Make sure arrow function grammar rules can deal with type annotations

Author: caitp

src/compiler/checker.ts

@@ -4392,7 +4392,7 @@ module ts {
         }
 
         /**
-         * Check if a Type was written as a tuple type literal. 
+         * Check if a Type was written as a tuple type literal.
          * Prefer using isTupleLikeType() unless the use of `elementTypes` is required.
          */
         function isTupleType(type: Type) : boolean {
@@ -11364,9 +11364,9 @@ module ts {
             if (node.kind === SyntaxKind.ArrowFunction) {
                 var arrowFunction = <ArrowFunction>node;
                 var sourceFile = getSourceFileOfNode(node);
-                var equalsGreaterThanLine = getLineAndCharacterOfPosition(sourceFile, getTokenPosOfNode(arrowFunction.equalsGreaterThanToken, sourceFile)).line;
-                var parametersLine = getLineAndCharacterOfPosition(sourceFile, arrowFunction.parameters.end).line;
-                if (equalsGreaterThanLine !== parametersLine) {
+                var startLine = getLineAndCharacterOfPosition(sourceFile, arrowFunction.equalsGreaterThanToken.pos).line;
+                var endLine = getLineAndCharacterOfPosition(sourceFile, arrowFunction.equalsGreaterThanToken.end).line;
+                if (startLine !== endLine) {
                     return grammarErrorOnNode(arrowFunction.equalsGreaterThanToken, Diagnostics.Line_terminator_not_permitted_before_arrow);
                 }
             }

tests/baselines/reference/disallowLineTerminatorBeforeArrow.errors.txt

@@ -12,9 +12,10 @@ tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts(2
 tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts(31,13): error TS1200: Line terminator not permitted before arrow.
 tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts(36,13): error TS1200: Line terminator not permitted before arrow.
 tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts(40,9): error TS1200: Line terminator not permitted before arrow.
+tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts(44,5): error TS1200: Line terminator not permitted before arrow.
 
 
-==== tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts (14 errors) ====
+==== tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts (15 errors) ====
     var f1 = ()
         => { }
         ~~
@@ -84,4 +85,21 @@ tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts(4
             ~~
 !!! error TS1200: Line terminator not permitted before arrow.
     }
+    
+    var func = (a: number): number
+        => a;
+        ~~
+!!! error TS1200: Line terminator not permitted before arrow.
+    
+    // Should be valid.
+    var funk = (a: number
+        ) => a;
+    
+    // Should be valid.
+    var funkier = (a: number)
+        : number => a;
+    
+    // Should be valid.
+    var funkiest = (a: number):
+        number => a;
 

tests/baselines/reference/disallowLineTerminatorBeforeArrow.js

@@ -40,6 +40,21 @@ module m {
     export var v = x
         => new City(Enum.claw);
 }
+
+var func = (a: number): number
+    => a;
+
+// Should be valid.
+var funk = (a: number
+    ) => a;
+
+// Should be valid.
+var funkier = (a: number)
+    : number => a;
+
+// Should be valid.
+var funkiest = (a: number):
+    number => a;
 
 
 //// [disallowLineTerminatorBeforeArrow.js]
@@ -108,3 +123,18 @@ var m;
         return new City(Enum.claw);
     };
 })(m || (m = {}));
+var func = function (a) {
+    return a;
+};
+// Should be valid.
+var funk = function (a) {
+    return a;
+};
+// Should be valid.
+var funkier = function (a) {
+    return a;
+};
+// Should be valid.
+var funkiest = function (a) {
+    return a;
+};

tests/cases/conformance/es6/arrowFunction/disallowLineTerminatorBeforeArrow.ts

@@ -39,3 +39,18 @@ module m {
     export var v = x
         => new City(Enum.claw);
 }
+
+var func = (a: number): number
+    => a;
+
+// Should be valid.
+var funk = (a: number
+    ) => a;
+
+// Should be valid.
+var funkier = (a: number)
+    : number => a;
+
+// Should be valid.
+var funkiest = (a: number):
+    number => a;