Add experimental flag for case function

expressions/src/features.ts

@@ -28,6 +28,12 @@ export interface ExperimentalFeatures {
    * @default false
    */
   blockScalarChompingWarning?: boolean;
+
+  /**
+   * Enable the case() function in expressions.
+   * @default false
+   */
+  allowCaseFunction?: boolean;
 }
 
 /**
@@ -39,7 +45,7 @@ export type ExperimentalFeatureKey = Exclude<keyof ExperimentalFeatures, "all">;
  * All known experimental feature keys.
  * This list must be kept in sync with the ExperimentalFeatures interface.
  */
-const allFeatureKeys: ExperimentalFeatureKey[] = ["missingInputsQuickfix", "blockScalarChompingWarning"];
+const allFeatureKeys: ExperimentalFeatureKey[] = ["missingInputsQuickfix", "blockScalarChompingWarning", "allowCaseFunction"];
 
 export class FeatureFlags {
   private readonly features: ExperimentalFeatures;