Add support for function declarations export statements

Author: kl0tl

src/Language/JavaScript/Parser/Grammar7.y

@@ -1262,6 +1262,15 @@ ImportSpecifier : IdentifierName
 -- [x]    export ExportClause ;
 -- [x]    export VariableStatement
 -- [ ]    export Declaration
+-- [ ]    Declaration :
+-- [ ]       HoistableDeclaration
+-- [ ]       ClassDeclaration
+-- [x]       LexicalDeclaration
+-- [ ]    HoistableDeclaration :
+-- [x]       FunctionDeclaration
+-- [ ]       GeneratorDeclaration
+-- [ ]       AsyncFunctionDeclaration
+-- [ ]       AsyncGeneratorDeclaration
 -- [ ]    export default HoistableDeclaration[Default]
 -- [ ]    export default ClassDeclaration[Default]
 -- [ ]    export default [lookahead ∉ { function, class }] AssignmentExpression[In] ;
@@ -1270,6 +1279,8 @@ ExportDeclaration : ExportClause AutoSemi
                          { $1                    {- 'ExportDeclaration1' -} }
                   | VariableStatement AutoSemi
                          { AST.JSExport $1 $2    {- 'ExportDeclaration2' -} }
+                  | FunctionDeclaration AutoSemi
+                         { AST.JSExport $1 $2    {- 'ExportDeclaration2' -} }
 
 -- ExportClause :
 --           { }

test/Test/Language/Javascript/ModuleParser.hs

@@ -47,6 +47,9 @@ testModuleParser = describe "Parse modules:" $ do
         test "export const a = 1;"
             `shouldBe`
             "Right (JSAstModule [JSModuleExportDeclaration (JSExport (JSConstant (JSVarInitExpression (JSIdentifier 'a') [JSDecimal '1'])))])"
+        test "export function f() {};"
+            `shouldBe`
+            "Right (JSAstModule [JSModuleExportDeclaration (JSExport (JSFunction 'f' () (JSBlock [])))])"
         test "export { a };"
             `shouldBe`
             "Right (JSAstModule [JSModuleExportDeclaration (JSExportLocals ((JSExportLocalSpecifier (JSIdentifier 'a'))))])"