Parser: Fix another break/continue/return issue

After the previous lexer/parser fix, another problem showed up
with these keywords enclosed in curly braces. The solution was
to update the AutoSemi parser rule to accept any of the following:

- A real semicolon
- An AutoSemiToken inserted by the lexer
- Nothing (which fixes this new case)

Tests added as well.

Author: erikd

runtests.hs

@@ -333,6 +333,10 @@ parserSuite = testGroup "Parser"
     , testCase "AutoSemiBreak"     (testProg "if(true)break \nfoo();"      "Right (JSSourceElementsTop [JSIf (JSExpression [JSLiteral \"true\"]) ([JSBreak [] JSLiteral \"\"]) ([]),JSExpression [JSIdentifier \"foo\",JSArguments []],JSLiteral \";\",JSLiteral \"\"])")
     , testCase "AutoSemiContinue"  (testProg "if(true)continue \nfoo();"   "Right (JSSourceElementsTop [JSIf (JSExpression [JSLiteral \"true\"]) ([JSContinue [] JSLiteral \"\"]) ([]),JSExpression [JSIdentifier \"foo\",JSArguments []],JSLiteral \";\",JSLiteral \"\"])")
     , testCase "AutoSemiReturn"    (testProg "if(true)break \nfoo();"      "Right (JSSourceElementsTop [JSIf (JSExpression [JSLiteral \"true\"]) ([JSBreak [] JSLiteral \"\"]) ([]),JSExpression [JSIdentifier \"foo\",JSArguments []],JSLiteral \";\",JSLiteral \"\"])")
+
+    , testCase "BreakBlock"       (testProg "{break}"      "Right (JSSourceElementsTop [JSBlock ([JSBreak [] JSLiteral \"\"]),JSLiteral \"\"])")
+    , testCase "ContinueBlock"    (testProg "{continue}"   "Right (JSSourceElementsTop [JSBlock ([JSContinue [] JSLiteral \"\"]),JSLiteral \"\"])")
+    , testCase "ReturnBlock"      (testProg "{return}"     "Right (JSSourceElementsTop [JSBlock ([JSReturn [] JSLiteral \"\"]),JSLiteral \"\"])")
     ]
 
 caseHelloWorld :: Assertion

src/Language/JavaScript/Parser/Grammar5.y

@@ -127,7 +127,7 @@ import qualified Language.JavaScript.Parser.AST as AST
 -- Sort out automatically inserted semi-colons.
 -- A MaybeSemi is an actual semi-colon or nothing.
 -- An AutoSemu is either an actual semi-colon or 'virtual' semi-colon inserted
--- by the Alex lexer.
+-- by the Alex lexer or nothing.
 
 MaybeSemi :: { AST.JSNode }
 MaybeSemi : ';' { AST.NT (AST.JSLiteral ";") (ss $1) (gc $1)}
@@ -136,6 +136,7 @@ MaybeSemi : ';' { AST.NT (AST.JSLiteral ";") (ss $1) (gc $1)}
 AutoSemi :: { AST.JSNode }
 AutoSemi : ';'         { AST.NT (AST.JSLiteral ";") (ss $1) (gc $1)}
          | 'autosemi'  { AST.NT (AST.JSLiteral "") (ss $1) (gc $1)}
+         |             { AST.NT (AST.JSLiteral "") tokenPosnEmpty []}
 
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