microsoft · sandersn · Sep 15, 2022 · Jul 5, 2022 · Jul 5, 2022 · Jul 5, 2022
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -29182,11 +29182,30 @@ namespace ts {
         }
 
         function reportObjectPossiblyNullOrUndefinedError(node: Node, facts: TypeFacts) {
-            error(node, facts & TypeFacts.IsUndefined ? facts & TypeFacts.IsNull ?
-                Diagnostics.Object_is_possibly_null_or_undefined :
-                Diagnostics.Object_is_possibly_undefined :
-                Diagnostics.Object_is_possibly_null
-            );
+            const nodeText = isEntityNameExpression(node) ? entityNameToString(node) : undefined;
+            if (node.kind === SyntaxKind.NullKeyword) {
+                error(node, Diagnostics.The_value_0_cannot_be_used_here, "null");
+                return;
+            }
+            if (nodeText !== undefined && nodeText.length < 100) {
+                if (isIdentifier(node) && nodeText === "undefined") {
+                    error(node, Diagnostics.The_value_0_cannot_be_used_here, "undefined");
+                    return;
+                }
+                error(node, facts & TypeFacts.IsUndefined ? facts & TypeFacts.IsNull ?
+                    Diagnostics._0_is_possibly_null_or_undefined :
+                    Diagnostics._0_is_possibly_undefined :
+                    Diagnostics._0_is_possibly_null,
+                    nodeText
+                );
+            }
+            else {
+                error(node, facts & TypeFacts.IsUndefined ? facts & TypeFacts.IsNull ?
+                    Diagnostics.Object_is_possibly_null_or_undefined :
+                    Diagnostics.Object_is_possibly_undefined :
+                    Diagnostics.Object_is_possibly_null
+                );
+            }
         }
 
         function reportCannotInvokePossiblyNullOrUndefinedError(node: Node, facts: TypeFacts) {
@@ -29203,6 +29222,13 @@ namespace ts {
             reportError: (node: Node, facts: TypeFacts) => void
         ): Type {
             if (strictNullChecks && type.flags & TypeFlags.Unknown) {
+                if (isEntityNameExpression(node)) {
+                    const nodeText = entityNameToString(node);
+                    if (nodeText.length < 100) {
+                        error(node, Diagnostics._0_is_of_type_unknown, nodeText);
+                        return errorType;
+                    }
+                }
                 error(node, Diagnostics.Object_is_of_type_unknown);
                 return errorType;
             }
@@ -29222,6 +29248,17 @@ namespace ts {
         function checkNonNullNonVoidType(type: Type, node: Node): Type {
             const nonNullType = checkNonNullType(type, node);
             if (nonNullType.flags & TypeFlags.Void) {
+                if (isEntityNameExpression(node)) {
+                    const nodeText = entityNameToString(node);
+                    if (isIdentifier(node) && nodeText === "undefined") {
+                        error(node, Diagnostics.The_value_0_cannot_be_used_here, nodeText);
+                        return nonNullType;
+                    }
+                    if (nodeText.length < 100) {
+                        error(node, Diagnostics._0_is_possibly_undefined, nodeText);
+                        return nonNullType;
+                    }
+                }
                 error(node, Diagnostics.Object_is_possibly_undefined);
             }
             return nonNullType;

diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
@@ -7497,5 +7497,25 @@
     "Properties with the 'accessor' modifier are only available when targeting ECMAScript 2015 and higher.": {
         "category": "Error",
         "code": 18045
+    },
+    "'{0}' is of type 'unknown'.": {
+        "category": "Error",
+        "code": 18046
+    },
+    "'{0}' is possibly 'null'.": {
+        "category": "Error",
+        "code": 18047
+    },
+    "'{0}' is possibly 'undefined'.": {
+        "category": "Error",
+        "code": 18048
+    },
+    "'{0}' is possibly 'null' or 'undefined'.": {
+        "category": "Error",
+        "code": 18049
+    },
+    "The value '{0}' cannot be used here.": {
+        "category": "Error",
+        "code": 18050
     }
 }
diff --git a/tests/baselines/reference/arithmeticOperatorWithNullValueAndInvalidOperands.errors.txt b/tests/baselines/reference/arithmeticOperatorWithNullValueAndInvalidOperands.errors.txt
diff --git a/tests/baselines/reference/arithmeticOperatorWithNullValueAndValidOperands.errors.txt b/tests/baselines/reference/arithmeticOperatorWithNullValueAndValidOperands.errors.txt
diff --git a/tests/baselines/reference/arithmeticOperatorWithOnlyNullValueOrUndefinedValue.errors.txt b/tests/baselines/reference/arithmeticOperatorWithOnlyNullValueOrUndefinedValue.errors.txt
diff --git a/tests/baselines/reference/arithmeticOperatorWithUndefinedValueAndInvalidOperands.errors.txt b/tests/baselines/reference/arithmeticOperatorWithUndefinedValueAndInvalidOperands.errors.txt
diff --git a/tests/baselines/reference/arithmeticOperatorWithUndefinedValueAndValidOperands.errors.txt b/tests/baselines/reference/arithmeticOperatorWithUndefinedValueAndValidOperands.errors.txt
diff --git a/tests/baselines/reference/binaryArithmatic1.errors.txt b/tests/baselines/reference/binaryArithmatic1.errors.txt
@@ -1,7 +1,7 @@
-tests/cases/compiler/binaryArithmatic1.ts(1,13): error TS2531: Object is possibly 'null'.
+tests/cases/compiler/binaryArithmatic1.ts(1,13): error TS18049: The value 'null' cannot be used here.
 
 
 ==== tests/cases/compiler/binaryArithmatic1.ts (1 errors) ====
     var v = 4 | null;
                 ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
diff --git a/tests/baselines/reference/binaryArithmatic2.errors.txt b/tests/baselines/reference/binaryArithmatic2.errors.txt
@@ -1,7 +1,7 @@
-tests/cases/compiler/binaryArithmatic2.ts(1,13): error TS2532: Object is possibly 'undefined'.
+tests/cases/compiler/binaryArithmatic2.ts(1,13): error TS18049: The value 'undefined' cannot be used here.
 
 
 ==== tests/cases/compiler/binaryArithmatic2.ts (1 errors) ====
     var v = 4 | undefined;
                 ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
diff --git a/tests/baselines/reference/binaryArithmatic3.errors.txt b/tests/baselines/reference/binaryArithmatic3.errors.txt
@@ -1,10 +1,10 @@
-tests/cases/compiler/binaryArithmatic3.ts(1,9): error TS2532: Object is possibly 'undefined'.
-tests/cases/compiler/binaryArithmatic3.ts(1,21): error TS2532: Object is possibly 'undefined'.
+tests/cases/compiler/binaryArithmatic3.ts(1,9): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/compiler/binaryArithmatic3.ts(1,21): error TS18049: The value 'undefined' cannot be used here.
 
 
 ==== tests/cases/compiler/binaryArithmatic3.ts (2 errors) ====
     var v = undefined | undefined;
             ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
                         ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
diff --git a/tests/baselines/reference/binaryArithmatic4.errors.txt b/tests/baselines/reference/binaryArithmatic4.errors.txt
@@ -1,10 +1,10 @@
-tests/cases/compiler/binaryArithmatic4.ts(1,9): error TS2531: Object is possibly 'null'.
-tests/cases/compiler/binaryArithmatic4.ts(1,16): error TS2531: Object is possibly 'null'.
+tests/cases/compiler/binaryArithmatic4.ts(1,9): error TS18049: The value 'null' cannot be used here.
+tests/cases/compiler/binaryArithmatic4.ts(1,16): error TS18049: The value 'null' cannot be used here.
 
 
 ==== tests/cases/compiler/binaryArithmatic4.ts (2 errors) ====
     var v = null | null;
             ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
                    ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
diff --git a/tests/baselines/reference/bitwiseNotOperatorWithAnyOtherType.errors.txt b/tests/baselines/reference/bitwiseNotOperatorWithAnyOtherType.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/conformance/expressions/unaryOperators/bitwiseNotOperator/bitwiseNotOperatorWithAnyOtherType.ts(34,24): error TS2532: Object is possibly 'undefined'.
-tests/cases/conformance/expressions/unaryOperators/bitwiseNotOperator/bitwiseNotOperatorWithAnyOtherType.ts(35,24): error TS2531: Object is possibly 'null'.
+tests/cases/conformance/expressions/unaryOperators/bitwiseNotOperator/bitwiseNotOperatorWithAnyOtherType.ts(34,24): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/conformance/expressions/unaryOperators/bitwiseNotOperator/bitwiseNotOperatorWithAnyOtherType.ts(35,24): error TS18049: The value 'null' cannot be used here.
 tests/cases/conformance/expressions/unaryOperators/bitwiseNotOperator/bitwiseNotOperatorWithAnyOtherType.ts(46,26): error TS2365: Operator '+' cannot be applied to types 'null' and 'undefined'.
 tests/cases/conformance/expressions/unaryOperators/bitwiseNotOperator/bitwiseNotOperatorWithAnyOtherType.ts(47,26): error TS2365: Operator '+' cannot be applied to types 'null' and 'null'.
 tests/cases/conformance/expressions/unaryOperators/bitwiseNotOperator/bitwiseNotOperatorWithAnyOtherType.ts(48,26): error TS2365: Operator '+' cannot be applied to types 'undefined' and 'undefined'.
@@ -41,10 +41,10 @@ tests/cases/conformance/expressions/unaryOperators/bitwiseNotOperator/bitwiseNot
     // any type literal
     var ResultIsNumber6 = ~undefined;
                            ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
     var ResultIsNumber7 = ~null;
                            ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
 
     // any type expressions
     var ResultIsNumber8 = ~ANY2[0]

diff --git a/tests/baselines/reference/circularOptionalityRemoval.errors.txt b/tests/baselines/reference/circularOptionalityRemoval.errors.txt
@@ -1,6 +1,6 @@
 tests/cases/compiler/circularOptionalityRemoval.ts(2,14): error TS2502: 'x' is referenced directly or indirectly in its own type annotation.
 tests/cases/compiler/circularOptionalityRemoval.ts(2,38): error TS2372: Parameter 'x' cannot reference itself.
-tests/cases/compiler/circularOptionalityRemoval.ts(2,38): error TS2532: Object is possibly 'undefined'.
+tests/cases/compiler/circularOptionalityRemoval.ts(2,38): error TS18047: 'x' is possibly 'undefined'.
 tests/cases/compiler/circularOptionalityRemoval.ts(2,46): error TS2372: Parameter 'x' cannot reference itself.
 tests/cases/compiler/circularOptionalityRemoval.ts(5,14): error TS1015: Parameter cannot have question mark and initializer.
 tests/cases/compiler/circularOptionalityRemoval.ts(5,14): error TS2502: 'x' is referenced directly or indirectly in its own type annotation.
@@ -16,7 +16,7 @@ tests/cases/compiler/circularOptionalityRemoval.ts(5,54): error TS2372: Paramete
                                          ~
 !!! error TS2372: Parameter 'x' cannot reference itself.
                                          ~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18047: 'x' is possibly 'undefined'.
                                                  ~
 !!! error TS2372: Parameter 'x' cannot reference itself.
 

diff --git a/tests/baselines/reference/comparisonOperatorWithIdenticalPrimitiveType.errors.txt b/tests/baselines/reference/comparisonOperatorWithIdenticalPrimitiveType.errors.txt
@@ -1,19 +1,19 @@
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(15,11): error TS2531: Object is possibly 'null'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(15,18): error TS2531: Object is possibly 'null'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(16,11): error TS2532: Object is possibly 'undefined'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(16,23): error TS2532: Object is possibly 'undefined'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(24,11): error TS2531: Object is possibly 'null'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(24,18): error TS2531: Object is possibly 'null'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(25,11): error TS2532: Object is possibly 'undefined'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(25,23): error TS2532: Object is possibly 'undefined'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(33,11): error TS2531: Object is possibly 'null'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(33,19): error TS2531: Object is possibly 'null'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(34,11): error TS2532: Object is possibly 'undefined'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(34,24): error TS2532: Object is possibly 'undefined'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(42,11): error TS2531: Object is possibly 'null'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(42,19): error TS2531: Object is possibly 'null'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(43,11): error TS2532: Object is possibly 'undefined'.
-tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(43,24): error TS2532: Object is possibly 'undefined'.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(15,11): error TS18049: The value 'null' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(15,18): error TS18049: The value 'null' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(16,11): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(16,23): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(24,11): error TS18049: The value 'null' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(24,18): error TS18049: The value 'null' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(25,11): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(25,23): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(33,11): error TS18049: The value 'null' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(33,19): error TS18049: The value 'null' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(34,11): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(34,24): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(42,11): error TS18049: The value 'null' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(42,19): error TS18049: The value 'null' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(43,11): error TS18049: The value 'undefined' cannot be used here.
+tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts(43,24): error TS18049: The value 'undefined' cannot be used here.
 
 
 ==== tests/cases/conformance/expressions/binaryOperators/comparisonOperator/comparisonOperatorWithIdenticalPrimitiveType.ts (16 errors) ====
@@ -33,14 +33,14 @@ tests/cases/conformance/expressions/binaryOperators/comparisonOperator/compariso
     var ra5 = e < e;
     var ra6 = null < null;
               ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
                      ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
     var ra7 = undefined < undefined;
               ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
                           ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
 
     // operator >
     var rb1 = a > a;
@@ -50,14 +50,14 @@ tests/cases/conformance/expressions/binaryOperators/comparisonOperator/compariso
     var rb5 = e > e;
     var rb6 = null > null;
               ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
                      ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
     var rb7 = undefined > undefined;
               ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
                           ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
 
     // operator <=
     var rc1 = a <= a;
@@ -67,14 +67,14 @@ tests/cases/conformance/expressions/binaryOperators/comparisonOperator/compariso
     var rc5 = e <= e;
     var rc6 = null <= null;
               ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
                       ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
     var rc7 = undefined <= undefined;
               ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
                            ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
 
     // operator >=
     var rd1 = a >= a;
@@ -84,14 +84,14 @@ tests/cases/conformance/expressions/binaryOperators/comparisonOperator/compariso
     var rd5 = e >= e;
     var rd6 = null >= null;
               ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
                       ~~~~
-!!! error TS2531: Object is possibly 'null'.
+!!! error TS18049: The value 'null' cannot be used here.
     var rd7 = undefined >= undefined;
               ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
                            ~~~~~~~~~
-!!! error TS2532: Object is possibly 'undefined'.
+!!! error TS18049: The value 'undefined' cannot be used here.
 
     // operator ==
     var re1 = a == a;