Use ts-expect-error in platform code (#69883)

* ts-ignore --> ts-expect-error

* fix error with mutable array

* fix errors in consumers code

* update SOM

* fix FeatureConfig & Feature compatibility

* do not re-export from code. it breaks built version

* update docs

* add eslint rule for platform team code

* remove test. this is covered by ts-expect-error in unit tests

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

x-pack/plugins/features/common/feature.ts

@@ -49,7 +49,9 @@ export interface FeatureConfig {
    * This does not restrict access to your feature based on license.
    * Its only purpose is to inform the space and roles UIs on which features to display.
    */
-  validLicenses?: Array<'basic' | 'standard' | 'gold' | 'platinum' | 'enterprise' | 'trial'>;
+  validLicenses?: ReadonlyArray<
+    'basic' | 'standard' | 'gold' | 'platinum' | 'enterprise' | 'trial'
+  >;
 
   /**
    * An optional EUI Icon to be used when displaying your feature.
@@ -66,7 +68,7 @@ export interface FeatureConfig {
    * An array of app ids that are enabled when this feature is enabled.
    * Apps specified here will automatically cascade to the privileges defined below, unless specified differently there.
    */
-  app: string[];
+  app: readonly string[];
 
   /**
    * If this feature includes management sections, you can specify them here to control visibility of those
@@ -83,14 +85,14 @@ export interface FeatureConfig {
    * ```
    */
   management?: {
-    [sectionId: string]: string[];
+    [sectionId: string]: readonly string[];
   };
   /**
    * If this feature includes a catalogue entry, you can specify them here to control visibility based on the current space.
    *
    * Items specified here will automatically cascade to the privileges defined below, unless specified differently there.
    */
-  catalogue?: string[];
+  catalogue?: readonly string[];
 
   /**
    * Feature privilege definition.
@@ -112,7 +114,7 @@ export interface FeatureConfig {
   /**
    * Optional sub-feature privilege definitions. This can only be specified if `privileges` are are also defined.
    */
-  subFeatures?: SubFeatureConfig[];
+  subFeatures?: readonly SubFeatureConfig[];
 
   /**
    * Optional message to display on the Role Management screen when configuring permissions for this feature.
@@ -124,7 +126,7 @@ export interface FeatureConfig {
    */
   reserved?: {
     description: string;
-    privileges: ReservedKibanaPrivilege[];
+    privileges: readonly ReservedKibanaPrivilege[];
   };
 }
 

x-pack/plugins/features/common/feature_kibana_privileges.ts

@@ -26,13 +26,13 @@ export interface FeatureKibanaPrivileges {
    * ```
    */
   management?: {
-    [sectionId: string]: string[];
+    [sectionId: string]: readonly string[];
   };
 
   /**
    * If this feature includes a catalogue entry, you can specify them here to control visibility based on user permissions.
    */
-  catalogue?: string[];
+  catalogue?: readonly string[];
 
   /**
    * If your feature includes server-side APIs, you can tag those routes to secure access based on user permissions.
@@ -60,7 +60,7 @@ export interface FeatureKibanaPrivileges {
    * A generic tag name like "access:read" could be used elsewhere, and access to that API endpoint would also
    * extend to any routes you have also tagged with that name.
    */
-  api?: string[];
+  api?: readonly string[];
 
   /**
    * If your feature exposes a client-side application (most of them do!), then you can control access to them here.
@@ -73,7 +73,7 @@ export interface FeatureKibanaPrivileges {
    * ```
    *
    */
-  app?: string[];
+  app?: readonly string[];
 
   /**
    * If your feature requires access to specific saved objects, then specify your access needs here.
@@ -88,7 +88,7 @@ export interface FeatureKibanaPrivileges {
      *  }
      * ```
      */
-    all: string[];
+    all: readonly string[];
 
     /**
      * List of saved object types which users should have read-only access to when granted this privilege.
@@ -99,7 +99,7 @@ export interface FeatureKibanaPrivileges {
      *  }
      * ```
      */
-    read: string[];
+    read: readonly string[];
   };
   /**
    * A list of UI Capabilities that should be granted to users with this privilege.
@@ -121,5 +121,5 @@ export interface FeatureKibanaPrivileges {
    *
    * @see UICapabilities
    */
-  ui: string[];
+  ui: readonly string[];
 }

x-pack/plugins/features/common/sub_feature.ts

@@ -15,7 +15,7 @@ export interface SubFeatureConfig {
   name: string;
 
   /** Collection of privilege groups */
-  privilegeGroups: SubFeaturePrivilegeGroupConfig[];
+  privilegeGroups: readonly SubFeaturePrivilegeGroupConfig[];
 }
 
 /**
@@ -45,7 +45,7 @@ export interface SubFeaturePrivilegeGroupConfig {
   /**
    * The privileges which belong to this group.
    */
-  privileges: SubFeaturePrivilegeConfig[];
+  privileges: readonly SubFeaturePrivilegeConfig[];
 }
 
 /**