feat(es/transforms/compat): Add more loose mode (#2611)

swc_ecma_transforms_compat: - `computed_properties`: Add loose mode. - `template_literals`: Add loose mode. - `object_spread`: Add loose mode. - `optional_chaining`: Add loose mode. - `nullish_coalescing`: Add loose mode. - `optional_chaining`: Fix #2734.
swc-project · Nov 15, 2021 · dc58122 · dc58122
1 parent f2c67b8
commit dc58122
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Showing 28 changed files with 1,863 additions and 379 deletions.
diff --git a/crates/swc/src/builder.rs b/crates/swc/src/builder.rs
@@ -186,15 +186,28 @@ impl<'a, 'b, P: swc_ecma_visit::Fold> PassBuilder<'a, 'b, P> {
                     should_enable(self.target, EsVersion::Es2021)
                 ),
                 Optional::new(
-                    compat::es2020::es2020(),
+                    compat::es2020::es2020(compat::es2020::Config {
+                        nullish_coalescing: compat::es2020::nullish_coalescing::Config {
+                            no_document_all: self.loose
+                        },
+                        optional_chaining: compat::es2020::opt_chaining::Config {
+                            no_document_all: self.loose,
+                            pure_getter: self.loose
+                        }
+                    }),
                     should_enable(self.target, EsVersion::Es2020)
                 ),
                 Optional::new(
                     compat::es2019::es2019(),
                     should_enable(self.target, EsVersion::Es2019)
                 ),
                 Optional::new(
-                    compat::es2018(),
+                    compat::es2018(compat::es2018::Config {
+                        object_rest_spread: compat::es2018::object_rest_spread::Config {
+                            no_symbol: self.loose,
+                            set_property: self.loose
+                        }
+                    }),
                     should_enable(self.target, EsVersion::Es2018)
                 ),
                 Optional::new(
@@ -210,6 +223,9 @@ impl<'a, 'b, P: swc_ecma_visit::Fold> PassBuilder<'a, 'b, P> {
                         self.top_level_mark,
                         comments.clone(),
                         compat::es2015::Config {
+                            computed_props: compat::es2015::computed_props::Config {
+                                loose: self.loose
+                            },
                             for_of: compat::es2015::for_of::Config {
                                 assume_array: self.loose
                             },
@@ -218,6 +234,10 @@ impl<'a, 'b, P: swc_ecma_visit::Fold> PassBuilder<'a, 'b, P> {
                                 loose: self.loose
                             },
                             regenerator: self.regenerator,
+                            template_literal: compat::es2015::template_literal::Config {
+                                ignore_to_primitive: self.loose,
+                                mutable_template: self.loose
+                            }
                         }
                     ),
                     should_enable(self.target, EsVersion::Es2015)

diff --git a/...ences/expressions/optionalChaining/callChain/callChain/input.ts/es2015.1.normal/output.js b/...ences/expressions/optionalChaining/callChain/callChain/input.ts/es2015.1.normal/output.js
@@ -1,4 +1,4 @@
-var ref, ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10, ref11, _obj, ref12;
+var ref, ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10, ref11, ref12;
 o1 === null || o1 === void 0 ? void 0 : o1();
 o1 === null || o1 === void 0 ? void 0 : o1(1);
 o1 === null || o1 === void 0 ? void 0 : o1(...[
@@ -60,7 +60,7 @@ o2 === null || o2 === void 0 ? void 0 : o2["b"](1, ...[
     3
 ], 4).c;
 const v = o4 === null || o4 === void 0 ? void 0 : o4(incr);
-(ref12 = _obj = o5()) === null || ref12 === void 0 ? void 0 : ref12.call(_obj);
+(ref12 = o5()) === null || ref12 === void 0 ? void 0 : ref12();
 // GH#36031
 o2 === null || o2 === void 0 ? void 0 : o2.b().toString;
 o2 === null || o2 === void 0 ? void 0 : o2.b().toString;
diff --git a/...ces/expressions/optionalChaining/callChain/callChain/input.ts/es2015.2.minified/output.js b/...ces/expressions/optionalChaining/callChain/callChain/input.ts/es2015.2.minified/output.js
@@ -1,4 +1,4 @@
-var ref, ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10, ref11, _obj, ref12;
+var ref, ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10, ref11, ref12;
 null == o1 || o1(), null == o1 || o1(1), null == o1 || o1(...[
     1,
     2
@@ -35,4 +35,4 @@ null == o1 || o1(), null == o1 || o1(1), null == o1 || o1(...[
 ]).c, null === (ref11 = o3.b) || void 0 === ref11 || ref11.call(o3, 1, ...[
     2,
     3
-], 4).c, null == o4 || o4(incr), null === (ref12 = _obj = o5()) || void 0 === ref12 || ref12.call(_obj), null == o2 || o2.b().toString, null == o2 || o2.b().toString;
+], 4).c, null == o4 || o4(incr), null === (ref12 = o5()) || void 0 === ref12 || ref12(), null == o2 || o2.b().toString, null == o2 || o2.b().toString;
diff --git a/...ferences/expressions/optionalChaining/callChain/callChain/input.ts/es5.1.normal/output.js b/...ferences/expressions/optionalChaining/callChain/callChain/input.ts/es5.1.normal/output.js
@@ -16,7 +16,7 @@ function _toConsumableArray(arr) {
     return _arrayWithoutHoles(arr) || _iterableToArray(arr) || _nonIterableSpread();
 }
 var _o2, _o21, _o22, _o23, _ref, _ref1, _ref2, _ref3, _ref4, _ref5;
-var ref, ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10, ref11, _obj, ref12;
+var ref, ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10, ref11, ref12;
 o1 === null || o1 === void 0 ? void 0 : o1();
 o1 === null || o1 === void 0 ? void 0 : o1(1);
 o1 === null || o1 === void 0 ? void 0 : o1.apply(void 0, [
@@ -102,7 +102,7 @@ o2 === null || o2 === void 0 ? void 0 : (_o23 = o2)["b"].apply(_o23, [
     4
 ])).c;
 var v = o4 === null || o4 === void 0 ? void 0 : o4(incr);
-(ref12 = _obj = o5()) === null || ref12 === void 0 ? void 0 : ref12.call(_obj);
+(ref12 = o5()) === null || ref12 === void 0 ? void 0 : ref12();
 // GH#36031
 o2 === null || o2 === void 0 ? void 0 : o2.b().toString;
 o2 === null || o2 === void 0 ? void 0 : o2.b().toString;
diff --git a/...rences/expressions/optionalChaining/callChain/callChain/input.ts/es5.2.minified/output.js b/...rences/expressions/optionalChaining/callChain/callChain/input.ts/es5.2.minified/output.js
@@ -1,4 +1,4 @@
-var _o2, _o21, _o22, _o23, _ref, _ref1, _ref2, _ref3, _ref4, _ref5, ref, ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10, ref11, _obj, ref12;
+var _o2, _o21, _o22, _o23, _ref, _ref1, _ref2, _ref3, _ref4, _ref5, ref, ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10, ref11, ref12;
 function _toConsumableArray(arr) {
     return (function(arr) {
         if (Array.isArray(arr)) {
@@ -71,4 +71,4 @@ null == o1 || o1(), null == o1 || o1(1), null == o1 || o1.apply(void 0, [
     3
 ]), [
     4
-])).c, null == o4 || o4(incr), null === (ref12 = _obj = o5()) || void 0 === ref12 || ref12.call(_obj), null == o2 || o2.b().toString, null == o2 || o2.b().toString;
+])).c, null == o4 || o4(incr), null === (ref12 = o5()) || void 0 === ref12 || ref12(), null == o2 || o2.b().toString, null == o2 || o2.b().toString;
diff --git a/crates/swc_babel_compat/benches/babelify.rs b/crates/swc_babel_compat/benches/babelify.rs
@@ -55,7 +55,7 @@ fn babelify_only(b: &mut Bencher) {
     let module = c.run_transform(&handler, false, || {
         module
             .fold_with(&mut typescript::strip())
-            .fold_with(&mut es2020())
+            .fold_with(&mut es2020(Default::default()))
     });
 
     b.iter(|| {

diff --git a/crates/swc_ecma_preset_env/src/lib.rs b/crates/swc_ecma_preset_env/src/lib.rs
@@ -105,15 +105,35 @@ where
     // ES2020
 
     let pass = add!(pass, ExportNamespaceFrom, es2020::export_namespace_from());
-    let pass = add!(pass, NullishCoalescing, es2020::nullish_coalescing());
+    let pass = add!(
+        pass,
+        NullishCoalescing,
+        es2020::nullish_coalescing(es2020::nullish_coalescing::Config {
+            no_document_all: loose
+        })
+    );
 
-    let pass = add!(pass, OptionalChaining, es2020::optional_chaining());
+    let pass = add!(
+        pass,
+        OptionalChaining,
+        es2020::optional_chaining(es2020::opt_chaining::Config {
+            no_document_all: loose,
+            pure_getter: loose
+        })
+    );
 
     // ES2019
     let pass = add!(pass, OptionalCatchBinding, es2019::optional_catch_binding());
 
     // ES2018
-    let pass = add!(pass, ObjectRestSpread, es2018::object_rest_spread());
+    let pass = add!(
+        pass,
+        ObjectRestSpread,
+        es2018::object_rest_spread(es2018::object_rest_spread::Config {
+            no_symbol: loose,
+            set_property: loose
+        })
+    );
 
     // ES2017
     let pass = add!(pass, AsyncToGenerator, es2017::async_to_generator());
@@ -123,7 +143,15 @@ where
 
     // ES2015
     let pass = add!(pass, BlockScopedFunctions, es2015::block_scoped_functions());
-    let pass = add!(pass, TemplateLiterals, es2015::template_literal(), true);
+    let pass = add!(
+        pass,
+        TemplateLiterals,
+        es2015::template_literal(es2015::template_literal::Config {
+            ignore_to_primitive: loose,
+            mutable_template: loose
+        }),
+        true
+    );
     let pass = add!(pass, Classes, es2015::classes(comments));
     let pass = add!(
         pass,
@@ -150,7 +178,7 @@ where
     let pass = add!(
         pass,
         ComputedProperties,
-        es2015::computed_properties(),
+        es2015::computed_properties(es2015::computed_props::Config { loose }),
         true
     );
     let pass = add!(

diff --git a/crates/swc_ecma_transforms_compat/src/es2015/computed_props.rs b/crates/swc_ecma_transforms_compat/src/es2015/computed_props.rs
@@ -1,3 +1,4 @@
+use serde::Deserialize;
 use swc_common::{Mark, Spanned, DUMMY_SP};
 use swc_ecma_ast::*;
 use swc_ecma_transforms_base::helper;
@@ -35,16 +36,26 @@ use swc_ecma_visit::{noop_fold_type, noop_visit_type, Fold, FoldWith, Node, Visi
 ///
 /// TODO(kdy1): cache reference like (_f = f, mutatorMap[_f].get = function(){})
 ///     instead of (mutatorMap[f].get = function(){}
-pub fn computed_properties() -> impl Fold {
-    ComputedProps
+pub fn computed_properties(c: Config) -> impl Fold {
+    ComputedProps { c }
 }
 
-struct ComputedProps;
+#[derive(Debug, Clone, Copy, Default, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Config {
+    #[serde(default)]
+    pub loose: bool,
+}
+
+struct ComputedProps {
+    c: Config,
+}
 
 #[derive(Default)]
 struct ObjectLitFolder {
     vars: Vec<VarDeclarator>,
     used_define_enum_props: bool,
+    c: Config,
 }
 
 /// TODO: VisitMut
@@ -75,7 +86,7 @@ impl Fold for ObjectLitFolder {
 
                 let props_cnt = props.len();
 
-                exprs.push(if props_cnt == 1 {
+                exprs.push(if !self.c.loose && props_cnt == 1 {
                     Box::new(Expr::Object(ObjectLit {
                         span: DUMMY_SP,
                         props: obj_props,
@@ -95,19 +106,26 @@ impl Fold for ObjectLitFolder {
                 for prop in props {
                     let span = prop.span();
 
-                    let (key, value) = match prop {
+                    let ((key, is_compute), value) = match prop {
                         PropOrSpread::Prop(prop) => match *prop {
                             Prop::Shorthand(ident) => (
-                                Expr::Lit(Lit::Str(Str {
-                                    span: ident.span,
-                                    value: ident.sym.clone(),
-                                    has_escape: false,
-                                    kind: Default::default(),
-                                })),
+                                (
+                                    if self.c.loose {
+                                        Expr::Ident(ident.clone())
+                                    } else {
+                                        Expr::Lit(Lit::Str(Str {
+                                            span: ident.span,
+                                            value: ident.sym.clone(),
+                                            has_escape: false,
+                                            kind: Default::default(),
+                                        }))
+                                    },
+                                    false,
+                                ),
                                 Expr::Ident(ident),
                             ),
                             Prop::KeyValue(KeyValueProp { key, value }) => {
-                                (prop_name_to_expr(key), *value)
+                                (prop_name_to_expr(key, self.c.loose), *value)
                             }
                             Prop::Assign(..) => {
                                 unreachable!("assign property in object literal is invalid")
@@ -167,8 +185,9 @@ impl Fold for ObjectLitFolder {
                                 };
 
                                 // mutator[f]
-                                let mutator_elem =
-                                    mutator_map.clone().computed_member(prop_name_to_expr(key));
+                                let mutator_elem = mutator_map
+                                    .clone()
+                                    .computed_member(prop_name_to_expr(key, false).0);
 
                                 // mutator[f] = mutator[f] || {}
                                 exprs.push(Box::new(Expr::Assign(AssignExpr {
@@ -204,7 +223,7 @@ impl Fold for ObjectLitFolder {
                                 // unimplemented!("getter /setter property")
                             }
                             Prop::Method(MethodProp { key, function }) => (
-                                prop_name_to_expr(key),
+                                prop_name_to_expr(key, self.c.loose),
                                 Expr::Fn(FnExpr {
                                     ident: None,
                                     function,
@@ -214,20 +233,34 @@ impl Fold for ObjectLitFolder {
                         PropOrSpread::Spread(..) => unimplemented!("computed spread property"),
                     };
 
-                    if props_cnt == 1 {
+                    if !self.c.loose && props_cnt == 1 {
                         return Expr::Call(CallExpr {
                             span,
                             callee: helper!(define_property, "defineProperty"),
                             args: vec![exprs.pop().unwrap().as_arg(), key.as_arg(), value.as_arg()],
                             type_args: Default::default(),
                         });
                     }
-                    exprs.push(Box::new(Expr::Call(CallExpr {
-                        span,
-                        callee: helper!(define_property, "defineProperty"),
-                        args: vec![obj_ident.clone().as_arg(), key.as_arg(), value.as_arg()],
-                        type_args: Default::default(),
-                    })));
+                    exprs.push(if self.c.loose {
+                        let left = if is_compute {
+                            obj_ident.clone().computed_member(key)
+                        } else {
+                            obj_ident.clone().make_member(key)
+                        };
+                        Box::new(Expr::Assign(AssignExpr {
+                            span,
+                            op: AssignOp::Assign,
+                            left: PatOrExpr::Expr(Box::new(left)),
+                            right: value.into(),
+                        }))
+                    } else {
+                        Box::new(Expr::Call(CallExpr {
+                            span,
+                            callee: helper!(define_property, "defineProperty"),
+                            args: vec![obj_ident.clone().as_arg(), key.as_arg(), value.as_arg()],
+                            type_args: Default::default(),
+                        }))
+                    });
                 }
 
                 self.vars.push(VarDeclarator {
@@ -317,7 +350,10 @@ impl ComputedProps {
                 continue;
             }
 
-            let mut folder = ObjectLitFolder::default();
+            let mut folder = ObjectLitFolder {
+                c: self.c,
+                ..Default::default()
+            };
             let stmt = stmt.fold_with(&mut folder);
 
             // Add variable declaration
@@ -338,18 +374,25 @@ impl ComputedProps {
     }
 }
 
-fn prop_name_to_expr(p: PropName) -> Expr {
+fn prop_name_to_expr(p: PropName, loose: bool) -> (Expr, bool) {
     match p {
-        PropName::Ident(i) => Expr::Lit(Lit::Str(Str {
-            value: i.sym,
-            span: i.span,
-            has_escape: false,
-            kind: Default::default(),
-        })),
-        PropName::Str(s) => Expr::Lit(Lit::Str(s)),
-        PropName::Num(n) => Expr::Lit(Lit::Num(n)),
-        PropName::BigInt(b) => Expr::Lit(Lit::BigInt(b)),
-        PropName::Computed(c) => *c.expr,
+        PropName::Ident(i) => (
+            if loose {
+                Expr::Ident(i)
+            } else {
+                Expr::Lit(Lit::Str(Str {
+                    value: i.sym,
+                    span: i.span,
+                    has_escape: false,
+                    kind: Default::default(),
+                }))
+            },
+            false,
+        ),
+        PropName::Str(s) => (Expr::Lit(Lit::Str(s)), true),
+        PropName::Num(n) => (Expr::Lit(Lit::Num(n)), true),
+        PropName::BigInt(b) => (Expr::Lit(Lit::BigInt(b)), true),
+        PropName::Computed(c) => (*c.expr, true),
     }
 }