Return group confirm hints in SuggestedReviewerInfo

These hints help a client or frontend prompt a user for confirmation
in advance if the user selects a suggested group that would need to
be explicitly confirmed to add as a reviewer.

Change-Id: Id1323c5a071ac954dfcbd250fa1a6c246258755a

Documentation/rest-api-changes.txt

@@ -2209,13 +2209,15 @@ As result a list of link:#suggested-reviewer-info[SuggestedReviewerInfo] entries
         "_account_id": 1000097,
         "name": "Jane Roe",
         "email": "jane.roe@example.com"
-      }
+      },
+      "count": 1
     },
     {
       "group": {
         "id": "4fd581c0657268f2bdcc26699fbf9ddb76e3a279",
         "name": "Joiner"
-      }
+      },
+      "count": 5
     }
   ]
 ----
@@ -5260,6 +5262,25 @@ the link:rest-api-accounts.html#account-info[AccountInfo] entity, or
 the `group` field that contains the
 link:rest-api-changes.html#group-base-info[GroupBaseInfo] entity.
 
+[options="header",cols="1,^1,5"]
+|===========================
+|Field Name    ||Description
+|`account`     |optional|
+An link:rest-api-accounts.html#account-info[AccountInfo] entity, if the
+suggestion is an account.
+|`group`       |optional|
+A link:rest-api-changes.html#group-base-info[GroupBaseInfo] entity, if the
+suggestion is a group.
+|`count`       ||
+The total number of accounts in the suggestion. This is `1` if `account` is
+present. If `group` is present, the total number of accounts that are
+members of the group is returned (this count includes members of nested
+groups).
+|`confirm`     |optional|
+True if `group` is present and `count` is above the threshold where the
+`confirmed` flag must be passed to add the group as a reviewer.
+|===========================
+
 [[topic-input]]
 === TopicInput
 The `TopicInput` entity contains information for setting a topic.

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/SuggestReviewersIT.java

@@ -230,6 +230,45 @@ public class SuggestReviewersIT extends AbstractDaemonTest {
     assertThat(suggestedReviewerInfos).hasSize(1);
   }
 
+  @Test
+  @GerritConfigs({
+    @GerritConfig(name = "addreviewer.maxAllowed", value="2"),
+    @GerritConfig(name = "addreviewer.maxWithoutConfirmation", value="1"),
+  })
+  public void suggestReviewersGroupSizeConsiderations() throws Exception {
+    AccountGroup largeGroup = group("large");
+    AccountGroup mediumGroup = group("medium");
+
+    // Both groups have Administrator as a member. Add two users to large
+    // group to push it past maxAllowed, and one to medium group to push it
+    // past maxWithoutConfirmation.
+    user("individual 0", "Test0 Last0", largeGroup, mediumGroup);
+    user("individual 1", "Test1 Last1", largeGroup);
+
+    String changeId = createChange().getChangeId();
+    List<SuggestedReviewerInfo> reviewers;
+    SuggestedReviewerInfo reviewer;
+
+    // Individual account suggestions have count of 1 and no confirm.
+    reviewers = suggestReviewers(changeId, "test", 10);
+    assertThat(reviewers).hasSize(2);
+    reviewer = reviewers.get(0);
+    assertThat(reviewer.count).isEqualTo(1);
+    assertThat(reviewer.confirm).isNull();
+
+    // Large group should never be suggested.
+    reviewers = suggestReviewers(changeId, largeGroup.getName(), 10);
+    assertThat(reviewers).isEmpty();
+
+    // Medium group should be suggested with appropriate count and confirm.
+    reviewers = suggestReviewers(changeId, mediumGroup.getName(), 10);
+    assertThat(reviewers).hasSize(1);
+    reviewer = reviewers.get(0);
+    assertThat(reviewer.group.name).isEqualTo(mediumGroup.getName());
+    assertThat(reviewer.count).isEqualTo(2);
+    assertThat(reviewer.confirm).isTrue();
+  }
+
   private List<SuggestedReviewerInfo> suggestReviewers(String changeId,
       String query, int n) throws Exception {
     return gApi.changes()

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/SuggestedReviewerInfo.java

@@ -17,4 +17,6 @@ package com.google.gerrit.extensions.common;
 public class SuggestedReviewerInfo {
   public AccountInfo account;
   public GroupBaseInfo group;
-}
+  public int count;
+  public Boolean confirm;
+}

gerrit-server/src/main/java/com/google/gerrit/server/ReviewersUtil.java

@@ -145,17 +145,23 @@ public class ReviewersUtil {
     for (AccountInfo a : suggestedAccounts) {
       SuggestedReviewerInfo info = new SuggestedReviewerInfo();
       info.account = a;
+      info.count = 1;
       reviewer.add(info);
     }
 
     for (GroupReference g : suggestAccountGroup(suggestReviewers, projectControl)) {
-      if (suggestGroupAsReviewer(suggestReviewers, projectControl.getProject(),
-          g, visibilityControl)) {
+      GroupAsReviewer result = suggestGroupAsReviewer(
+          suggestReviewers, projectControl.getProject(), g, visibilityControl);
+      if (result.allowed || result.allowedWithConfirmation) {
         GroupBaseInfo info = new GroupBaseInfo();
         info.id = Url.encode(g.getUUID().get());
         info.name = g.getName();
         SuggestedReviewerInfo suggestedReviewerInfo = new SuggestedReviewerInfo();
         suggestedReviewerInfo.group = info;
+        suggestedReviewerInfo.count = result.size;
+        if (result.allowedWithConfirmation) {
+          suggestedReviewerInfo.confirm = true;
+        }
         reviewer.add(suggestedReviewerInfo);
       }
     }
@@ -270,13 +276,22 @@ public class ReviewersUtil {
             suggestReviewers.getLimit()));
   }
 
-  private boolean suggestGroupAsReviewer(SuggestReviewers suggestReviewers,
+  private class GroupAsReviewer {
+    boolean allowed;
+    boolean allowedWithConfirmation;
+    int size;
+  }
+
+  private GroupAsReviewer suggestGroupAsReviewer(SuggestReviewers suggestReviewers,
       Project project, GroupReference group,
       VisibilityControl visibilityControl) throws OrmException, IOException {
+    GroupAsReviewer result = new GroupAsReviewer();
     int maxAllowed = suggestReviewers.getMaxAllowed();
+    int maxAllowedWithoutConfirmation =
+        suggestReviewers.getMaxAllowedWithoutConfirmation();
 
     if (!PostReviewers.isLegalReviewerGroup(group.getUUID())) {
-      return false;
+      return result;
     }
 
     try {
@@ -285,25 +300,33 @@ public class ReviewersUtil {
           .listAccounts(group.getUUID(), project.getNameKey());
 
       if (members.isEmpty()) {
-        return false;
+        return result;
       }
 
-      if (maxAllowed > 0 && members.size() > maxAllowed) {
-        return false;
+      result.size = members.size();
+      if (maxAllowed > 0 && result.size > maxAllowed) {
+        return result;
       }
 
+      boolean needsConfirmation = result.size > maxAllowedWithoutConfirmation;
+
       // require that at least one member in the group can see the change
       for (Account account : members) {
         if (visibilityControl.isVisibleTo(account.getId())) {
-          return true;
+          if (needsConfirmation) {
+            result.allowedWithConfirmation = true;
+          } else {
+            result.allowed = true;
+          }
+          return result;
         }
       }
     } catch (NoSuchGroupException e) {
-      return false;
+      return result;
     } catch (NoSuchProjectException e) {
-      return false;
+      return result;
     }
 
-    return false;
+    return result;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestReviewers.java

@@ -35,6 +35,7 @@ public class SuggestReviewers {
   private final boolean suggestAccounts;
   private final int suggestFrom;
   private final int maxAllowed;
+  private final int maxAllowedWithoutConfirmation;
   protected int limit;
   protected String query;
   protected final int maxSuggestedReviewers;
@@ -73,6 +74,10 @@ public class SuggestReviewers {
     return maxAllowed;
   }
 
+  public int getMaxAllowedWithoutConfirmation() {
+    return maxAllowedWithoutConfirmation;
+  }
+
   @Inject
   public SuggestReviewers(AccountVisibility av,
       IdentifiedUser.GenericFactory identifiedUserFactory,
@@ -96,5 +101,8 @@ public class SuggestReviewers {
     this.suggestFrom = cfg.getInt("suggest", null, "from", 0);
     this.maxAllowed = cfg.getInt("addreviewer", "maxAllowed",
         PostReviewers.DEFAULT_MAX_REVIEWERS);
+    this.maxAllowedWithoutConfirmation = cfg.getInt(
+        "addreviewer", "maxWithoutConfirmation",
+        PostReviewers.DEFAULT_MAX_REVIEWERS_WITHOUT_CHECK);
   }
 }