feat(40663/40664): improve error messages for assignment assertions '!' (#40669)

Author: a-tarasyuk

src/compiler/checker.ts

@@ -39485,11 +39485,13 @@ namespace ts {
             }
 
             if (node.exclamationToken && (node.parent.parent.kind !== SyntaxKind.VariableStatement || !node.type || node.initializer || node.flags & NodeFlags.Ambient)) {
-                return grammarErrorOnNode(node.exclamationToken, Diagnostics.Definite_assignment_assertions_can_only_be_used_along_with_a_type_annotation);
+                const message = node.initializer
+                    ? Diagnostics.Declarations_with_initializers_cannot_also_have_definite_assignment_assertions
+                    : Diagnostics.Definite_assignment_assertions_can_only_be_used_along_with_a_type_annotation;
+                return grammarErrorOnNode(node.exclamationToken, message);
             }
 
             const moduleKind = getEmitModuleKind(compilerOptions);
-
             if (moduleKind < ModuleKind.ES2015 && moduleKind !== ModuleKind.System &&
                 !(node.parent.parent.flags & NodeFlags.Ambient) && hasSyntacticModifier(node.parent.parent, ModifierFlags.Export)) {
                 checkESModuleMarker(node.name);
@@ -39689,7 +39691,12 @@ namespace ts {
 
             if (isPropertyDeclaration(node) && node.exclamationToken && (!isClassLike(node.parent) || !node.type || node.initializer ||
                 node.flags & NodeFlags.Ambient || hasSyntacticModifier(node, ModifierFlags.Static | ModifierFlags.Abstract))) {
-                return grammarErrorOnNode(node.exclamationToken, Diagnostics.A_definite_assignment_assertion_is_not_permitted_in_this_context);
+                const message = node.initializer
+                    ? Diagnostics.Declarations_with_initializers_cannot_also_have_definite_assignment_assertions
+                    : !node.type
+                        ? Diagnostics.Declarations_with_definite_assignment_assertions_must_also_have_type_annotations
+                        : Diagnostics.A_definite_assignment_assertion_is_not_permitted_in_this_context;
+                return grammarErrorOnNode(node.exclamationToken, message);
             }
         }
 

src/compiler/diagnosticMessages.json

@@ -871,6 +871,14 @@
         "category": "Error",
         "code": 1262
     },
+    "Declarations with initializers cannot also have definite assignment assertions.": {
+        "category": "Error",
+        "code": 1263
+    },
+    "Declarations with definite assignment assertions must also have type annotations.": {
+        "category": "Error",
+        "code": 1264
+    },
 
     "'with' statements are not allowed in an async function block.": {
         "category": "Error",

tests/baselines/reference/definiteAssignmentAssertions.errors.txt

@@ -1,17 +1,19 @@
 tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(5,5): error TS2564: Property 'b' has no initializer and is not definitely assigned in the constructor.
-tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(20,6): error TS1255: A definite assignment assertion '!' is not permitted in this context.
-tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(21,6): error TS1255: A definite assignment assertion '!' is not permitted in this context.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(20,6): error TS1263: Declarations with initializers cannot also have definite assignment assertions.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(21,6): error TS1263: Declarations with initializers cannot also have definite assignment assertions.
 tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(22,13): error TS1255: A definite assignment assertion '!' is not permitted in this context.
-tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(28,6): error TS1255: A definite assignment assertion '!' is not permitted in this context.
-tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(34,15): error TS1255: A definite assignment assertion '!' is not permitted in this context.
-tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(68,10): error TS1258: Definite assignment assertions can only be used along with a type annotation.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(23,5): error TS7008: Member 'd' implicitly has an 'any' type.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(23,6): error TS1264: Declarations with definite assignment assertions must also have type annotations.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(29,6): error TS1255: A definite assignment assertion '!' is not permitted in this context.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(35,15): error TS1255: A definite assignment assertion '!' is not permitted in this context.
 tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(69,10): error TS1258: Definite assignment assertions can only be used along with a type annotation.
-tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(70,10): error TS1258: Definite assignment assertions can only be used along with a type annotation.
-tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(75,15): error TS1258: Definite assignment assertions can only be used along with a type annotation.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(70,10): error TS1263: Declarations with initializers cannot also have definite assignment assertions.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(71,10): error TS1263: Declarations with initializers cannot also have definite assignment assertions.
 tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(76,15): error TS1258: Definite assignment assertions can only be used along with a type annotation.
+tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(77,15): error TS1258: Definite assignment assertions can only be used along with a type annotation.
 
 
-==== tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts (11 errors) ====
+==== tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts (13 errors) ====
     // Suppress strict property initialization check
 
     class C1 {
@@ -35,13 +37,18 @@ tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(76,15): erro
     class C3 {
         a! = 1;
          ~
-!!! error TS1255: A definite assignment assertion '!' is not permitted in this context.
+!!! error TS1263: Declarations with initializers cannot also have definite assignment assertions.
         b!: number = 1;
          ~
-!!! error TS1255: A definite assignment assertion '!' is not permitted in this context.
+!!! error TS1263: Declarations with initializers cannot also have definite assignment assertions.
         static c!: number;
                 ~
 !!! error TS1255: A definite assignment assertion '!' is not permitted in this context.
+        d!;
+        ~
+!!! error TS7008: Member 'd' implicitly has an 'any' type.
+         ~
+!!! error TS1264: Declarations with definite assignment assertions must also have type annotations.
     }
 
     // Definite assignment assertion not permitted in ambient context
@@ -96,10 +103,10 @@ tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts(76,15): erro
 !!! error TS1258: Definite assignment assertions can only be used along with a type annotation.
         let b! = 1;
              ~
-!!! error TS1258: Definite assignment assertions can only be used along with a type annotation.
+!!! error TS1263: Declarations with initializers cannot also have definite assignment assertions.
         let c!: number = 1;
              ~
-!!! error TS1258: Definite assignment assertions can only be used along with a type annotation.
+!!! error TS1263: Declarations with initializers cannot also have definite assignment assertions.
     }
 
     // Definite assignment assertion not permitted in ambient context

tests/baselines/reference/definiteAssignmentAssertions.js

@@ -21,6 +21,7 @@ class C3 {
     a! = 1;
     b!: number = 1;
     static c!: number;
+    d!;
 }
 
 // Definite assignment assertion not permitted in ambient context
@@ -151,6 +152,7 @@ declare class C3 {
     a: number;
     b: number;
     static c: number;
+    d: any;
 }
 declare class C4 {
     a: number;

tests/baselines/reference/definiteAssignmentAssertions.symbols

@@ -41,106 +41,109 @@ class C3 {
 
     static c!: number;
 >c : Symbol(C3.c, Decl(definiteAssignmentAssertions.ts, 20, 19))
+
+    d!;
+>d : Symbol(C3.d, Decl(definiteAssignmentAssertions.ts, 21, 22))
 }
 
 // Definite assignment assertion not permitted in ambient context
 
 declare class C4 {
->C4 : Symbol(C4, Decl(definiteAssignmentAssertions.ts, 22, 1))
+>C4 : Symbol(C4, Decl(definiteAssignmentAssertions.ts, 23, 1))
 
     a!: number;
->a : Symbol(C4.a, Decl(definiteAssignmentAssertions.ts, 26, 18))
+>a : Symbol(C4.a, Decl(definiteAssignmentAssertions.ts, 27, 18))
 }
 
 // Definite assignment assertion not permitted on abstract property
 
 abstract class C5 {
->C5 : Symbol(C5, Decl(definiteAssignmentAssertions.ts, 28, 1))
+>C5 : Symbol(C5, Decl(definiteAssignmentAssertions.ts, 29, 1))
 
     abstract a!: number;
->a : Symbol(C5.a, Decl(definiteAssignmentAssertions.ts, 32, 19))
+>a : Symbol(C5.a, Decl(definiteAssignmentAssertions.ts, 33, 19))
 }
 
 // Suppress definite assignment check for variable
 
 function f1() {
->f1 : Symbol(f1, Decl(definiteAssignmentAssertions.ts, 34, 1))
+>f1 : Symbol(f1, Decl(definiteAssignmentAssertions.ts, 35, 1))
 
     let x!: number;
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 39, 7))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 40, 7))
 
     let y = x;
->y : Symbol(y, Decl(definiteAssignmentAssertions.ts, 40, 7))
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 39, 7))
+>y : Symbol(y, Decl(definiteAssignmentAssertions.ts, 41, 7))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 40, 7))
 
     var a!: number;
->a : Symbol(a, Decl(definiteAssignmentAssertions.ts, 41, 7))
+>a : Symbol(a, Decl(definiteAssignmentAssertions.ts, 42, 7))
 
     var b = a;
->b : Symbol(b, Decl(definiteAssignmentAssertions.ts, 42, 7))
->a : Symbol(a, Decl(definiteAssignmentAssertions.ts, 41, 7))
+>b : Symbol(b, Decl(definiteAssignmentAssertions.ts, 43, 7))
+>a : Symbol(a, Decl(definiteAssignmentAssertions.ts, 42, 7))
 }
 
 function f2() {
->f2 : Symbol(f2, Decl(definiteAssignmentAssertions.ts, 43, 1))
+>f2 : Symbol(f2, Decl(definiteAssignmentAssertions.ts, 44, 1))
 
     let x!: string | number;
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 46, 7))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 47, 7))
 
     if (typeof x === "string") {
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 46, 7))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 47, 7))
 
         let s: string = x;
->s : Symbol(s, Decl(definiteAssignmentAssertions.ts, 48, 11))
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 46, 7))
+>s : Symbol(s, Decl(definiteAssignmentAssertions.ts, 49, 11))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 47, 7))
     }
     else {
         let n: number = x;
->n : Symbol(n, Decl(definiteAssignmentAssertions.ts, 51, 11))
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 46, 7))
+>n : Symbol(n, Decl(definiteAssignmentAssertions.ts, 52, 11))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 47, 7))
     }
 }
 
 function f3() {
->f3 : Symbol(f3, Decl(definiteAssignmentAssertions.ts, 53, 1))
+>f3 : Symbol(f3, Decl(definiteAssignmentAssertions.ts, 54, 1))
 
     let x!: number;
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 56, 7))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 57, 7))
 
     const g = () => {
->g : Symbol(g, Decl(definiteAssignmentAssertions.ts, 57, 9))
+>g : Symbol(g, Decl(definiteAssignmentAssertions.ts, 58, 9))
 
         x = 1;
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 56, 7))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 57, 7))
     }
     g();
->g : Symbol(g, Decl(definiteAssignmentAssertions.ts, 57, 9))
+>g : Symbol(g, Decl(definiteAssignmentAssertions.ts, 58, 9))
 
     let y = x;
->y : Symbol(y, Decl(definiteAssignmentAssertions.ts, 61, 7))
->x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 56, 7))
+>y : Symbol(y, Decl(definiteAssignmentAssertions.ts, 62, 7))
+>x : Symbol(x, Decl(definiteAssignmentAssertions.ts, 57, 7))
 }
 
 // Definite assignment assertion requires type annotation and no initializer
 
 function f4() {
->f4 : Symbol(f4, Decl(definiteAssignmentAssertions.ts, 62, 1))
+>f4 : Symbol(f4, Decl(definiteAssignmentAssertions.ts, 63, 1))
 
     let a!;
->a : Symbol(a, Decl(definiteAssignmentAssertions.ts, 67, 7))
+>a : Symbol(a, Decl(definiteAssignmentAssertions.ts, 68, 7))
 
     let b! = 1;
->b : Symbol(b, Decl(definiteAssignmentAssertions.ts, 68, 7))
+>b : Symbol(b, Decl(definiteAssignmentAssertions.ts, 69, 7))
 
     let c!: number = 1;
->c : Symbol(c, Decl(definiteAssignmentAssertions.ts, 69, 7))
+>c : Symbol(c, Decl(definiteAssignmentAssertions.ts, 70, 7))
 }
 
 // Definite assignment assertion not permitted in ambient context
 
 declare let v1!: number;
->v1 : Symbol(v1, Decl(definiteAssignmentAssertions.ts, 74, 11))
+>v1 : Symbol(v1, Decl(definiteAssignmentAssertions.ts, 75, 11))
 
 declare var v2!: number;
->v2 : Symbol(v2, Decl(definiteAssignmentAssertions.ts, 75, 11))
+>v2 : Symbol(v2, Decl(definiteAssignmentAssertions.ts, 76, 11))
 

tests/baselines/reference/definiteAssignmentAssertions.types

@@ -43,6 +43,9 @@ class C3 {
 
     static c!: number;
 >c : number
+
+    d!;
+>d : any
 }
 
 // Definite assignment assertion not permitted in ambient context

tests/baselines/reference/definiteAssignmentWithErrorStillStripped.errors.txt

@@ -1,9 +1,9 @@
-tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts(2,6): error TS1255: A definite assignment assertion '!' is not permitted in this context.
+tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts(2,6): error TS1264: Declarations with definite assignment assertions must also have type annotations.
 
 
 ==== tests/cases/compiler/definiteAssignmentWithErrorStillStripped.ts (1 errors) ====
     class C {
         p!;
          ~
-!!! error TS1255: A definite assignment assertion '!' is not permitted in this context.
+!!! error TS1264: Declarations with definite assignment assertions must also have type annotations.
     }

tests/cases/conformance/controlFlow/definiteAssignmentAssertions.ts

@@ -23,6 +23,7 @@ class C3 {
     a! = 1;
     b!: number = 1;
     static c!: number;
+    d!;
 }
 
 // Definite assignment assertion not permitted in ambient context