feat(transformer): add transform literal for numeric literals. (#2797)

[es2015 transform
literals](https://babeljs.io/docs/babel-plugin-transform-literals)

---------

Co-authored-by: Dunqing <[email protected]>

crates/oxc_transformer/src/es2015/literals.rs

@@ -0,0 +1,45 @@
+use std::rc::Rc;
+
+use oxc_ast::{ast::*, AstBuilder};
+
+use crate::{
+    context::TransformerCtx,
+    options::{TransformOptions, TransformTarget},
+};
+
+/// ES2015: Shorthand Properties
+///
+/// References:
+/// * <https://babeljs.io/docs/babel-plugin-transform-literals>
+/// * <https://github.com/babel/babel/blob/main/packages/babel-plugin-transform-literals/src/index.ts>
+pub struct Literals<'a> {
+    _ast: Rc<AstBuilder<'a>>,
+}
+
+impl<'a> Literals<'a> {
+    #![allow(clippy::unused_self)]
+
+    pub fn new(ctx: TransformerCtx<'a>, options: &TransformOptions) -> Option<Self> {
+        (options.target < TransformTarget::ES2015 || options.literals)
+            .then_some(Self { _ast: ctx.ast })
+    }
+
+    pub fn transform_number_literal(&mut self, lit: &mut NumericLiteral<'a>) {
+        // early return if number's raw value is empty or shorter than 2 characters,
+        // both `0bxxx` and `0oxxx` need at least 3 characters be defined.
+        if lit.raw.len() <= 2 {
+            return;
+        }
+
+        if let [b'0', b'b' | b'B' | b'o' | b'O'] = lit.raw[0..2].as_bytes() {
+            // Set binary and octal raw values to empty, It would force the codegen,
+            // to generate them from their value.
+            lit.raw = "";
+        }
+    }
+
+    pub fn transform_string_literal(&mut self, _: &mut StringLiteral<'a>) {
+        // TODO: As of today oxc_lexer takes care of this, We have to rework it
+        // so it can be controlled via the transformer.
+    }
+}

crates/oxc_transformer/src/es2015/mod.rs

@@ -2,6 +2,7 @@ mod arrow_functions;
 mod duplicate_keys;
 mod function_name;
 mod instanceof;
+mod literals;
 mod new_target;
 mod shorthand_properties;
 mod template_literals;
@@ -10,6 +11,7 @@ pub use arrow_functions::{ArrowFunctions, ArrowFunctionsOptions};
 pub use duplicate_keys::DuplicateKeys;
 pub use function_name::FunctionName;
 pub use instanceof::Instanceof;
+pub use literals::Literals;
 pub use new_target::NewTarget;
 pub use shorthand_properties::ShorthandProperties;
 pub use template_literals::TemplateLiterals;

crates/oxc_transformer/src/lib.rs

@@ -92,6 +92,7 @@ pub struct Transformer<'a> {
     es2015_template_literals: Option<TemplateLiterals<'a>>,
     es2015_duplicate_keys: Option<DuplicateKeys<'a>>,
     es2015_instanceof: Option<Instanceof<'a>>,
+    es2015_literals: Option<Literals<'a>>,
     es2015_new_target: Option<NewTarget<'a>>,
     es3_property_literal: Option<PropertyLiteral<'a>>,
 }
@@ -133,6 +134,7 @@ impl<'a> Transformer<'a> {
             es2015_template_literals: TemplateLiterals::new(Rc::clone(&ast), &options),
             es2015_duplicate_keys: DuplicateKeys::new(Rc::clone(&ast), &options),
             es2015_instanceof: Instanceof::new(Rc::clone(&ast), ctx.clone(), &options),
+            es2015_literals: Literals::new(ctx.clone(), &options),
             es2015_new_target: NewTarget::new(Rc::clone(&ast),ctx.clone(), &options),
             // other
             es3_property_literal: PropertyLiteral::new(Rc::clone(&ast), &options),
@@ -252,10 +254,15 @@ impl<'a> VisitMut<'a> for Transformer<'a> {
         // walk_directive_mut(self, directive);
     }
 
-    fn visit_string_literal(&mut self, lit: &mut StringLiteral) {
+    fn visit_number_literal(&mut self, lit: &mut NumericLiteral<'a>) {
+        self.es2015_literals.as_mut().map(|t| t.transform_number_literal(lit));
+    }
+
+    fn visit_string_literal(&mut self, lit: &mut StringLiteral<'a>) {
         self.es2019_json_strings
             .as_mut()
             .map(|t: &mut JsonStrings| t.transform_string_literal(lit));
+        self.es2015_literals.as_mut().map(|t| t.transform_string_literal(lit));
     }
 
     fn visit_method_definition(&mut self, def: &mut MethodDefinition<'a>) {

crates/oxc_transformer/src/options.rs

@@ -30,6 +30,7 @@ pub struct TransformOptions {
     pub function_name: bool,
     pub arrow_functions: Option<ArrowFunctionsOptions>,
     pub shorthand_properties: bool,
+    pub literals: bool,
     pub sticky_regex: bool,
     pub template_literals: bool,
     pub property_literals: bool,

tasks/transform_conformance/src/test_case.rs

@@ -101,6 +101,7 @@ pub trait TestCase {
             assumptions: options.assumptions,
             class_static_block: options.get_plugin("transform-class-static-block").is_some(),
             instanceof: options.get_plugin("transform-instanceof").is_some(),
+            literals: options.get_plugin("transform-literals").is_some(),
             function_name: options.get_plugin("transform-function-name").is_some(),
             arrow_functions: options
                 .get_plugin("transform-arrow-functions")