Report TS2516 for non-consecutive abstract method declarations

Author: Shadow0Bit

tsc/internal/checker/checker.go

@@ -3639,7 +3639,8 @@ func (c *Checker) checkFunctionOrConstructorSymbolWorker(symbol *ast.Symbol) {
 					}
 					return
 				}
-				if ast.NodeIsPresent(subsequentNode.Body()) {
+				// Abstract methods can't have an implementation in the same class, so the next method can't be a misnamed one.
+				if ast.NodeIsPresent(subsequentNode.Body()) && !ast.HasSyntacticModifier(node, ast.ModifierFlagsAbstract) {
 					c.error(errorNode, diagnostics.Function_implementation_name_must_be_0, scanner.DeclarationNameToString(name))
 					return
 				}

tsc/testdata/baselines/reference/compiler/abstractMethodNonConsecutiveDeclarations.errors.txt

@@ -1,4 +1,4 @@
-abstractMethodNonConsecutiveDeclarations.ts(6,5): error TS2389: Function implementation name must be 'func1'.
+abstractMethodNonConsecutiveDeclarations.ts(4,14): error TS2516: All declarations of an abstract method must be consecutive.
 abstractMethodNonConsecutiveDeclarations.ts(14,14): error TS2516: All declarations of an abstract method must be consecutive.
 
 
@@ -7,10 +7,10 @@ abstractMethodNonConsecutiveDeclarations.ts(14,14): error TS2516: All declaratio
 
     abstract class SeparatedByMethod {
         abstract func1(): void;
+                 ~~~~~
+!!! error TS2516: All declarations of an abstract method must be consecutive.
 
         func2(): string {
-        ~~~~~
-!!! error TS2389: Function implementation name must be 'func1'.
             return 'hi';
         }