[Cases] Decode responses from the user actions service (elastic#157971)

## Summary

This PR decodes the response returned by the user actions service.

Depends on: elastic#157858,
elastic#156622

### Checklist

Delete any items that are not applicable to this PR.

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

### For maintainers

- [x] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/cases/common/api/cases/user_actions/response.ts

@@ -69,10 +69,13 @@ const CaseUserActionDeprecatedResponseRt = rt.intersection([
 /**
  * This includes the comment_id but not the action_id or case_id
  */
-const UserActionAttributes = rt.intersection([CaseUserActionBasicRt, CaseUserActionInjectedIdsRt]);
+export const UserActionAttributesRt = rt.intersection([
+  CaseUserActionBasicRt,
+  CaseUserActionInjectedIdsRt,
+]);
 
 const UserActionRt = rt.intersection([
-  UserActionAttributes,
+  UserActionAttributesRt,
   rt.type({
     id: rt.string,
     version: rt.string,
@@ -93,7 +96,7 @@ export type CaseUserActionsDeprecatedResponse = rt.TypeOf<
   typeof CaseUserActionsDeprecatedResponseRt
 >;
 export type CaseUserActionDeprecatedResponse = rt.TypeOf<typeof CaseUserActionDeprecatedResponseRt>;
-export type UserActionAttributes = rt.TypeOf<typeof UserActionAttributes>;
+export type UserActionAttributes = rt.TypeOf<typeof UserActionAttributesRt>;
 
 /**
  * This defines the high level category for the user action. Whether the user add, removed, updated something

x-pack/plugins/cases/server/common/types/user_actions.ts

@@ -7,6 +7,7 @@
 
 import type { SavedObject } from '@kbn/core/server';
 import type { UserActionAttributes } from '../../../common/api';
+import { UserActionAttributesRt } from '../../../common/api';
 import type { User } from './user';
 
 interface UserActionCommonPersistedAttributes {
@@ -21,5 +22,7 @@ export interface UserActionPersistedAttributes extends UserActionCommonPersisted
   payload: Record<string, unknown>;
 }
 
+export const UserActionTransformedAttributesRt = UserActionAttributesRt;
+
 export type UserActionTransformedAttributes = UserActionAttributes;
 export type UserActionSavedObjectTransformed = SavedObject<UserActionTransformedAttributes>;

x-pack/plugins/cases/server/services/cases/index.test.ts

@@ -1863,7 +1863,7 @@ describe('CasesService', () => {
     });
   });
 
-  describe('Encoding responses', () => {
+  describe('Decoding responses', () => {
     const caseTransformedAttributesProps = CaseTransformedAttributesRt.types.reduce(
       (acc, type) => ({ ...acc, ...type.props }),
       {}
@@ -1883,7 +1883,7 @@ describe('CasesService', () => {
     );
 
     describe('getCase', () => {
-      it('encodes correctly', async () => {
+      it('decodes correctly', async () => {
         unsecuredSavedObjectsClient.get.mockResolvedValue(createCaseSavedObjectResponse());
 
         await expect(service.getCase({ id: 'a' })).resolves.not.toThrow();
@@ -1913,7 +1913,7 @@ describe('CasesService', () => {
     });
 
     describe('getResolveCase', () => {
-      it('encodes correctly', async () => {
+      it('decodes correctly', async () => {
         unsecuredSavedObjectsClient.resolve.mockResolvedValue({
           saved_object: createCaseSavedObjectResponse(),
           outcome: 'exactMatch',
@@ -1952,7 +1952,7 @@ describe('CasesService', () => {
     });
 
     describe('getCases', () => {
-      it('encodes correctly', async () => {
+      it('decodes correctly', async () => {
         unsecuredSavedObjectsClient.bulkGet.mockResolvedValue({
           saved_objects: [
             createCaseSavedObjectResponse({ caseId: '1' }),
@@ -1963,7 +1963,7 @@ describe('CasesService', () => {
         await expect(service.getCases({ caseIds: ['a', 'b'] })).resolves.not.toThrow();
       });
 
-      it('do not encodes errors', async () => {
+      it('do not decodes errors', async () => {
         const errorSO = {
           ...omit(createCaseSavedObjectResponse({ caseId: '2' }), 'attributes'),
           error: {
@@ -2078,7 +2078,7 @@ describe('CasesService', () => {
     });
 
     describe('findCases', () => {
-      it('encodes correctly', async () => {
+      it('decodes correctly', async () => {
         const findMockReturn = createSOFindResponse([
           createFindSO({ caseId: '1' }),
           createFindSO({ caseId: '2' }),
@@ -2123,7 +2123,7 @@ describe('CasesService', () => {
     });
 
     describe('post', () => {
-      it('encodes correctly', async () => {
+      it('decodes correctly', async () => {
         unsecuredSavedObjectsClient.create.mockResolvedValue(createCaseSavedObjectResponse());
 
         await expect(
@@ -2166,7 +2166,7 @@ describe('CasesService', () => {
     });
 
     describe('patchCase', () => {
-      it('encodes correctly', async () => {
+      it('decodes correctly', async () => {
         unsecuredSavedObjectsClient.update.mockResolvedValue(createUpdateSOResponse());
 
         await expect(
@@ -2199,7 +2199,7 @@ describe('CasesService', () => {
     });
 
     describe('patchCases', () => {
-      it('encodes correctly', async () => {
+      it('decodes correctly', async () => {
         unsecuredSavedObjectsClient.bulkUpdate.mockResolvedValue({
           saved_objects: [
             createCaseSavedObjectResponse({ caseId: '1' }),
@@ -2222,7 +2222,7 @@ describe('CasesService', () => {
         ).resolves.not.toThrow();
       });
 
-      it('do not encodes errors', async () => {
+      it('do not decodes errors', async () => {
         const errorSO = {
           ...omit(createCaseSavedObjectResponse({ caseId: '2' }), 'attributes'),
           error: {