Ticket #4: assert-assign.patch

Source/Compiler.cobra

@@ -1141 +1141 @@
     def warning(cw as CobraWarning)
         require not cw.isError
         _addMessage(cw)
-
+        
+    def augmentWarning(node as ISyntaxNode, lookFor as String, srch as String, augment as String) as bool
+        require 
+            lookFor.length
+            augment.length
+        body
+            return _augmentWarning(CobraWarning(node.token, lookFor), srch, augment)
+        
     shared
         var _unknownSuggestions = {
         # literals
@@ -1207 +1214 @@
             _errors.add(message)
         else
             _warnings.add(message)
-
+            
+    def _augmentWarning(message as SourceException, srch as String, augment as String) as bool
+        key = if(message.hasSourceSite, '[message.fileName]:[message.lineNum]', '')
+        if not _messagesPerSourceLine.containsKey(key)
+            return false
+            
+        lowerToMatch = message.message.toLower
+        lowerSrch = if(srch.length > 0, srch.toLower, '')
+        for se in _messagesPerSourceLine[key]
+            lowerMsg = se.message.toLower
+            if lowerMsg.contains(lowerToMatch)   # matched
+                if srch.length == 0 or lowerMsg.contains(lowerSrch)
+                    se.augmentMessage(augment)
+                    return true
+        return false
+            
     ##
     ## Generating and compiling C#
     ##

Source/Node.cobra

@@ -54 +54 @@
         else
             return '[type]: ' + .message
 
+    def augmentMessage(augment as String)
+        _message = _message + augment
+        
     def toString as String is override
         return '[.getType.name]: [.consoleString]'
 

Source/CobraParser.cobra

@@ -40 +40 @@
 
     def warning(we as CobraWarning)
 
-
 interface IErrorRecorder
 
     def recordError(error as SourceException)
@@ -1775 +1774 @@
     def assertStmt as Stmt
         token = .expect('ASSERT')
         expr = .expression
+        if expr inherits AbstractAssignExpr  # ++ [Inverse]CoalesceAssign expr?
+            .throwError("Assert condition is an assignment. Since asserts may be suppressed these conditions should not have side effects. Perhaps you meant to do a comparison '==' instead of assignment '='")
         info = if(.optional('COMMA'), .expression, nil)
         return AssertStmt(token, expr, info)
 
+
     def branchStmt as Stmt
         token = .expect('BRANCH')
         e = .expression

Source/Statements.cobra

@@ -188 +188 @@
     def _bindImp
         base._bindImp
         _expr.bindImp
+        # Augment any warning about non nilable expr evaluate to true
+        .compiler.augmentWarning(this, "always evaluate to true because it is not nilable", _
+            'You can remove the expression', _
+            "This assertion is always true. You can remove the assertion or correct the condition")
         if _info
             _info.bindImp
 

Tests/820-errors/300-statements/400-assert-assign.cobra

@@ +1 @@
+# .error. assert condition is an assignment
+class Test
+
+    def main
+        is shared
+        
+        a = 23+1
+        assert a=24 

Tests/800-warnings/400-assert-true.cobra

@@ +1 @@
+class AssertTrue
+
+    def main is shared
+        a= 'MyString'
+        assert a   #.warning. This assertion is always true

Developer/IntermediateReleaseNotes.text

@@ -35 +35 @@
 * Fixed: Cannot implement a method whose signature is matched by an extension method of a base class.
 
 * Fixed: Method return types from generics in DLLs are always considered nilable even if the generic parameter was not (such as `bool`).
+
+*Fixed: Disallow assignment in an assert: ticket4 (hopscc)