Add decision manager to decide on final approval vote

[changelog:added]

lib/api-helper/machine/AbstractSoftwareDeliveryMachine.ts

@@ -43,10 +43,7 @@ import { ExtensionPack } from "../../api/machine/ExtensionPack";
 import { registrableManager } from "../../api/machine/Registerable";
 import { SoftwareDeliveryMachine } from "../../api/machine/SoftwareDeliveryMachine";
 import { SoftwareDeliveryMachineConfiguration } from "../../api/machine/SoftwareDeliveryMachineOptions";
-import {
-    GoalSetter,
-    GoalSettingStructure,
-} from "../../api/mapping/GoalSetter";
+import { GoalSetter } from "../../api/mapping/GoalSetter";
 import { PushMapping } from "../../api/mapping/PushMapping";
 import { PushTest } from "../../api/mapping/PushTest";
 import { AnyPush } from "../../api/mapping/support/commonPushTests";
@@ -56,7 +53,11 @@ import { CodeTransformRegistration } from "../../api/registration/CodeTransformR
 import { CommandHandlerRegistration } from "../../api/registration/CommandHandlerRegistration";
 import { EventHandlerRegistration } from "../../api/registration/EventHandlerRegistration";
 import { GeneratorRegistration } from "../../api/registration/GeneratorRegistration";
-import { GoalApprovalRequestVoter } from "../../api/registration/GoalApprovalRequestVoter";
+import {
+    GoalApprovalRequestVoteDecisionManager,
+    GoalApprovalRequestVoter,
+    UnanimousGoalApprovalRequestVoteDecisionManager,
+} from "../../api/registration/GoalApprovalRequestVoter";
 import { IngesterRegistration } from "../../api/registration/IngesterRegistration";
 import { InterpretLog } from "../../spi/log/InterpretedLog";
 import { DefaultGoalImplementationMapper } from "../goal/DefaultGoalImplementationMapper";
@@ -85,6 +86,9 @@ export abstract class AbstractSoftwareDeliveryMachine<O extends SoftwareDelivery
 
     protected readonly goalApprovalRequestVoters: GoalApprovalRequestVoter[] = [];
 
+    private goalApprovalRequestVoteDecisionManager: GoalApprovalRequestVoteDecisionManager =
+        UnanimousGoalApprovalRequestVoteDecisionManager;
+
     private pushMap: GoalSetter;
 
     private fulfillmentMapper;
@@ -142,6 +146,11 @@ export abstract class AbstractSoftwareDeliveryMachine<O extends SoftwareDelivery
         return this;
     }
 
+    public setGoalApprovalRequestVoteDecisionManager(manager: GoalApprovalRequestVoteDecisionManager): this {
+        this.goalApprovalRequestVoteDecisionManager = manager;
+        return this;
+    }
+
     public addCommand<P>(cmd: CommandHandlerRegistration<P>): this {
         this.registrationManager.addCommand(cmd);
         return this;

lib/api/machine/GoalDrivenMachine.ts

@@ -21,7 +21,10 @@ import { GoalImplementationMapper } from "../goal/support/GoalImplementationMapp
 import { PushListenerInvocation } from "../listener/PushListener";
 import { GoalSetter } from "../mapping/GoalSetter";
 import { PushMapping } from "../mapping/PushMapping";
-import { GoalApprovalRequestVoter } from "../registration/GoalApprovalRequestVoter";
+import {
+    GoalApprovalRequestVoteDecisionManager,
+    GoalApprovalRequestVoter,
+} from "../registration/GoalApprovalRequestVoter";
 import { MachineConfiguration } from "./MachineConfiguration";
 import { SoftwareDeliveryMachineConfiguration } from "./SoftwareDeliveryMachineOptions";
 
@@ -74,4 +77,10 @@ export interface GoalDrivenMachine<O extends SoftwareDeliveryMachineConfiguratio
      */
     addGoalApprovalRequestVoter(vote: GoalApprovalRequestVoter): this;
 
+    /**
+     * Set the decision manager used to make final decision on GoalApprovalRequestVoteResult instances.
+     * @param manager
+     */
+    setGoalApprovalRequestVoteDecisionManager(manager: GoalApprovalRequestVoteDecisionManager): this;
+
 }

lib/api/registration/GoalApprovalRequestVoter.ts

@@ -14,32 +14,33 @@
  * limitations under the License.
  */
 
+import { logger } from "@atomist/automation-client";
 import { RepoContext } from "../context/SdmContext";
 import { SdmGoalEvent } from "../goal/SdmGoalEvent";
 
 /**
- * Represents a vote on a approval request.
+ * Represents a vote on a approval request
  */
 export enum GoalApprovalRequestVote {
 
     /**
-     * Voter decided to abstain from voting.
+     * Voter decided to abstain from voting
      */
-    Abstain,
+    Abstain = "abstain",
 
     /**
-     * Voter decided to grant the approval request.
+     * Voter decided to grant the approval request
      */
-    Granted,
+    Granted = "granted",
 
     /**
-     * Voter decided to deny the approval request.
+     * Voter decided to deny the approval request
      */
-    Denied,
+    Denied = "denied",
 }
 
 /**
- * Result from executing GoalApprovalRequestVoter.
+ * Result from executing GoalApprovalRequestVoter
  */
 export interface GoalApprovalRequestVoteResult {
 
@@ -60,13 +61,41 @@ export interface GoalApprovalRequestVoteResult {
 export interface GoalApprovalRequestVoterInvocation extends RepoContext {
 
     /**
-     * Goal that was requested for approval.
+     * Goal that was requested for approval
      */
     goal: SdmGoalEvent;
 }
 
 /**
- * Voter on a request to approve a goal.
+ * Voter on a request to approve a goal
  */
 export type GoalApprovalRequestVoter =
     (garvi: GoalApprovalRequestVoterInvocation) => Promise<GoalApprovalRequestVoteResult>;
+
+/**
+ * Decide resulting vote on a set of votes
+ */
+export type GoalApprovalRequestVoteDecisionManager =
+    (votes: GoalApprovalRequestVoteResult[]) => GoalApprovalRequestVote;
+
+
+/**
+ * Default GoalApprovalRequestVoteDecisionManager that decides unanimously on votes.
+ * One denied vote will deny the approval request; all granted votes with grant the request.
+ * All other votes with result in an abstained approval request.
+ * @param votes
+ */
+export const UnanimousGoalApprovalRequestVoteDecisionManager: GoalApprovalRequestVoteDecisionManager =
+    (votes: GoalApprovalRequestVoteResult[]) => {
+        logger.debug(`Deciding on provided votes '${votes.map(v => v.vote).join(", ")}'`);
+        if (votes.some(v => v.vote === GoalApprovalRequestVote.Denied)) {
+            logger.debug("At least one denied vote. Denying approval request");
+            return GoalApprovalRequestVote.Denied;
+        } else if (!votes.some(v => v.vote !== GoalApprovalRequestVote.Granted)) {
+            logger.debug("All votes granted. Granting approval request");
+            return GoalApprovalRequestVote.Granted;
+        } else {
+            logger.debug("Some abstain and granted votes. Abstaining approval request");
+            return GoalApprovalRequestVote.Abstain;
+        }
+    };