feat(minifier): fold single arg new array expressions

crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs

@@ -1,5 +1,5 @@
-use oxc_allocator::Vec;
-use oxc_ast::ast::*;
+use oxc_allocator::{CloneIn, Vec};
+use oxc_ast::{ast::*, NONE};
 use oxc_semantic::IsGlobalReference;
 use oxc_span::{GetSpan, SPAN};
 use oxc_syntax::number::ToJsInt32;
@@ -321,13 +321,57 @@ impl<'a> PeepholeSubstituteAlternateSyntax {
                 *expr =
                     ctx.ast.expression_object(expr.span(), Vec::new_in(ctx.ast.allocator), None);
                 self.changed = true;
-            }
-            // `new Array` -> `[]`
-            else if new_expr.arguments.is_empty()
-                && new_expr.callee.is_global_reference_name("Array", ctx.symbols())
-            {
-                *expr = ctx.ast.expression_array(expr.span(), Vec::new_in(ctx.ast.allocator), None);
-                self.changed = true;
+            } else if new_expr.callee.is_global_reference_name("Array", ctx.symbols()) {
+                // `new Array` -> `[]`
+                if new_expr.arguments.is_empty() {
+                    *expr =
+                        ctx.ast.expression_array(expr.span(), Vec::new_in(ctx.ast.allocator), None);
+                    self.changed = true;
+                } else if new_expr.arguments.len() == 1 {
+                    let Some(arg) = new_expr.arguments[0].as_expression() else { return };
+                    // `new Array(0)` -> `[]`
+                    if arg.is_number_0() {
+                        *expr = ctx.ast.expression_array(
+                            expr.span(),
+                            Vec::new_in(ctx.ast.allocator),
+                            None,
+                        );
+                        self.changed = true;
+                    }
+                    // `new Array(8)` -> `Array(8)`
+                    else if arg.is_number_literal() {
+                        let mut arguments = Vec::new_in(ctx.ast.allocator);
+                        arguments
+                            .push(ctx.ast.argument_expression((*arg).clone_in(ctx.ast.allocator)));
+                        *expr = ctx.ast.expression_call(
+                            new_expr.span,
+                            new_expr.callee.clone_in(ctx.ast.allocator),
+                            NONE,
+                            arguments,
+                            false,
+                        )
+                    }
+                    // `new Array(literal)` -> `[literal]`
+                    else if arg.is_literal() {
+                        let mut elements = Vec::new_in(ctx.ast.allocator);
+                        let element = ctx.ast.array_expression_element_expression(
+                            (*arg).clone_in(ctx.ast.allocator),
+                        );
+                        elements.push(element);
+                        *expr = ctx.ast.expression_array(expr.span(), elements, None);
+                        self.changed = true;
+                    }
+                    // `new Array()` -> `Array()`
+                    else {
+                        *expr = ctx.ast.expression_call(
+                            new_expr.span,
+                            new_expr.callee.clone_in(ctx.ast.allocator),
+                            NONE,
+                            new_expr.arguments.clone_in(ctx.ast.allocator),
+                            false,
+                        )
+                    }
+                }
             }
         }
     }
@@ -434,15 +478,15 @@ mod test {
         test_same("x = Array?.()");
 
         // One argument
-        // test("x = new Array(0)", "x = []");
+        test("x = new Array(0)", "x = []");
+        test("x = new Array(\"a\")", "x = [\"a\"]");
+        test("x = new Array(7)", "x = Array(7)");
+        test("x = new Array(y)", "x = Array(y)");
+        test("x = new Array(foo())", "x = Array(foo())");
         // test("x = Array(0)", "x = []");
-        // test("x = new Array(\"a\")", "x = [\"a\"]");
         // test("x = Array(\"a\")", "x = [\"a\"]");
-        // test("x = new Array(7)", "x = Array(7)");
         // test_same("x = Array(7)");
-        // test("x = new Array(y)", "x = Array(y)");
         // test_same("x = Array(y)");
-        // test("x = new Array(foo())", "x = Array(foo())");
         // test_same("x = Array(foo())");
 
         // // 1+ arguments

tasks/minsize/minsize.snap

@@ -1,26 +1,26 @@
 Original   | Minified   | esbuild    | Gzip       | esbuild   
 
-72.14 kB   | 24.47 kB   | 23.70 kB   | 8.65 kB    | 8.54 kB    | react.development.js
+72.14 kB   | 24.46 kB   | 23.70 kB   | 8.65 kB    | 8.54 kB    | react.development.js
 
 173.90 kB  | 61.69 kB   | 59.82 kB   | 19.54 kB   | 19.33 kB   | moment.js 
 
 287.63 kB  | 92.83 kB   | 90.07 kB   | 32.29 kB   | 31.95 kB   | jquery.js 
 
-342.15 kB  | 124.14 kB  | 118.14 kB  | 44.81 kB   | 44.37 kB   | vue.js    
+342.15 kB  | 124.11 kB  | 118.14 kB  | 44.80 kB   | 44.37 kB   | vue.js    
 
 544.10 kB  | 74.13 kB   | 72.48 kB   | 26.23 kB   | 26.20 kB   | lodash.js 
 
-555.77 kB  | 278.68 kB  | 270.13 kB  | 91.39 kB   | 90.80 kB   | d3.js     
+555.77 kB  | 278.24 kB  | 270.13 kB  | 91.36 kB   | 90.80 kB   | d3.js     
 
 1.01 MB    | 470.11 kB  | 458.89 kB  | 126.97 kB  | 126.71 kB  | bundle.min.js
 
-1.25 MB    | 671.00 kB  | 646.76 kB  | 164.72 kB  | 163.73 kB  | three.js  
+1.25 MB    | 670.97 kB  | 646.76 kB  | 164.72 kB  | 163.73 kB  | three.js  
 
-2.14 MB    | 756.69 kB  | 724.14 kB  | 182.87 kB  | 181.07 kB  | victory.js
+2.14 MB    | 756.33 kB  | 724.14 kB  | 182.74 kB  | 181.07 kB  | victory.js
 
 3.20 MB    | 1.05 MB    | 1.01 MB    | 334.10 kB  | 331.56 kB  | echarts.js
 
-4.12 MB    | 1.68 MB    | 2.31 MB    | 484.25 kB  | 488.28 kB  | antd.js   
+4.12 MB    | 1.68 MB    | 2.31 MB    | 484.21 kB  | 488.28 kB  | antd.js   
 
-10.95 MB   | 3.59 MB    | 3.49 MB    | 913.96 kB  | 915.50 kB  | typescript.js
+10.95 MB   | 3.59 MB    | 3.49 MB    | 913.92 kB  | 915.50 kB  | typescript.js