feat(49385): forbid inlay hints for literal-initialized constants

Author: a-tarasyuk

src/compiler/checker.ts

@@ -655,6 +655,7 @@ namespace ts {
             isArrayType,
             isTupleType,
             isArrayLikeType,
+            isLiteralConstDeclaration,
             isTypeInvalidDueToUnionDiscriminant,
             getExactOptionalProperties,
             getAllPossiblePropertiesOfTypes,

src/compiler/types.ts

@@ -4401,6 +4401,7 @@ namespace ts {
         /* @internal */ isArrayType(type: Type): boolean;
         /* @internal */ isTupleType(type: Type): boolean;
         /* @internal */ isArrayLikeType(type: Type): boolean;
+        /* @internal */ isLiteralConstDeclaration(node: VariableDeclaration | PropertyDeclaration | PropertySignature | ParameterDeclaration): boolean;
 
         /**
          * True if `contextualType` should not be considered for completions because

src/services/inlayHints.ts

@@ -121,7 +121,7 @@ namespace ts.InlayHints {
         }
 
         function visitVariableLikeDeclaration(decl: VariableDeclaration | PropertyDeclaration) {
-            if (!decl.initializer || isBindingPattern(decl.name)) {
+            if (!decl.initializer || isBindingPattern(decl.name) || checker.isLiteralConstDeclaration(decl)) {
                 return;
             }
 

tests/cases/fourslash/inlayHintsShouldWork15.ts

@@ -1,15 +1,9 @@
 /// <reference path="fourslash.ts" />
 
-//// const a/*a*/ = 123;
+////const a = "a";
+////const b = 1;
+////const c = true;
 
-const markers = test.markers();
-verify.getInlayHints([
-    {
-        text: ': 123',
-        position: markers[0].position,
-        kind: ts.InlayHintKind.Type,
-        whitespaceBefore: true
-    },
-], undefined, {
+verify.getInlayHints([], undefined, {
     includeInlayVariableTypeHints: true
 });

tests/cases/fourslash/inlayHintsShouldWork16.ts

@@ -1,15 +1,7 @@
 /// <reference path="fourslash.ts" />
 
-//// const a/*a*/ = "I'm very very very very very very very very very long";
+////const a = "I'm very very very very very very very very very long";
 
-const markers = test.markers();
-verify.getInlayHints([
-    {
-        text: `: "I'm very very very very ve...`,
-        position: markers[0].position,
-        kind: ts.InlayHintKind.Type,
-        whitespaceBefore: true
-    },
-], undefined, {
+verify.getInlayHints([], undefined, {
     includeInlayVariableTypeHints: true
 });