KT-1019 parser should recover from missing parentheses in function declaration

#KT-1019 Fixed

compiler/frontend/src/org/jetbrains/jet/lang/parsing/JetParsing.java

@@ -1042,7 +1042,12 @@ public class JetParsing extends AbstractJetParsing {
             typeParameterListOccurred = true;
         }
 
-        parseValueParameterList(false, valueParametersFollow);
+        if (at(LPAR)) {
+            parseValueParameterList(false, valueParametersFollow);
+        }
+        else {
+            error("Expecting '('");
+        }
 
         if (at(COLON)) {
             advance(); // COLON
@@ -1648,10 +1653,11 @@ public class JetParsing extends AbstractJetParsing {
      *   ;
      */
     void parseValueParameterList(boolean isFunctionTypeContents, TokenSet recoverySet) {
+        assert _at(LPAR);
         PsiBuilder.Marker parameters = mark();
 
         myBuilder.disableNewlines();
-        expect(LPAR, "Expecting '(", recoverySet);
+        advance(); // LPAR
 
         if (!parseIdeTemplate()) {
             if (!at(RPAR) && !atSet(recoverySet)) {

compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/funKeyword.kt

@@ -1 +1 @@
-fun<!SYNTAX, SYNTAX, SYNTAX, SYNTAX, SYNTAX!><!>
+fun<!SYNTAX, SYNTAX!><!>

compiler/testData/psi/FunctionNoParameterList.kt

@@ -0,0 +1,6 @@
+class A {
+    fun foo
+    class B {}
+    fun bar
+}
+class C {}

compiler/testData/psi/FunctionNoParameterList.txt

@@ -0,0 +1,50 @@
+JetFile: FunctionNoParameterList.kt
+  NAMESPACE_HEADER
+    <empty list>
+  CLASS
+    PsiElement(class)('class')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('A')
+    PsiWhiteSpace(' ')
+    TYPE_PARAMETER_LIST
+      <empty list>
+    CLASS_BODY
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      FUN
+        PsiElement(fun)('fun')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('foo')
+        PsiErrorElement:Expecting '('
+          <empty list>
+      PsiWhiteSpace('\n    ')
+      CLASS
+        PsiElement(class)('class')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('B')
+        PsiWhiteSpace(' ')
+        TYPE_PARAMETER_LIST
+          <empty list>
+        CLASS_BODY
+          PsiElement(LBRACE)('{')
+          PsiElement(RBRACE)('}')
+      PsiWhiteSpace('\n    ')
+      FUN
+        PsiElement(fun)('fun')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('bar')
+        PsiErrorElement:Expecting '('
+          <empty list>
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')
+  PsiWhiteSpace('\n')
+  CLASS
+    PsiElement(class)('class')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('C')
+    PsiWhiteSpace(' ')
+    TYPE_PARAMETER_LIST
+      <empty list>
+    CLASS_BODY
+      PsiElement(LBRACE)('{')
+      PsiElement(RBRACE)('}')

compiler/testData/psi/Functions_ERR.jet

@@ -1,5 +1,4 @@
 fun foo)
-fun [a] f foo()
 fun [a] T.foo(a : ) : bar
 fun [a()] T.foo<>(a : foo) : bar
 fun [a()] T.foo<T, , T>(a : foo) : bar

compiler/testData/psi/Functions_ERR.txt

@@ -5,35 +5,10 @@ JetFile: Functions_ERR.jet
     PsiElement(fun)('fun')
     PsiWhiteSpace(' ')
     PsiElement(IDENTIFIER)('foo')
-    VALUE_PARAMETER_LIST
+    PsiErrorElement:Expecting '('
-      PsiErrorElement:Expecting '(
+      <empty list>
-        <empty list>
+  PsiErrorElement:Expecting package directive or top level declaration
-      PsiElement(RPAR)(')')
+    PsiElement(RPAR)(')')
-  PsiWhiteSpace('\n')
-  FUN
-    PsiElement(fun)('fun')
-    PsiWhiteSpace(' ')
-    ANNOTATION
-      PsiElement(LBRACKET)('[')
-      ANNOTATION_ENTRY
-        CONSTRUCTOR_CALLEE
-          TYPE_REFERENCE
-            USER_TYPE
-              REFERENCE_EXPRESSION
-                PsiElement(IDENTIFIER)('a')
-      PsiElement(RBRACKET)(']')
-    PsiWhiteSpace(' ')
-    PsiElement(IDENTIFIER)('f')
-    PsiWhiteSpace(' ')
-    VALUE_PARAMETER_LIST
-      PsiErrorElement:Expecting '(
-        PsiElement(IDENTIFIER)('foo')
-      VALUE_PARAMETER
-        PsiErrorElement:Parameter name expected
-          PsiElement(LPAR)('(')
-        PsiErrorElement:Parameters must have type annotation
-          <empty list>
-      PsiElement(RPAR)(')')
   PsiWhiteSpace('\n')
   FUN
     PsiElement(fun)('fun')