Expose hasOnlyExpressionInitializer as a public type guard (#33229)

Exposes `hasOnlyExpressionInitializer` as a public function so users of TypeScript compiler APIs do not have to roll their own `HasExpressionInitializer` type guards. Co-authored-by: Nathan Shively-Sanders <[email protected]>
microsoft · Feb 5, 2020 · 0944110 · 0944110
1 parent 044355b
commit 0944110
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Showing 3 changed files with 16 additions and 2 deletions.
diff --git a/src/compiler/utilitiesPublic.ts b/src/compiler/utilitiesPublic.ts
@@ -2507,9 +2507,19 @@ 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 {

diff --git a/tests/baselines/reference/api/tsserverlibrary.d.ts b/tests/baselines/reference/api/tsserverlibrary.d.ts
@@ -3787,6 +3787,8 @@ 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;
 }

diff --git a/tests/baselines/reference/api/typescript.d.ts b/tests/baselines/reference/api/typescript.d.ts
@@ -3787,6 +3787,8 @@ 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;
 }