Fix bugs (swc-project#687)

- stript type-only export default
- allow `continue` in a for loop

ecmascript/transforms/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "swc_ecma_transforms"
-version = "0.7.0"
+version = "0.7.1"
 authors = ["강동윤 <[email protected]>"]
 license = "Apache-2.0/MIT"
 repository = "https://github.com/swc-project/swc.git"

ecmascript/transforms/src/compat/es2015/block_scoping.rs

@@ -134,9 +134,9 @@ impl BlockScoping {
                                     })
                                     .collect(),
                                 decorators: Default::default(),
-                                body: Some(match body {
+                                body: Some(match body.fold_with(&mut FlowHelper) {
                                     Stmt::Block(bs) => bs,
-                                    _ => BlockStmt {
+                                    body => BlockStmt {
                                         span: DUMMY_SP,
                                         stmts: vec![body],
                                     },
@@ -195,6 +195,7 @@ impl Fold<WhileStmt> for BlockScoping {
 impl Fold<ForStmt> for BlockScoping {
     fn fold(&mut self, node: ForStmt) -> ForStmt {
         let init = node.init.fold_with(self);
+
         let mut vars = find_vars(&init);
         let args = vars.clone();
 
@@ -502,6 +503,22 @@ impl Visit<Ident> for InfectionFinder<'_> {
     }
 }
 
+#[derive(Debug)]
+struct FlowHelper;
+
+noop_fold_type!(FlowHelper);
+
+impl Fold<Stmt> for FlowHelper {
+    fn fold(&mut self, node: Stmt) -> Stmt {
+        let span = node.span();
+
+        match node {
+            Stmt::Continue(..) => return Stmt::Return(ReturnStmt { span, arg: None }),
+            _ => node.fold_children(self),
+        }
+    }
+}
+
 #[derive(Debug)]
 struct FunctionFinder {
     found: bool,
@@ -674,4 +691,83 @@ foo();",
 
 foo();"
     );
+
+    test!(
+        ::swc_ecma_parser::Syntax::default(),
+        |_| block_scoping(),
+        issue_686,
+        "module.exports = function(values) {
+    var vars = [];
+    var elem = null, name, val;
+    for (var i = 0; i < this.elements.length; i++) {
+      elem = this.elements[i];
+      name = elem.name;
+      if (!name) continue;
+      val = values[name];
+      if (val == null) val = '';
+      switch (elem.type) {
+      case 'submit':
+        break;
+      case 'radio':
+      case 'checkbox':
+        elem.checked = val.some(function(str) {
+          return str.toString() == elem.value;
+        });
+        break;
+      case 'select-multiple':
+        elem.fill(val);
+        break;
+      case 'textarea':
+        elem.innerText = val;
+        break;
+      case 'hidden':
+        break;
+      default:
+        if (elem.fill) {
+          elem.fill(val);
+        } else {
+          elem.value = val;
+        }
+        break;
+      }
+    }
+    return vars;
+  };",
+        "module.exports = function(values) {
+    var _loop = function(i) {
+        elem = this.elements[i];
+        name = elem.name;
+        if (!name) return;
+        val = values[name];
+        if (val == null) val = '';
+        switch(elem.type){
+            case 'submit': break;
+            case 'radio':
+            case 'checkbox':
+                elem.checked = val.some(function(str) {
+                    return str.toString() == elem.value;
+                });
+                break;
+            case 'select-multiple':
+                elem.fill(val);
+                break;
+            case 'textarea':
+                elem.innerText = val;
+                break;
+            case 'hidden': break;
+            default:
+                if (elem.fill) {
+                    elem.fill(val);
+                } else {
+                    elem.value = val;
+                }
+                break;
+        }
+    };
+    var vars = [];
+    var elem = null, name, val;
+    for(var i = 0; i < this.elements.length; i++)_loop(i);
+    return vars;
+};"
+    );
 }

ecmascript/transforms/src/typescript.rs

@@ -6,7 +6,7 @@ use fxhash::FxHashMap;
 use swc_atoms::js_word;
 use swc_common::{util::move_map::MoveMap, Fold, FoldWith, Spanned, Visit, VisitWith, DUMMY_SP};
 use swc_ecma_ast::*;
-use swc_ecma_utils::Id;
+use swc_ecma_utils::{ident::IdentLike, Id};
 
 /// Strips type annotations out.
 pub fn strip() -> impl Pass {
@@ -199,10 +199,12 @@ impl Fold<Vec<Pat>> for Strip {
 
 impl Fold<Vec<ModuleItem>> for Strip {
     fn fold(&mut self, items: Vec<ModuleItem>) -> Vec<ModuleItem> {
+        let old = self.phase;
+
         // First pass
+        self.phase = Phase::Analysis;
         let items = items.fold_children(self);
 
-        let old = self.phase;
         self.phase = Phase::DropImports;
 
         // Second pass
@@ -270,6 +272,25 @@ impl Fold<Vec<ModuleItem>> for Strip {
                     self.handle_enum(e, &mut stmts)
                 }
 
+                ModuleItem::ModuleDecl(ModuleDecl::ExportDefaultExpr(ExportDefaultExpr {
+                    expr: box Expr::Ident(ref i),
+                    ..
+                })) => {
+                    // type MyType = string;
+                    // export default MyType;
+
+                    let preserve = if let Some(decl_info) = self.scope.decls.get(&i.to_id()) {
+                        decl_info.has_concrete
+                    } else {
+                        true
+                    };
+
+                    if preserve {
+                        stmts.push(item)
+                    }
+                }
+
+                // Strip out ts-only extensions
                 ModuleItem::Stmt(Stmt::Decl(Decl::Fn(FnDecl {
                     function: Function { body: None, .. },
                     ..

ecmascript/transforms/tests/typescript_strip.rs

@@ -334,3 +334,33 @@ test!(
 to!(import_type, "import type foo from 'foo'", "");
 
 to!(export_type, "export type { foo }", "");
+
+to!(
+    issue_685,
+    "
+    type MyType = string;
+    export default MyType;",
+    ""
+);
+
+to!(
+    issue_685_2,
+    "
+    class MyType {}
+    type MyType = string;
+    export default MyType;",
+    "
+    class MyType {}
+    export default MyType;"
+);
+
+to!(
+    issue_685_3,
+    "
+    var MyType = function(){};
+    type MyType = string;
+    export default MyType;",
+    "
+    var MyType = function(){};
+    export default MyType;"
+);