feat(linter) eslint plugin unicorn: empty-brace-spaces (#1249)

New contributor here to an amazing project. I think I covered all the
cases where braces can be used.
Plugin: #684 

[Rule](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/empty-brace-spaces.md)

---------

Co-authored-by: Radu Baston <radu.baston@sectorlabs.ro>

crates/oxc_linter/src/rules.rs

@@ -143,6 +143,7 @@ mod react {
 
 mod unicorn {
     pub mod catch_error_name;
+    pub mod empty_brace_spaces;
     pub mod error_message;
     pub mod filename_case;
     pub mod new_for_builtins;
@@ -293,6 +294,7 @@ oxc_macros::declare_all_lint_rules! {
     jest::valid_expect,
     jest::valid_title,
     unicorn::catch_error_name,
+    unicorn::empty_brace_spaces,
     unicorn::error_message,
     unicorn::filename_case,
     unicorn::new_for_builtins,

crates/oxc_linter/src/rules/unicorn/empty_brace_spaces.rs

@@ -0,0 +1,137 @@
+use oxc_ast::AstKind;
+use oxc_diagnostics::{
+    miette::{self, Diagnostic},
+    thiserror::Error,
+};
+use oxc_macros::declare_oxc_lint;
+use oxc_span::Span;
+
+use crate::{context::LintContext, rule::Rule, AstNode, Fix};
+
+#[derive(Debug, Error, Diagnostic)]
+#[error("eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed")]
+#[diagnostic(severity(warning), help("There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code."))]
+struct EmptyBraceSpacesDiagnostic(#[label] pub Span);
+
+#[derive(Debug, Default, Clone)]
+pub struct EmptyBraceSpaces;
+
+declare_oxc_lint!(
+    /// ### What it does
+    /// Removes the extra spaces or new line characters inside a pair of braces that does not contain additional code.
+    ///
+    /// ### Why is this bad?
+    /// There should be no spaces inside a pair of braces as it affects the overall readability of the code.
+    ///
+    /// ### Example
+    /// ```javascript
+    /// const a = {  };
+    /// class A {
+    /// }
+    /// ```
+    EmptyBraceSpaces,
+    style
+);
+
+impl Rule for EmptyBraceSpaces {
+    fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
+        match node.kind() {
+            AstKind::StaticBlock(static_block) => {
+                let Span { start, end } = static_block.span;
+                if static_block.body.is_empty() && end - start > 9 {
+                    // length of "static {}"
+                    ctx.diagnostic_with_fix(EmptyBraceSpacesDiagnostic(static_block.span), || {
+                        Fix::new("static {}", static_block.span)
+                    });
+                }
+            }
+            AstKind::ObjectExpression(obj) => {
+                remove_empty_braces_spaces(ctx, obj.properties.is_empty(), obj.span);
+            }
+            AstKind::FunctionBody(fb) => {
+                remove_empty_braces_spaces(ctx, fb.is_empty(), fb.span);
+            }
+            AstKind::Class(class) => {
+                remove_empty_braces_spaces(ctx, class.body.body.is_empty(), class.body.span);
+            }
+            AstKind::BlockStatement(block_stmt) => {
+                remove_empty_braces_spaces(ctx, block_stmt.body.is_empty(), block_stmt.span);
+            }
+            AstKind::CatchClause(catch_clause) => {
+                remove_empty_braces_spaces(
+                    ctx,
+                    catch_clause.body.body.is_empty(),
+                    catch_clause.body.span,
+                );
+            }
+            _ => (),
+        };
+    }
+}
+
+fn remove_empty_braces_spaces(ctx: &LintContext, is_empty_body: bool, span: Span) {
+    let Span { start, end } = span;
+    if is_empty_body && end - start > 2 {
+        // length of "{}"
+        ctx.diagnostic_with_fix(EmptyBraceSpacesDiagnostic(span), || Fix::new("{}", span));
+    }
+}
+
+#[test]
+fn test() {
+    use crate::tester::Tester;
+
+    let pass = vec![
+        "class A {\nstatic {}\n}",
+        "function b() {}",
+        "class A {}",
+        "const x = () => {};",
+        "with (foo) {}",
+        "for(let i = 0; i < 3; i += 1) {}",
+        "\nif(true){}",
+        "try{}catch{}",
+        "try{\nconsole.log(\'test\');\n} catch {}",
+    ];
+
+    let fail = vec![
+        "try{console.log('Hello');}finally{ \n}",
+        "const a = {\n};",
+        "return {\n\n};",
+        "const x = () => {\n\n};",
+        "class A {\n}",
+        "function a(){ }",
+        "do { }while(true)",
+        "class A {\nstatic { }\n}",
+        "with (foo) {   }",
+        "for(let i = 0; i <3; i += 1) {\n  }",
+        "\nif (true) {\n}",
+        "\nif (true) {   }",
+        "try{  }catch{  }",
+        "try{\nconsole.log(\'test\');\n}catch{ }\n",
+    ];
+
+    let fix = vec![
+        ("const a = {\n};", "const a = {};", None),
+        ("return {\n\n};", "return {};", None),
+        ("const x = () => {\n\n};", "const x = () => {};", None),
+        ("class A {\n}", "class A {}", None),
+        ("function a(){ }", "function a(){}", None),
+        ("do { }while(true)", "do {}while(true)", None),
+        ("class A {\nstatic { }\n}", "class A {\nstatic {}\n}", None),
+        ("with (foo) {   }", "with (foo) {}", None),
+        ("\nif (true) {\n}", "\nif (true) {}", None),
+        ("\nif (true) {   }", "\nif (true) {}", None),
+        ("try{  }catch{  }", "try{}catch{}", None),
+        ("for(let i = 0; i <3; i += 1) {\n  }", "for(let i = 0; i <3; i += 1) {}", None),
+        ("try{console.log('Hello');}finally{ \n}", "try{console.log('Hello');}finally{}", None),
+        (
+            "try{\nconsole.log(\'test\');\n}catch{ }\n",
+            "try{\nconsole.log(\'test\');\n}catch{}\n",
+            None,
+        ),
+    ];
+
+    Tester::new_without_config(EmptyBraceSpaces::NAME, pass, fail)
+        .expect_fix(fix)
+        .test_and_snapshot();
+}

crates/oxc_linter/src/snapshots/empty_brace_spaces.snap

@@ -0,0 +1,117 @@
+---
+source: crates/oxc_linter/src/tester.rs
+expression: empty_brace_spaces
+---
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ ╭─▶ try{console.log('Hello');}finally{ 
+ 2 │ ╰─▶ }
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ ╭─▶ const a = {
+ 2 │ ╰─▶ };
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ ╭─▶ return {
+ 2 │ │   
+ 3 │ ╰─▶ };
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ ╭─▶ const x = () => {
+ 2 │ │   
+ 3 │ ╰─▶ };
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ ╭─▶ class A {
+ 2 │ ╰─▶ }
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ function a(){ }
+   ·             ───
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ do { }while(true)
+   ·    ───
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ class A {
+ 2 │ static { }
+   · ──────────
+ 3 │ }
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ with (foo) {   }
+   ·            ─────
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ ╭─▶ for(let i = 0; i <3; i += 1) {
+ 2 │ ╰─▶   }
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │     
+ 2 │ ╭─▶ if (true) {
+ 3 │ ╰─▶ }
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ 
+ 2 │ if (true) {   }
+   ·           ─────
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ try{  }catch{  }
+   ·    ────
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:1:1]
+ 1 │ try{  }catch{  }
+   ·             ────
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+  ⚠ eslint-plugin-unicorn(empty-brace-spaces): No spaces inside empty pair of braces allowed
+   ╭─[empty_brace_spaces.tsx:2:1]
+ 2 │ console.log('test');
+ 3 │ }catch{ }
+   ·       ───
+   ╰────
+  help: There should be no spaces or new lines inside a pair of empty braces as it affects the overall readability of the code.
+
+