feat(linter) eslint plugin unicorn: no new buffer (#1174)

crates/oxc_linter/src/rules.rs

@@ -149,6 +149,7 @@ mod unicorn {
     pub mod no_instanceof_array;
     pub mod no_invalid_remove_event_listener;
     pub mod no_new_array;
+    pub mod no_new_buffer;
     pub mod no_object_as_default_parameter;
     pub mod no_static_only_class;
     pub mod no_thenable;
@@ -282,6 +283,7 @@ oxc_macros::declare_all_lint_rules! {
     unicorn::no_instanceof_array,
     unicorn::no_invalid_remove_event_listener,
     unicorn::no_new_array,
+    unicorn::no_new_buffer,
     unicorn::no_object_as_default_parameter,
     unicorn::no_static_only_class,
     unicorn::no_thenable,

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

@@ -0,0 +1,88 @@
+use oxc_ast::{ast::Expression, 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-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.")]
+#[diagnostic(
+    severity(warning),
+    help("`new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.")
+)]
+struct NoNewBufferDiagnostic(#[label] pub Span);
+
+#[derive(Debug, Default, Clone)]
+pub struct NoNewBuffer;
+
+declare_oxc_lint!(
+    /// ### What it does
+    ///
+    /// Disallows the deprecated `new Buffer()` constructor.
+    ///
+    /// ### Why is this bad?
+    ///
+    /// Enforces the use of [Buffer.from](https://nodejs.org/api/buffer.html#static-method-bufferfromarray) and [Buffer.alloc()](https://nodejs.org/api/buffer.html#static-method-bufferallocsize-fill-encoding) instead of [new Buffer()](https://nodejs.org/api/buffer.html#new-bufferarray), which has been deprecated since Node.js 4.
+    ///
+    /// ### Example
+    /// ```javascript
+    /// // Bad
+    /// const buffer = new Buffer(10);
+    ///
+    /// // Good
+    /// const buffer = Buffer.alloc(10);
+    /// ```
+    NoNewBuffer,
+    pedantic
+);
+
+impl Rule for NoNewBuffer {
+    fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
+        let AstKind::NewExpression(new_expr) = node.kind() else { return };
+
+        let Expression::Identifier(ident) = &new_expr.callee.without_parenthesized() else {
+            return;
+        };
+        if ident.name != "Buffer" {
+            return;
+        }
+        ctx.diagnostic(NoNewBufferDiagnostic(ident.span));
+    }
+}
+
+#[test]
+fn test() {
+    use crate::tester::Tester;
+
+    let pass = vec![
+        r#"const buffer = Buffer"#,
+        r#"const buffer = new NotBuffer(1)"#,
+        r#"const buffer = Buffer.from('buf')"#,
+        r#"const buffer = Buffer.from('7468697320697320612074c3a97374', 'hex')"#,
+        r#"const buffer = Buffer.from([0x62, 0x75, 0x66, 0x66, 0x65, 0x72])"#,
+        r#"const buffer = Buffer.alloc(10)"#,
+    ];
+
+    let fail = vec![
+        r#"const buffer = new Buffer([0x62, 0x75, 0x66, 0x66, 0x65, 0x72])"#,
+        r#"const buffer = new Buffer([0x62, bar])"#,
+        r#"const buffer = new Buffer(10);"#,
+        r#"new Buffer(foo.length)"#,
+        r#"new Buffer(Math.min(foo, bar))"#,
+        r#"const buffer = new Buffer("string");"#,
+        r#"const buffer = new Buffer("7468697320697320612074c3a97374", "hex")"#,
+        r#"const buffer = new Buffer(`${unknown}`)"#,
+        r#"const buffer = new (Buffer)(unknown)"#,
+        r#"const buffer = new Buffer(unknown, 2)"#,
+        r#"const buffer = new Buffer(...unknown)"#,
+        r#"const buffer = new /* comment */ Buffer()"#,
+        r#"const buffer = new /* comment */ Buffer"#,
+        r#"new Buffer(input, encoding);"#,
+    ];
+
+    Tester::new_without_config(NoNewBuffer::NAME, pass, fail).test_and_snapshot();
+}

crates/oxc_linter/src/snapshots/no_new_buffer.snap

@@ -0,0 +1,103 @@
+---
+source: crates/oxc_linter/src/tester.rs
+expression: no_new_buffer
+---
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new Buffer([0x62, 0x75, 0x66, 0x66, 0x65, 0x72])
+   ·                    ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new Buffer([0x62, bar])
+   ·                    ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new Buffer(10);
+   ·                    ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ new Buffer(foo.length)
+   ·     ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ new Buffer(Math.min(foo, bar))
+   ·     ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new Buffer("string");
+   ·                    ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new Buffer("7468697320697320612074c3a97374", "hex")
+   ·                    ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new Buffer(`${unknown}`)
+   ·                    ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new (Buffer)(unknown)
+   ·                     ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new Buffer(unknown, 2)
+   ·                    ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new Buffer(...unknown)
+   ·                    ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new /* comment */ Buffer()
+   ·                                  ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ const buffer = new /* comment */ Buffer
+   ·                                  ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+  ⚠ eslint-plugin-unicorn(no-new-buffer): Use `Buffer.alloc()` or `Buffer.from()` instead of the deprecated `new Buffer()` constructor.
+   ╭─[no_new_buffer.tsx:1:1]
+ 1 │ new Buffer(input, encoding);
+   ·     ──────
+   ╰────
+  help: `new Buffer()` is deprecated, use `Buffer.alloc()` or `Buffer.from()` instead.
+
+