fix & improve coverage of `estree` (#1935)

- fix `estree` conversion of getter/setter
- fix non-directive literal in `to_mozilla_ast()`
- revamp `test/mozilla-ast.js`
  - reuse `test/ufuzz.js` for code generation
  - use `acorn.parse()` for creating `estree`
- extend `test/ufuzz.js` for `acorn` workaround
  - catch variable redefinition
  - non-trivial literal as directive
  - adjust options for tolerance

Miscellaneous
- optional semi-colon when parsing directives

fixes #1914
closes #1915

2 files changed, 35 insertions, 37 deletions

diff --git a/lib/mozilla-ast.js b/lib/mozilla-ast.js
index 7d246758..8d7ee4b8 100644
--- a/lib/mozilla-ast.js
+++ b/lib/mozilla-ast.js
@@ -111,23 +111,19 @@
         },
         Property: function(M) {
             var key = M.key;
-            var name = key.type == "Identifier" ? key.name : key.value;
             var args = {
                 start    : my_start_token(key),
                 end      : my_end_token(M.value),
-                key      : name,
+                key      : key.type == "Identifier" ? key.name : key.value,
                 value    : from_moz(M.value)
             };
-            switch (M.kind) {
-              case "init":
-                return new AST_ObjectKeyVal(args);
-              case "set":
-                args.value.name = from_moz(key);
-                return new AST_ObjectSetter(args);
-              case "get":
-                args.value.name = from_moz(key);
-                return new AST_ObjectGetter(args);
-            }
+            if (M.kind == "init") return new AST_ObjectKeyVal(args);
+            args.key = new AST_SymbolAccessor({
+                name: args.key
+            });
+            args.value = new AST_Accessor(args.value);
+            if (M.kind == "get") return new AST_ObjectGetter(args);
+            if (M.kind == "set") return new AST_ObjectSetter(args);
         },
         ArrayExpression: function(M) {
             return new AST_Array({
@@ -260,10 +256,7 @@
     map("CallExpression", AST_Call, "callee>expression, arguments@args");
 
     def_to_moz(AST_Toplevel, function To_Moz_Program(M) {
-        return {
-            type: "Program",
-            body: M.body.map(to_moz)
-        };
+        return to_moz_scope("Program", M);
     });
 
     def_to_moz(AST_Defun, function To_Moz_FunctionDeclaration(M) {
@@ -271,7 +264,7 @@
             type: "FunctionDeclaration",
             id: to_moz(M.name),
             params: M.argnames.map(to_moz),
-            body: to_moz_block(M)
+            body: to_moz_scope("BlockStatement", M)
         }
     });
 
@@ -280,7 +273,7 @@
             type: "FunctionExpression",
             id: to_moz(M.name),
             params: M.argnames.map(to_moz),
-            body: to_moz_block(M)
+            body: to_moz_scope("BlockStatement", M)
         }
     });
 
@@ -386,11 +379,10 @@
     });
 
     def_to_moz(AST_ObjectProperty, function To_Moz_Property(M) {
-        var key = (
-            is_identifier(M.key)
-            ? {type: "Identifier", name: M.key}
-            : {type: "Literal", value: M.key}
-        );
+        var key = {
+            type: "Literal",
+            value: M.key instanceof AST_SymbolAccessor ? M.key.name : M.key
+        };
         var kind;
         if (M instanceof AST_ObjectKeyVal) {
             kind = "init";
@@ -551,8 +543,8 @@
         moz_to_me = new Function("U2", "my_start_token", "my_end_token", "from_moz", "return(" + moz_to_me + ")")(
             exports, my_start_token, my_end_token, from_moz
         );
-        me_to_moz = new Function("to_moz", "to_moz_block", "return(" + me_to_moz + ")")(
-            to_moz, to_moz_block
+        me_to_moz = new Function("to_moz", "to_moz_block", "to_moz_scope", "return(" + me_to_moz + ")")(
+            to_moz, to_moz_block, to_moz_scope
         );
         MOZ_TO_ME[moztype] = moz_to_me;
         def_to_moz(mytype, me_to_moz);
@@ -610,4 +602,14 @@
         };
     };
 
+    function to_moz_scope(type, node) {
+        var body = node.body.map(to_moz);
+        if (node.body[0] instanceof AST_SimpleStatement && node.body[0].body instanceof AST_String) {
+            body.unshift(to_moz(new AST_EmptyStatement(node.body[0])));
+        }
+        return {
+            type: type,
+            body: body
+        };
+    };
 })();
diff --git a/lib/parse.js b/lib/parse.js
index f1089501..74c00b74 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -805,24 +805,20 @@ function parse($TEXT, options) {
         handle_regexp();
         switch (S.token.type) {
           case "string":
-            var dir = false;
-            if (S.in_directives === true) {
-                if ((is_token(peek(), "punc", ";") || peek().nlb) && S.token.raw.indexOf("\\") === -1) {
+            if (S.in_directives) {
+                tmp = peek();
+                if (S.token.raw.indexOf("\\") == -1
+                    && (tmp.nlb
+                        || is_token(tmp, "eof")
+                        || is_token(tmp, "punc", ";")
+                        || is_token(tmp, "punc", "}"))) {
                     S.input.add_directive(S.token.value);
                 } else {
                     S.in_directives = false;
                 }
             }
             var dir = S.in_directives, stat = simple_statement();
-            if (dir) {
-                return new AST_Directive({
-                    start : stat.body.start,
-                    end   : stat.body.end,
-                    quote : stat.body.quote,
-                    value : stat.body.value,
-                });
-            }
-            return stat;
+            return dir ? new AST_Directive(stat.body) : stat;
           case "num":
           case "regexp":
           case "operator":