preset-env

.gitignore

@@ -19,4 +19,5 @@ node_modules/
 
 # Flamegraph
 *.html
-*.svg
+*.svg
+package-lock.json

.travis.yml

@@ -26,6 +26,7 @@ before_install:
   - git submodule update --init --recursive
 
 install:
+  - npm install browserslist
   - cargo test --no-run --color always --all --all-features
 
 script:

Cargo.toml

@@ -24,6 +24,7 @@ path-clean = "0.1"
 lazy_static = "1"
 hashbrown = "0.6"
 regex = "1"
+either = "1"
 chashmap = "2.2.2"
 sourcemap = "4.1.1  "
 

README.md

@@ -148,6 +148,11 @@ New generation javascript to old-days javascript.
 - react
   - [x] jsx
 
+- preset-env
+  - [x] `entry` with core-js@2/3
+  - [ ] `usage` with core-js@2/3
+It's implemented, but it's not perfect.
+
 # Performance
 
 The lower bound of the speedup compared to babel is **18**. The benchmarks were run on Macbook pro, dual core, 2.3GHz Intel Core i5, 16 GB ram

atoms/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "swc_atoms"
 build = "build.rs"
-version = "0.2.0"
+version = "0.2.1"
 authors = ["강동윤 <[email protected]>"]
 license = "Apache-2.0/MIT"
 repository = "https://github.com/swc-project/swc.git"

atoms/scripts/sort.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -eu
 
 cat words.txt | awk '{$1=$1};1' | uniq | sort > words_sorted.txt

atoms/words.txt

@@ -576,7 +576,6 @@ abstract
 any
 apply
 arguments
-arguments
 as
 async
 await
@@ -620,6 +619,7 @@ infer
 instanceof
 interface
 is
+iterator
 key
 keyof
 length

ecmascript/Cargo.toml

@@ -14,5 +14,6 @@ ast = { package = "swc_ecma_ast", path ="./ast" }
 codegen = { package = "swc_ecma_codegen", path ="./codegen" }
 parser = { package = "swc_ecma_parser", path ="./parser", features = ["verify"] }
 transforms = { package = "swc_ecma_transforms", path ="./transforms" }
+preset_env = { package = "swc_ecma_preset_env", path ="preset_env" }
 
 [dev-dependencies]

ecmascript/codegen/src/lib.rs

@@ -393,7 +393,11 @@ impl<'a> Emitter<'a> {
             }
             self.wr.write_str_lit(num.span, "Infinity")?;
         } else {
-            self.wr.write_str_lit(num.span, &format!("{}", num.value))?;
+            if num.value.is_sign_negative() && num.value == 0.0 {
+                self.wr.write_str_lit(num.span, "-0.0")?;
+            } else {
+                self.wr.write_str_lit(num.span, &format!("{}", num.value))?;
+            }
         }
     }
 
@@ -481,7 +485,7 @@ impl<'a> Emitter<'a> {
             Expr::TsConstAssertion(ref n) => emit!(n),
             Expr::TsTypeCast(ref n) => emit!(n),
             Expr::OptChain(ref n) => emit!(n),
-            Expr::Invalid(..) => unimplemented!("emit Expr::Invalid"),
+            Expr::Invalid(ref n) => emit!(n),
         }
     }
 
@@ -514,6 +518,13 @@ impl<'a> Emitter<'a> {
         }
     }
 
+    #[emitter]
+    pub fn emit_invalid(&mut self, n: &Invalid) -> Result {
+        self.emit_leading_comments_of_pos(n.span.lo())?;
+
+        self.wr.write_str_lit(n.span, "<invalid>")?;
+    }
+
     #[emitter]
     pub fn emit_call_expr(&mut self, node: &CallExpr) -> Result {
         self.emit_leading_comments_of_pos(node.span().lo())?;

ecmascript/preset_env/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "swc_ecma_preset_env"
+version = "0.1.0"
+authors = ["강동윤 <[email protected]>"]
+edition = "2018"
+publish = false
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+swc_atoms = { path = "../../atoms" }
+swc_common = { path = "../../common" }
+swc_ecma_ast = { path = "../ast" }
+swc_ecma_transforms = { path = "../transforms" }
+string_enum = { path = "../../macros/string_enum" }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+walkdir = "2"
+semver = { version = "0.9.0", features = ["serde"] }
+once_cell = "1.2.0"
+hashbrown = "0.6"
+st-map = "0.1.2"
+fxhash = "0.2.1"
+chashmap = "2.2"
+
+[dev-dependencies]
+swc_ecma_codegen = { path = "../codegen" }
+swc_ecma_parser = { path = "../parser", features = ["verify"] }
+testing = { path = "../../testing" }
+pretty_assertions = "0.6"

ecmascript/preset_env/benches/polyfills.rs

@@ -0,0 +1,85 @@
+#![feature(test)]
+#![feature(specialization)]
+#![feature(box_syntax)]
+
+extern crate test;
+
+use swc_common::{FileName, FoldWith};
+use swc_ecma_parser::{Parser, Session, SourceFileInput, Syntax};
+use swc_ecma_preset_env::{preset_env, Config};
+use test::Bencher;
+
+fn run(b: &mut Bencher, src: &str, config: Config) {
+    b.bytes = src.len() as _;
+
+    let _ = ::testing::run_test(false, |cm, handler| {
+        let fm = cm.new_source_file(FileName::Anon, src.into());
+
+        let mut parser = Parser::new(
+            Session { handler: &handler },
+            Syntax::default(),
+            SourceFileInput::from(&*fm),
+            None,
+        );
+        let module = parser
+            .parse_module()
+            .map_err(|mut e| {
+                e.emit();
+            })
+            .unwrap();
+        let mut folder = preset_env(config);
+
+        b.iter(|| test::black_box(module.clone().fold_with(&mut folder)));
+        Ok(())
+    });
+}
+
+#[bench]
+fn usage_builtin_type(b: &mut Bencher) {
+    const SOURCE: &str = r#"
+// From a length
+var float32 = new Float32Array(2);
+float32[0] = 42;
+console.log(float32[0]); // 42
+console.log(float32.length); // 2
+console.log(float32.BYTES_PER_ELEMENT); // 4
+
+// From an array
+var arr = new Float32Array([21,31]);
+console.log(arr[1]); // 31
+
+// From another TypedArray
+var x = new Float32Array([21, 31]);
+var y = new Float32Array(x);
+console.log(y[0]); // 21
+
+// From an ArrayBuffer
+var buffer = new ArrayBuffer(16);
+var z = new Float32Array(buffer, 0, 4);
+
+// From an iterable 
+var iterable = function*(){ yield* [1,2,3]; }(); 
+var float32 = new Float32Array(iterable); 
+// Float32Array[1, 2, 3]
+"#;
+
+    run(b, SOURCE, Default::default())
+}
+
+#[bench]
+fn usage_property(b: &mut Bencher) {
+    const SOURCE: &str = r#"
+const target = { a: 1, b: 2 };
+const source = { b: 4, c: 5 };
+
+const returnedTarget = Object.assign(target, source);
+
+console.log(target);
+// expected output: Object { a: 1, b: 4, c: 5 }
+
+console.log(returnedTarget);
+// expected output: Object { a: 1, b: 4, c: 5 }
+"#;
+
+    run(b, SOURCE, Default::default())
+}

ecmascript/preset_env/package.json

@@ -0,0 +1,5 @@
+{
+  "devDependencies": {
+    "browserslist": "=4.7.3"
+  }
+}

ecmascript/preset_env/scripts/corejs-compat-gen.js

@@ -0,0 +1,8 @@
+const data = require('core-js-compat/data');
+
+// for (const feature in data) {
+//     const browserData = data[feature];
+//
+// }
+
+console.log(JSON.stringify(data))