_whitespace
+            "impl TestContract for Contract {
+    fn return_configurables(    ) -> ( u8, bool, [u32; 3], str[4], StructWithGeneric<u8>, EnumWithGeneric<bool> 
+    ) {
+        ( U8, BOOL,  ARRAY, STR_4 , STRUCT, ENUM )
+    }
+}
+"
+);