Expose hasOnlyExpressionInitializer as a public type guard

Exposes `hasOnlyExpressionInitializer` as a public function so users of
TypeScript compiler APIs do not have to roll their own
`HasExpressionInitializer` type guards.

Author: ayazhafiz

src/compiler/utilities.ts

@@ -7054,9 +7054,19 @@ namespace ts {
     }
 
     /** True if has initializer node attached to it. */
-    /* @internal */
     export function hasOnlyExpressionInitializer(node: Node): node is HasExpressionInitializer {
-        return hasInitializer(node) && !isForStatement(node) && !isForInStatement(node) && !isForOfStatement(node) && !isJsxAttribute(node);
+        switch (node.kind) {
+            case SyntaxKind.VariableDeclaration:
+            case SyntaxKind.Parameter:
+            case SyntaxKind.BindingElement:
+            case SyntaxKind.PropertySignature:
+            case SyntaxKind.PropertyDeclaration:
+            case SyntaxKind.PropertyAssignment:
+            case SyntaxKind.EnumMember:
+                return true;
+            default:
+                return false;
+        }
     }
 
     export function isObjectLiteralElement(node: Node): node is ObjectLiteralElement {

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

@@ -3612,6 +3612,8 @@ declare namespace ts {
     function isJSDocCommentContainingNode(node: Node): boolean;
     function isSetAccessor(node: Node): node is SetAccessorDeclaration;
     function isGetAccessor(node: Node): node is GetAccessorDeclaration;
+    /** True if has initializer node attached to it. */
+    function hasOnlyExpressionInitializer(node: Node): node is HasExpressionInitializer;
     function isObjectLiteralElement(node: Node): node is ObjectLiteralElement;
     function isStringLiteralLike(node: Node): node is StringLiteralLike;
 }

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

@@ -3612,6 +3612,8 @@ declare namespace ts {
     function isJSDocCommentContainingNode(node: Node): boolean;
     function isSetAccessor(node: Node): node is SetAccessorDeclaration;
     function isGetAccessor(node: Node): node is GetAccessorDeclaration;
+    /** True if has initializer node attached to it. */
+    function hasOnlyExpressionInitializer(node: Node): node is HasExpressionInitializer;
     function isObjectLiteralElement(node: Node): node is ObjectLiteralElement;
     function isStringLiteralLike(node: Node): node is StringLiteralLike;
 }