feat(linter): eslint-plugin-unicorn switch-case-braces

crates/oxc_linter/src/rules.rs

@@ -145,6 +145,7 @@ mod unicorn {
     pub mod no_thenable;
     pub mod no_unnecessary_await;
     pub mod prefer_array_flat_map;
+    pub mod switch_case_braces;
     pub mod throw_new_error;
 }
 
@@ -253,10 +254,11 @@ oxc_macros::declare_all_lint_rules! {
     unicorn::filename_case,
     unicorn::no_console_spaces,
     unicorn::no_instanceof_array,
-    unicorn::no_unnecessary_await,
     unicorn::no_thenable,
-    unicorn::throw_new_error,
+    unicorn::no_unnecessary_await,
     unicorn::prefer_array_flat_map,
+    unicorn::switch_case_braces,
+    unicorn::throw_new_error,
     react::jsx_key,
     react::jsx_no_comment_text_nodes,
     react::jsx_no_duplicate_props,

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

@@ -0,0 +1,139 @@
+use oxc_ast::{ast::Statement, AstKind};
+use oxc_diagnostics::{
+    miette::{self, Diagnostic},
+    thiserror::Error,
+};
+use oxc_formatter::Gen;
+use oxc_macros::declare_oxc_lint;
+use oxc_span::Span;
+
+use crate::{context::LintContext, fixer::Fix, rule::Rule, AstNode};
+
+#[derive(Debug, Error, Diagnostic)]
+#[error("eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.")]
+#[diagnostic(
+    severity(warning),
+    help("There is less visual clutter for empty cases and proper scope for non-empty cases.")
+)]
+struct SwitchCaseBracesDiagnostic(#[label] pub Span);
+
+#[derive(Debug, Default, Clone)]
+pub struct SwitchCaseBraces;
+
+declare_oxc_lint!(
+    /// ### What it does
+    /// Require empty switch cases to not have braces. Non-empty braces are required to have braces around them.
+    ///
+    /// ### Why is this bad?
+    /// There is less visual clutter for empty cases and proper scope for non-empty cases.
+    ///
+    /// ### Example
+    /// ```javascript
+    /// switch (num) {
+    ///     case 1: {
+    ///
+    ///     }
+    ///     case 2:
+    ///         console.log('Case 2');
+    ///         break;
+    /// }
+    /// ```
+    SwitchCaseBraces,
+    correctness
+);
+
+impl Rule for SwitchCaseBraces {
+    fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
+        let AstKind::SwitchStatement(switch) = node.kind() else { return };
+
+        if switch.cases.is_empty() {
+            return;
+        }
+
+        for case in &switch.cases {
+            for case_body in &case.consequent {
+                match case_body {
+                    Statement::BlockStatement(case_block) => {
+                        if case_block.body.is_empty() {
+                            ctx.diagnostic_with_fix(
+                                SwitchCaseBracesDiagnostic(case_block.span),
+                                || Fix::new("", case_block.span),
+                            );
+                        }
+                    }
+                    Statement::EmptyStatement(_) => {}
+                    _ => {
+                        ctx.diagnostic_with_fix(SwitchCaseBracesDiagnostic(case.span), || {
+                            let modified_code = {
+                                let mut formatter = ctx.formatter();
+
+                                if let Some(case_test) = &case.test {
+                                    formatter.print_str(b"case ");
+                                    case_test.gen(&mut formatter);
+                                } else {
+                                    formatter.print_str(b"default")
+                                }
+
+                                formatter.print_colon();
+                                formatter.print_space();
+                                formatter.print(b'{');
+                                case.consequent.iter().for_each(|x| x.gen(&mut formatter));
+                                formatter.print(b'}');
+
+                                formatter.into_code()
+                            };
+
+                            Fix::new(modified_code, case.span)
+                        });
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[test]
+fn test() {
+    use crate::tester::Tester;
+
+    let pass = vec![
+        "switch(something) { case 1: case 2: {console.log('something'); break;}}",
+        "switch(foo){ case 1: { break; } }",
+        "switch(foo){ case 1: { ; /* <-- not empty */} }",
+        "switch(foo){ case 1: { {} /* <-- not empty */} }",
+        "switch(foo){ case 1: { break; } }",
+        "switch(foo){ default: { doSomething(); } }",
+    ];
+
+    let fail = vec![
+        "switch(something) { case 1: {} case 2: {console.log('something'); break;}}",
+        "switch(something) { case 1: case 2: console.log('something'); break;}",
+        "switch(foo) { case 1: {} case 2: {} default: { doSomething(); } }",
+        "switch(foo) { case 1: { /* fallthrough */ } default: {}/* fallthrough */ case 3: { doSomething(); break; } }",
+        "switch(foo) { default: doSomething(); }",
+        "switch(foo) { case 1: { doSomething(); } break; /* <-- This should be between braces */ }",
+        "switch(foo) { default: label: {} }",
+    ];
+
+    let fix = vec![
+        (
+            "switch(something) { case 1: {} case 2: {console.log('something'); break;}}",
+            "switch(something) { case 1:  case 2: {console.log('something'); break;}}",
+            None,
+        ),
+        (
+            "switch(something) { case 1: {} case 2: console.log('something'); break;}",
+            "switch(something) { case 1:  case 2: {console.log(\"something\");\nbreak;\n}}",
+            None,
+        ),
+        (
+            "switch(foo) { default: doSomething(); }",
+            "switch(foo) { default: {doSomething();\n} }",
+            None,
+        ),
+    ];
+
+    Tester::new_without_config(SwitchCaseBraces::NAME, pass, fail)
+        .expect_fix(fix)
+        .test_and_snapshot();
+}

crates/oxc_linter/src/snapshots/switch_case_braces.snap

@@ -0,0 +1,75 @@
+---
+source: crates/oxc_linter/src/tester.rs
+expression: switch_case_braces
+---
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(something) { case 1: {} case 2: {console.log('something'); break;}}
+   ·                             ──
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(something) { case 1: case 2: console.log('something'); break;}
+   ·                             ────────────────────────────────────────
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(something) { case 1: case 2: console.log('something'); break;}
+   ·                             ────────────────────────────────────────
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(foo) { case 1: {} case 2: {} default: { doSomething(); } }
+   ·                       ──
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(foo) { case 1: {} case 2: {} default: { doSomething(); } }
+   ·                                  ──
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(foo) { case 1: { /* fallthrough */ } default: {}/* fallthrough */ case 3: { doSomething(); break; } }
+   ·                       ─────────────────────
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(foo) { case 1: { /* fallthrough */ } default: {}/* fallthrough */ case 3: { doSomething(); break; } }
+   ·                                                      ──
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(foo) { default: doSomething(); }
+   ·               ───────────────────────
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(foo) { case 1: { doSomething(); } break; /* <-- This should be between braces */ }
+   ·               ─────────────────────────────────
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+  ⚠ eslint-plugin-unicorn(switch-case-braces):  Empty switch case shouldn't have braces and not-empty case should have braces around it.
+   ╭─[switch_case_braces.tsx:1:1]
+ 1 │ switch(foo) { default: label: {} }
+   ·               ──────────────────
+   ╰────
+  help: There is less visual clutter for empty cases and proper scope for non-empty cases.
+
+