Change diagnostic

src/compiler/checker.ts

@@ -25518,7 +25518,7 @@ namespace ts {
                 switch (modifier.kind) {
                     case SyntaxKind.ConstKeyword:
                         if (node.kind !== SyntaxKind.EnumDeclaration) {
-                            return grammarErrorOnNode(node, Diagnostics.A_class_member_cannot_have_the_0_keyword, tokenToString(SyntaxKind.ConstKeyword));
+                            return grammarErrorOnNode(node, Diagnostics._0_modifier_cannot_be_used_here, tokenToString(SyntaxKind.ConstKeyword));
                         }
                         break;
                     case SyntaxKind.PublicKeyword:

src/compiler/diagnosticMessages.json

@@ -803,10 +803,6 @@
         "category": "Error",
         "code": 1247
     },
-    "A class member cannot have the '{0}' keyword.": {
-        "category": "Error",
-        "code": 1248
-    },
     "A decorator can only decorate a method implementation, not an overload.": {
         "category": "Error",
         "code": 1249

src/harness/parallel/worker.ts

@@ -55,7 +55,7 @@ namespace Harness.Parallel.Worker {
             retries() { return this; },
             slow() { return this; },
             timeout(n) {
-                timeout = n;
+                timeout = n as number;
                 return this;
             },
         };
@@ -127,7 +127,7 @@ namespace Harness.Parallel.Worker {
         const fakeContext: Mocha.ITestCallbackContext = {
             skip() { return this; },
             timeout(n) {
-                timeout = n;
+                timeout = n as number;
                 return this;
             },
             retries() { return this; },

tests/baselines/reference/ClassDeclarationWithInvalidConstOnPropertyDeclaration.errors.txt

@@ -1,9 +1,9 @@
-tests/cases/compiler/ClassDeclarationWithInvalidConstOnPropertyDeclaration.ts(2,3): error TS1248: A class member cannot have the 'const' keyword.
+tests/cases/compiler/ClassDeclarationWithInvalidConstOnPropertyDeclaration.ts(2,3): error TS1042: 'const' modifier cannot be used here.
 
 
 ==== tests/cases/compiler/ClassDeclarationWithInvalidConstOnPropertyDeclaration.ts (1 errors) ====
     class AtomicNumbers {
       static const H = 1;
       ~~~~~~~~~~~~~~~~~~~
-!!! error TS1248: A class member cannot have the 'const' keyword.
+!!! error TS1042: 'const' modifier cannot be used here.
     }