diff --git a/crates/oxc_linter/src/rules.rs b/crates/oxc_linter/src/rules.rs index d8cbd9766..64393b75b 100644 --- a/crates/oxc_linter/src/rules.rs +++ b/crates/oxc_linter/src/rules.rs @@ -149,6 +149,7 @@ mod unicorn { pub mod no_invalid_remove_event_listener; pub mod no_new_array; pub mod no_object_as_default_parameter; + pub mod no_static_only_class; pub mod no_thenable; pub mod no_unnecessary_await; pub mod prefer_array_flat_map; @@ -278,6 +279,7 @@ oxc_macros::declare_all_lint_rules! { unicorn::no_invalid_remove_event_listener, unicorn::no_new_array, unicorn::no_object_as_default_parameter, + unicorn::no_static_only_class, unicorn::no_thenable, unicorn::no_unnecessary_await, unicorn::prefer_array_flat_map, diff --git a/crates/oxc_linter/src/rules/unicorn/no_static_only_class.rs b/crates/oxc_linter/src/rules/unicorn/no_static_only_class.rs new file mode 100644 index 000000000..2e4766f8b --- /dev/null +++ b/crates/oxc_linter/src/rules/unicorn/no_static_only_class.rs @@ -0,0 +1,156 @@ +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}; + +#[derive(Debug, Error, Diagnostic)] +#[error( + "eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members." +)] +#[diagnostic( + severity(warning), + help("A class with only static members could just be an object instead.") +)] +struct NoStaticOnlyClassDiagnostic(#[label] pub Span); + +#[derive(Debug, Default, Clone)] +pub struct NoStaticOnlyClass; + +declare_oxc_lint!( + /// ### What it does + /// + /// Disallow classes that only have static members. + /// + /// ### Why is this bad? + /// + /// A class with only static members could just be an object instead. + /// + /// + /// ### Example + /// ```javascript + /// // Bad + /// class A { + /// static a() {} + /// } + /// + /// // Good + /// class A { + /// static a() {} + /// + /// constructor() {} + /// } + /// ``` + NoStaticOnlyClass, + pedantic +); + +impl Rule for NoStaticOnlyClass { + fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) { + let AstKind::Class(class) = node.kind() else { return }; + + if class.super_class.is_some() { + return; + } + if class.decorators.len() > 0 { + return; + } + if class.body.body.len() == 0 { + return; + } + if class.body.body.iter().any(|node| { + match node { + oxc_ast::ast::ClassElement::MethodDefinition(v) => { + if v.accessibility.is_some() { + return true; + } + } + oxc_ast::ast::ClassElement::PropertyDefinition(v) => { + if v.accessibility.is_some() || v.readonly || v.declare { + return true; + } + } + oxc_ast::ast::ClassElement::TSAbstractMethodDefinition(v) => { + if v.method_definition.accessibility.is_some() { + return true; + } + } + oxc_ast::ast::ClassElement::TSAbstractPropertyDefinition(v) => { + if v.property_definition.accessibility.is_some() { + return true; + } + } + oxc_ast::ast::ClassElement::AccessorProperty(_) + | oxc_ast::ast::ClassElement::StaticBlock(_) + | oxc_ast::ast::ClassElement::TSIndexSignature(_) => {} + } + + if node.r#static() { + if let Some(k) = node.property_key() { + return k.is_private_identifier(); + } + return false; + } + true + }) { + return; + } + + ctx.diagnostic(NoStaticOnlyClassDiagnostic(class.span)); + } +} + +#[test] +fn test() { + use crate::tester::Tester; + + let pass = vec![ + r#"class A {}"#, + r#"const A = class {}"#, + r#"class A extends B { static a() {}; }"#, + r#"const A = class extends B { static a() {}; }"#, + r#"class A { a() {} }"#, + r#"class A { constructor() {} }"#, + r#"class A { get a() {} }"#, + r#"class A { set a(value) {} }"#, + r#"class A3 { static #a() {}; }"#, + r#"class A3 { static #a = 1; }"#, + r#"const A3 = class { static #a() {}; }"#, + r#"const A3 = class { static #a = 1; }"#, + r#"class A2 { static {}; }"#, + r#"class A { static #a() {}; }"#, + r#"class A { static #a = 1; }"#, + r#"const A = class { static #a() {}; }"#, + r#"const A = class { static #a = 1; }"#, + r#"@decorator class A { static a = 1; }"#, + r#"class A { static public a = 1; }"#, + r#"class A { static private a = 1; }"#, + r#"class A { static readonly a = 1; }"#, + r#"class A { static declare a = 1; }"#, + r#"class A { static {}; }"#, + r#"class A2 { static #a() {}; }"#, + r#"class A2 { static #a = 1; }"#, + r#"const A2 = class { static #a() {}; }"#, + r#"const A2 = class { static #a = 1; }"#, + r#"class A2 { static {}; }"#, + ]; + + let fail = vec![ + r#"class A { static a() {}; }"#, + r#"class A { static a() {} }"#, + r#"const A = class A { static a() {}; }"#, + r#"const A = class { static a() {}; }"#, + r#"class A { static constructor() {}; }"#, + r#"export default class A { static a() {}; }"#, + r#"export default class { static a() {}; }"#, + r#"export class A { static a() {}; }"#, + r#"class A {static [this.a] = 1}"#, + r#"class A { static a() {} }"#, + ]; + + Tester::new_without_config(NoStaticOnlyClass::NAME, pass, fail).test_and_snapshot(); +} diff --git a/crates/oxc_linter/src/snapshots/no_static_only_class.snap b/crates/oxc_linter/src/snapshots/no_static_only_class.snap new file mode 100644 index 000000000..6da771e99 --- /dev/null +++ b/crates/oxc_linter/src/snapshots/no_static_only_class.snap @@ -0,0 +1,75 @@ +--- +source: crates/oxc_linter/src/tester.rs +expression: no_static_only_class +--- + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ class A { static a() {}; } + · ────────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ class A { static a() {} } + · ───────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ const A = class A { static a() {}; } + · ────────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ const A = class { static a() {}; } + · ──────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ class A { static constructor() {}; } + · ──────────────────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ export default class A { static a() {}; } + · ────────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ export default class { static a() {}; } + · ──────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ export class A { static a() {}; } + · ────────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ class A {static [this.a] = 1} + · ───────────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + + ⚠ eslint-plugin-unicorn(no-static-only-class): Disallow classes that only have static members. + ╭─[no_static_only_class.tsx:1:1] + 1 │ class A { static a() {} } + · ───────────────────────── + ╰──── + help: A class with only static members could just be an object instead. + +