fix(es/codegen): Fix codegen of arrow expressions. (#1452)

swc_ecma_codegen:
 - Fix codegen of arrow functions.  (#1451)

ecmascript/codegen/src/lib.rs

@@ -648,9 +648,19 @@ impl<'a> Emitter<'a> {
     fn emit_arrow_expr(&mut self, node: &ArrowExpr) -> Result {
         self.emit_leading_comments_of_pos(node.span().lo())?;
 
+        let space = !self.cfg.minify
+            || match node.params.as_slice() {
+                [Pat::Ident(_)] => true,
+                _ => false,
+            };
+
         if node.is_async {
             keyword!("async");
-            formatting_space!();
+            if space {
+                space!();
+            } else {
+                formatting_space!();
+            }
         }
         if node.is_generator {
             punct!("*")

ecmascript/codegen/src/tests.rs

@@ -556,6 +556,11 @@ fn deno_8541_2() {
     );
 }
 
+#[test]
+fn issue_1452_1() {
+    assert_min("async foo => 0", "async foo=>0");
+}
+
 #[derive(Debug, Clone)]
 struct Buf(Arc<RwLock<Vec<u8>>>);
 impl Write for Buf {

ecmascript/loader/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+authors = ["강동윤 <kdy1997.dev@gmail.com>"]
+description = "General ecmascript loader used for transforms"
+documentation = "https://swc.rs/rustdoc/swc_ecma_loader/"
+edition = "2018"
+license = "Apache-2.0/MIT"
+name = "swc_ecma_loader"
+repository = "https://github.com/swc-project/swc.git"
+version = "0.1.0"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+swc_atoms = {version = "0.2.3", path = "../../atoms"}
+swc_common = {version = "0.10.10", path = "../../common"}
+swc_ecma_ast = {version = "0.40.0", path = "../ast"}
+swc_ecma_visit = {version = "0.26.0", path = "../visit"}
+
+[dev-dependencies]
+testing = {version = "0.10.3", path = "../../testing"}

ecmascript/loader/src/lib.rs

@@ -0,0 +1,7 @@
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}

ecmascript/transforms/Cargo.toml

@@ -14,6 +14,7 @@ all-features = true
 [features]
 compat = ["swc_ecma_transforms_compat"]
 module = ["swc_ecma_transforms_module"]
+multi-module-decorator = ["swc_ecma_transforms_proposal/multi-module"]
 optimization = ["swc_ecma_transforms_optimization"]
 proposal = ["swc_ecma_transforms_proposal"]
 react = ["swc_ecma_transforms_react"]

ecmascript/transforms/proposal/Cargo.toml

@@ -10,6 +10,10 @@ version = "0.8.0"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[features]
+default = []
+multi-module = ["swc_ecma_loader"]
+
 [dependencies]
 either = "1.6.1"
 fxhash = "0.2.1"
@@ -18,6 +22,7 @@ smallvec = "1.6.0"
 swc_atoms = {version = "0.2", path = "../../../atoms"}
 swc_common = {version = "0.10.10", path = "../../../common"}
 swc_ecma_ast = {version = "0.40.0", path = "../../ast"}
+swc_ecma_loader = {version = "0.1.0", path = "../../loader", optional = true}
 swc_ecma_parser = {version = "0.50.0", path = "../../parser"}
 swc_ecma_transforms_base = {version = "0.7.0", path = "../base"}
 swc_ecma_utils = {version = "0.30.0", path = "../../utils"}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@swc/core",
-  "version": "1.2.50",
+  "version": "1.2.51",
   "description": "Super-fast alternative for babel",
   "homepage": "https://swc.rs",
   "main": "./index.js",

wasm/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2018"
 license = "Apache-2.0/MIT"
 name = "wasm"
 repository = "https://github.com/swc-project/swc.git"
-version = "1.2.50"
+version = "1.2.51"
 
 [lib]
 crate-type = ["cdylib"]