feat(linter): eslint-plugin-unicorn - no-empty-file (#1052)

crates/oxc_linter/src/rules.rs

@@ -142,6 +142,7 @@ mod unicorn {
     pub mod error_message;
     pub mod filename_case;
     pub mod no_console_spaces;
+    pub mod no_empty_file;
     pub mod no_instanceof_array;
     pub mod no_thenable;
     pub mod no_unnecessary_await;
@@ -253,6 +254,7 @@ oxc_macros::declare_all_lint_rules! {
     unicorn::error_message,
     unicorn::filename_case,
     unicorn::no_console_spaces,
+    unicorn::no_empty_file,
     unicorn::no_instanceof_array,
     unicorn::no_unnecessary_await,
     unicorn::no_thenable,

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

@@ -0,0 +1,144 @@
+use oxc_ast::{ast::Statement, 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};
+
+#[derive(Debug, Error, Diagnostic)]
+#[error("eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.")]
+#[diagnostic(severity(warning), help("Delete this file or add some code to it."))]
+struct NoEmptyFileDiagnostic(#[label] pub Span);
+
+#[derive(Debug, Default, Clone)]
+pub struct NoEmptyFile;
+
+declare_oxc_lint!(
+    /// ### What it does
+    ///
+    ///
+    /// Disallows any files only containing the following:
+    ///  - Whitespace
+    ///  - Comments
+    ///  - Directives
+    ///  - Empty statements
+    ///  - Empty blocks
+    ///  - Hashbang
+    ///
+    /// ### Why is this bad?
+    ///
+    /// Meaningless files clutter a codebase.
+    ///
+    NoEmptyFile,
+    correctness,
+);
+
+impl Rule for NoEmptyFile {
+    fn run_once(&self, ctx: &LintContext) {
+        let Some(root) = ctx.nodes().iter().next() else { return };
+        let AstKind::Program(program) = root.kind() else { return };
+
+        if program.body.iter().any(|node| !is_empty_stmt(node)) {
+            return;
+        }
+
+        if has_triple_slash_directive(ctx) {
+            return;
+        }
+
+        ctx.diagnostic(NoEmptyFileDiagnostic(program.span));
+    }
+}
+
+fn is_empty_stmt(stmt: &Statement) -> bool {
+    match stmt {
+        Statement::BlockStatement(block_stmt) => {
+            if block_stmt.body.is_empty() || block_stmt.body.iter().all(|node| is_empty_stmt(node))
+            {
+                return true;
+            }
+            false
+        }
+        Statement::EmptyStatement(_) => true,
+        _ => false,
+    }
+}
+
+fn has_triple_slash_directive(ctx: &LintContext<'_>) -> bool {
+    for (start, comment) in ctx.semantic().trivias().comments() {
+        if !comment.is_single_line() {
+            continue;
+        }
+        let span = Span::new(*start, comment.end());
+
+        let text = span.source_text(ctx.source_text());
+
+        if text.starts_with("///") {
+            return true;
+        }
+    }
+
+    false
+}
+
+#[test]
+fn test() {
+    use crate::tester::Tester;
+
+    let pass = vec![
+        r#"const x = 0;"#,
+        r#";; const x = 0;"#,
+        r#"{{{;;const x = 0;}}}"#,
+        r#"
+            'use strict';
+            const x = 0;
+        "#,
+        ";;'use strict';",
+        "{'use strict';}",
+        r#"("use strict")"#,
+        r#"`use strict`"#,
+        r#"({})"#,
+        r#"#!/usr/bin/env node
+            console.log('done');
+        "#,
+        r#"false"#,
+        r#"("")"#,
+        r#"NaN"#,
+        r#"undefined"#,
+        r#"null"#,
+        r#"[]"#,
+        r#"(() => {})()"#,
+        "(() => {})();",
+    ];
+
+    let fail = vec![
+        r#""#,
+        r#" "#,
+        "\t",
+        "\n",
+        "\r",
+        "\r\n",
+        r#"
+
+        "#,
+        r#"// comment"#,
+        r#"/* comment */"#,
+        r#"#!/usr/bin/env node"#,
+        "'use asm';",
+        "'use strict';",
+        r#""use strict""#,
+        r#""""#,
+        r#";"#,
+        r#";;"#,
+        r#"{}"#,
+        r#"{;;}"#,
+        r#"{{}}"#,
+        r#""";"#,
+        r#""use strict";"#,
+    ];
+
+    Tester::new_without_config(NoEmptyFile::NAME, pass, fail).test_and_snapshot();
+}

crates/oxc_linter/src/snapshots/no_empty_file.snap

@@ -0,0 +1,151 @@
+---
+source: crates/oxc_linter/src/tester.rs
+expression: no_empty_file
+---
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │  
+   · ─
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │     
+   · ────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ 
+   · ─
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 0 │ 
+   · ─
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ 
+   · ─
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ ╭─▶ 
+ 2 │ │   
+ 3 │ ╰─▶         
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ // comment
+   · ──────────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ /* comment */
+   · ─────────────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ #!/usr/bin/env node
+   · ───────────────────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ 'use asm';
+   · ──────────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ 'use strict';
+   · ─────────────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ "use strict"
+   · ────────────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ ""
+   · ──
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ ;
+   · ─
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ ;;
+   · ──
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ {}
+   · ──
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ {;;}
+   · ────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ {{}}
+   · ────
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ "";
+   · ───
+   ╰────
+  help: Delete this file or add some code to it.
+
+  ⚠ eslint-plugin-unicorn(no-empty-file): Empty files are not allowed.
+   ╭─[no_empty_file.tsx:1:1]
+ 1 │ "use strict";
+   · ─────────────
+   ╰────
+  help: Delete this file or add some code to it.
+
+