Merge pull request #651 from Microsoft/testForDiagnosticBounds

Add asserts for bounds on diagnostics

Author: JsonFreeman

src/compiler/core.ts

@@ -198,6 +198,9 @@ module ts {
 
     export function createFileDiagnostic(file: SourceFile, start: number, length: number, message: DiagnosticMessage, ...args: any[]): Diagnostic;
     export function createFileDiagnostic(file: SourceFile, start: number, length: number, message: DiagnosticMessage): Diagnostic {
+        Debug.assert(start >= 0, "start must be non-negative, is " + start);
+        Debug.assert(length >= 0, "length must be non-negative, is " + length);
+
         var text = getLocaleSpecificMessage(message.key);
 
         if (arguments.length > 4) {
@@ -252,6 +255,9 @@ module ts {
     }
 
     export function flattenDiagnosticChain(file: SourceFile, start: number, length: number, diagnosticChain: DiagnosticMessageChain, newLine: string): Diagnostic {
+        Debug.assert(start >= 0, "start must be non-negative, is " + start);
+        Debug.assert(length >= 0, "length must be non-negative, is " + length);
+
         var code = diagnosticChain.code;
         var category = diagnosticChain.category;
         var messageText = "";

src/compiler/parser.ts

@@ -81,7 +81,7 @@ module ts {
     export function createDiagnosticForNode(node: Node, message: DiagnosticMessage, arg0?: any, arg1?: any, arg2?: any): Diagnostic {
         node = getErrorSpanForNode(node);
         var file = getSourceFileOfNode(node);
-        var start = skipTrivia(file.text, node.pos);
+        var start = node.kind === SyntaxKind.Missing ? node.pos : skipTrivia(file.text, node.pos);
         var length = node.end - start;
 
         return createFileDiagnostic(file, start, length, message, arg0, arg1, arg2);
@@ -2876,10 +2876,11 @@ module ts {
             parseExpected(SyntaxKind.VarKeyword);
             node.declarations = parseVariableDeclarationList(flags, /*noIn*/false);
             parseSemicolon();
+            finishNode(node);
             if (!node.declarations.length && file.syntacticErrors.length === errorCountBeforeVarStatement) {
                 grammarErrorOnNode(node, Diagnostics.Variable_declaration_list_cannot_be_empty);
             }
-            return finishNode(node);
+            return node;
         }
 
         function parseFunctionDeclaration(pos?: number, flags?: NodeFlags): FunctionDeclaration {

tests/baselines/reference/parserEqualsGreaterThanAfterFunction1.errors.txt

@@ -2,5 +2,5 @@
     function =>
              ~~
 !!! Identifier expected.
-             
+            
 !!! Function implementation is missing or not immediately following the declaration.

tests/baselines/reference/parserEqualsGreaterThanAfterFunction2.errors.txt

@@ -8,5 +8,5 @@
 !!! ',' expected.
 
 !!! ')' expected.
-             
+            
 !!! Function implementation is missing or not immediately following the declaration.

tests/baselines/reference/parserVariableDeclaration6.errors.txt

@@ -1,4 +1,4 @@
 ==== tests/cases/conformance/parser/ecmascript5/VariableDeclarations/parserVariableDeclaration6.ts (1 errors) ====
     var
-    
+    ~~~
 !!! Variable declaration list cannot be empty.

tests/baselines/reference/parserVariableDeclaration8.errors.txt

@@ -1,4 +1,4 @@
 ==== tests/cases/conformance/parser/ecmascript5/VariableDeclarations/parserVariableDeclaration8.ts (1 errors) ====
     var ;
-    
+    ~~~~~
 !!! Variable declaration list cannot be empty.