feat(es/renamer): Support safari10 from the name mangler (#6801)

Author: kdy1

crates/swc/src/config/mod.rs

@@ -503,7 +503,10 @@ impl Options {
         .hygiene(if self.disable_hygiene {
             None
         } else {
-            Some(hygiene::Config { keep_class_names })
+            Some(hygiene::Config {
+                keep_class_names,
+                ..Default::default()
+            })
         })
         .fixer(!self.disable_fixer)
         .preset_env(cfg.env)

crates/swc_ecma_minifier/src/pass/mangle_names/mod.rs

@@ -23,7 +23,13 @@ pub(crate) fn name_mangler(
             n: Default::default(),
         },
         self::private_name::private_name_mangler(options.keep_private_props, chars),
-        renamer(Default::default(), ManglingRenamer { chars, preserved })
+        renamer(
+            swc_ecma_transforms_base::hygiene::Config {
+                keep_class_names: options.keep_class_names,
+                safari_10: options.safari10,
+            },
+            ManglingRenamer { chars, preserved }
+        )
     )
 }
 

crates/swc_ecma_minifier/tests/TODO.txt

@@ -193,7 +193,6 @@ harmony/classes_extending_classes_out_of_pure_iifes/input.js
 harmony/default_assign/input.js
 harmony/expansion/input.js
 harmony/inline_arrow_using_arguments/input.js
-harmony/issue_1753_disable/input.js
 harmony/issue_2349b/input.js
 harmony/issue_2794_1/input.js
 harmony/issue_2794_2/input.js

crates/swc_ecma_minifier/tests/passing.txt

@@ -689,6 +689,7 @@ harmony/import_statement/input.js
 harmony/import_statement_mangling/input.js
 harmony/issue_1613/input.js
 harmony/issue_1753/input.js
+harmony/issue_1753_disable/input.js
 harmony/issue_1898/input.js
 harmony/issue_2028/input.js
 harmony/issue_2345/input.js
@@ -766,6 +767,7 @@ identity/inline_identity_regression/input.js
 identity/inline_identity_undefined/input.js
 ie8/do_screw/input.js
 ie8/do_screw_constants/input.js
+ie8/do_screw_try_catch/input.js
 ie8/dont_screw/input.js
 ie8/dont_screw_constants/input.js
 ie8/issue_1586_2/input.js

crates/swc_ecma_minifier/tests/postponed.txt

@@ -46,7 +46,6 @@ hoist_props/toplevel_const/input.js
 hoist_props/toplevel_let/input.js
 hoist_props/toplevel_var/input.js
 hoist_props/undefined_key/input.js
-ie8/do_screw_try_catch/input.js
 ie8/do_screw_try_catch_undefined/input.js
 ie8/dont_screw_try_catch/input.js
 ie8/dont_screw_try_catch_undefined/input.js

crates/swc_ecma_minifier/tests/terser/compress/harmony/class_name_can_be_preserved/output.js

@@ -1,6 +1,6 @@
 function x() {
     (class Baz {
     });
-    class Foo {
-    }
+    let Foo = class Foo {
+    };
 }

crates/swc_ecma_minifier/tests/terser/compress/keep_names/keep_classnames/output.js

@@ -1,3 +1,4 @@
 function foo() {
-    class Bar {}
+    let Bar = class Bar {
+    };
 }

crates/swc_ecma_minifier/tests/terser/compress/try_catch/broken_safari_catch_scope/output.js

@@ -6,8 +6,8 @@ new class {
             throw {
                 m: "PASS"
             };
-        } catch ({ m: A  }) {
-            console.log(A);
+        } catch ({ m: B  }) {
+            console.log(B);
         }
     }
 }().f();

crates/swc_ecma_minifier/tests/terser/compress/try_catch/broken_safari_catch_scope_caveat/output.js

@@ -1,11 +1,13 @@
 "AAAAAAAA";
 "BBBBBBB";
-new (class {
+new class {
     f(A) {
         try {
-            throw { m: "PASS" };
-        } catch ({ m: A }) {
-            console.log(A);
+            throw {
+                m: "PASS"
+            };
+        } catch ({ m: B  }) {
+            console.log(B);
         }
     }
-})().f();
+}().f();

crates/swc_ecma_transforms_base/src/hygiene/mod.rs

@@ -12,6 +12,9 @@ mod tests;
 pub struct Config {
     /// If true, the `hygiene` pass will preserve class names.
     pub keep_class_names: bool,
+
+    /// If true, the bug of safari 10 is avoided.
+    pub safari_10: bool,
 }
 
 /// See [hygiene_with_config] for doc. Creates a `hygiene` pass with default

crates/swc_ecma_transforms_base/src/hygiene/tests.rs

@@ -1247,6 +1247,7 @@ fn issue_1279() {
         ",
         Config {
             keep_class_names: true,
+            ..Default::default()
         },
     );
 }
@@ -1287,6 +1288,7 @@ fn issue_1507() {
         ",
         Config {
             keep_class_names: true,
+            ..Default::default()
         },
     );
 }

crates/swc_ecma_transforms_base/src/rename/analyzer/mod.rs

@@ -8,6 +8,8 @@ pub(super) mod scope;
 
 #[derive(Debug, Default)]
 pub(super) struct Analyzer {
+    pub safari_10: bool,
+
     pub is_pat_decl: bool,
     pub var_belong_to_fn_scope: bool,
     pub in_catch_params: bool,
@@ -42,6 +44,8 @@ impl Analyzer {
     {
         {
             let mut v = Analyzer {
+                safari_10: self.safari_10,
+
                 scope: Scope {
                     kind,
                     ..Default::default()
@@ -121,21 +125,56 @@ impl Visit for Analyzer {
         }
     }
 
+    fn visit_block_stmt(&mut self, n: &BlockStmt) {
+        self.with_scope(ScopeKind::Block, |v| n.visit_children_with(v))
+    }
+
+    fn visit_block_stmt_or_expr(&mut self, n: &BlockStmtOrExpr) {
+        match n {
+            // This avoid crating extra block scope for arrow function
+            BlockStmtOrExpr::BlockStmt(n) => n.visit_children_with(self),
+            BlockStmtOrExpr::Expr(n) => n.visit_with(self),
+        }
+    }
+
     fn visit_catch_clause(&mut self, n: &CatchClause) {
-        self.with_scope(ScopeKind::Block, |v| {
-            let old = v.is_pat_decl;
-            let old_in_catch_params = v.in_catch_params;
+        if self.safari_10 {
+            let old_is_pat_decl = self.is_pat_decl;
+            let old_in_catch_params = self.in_catch_params;
 
-            v.is_pat_decl = false;
-            n.body.visit_children_with(v);
+            self.is_pat_decl = true;
+            self.in_catch_params = true;
+            n.param.visit_with(self);
 
-            v.is_pat_decl = true;
-            v.in_catch_params = true;
-            n.param.visit_with(v);
+            self.in_catch_params = old_in_catch_params;
+            self.is_pat_decl = old_is_pat_decl;
 
-            v.is_pat_decl = old;
-            v.in_catch_params = old_in_catch_params;
-        })
+            self.with_scope(ScopeKind::Block, |v| {
+                let old = v.is_pat_decl;
+                let old_in_catch_params = v.in_catch_params;
+
+                v.is_pat_decl = false;
+                n.body.visit_children_with(v);
+
+                v.is_pat_decl = old;
+                v.in_catch_params = old_in_catch_params;
+            })
+        } else {
+            self.with_scope(ScopeKind::Block, |v| {
+                let old = v.is_pat_decl;
+                let old_in_catch_params = v.in_catch_params;
+
+                v.is_pat_decl = false;
+                n.body.visit_children_with(v);
+
+                v.is_pat_decl = true;
+                v.in_catch_params = true;
+                n.param.visit_with(v);
+
+                v.is_pat_decl = old;
+                v.in_catch_params = old_in_catch_params;
+            })
+        }
     }
 
     fn visit_class_decl(&mut self, c: &ClassDecl) {
@@ -251,6 +290,40 @@ impl Visit for Analyzer {
         }
     }
 
+    fn visit_for_in_stmt(&mut self, n: &ForInStmt) {
+        self.with_scope(ScopeKind::Block, |v| {
+            n.left.visit_with(v);
+            n.right.visit_with(v);
+
+            v.with_scope(ScopeKind::Block, |v| {
+                v.visit_for_body_within_same_scope(&n.body);
+            })
+        });
+    }
+
+    fn visit_for_of_stmt(&mut self, n: &ForOfStmt) {
+        self.with_scope(ScopeKind::Block, |v| {
+            n.left.visit_with(v);
+            n.right.visit_with(v);
+
+            v.with_scope(ScopeKind::Block, |v| {
+                v.visit_for_body_within_same_scope(&n.body);
+            })
+        });
+    }
+
+    fn visit_for_stmt(&mut self, n: &ForStmt) {
+        self.with_scope(ScopeKind::Block, |v| {
+            n.init.visit_with(v);
+            n.test.visit_with(v);
+            n.update.visit_with(v);
+
+            v.with_scope(ScopeKind::Block, |v| {
+                v.visit_for_body_within_same_scope(&n.body);
+            })
+        });
+    }
+
     fn visit_import_default_specifier(&mut self, n: &ImportDefaultSpecifier) {
         self.add_decl(n.local.to_id(), true);
     }
@@ -326,77 +399,31 @@ impl Visit for Analyzer {
         }
     }
 
+    fn visit_static_block(&mut self, n: &StaticBlock) {
+        self.with_fn_scope(|v| n.body.visit_children_with(v))
+    }
+
     fn visit_super_prop_expr(&mut self, e: &SuperPropExpr) {
         if let SuperProp::Computed(c) = &e.prop {
             c.visit_with(self);
         }
     }
 
-    fn visit_var_declarator(&mut self, v: &VarDeclarator) {
-        let old = self.is_pat_decl;
-        self.is_pat_decl = true;
-        v.name.visit_with(self);
-
-        self.is_pat_decl = false;
-        v.init.visit_with(self);
-
-        self.is_pat_decl = old;
-    }
-
     fn visit_var_decl(&mut self, n: &VarDecl) {
         let old_need_hoisted = self.var_belong_to_fn_scope;
         self.var_belong_to_fn_scope = n.kind == VarDeclKind::Var;
         n.visit_children_with(self);
         self.var_belong_to_fn_scope = old_need_hoisted;
     }
 
-    fn visit_block_stmt(&mut self, n: &BlockStmt) {
-        self.with_scope(ScopeKind::Block, |v| n.visit_children_with(v))
-    }
-
-    fn visit_block_stmt_or_expr(&mut self, n: &BlockStmtOrExpr) {
-        match n {
-            // This avoid crating extra block scope for arrow function
-            BlockStmtOrExpr::BlockStmt(n) => n.visit_children_with(self),
-            BlockStmtOrExpr::Expr(n) => n.visit_with(self),
-        }
-    }
-
-    fn visit_for_in_stmt(&mut self, n: &ForInStmt) {
-        self.with_scope(ScopeKind::Block, |v| {
-            n.left.visit_with(v);
-            n.right.visit_with(v);
-
-            v.with_scope(ScopeKind::Block, |v| {
-                v.visit_for_body_within_same_scope(&n.body);
-            })
-        });
-    }
-
-    fn visit_for_of_stmt(&mut self, n: &ForOfStmt) {
-        self.with_scope(ScopeKind::Block, |v| {
-            n.left.visit_with(v);
-            n.right.visit_with(v);
-
-            v.with_scope(ScopeKind::Block, |v| {
-                v.visit_for_body_within_same_scope(&n.body);
-            })
-        });
-    }
-
-    fn visit_for_stmt(&mut self, n: &ForStmt) {
-        self.with_scope(ScopeKind::Block, |v| {
-            n.init.visit_with(v);
-            n.test.visit_with(v);
-            n.update.visit_with(v);
+    fn visit_var_declarator(&mut self, v: &VarDeclarator) {
+        let old = self.is_pat_decl;
+        self.is_pat_decl = true;
+        v.name.visit_with(self);
 
-            v.with_scope(ScopeKind::Block, |v| {
-                v.visit_for_body_within_same_scope(&n.body);
-            })
-        });
-    }
+        self.is_pat_decl = false;
+        v.init.visit_with(self);
 
-    fn visit_static_block(&mut self, n: &StaticBlock) {
-        self.with_fn_scope(|v| n.body.visit_children_with(v))
+        self.is_pat_decl = old;
     }
 }

crates/swc_ecma_transforms_base/src/rename/mod.rs

@@ -113,6 +113,7 @@ where
     {
         let mut scope = {
             let mut v = Analyzer {
+                safari_10: self.config.safari_10,
                 ..Default::default()
             };
             if skip_one {

crates/swc_ecma_transforms_base/src/resolver/tests.rs

@@ -130,6 +130,7 @@ fn issue_1279_1() {
         ",
         Config {
             keep_class_names: true,
+            ..Default::default()
         },
     );
 }
@@ -163,6 +164,7 @@ fn issue_1279_2() {
         ",
         Config {
             keep_class_names: true,
+            ..Default::default()
         },
     );
 }
@@ -182,6 +184,7 @@ fn issue_2516() {
         ",
         Config {
             keep_class_names: true,
+            ..Default::default()
         },
     );
 }