25356 - Instance property is not a block scoped variable

src/compiler/checker.ts

@@ -17478,7 +17478,7 @@ namespace ts {
             if (isInPropertyInitializer(node) &&
                 !isBlockScopedNameDeclaredBeforeUse(valueDeclaration, right)
                 && !isPropertyDeclaredInAncestorClass(prop)) {
-                diagnosticMessage = error(right, Diagnostics.Block_scoped_variable_0_used_before_its_declaration, declarationName);
+                diagnosticMessage = error(right, Diagnostics.Property_0_is_used_before_its_initialization, declarationName);
             }
             else if (valueDeclaration.kind === SyntaxKind.ClassDeclaration &&
                 node.parent.kind !== SyntaxKind.TypeReference &&

src/compiler/diagnosticMessages.json

@@ -2401,6 +2401,10 @@
         "category": "Error",
         "code": 2728
     },
+    "Property '{0}' is used before its initialization.": {
+        "category": "Error",
+        "code": 2729
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -5419,6 +5419,7 @@ declare namespace ts {
         Cannot_find_lib_definition_for_0: DiagnosticMessage;
         Cannot_find_lib_definition_for_0_Did_you_mean_1: DiagnosticMessage;
         _0_was_declared_here: DiagnosticMessage;
+        Property_0_is_used_before_its_initialization: DiagnosticMessage;
         Import_declaration_0_is_using_private_name_1: DiagnosticMessage;
         Type_parameter_0_of_exported_class_has_or_is_using_private_name_1: DiagnosticMessage;
         Type_parameter_0_of_exported_interface_has_or_is_using_private_name_1: DiagnosticMessage;

tests/baselines/reference/classMergedWithInterfaceMultipleBasesNoError.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/compiler/classMergedWithInterfaceMultipleBasesNoError.ts(8,30): error TS2448: Block-scoped variable 'handleIntersection' used before its declaration.
+tests/cases/compiler/classMergedWithInterfaceMultipleBasesNoError.ts(8,30): error TS2729: Property 'handleIntersection' is used before its initialization.
 
 
 ==== tests/cases/compiler/classMergedWithInterfaceMultipleBasesNoError.ts (1 errors) ====
@@ -11,7 +11,7 @@ tests/cases/compiler/classMergedWithInterfaceMultipleBasesNoError.ts(8,30): erro
     export default class extends Foo {
         readonly observer = this.handleIntersection;
                                  ~~~~~~~~~~~~~~~~~~
-!!! error TS2448: Block-scoped variable 'handleIntersection' used before its declaration.
+!!! error TS2729: Property 'handleIntersection' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/classMergedWithInterfaceMultipleBasesNoError.ts:9:14: 'handleIntersection' was declared here.
         readonly handleIntersection = () => { }
     }

tests/baselines/reference/classStaticInitializersUsePropertiesBeforeDeclaration.errors.txt

@@ -1,8 +1,8 @@
 tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(2,25): error TS2450: Enum 'Enum' used before its declaration.
-tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(2,30): error TS2448: Block-scoped variable 'A' used before its declaration.
+tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(2,30): error TS2729: Property 'A' is used before its initialization.
 tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(3,31): error TS2448: Block-scoped variable 'ObjLiteral' used before its declaration.
-tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(3,42): error TS2448: Block-scoped variable 'A' used before its declaration.
-tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(4,40): error TS2448: Block-scoped variable 'A' used before its declaration.
+tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(3,42): error TS2729: Property 'A' is used before its initialization.
+tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(4,40): error TS2729: Property 'A' is used before its initialization.
 
 
 ==== tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts (5 errors) ====
@@ -12,18 +12,18 @@ tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts(4,
 !!! error TS2450: Enum 'Enum' used before its declaration.
 !!! related TS2728 tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts:7:6: 'Enum' was declared here.
                                  ~
-!!! error TS2448: Block-scoped variable 'A' used before its declaration.
+!!! error TS2729: Property 'A' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts:8:5: 'A' was declared here.
         static objLiteralMember = ObjLiteral.A;
                                   ~~~~~~~~~~
 !!! error TS2448: Block-scoped variable 'ObjLiteral' used before its declaration.
 !!! related TS2728 tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts:11:7: 'ObjLiteral' was declared here.
                                              ~
-!!! error TS2448: Block-scoped variable 'A' used before its declaration.
+!!! error TS2729: Property 'A' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts:12:5: 'A' was declared here.
         static namespaceMember = Namespace.A;
                                            ~
-!!! error TS2448: Block-scoped variable 'A' used before its declaration.
+!!! error TS2729: Property 'A' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/classStaticInitializersUsePropertiesBeforeDeclaration.ts:16:16: 'A' was declared here.
     }
 

tests/baselines/reference/forwardRefInClassProperties.errors.txt

@@ -1,5 +1,5 @@
-tests/cases/compiler/forwardRefInClassProperties.ts(3,15): error TS2448: Block-scoped variable '_a' used before its declaration.
-tests/cases/compiler/forwardRefInClassProperties.ts(6,22): error TS2448: Block-scoped variable '_A' used before its declaration.
+tests/cases/compiler/forwardRefInClassProperties.ts(3,15): error TS2729: Property '_a' is used before its initialization.
+tests/cases/compiler/forwardRefInClassProperties.ts(6,22): error TS2729: Property '_A' is used before its initialization.
 tests/cases/compiler/forwardRefInClassProperties.ts(11,17): error TS2448: Block-scoped variable 'b' used before its declaration.
 
 
@@ -8,19 +8,19 @@ tests/cases/compiler/forwardRefInClassProperties.ts(11,17): error TS2448: Block-
     {
         _b = this._a; // undefined, no error/warning
                   ~~
-!!! error TS2448: Block-scoped variable '_a' used before its declaration.
+!!! error TS2729: Property '_a' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/forwardRefInClassProperties.ts:4:5: '_a' was declared here.
         _a = 3;
 
         static _B = Test._A; // undefined, no error/warning
                          ~~
-!!! error TS2448: Block-scoped variable '_A' used before its declaration.
+!!! error TS2729: Property '_A' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/forwardRefInClassProperties.ts:7:12: '_A' was declared here.
         static _A = 3;
 
         method()
         {
-            let a = b; // Block-scoped variable 'b' used before its declaration
+            let a = b; // Property 'b' is used before its initialization.
                     ~
 !!! error TS2448: Block-scoped variable 'b' used before its declaration.
 !!! related TS2728 tests/cases/compiler/forwardRefInClassProperties.ts:12:13: 'b' was declared here.

tests/baselines/reference/forwardRefInClassProperties.js

@@ -9,7 +9,7 @@ class Test
 
     method()
     {
-        let a = b; // Block-scoped variable 'b' used before its declaration
+        let a = b; // Property 'b' is used before its initialization.
         let b = 3;
     }
 }
@@ -22,7 +22,7 @@ var Test = /** @class */ (function () {
         this._a = 3;
     }
     Test.prototype.method = function () {
-        var a = b; // Block-scoped variable 'b' used before its declaration
+        var a = b; // Property 'b' is used before its initialization.
         var b = 3;
     };
     Test._B = Test._A; // undefined, no error/warning

tests/baselines/reference/forwardRefInClassProperties.symbols

@@ -23,7 +23,7 @@ class Test
     method()
 >method : Symbol(Test.method, Decl(forwardRefInClassProperties.ts, 6, 18))
     {
-        let a = b; // Block-scoped variable 'b' used before its declaration
+        let a = b; // Property 'b' is used before its initialization.
 >a : Symbol(a, Decl(forwardRefInClassProperties.ts, 10, 11))
 >b : Symbol(b, Decl(forwardRefInClassProperties.ts, 11, 11))
 

tests/baselines/reference/forwardRefInClassProperties.types

@@ -25,7 +25,7 @@ class Test
     method()
 >method : () => void
     {
-        let a = b; // Block-scoped variable 'b' used before its declaration
+        let a = b; // Property 'b' is used before its initialization.
 >a : number
 >b : number
 

tests/baselines/reference/scopeCheckStaticInitializer.errors.txt

@@ -1,14 +1,14 @@
-tests/cases/compiler/scopeCheckStaticInitializer.ts(2,38): error TS2448: Block-scoped variable 'data' used before its declaration.
+tests/cases/compiler/scopeCheckStaticInitializer.ts(2,38): error TS2729: Property 'data' is used before its initialization.
 tests/cases/compiler/scopeCheckStaticInitializer.ts(5,23): error TS2449: Class 'After' used before its declaration.
-tests/cases/compiler/scopeCheckStaticInitializer.ts(5,29): error TS2448: Block-scoped variable 'data' used before its declaration.
+tests/cases/compiler/scopeCheckStaticInitializer.ts(5,29): error TS2729: Property 'data' is used before its initialization.
 tests/cases/compiler/scopeCheckStaticInitializer.ts(6,23): error TS2449: Class 'After' used before its declaration.
 
 
 ==== tests/cases/compiler/scopeCheckStaticInitializer.ts (4 errors) ====
     class X {
         static illegalBeforeProperty = X.data;
                                          ~~~~
-!!! error TS2448: Block-scoped variable 'data' used before its declaration.
+!!! error TS2729: Property 'data' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/scopeCheckStaticInitializer.ts:7:12: 'data' was declared here.
         static okBeforeMethod = X.method;
 
@@ -17,7 +17,7 @@ tests/cases/compiler/scopeCheckStaticInitializer.ts(6,23): error TS2449: Class '
 !!! error TS2449: Class 'After' used before its declaration.
 !!! related TS2728 tests/cases/compiler/scopeCheckStaticInitializer.ts:10:7: 'After' was declared here.
                                 ~~~~
-!!! error TS2448: Block-scoped variable 'data' used before its declaration.
+!!! error TS2729: Property 'data' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/scopeCheckStaticInitializer.ts:11:12: 'data' was declared here.
         static illegal3 = After.method;
                           ~~~~~

tests/baselines/reference/useBeforeDeclaration_propertyAssignment.errors.txt

@@ -1,11 +1,11 @@
-tests/cases/compiler/useBeforeDeclaration_propertyAssignment.ts(2,27): error TS2448: Block-scoped variable 'b' used before its declaration.
+tests/cases/compiler/useBeforeDeclaration_propertyAssignment.ts(2,27): error TS2729: Property 'b' is used before its initialization.
 
 
 ==== tests/cases/compiler/useBeforeDeclaration_propertyAssignment.ts (1 errors) ====
     export class C {
         public a =  { b: this.b };
                               ~
-!!! error TS2448: Block-scoped variable 'b' used before its declaration.
+!!! error TS2729: Property 'b' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/useBeforeDeclaration_propertyAssignment.ts:3:13: 'b' was declared here.
         private b = 0;
     }

tests/baselines/reference/useBeforeDeclaration_superClass.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/compiler/useBeforeDeclaration_superClass.ts(25,18): error TS2448: Block-scoped variable 'x' used before its declaration.
+tests/cases/compiler/useBeforeDeclaration_superClass.ts(25,18): error TS2729: Property 'x' is used before its initialization.
 
 
 ==== tests/cases/compiler/useBeforeDeclaration_superClass.ts (1 errors) ====
@@ -28,7 +28,7 @@ tests/cases/compiler/useBeforeDeclaration_superClass.ts(25,18): error TS2448: Bl
     class J implements I {
         old_x = this.x;
                      ~
-!!! error TS2448: Block-scoped variable 'x' used before its declaration.
+!!! error TS2729: Property 'x' is used before its initialization.
 !!! related TS2728 tests/cases/compiler/useBeforeDeclaration_superClass.ts:26:5: 'x' was declared here.
         x = 1;
     }

tests/cases/compiler/forwardRefInClassProperties.ts

@@ -8,7 +8,7 @@ class Test
 
     method()
     {
-        let a = b; // Block-scoped variable 'b' used before its declaration
+        let a = b; // Property 'b' is used before its initialization.
         let b = 3;
     }
 }