Support default query for groups

Change-Id: I9c8b2026bb872ae08f5435039280dfd1cb25433e
Signed-off-by: Edwin Kempin <ekempin@google.com>

Documentation/user-search-groups.txt

@@ -3,12 +3,26 @@
 Group queries only match internal groups. External groups and system
 groups are not included in the query result.
 
+== Basic Group Search
+
+Similar to many popular search engines on the web, just enter some
+text and let Gerrit figure out the meaning:
+
+[options="header"]
+|======================================================
+|Description | Examples
+|Name        | Foo-Verifiers
+|UUID        | 6a1e70e1a88782771a91808c8af9bbb7a9871389
+|Description | deprecated
+|======================================================
+
 [[search-operators]]
 == Search Operators
 
 Operators act as restrictions on the search. As more operators
 are added to the same query string, they further restrict the
-returned results.
+returned results. Search can also be performed by typing only a text
+with no operator, which will match against a variety of fields.
 
 [[description]]
 description:'DESCRIPTION'::

gerrit-server/src/main/java/com/google/gerrit/server/query/group/GroupPredicates.java

@@ -14,15 +14,31 @@
 
 package com.google.gerrit.server.query.group;
 
+import com.google.common.base.Strings;
+import com.google.common.collect.Lists;
 import com.google.gerrit.reviewdb.client.AccountGroup;
 import com.google.gerrit.server.index.FieldDef;
 import com.google.gerrit.server.index.IndexPredicate;
 import com.google.gerrit.server.index.group.GroupField;
 import com.google.gerrit.server.query.Predicate;
 
+import java.util.List;
 import java.util.Locale;
 
 public class GroupPredicates {
+  public static Predicate<AccountGroup> defaultPredicate(String query) {
+    // Adapt the capacity of this list when adding more default predicates.
+    List<Predicate<AccountGroup>> preds = Lists.newArrayListWithCapacity(5);
+    preds.add(uuid(new AccountGroup.UUID(query)));
+    preds.add(name(query));
+    preds.add(inname(query));
+    if (!Strings.isNullOrEmpty(query)) {
+      preds.add(description(query));
+    }
+    preds.add(owner(query));
+    return Predicate.or(preds);
+  }
+
   public static Predicate<AccountGroup> uuid(AccountGroup.UUID uuid) {
     return new GroupPredicate(GroupField.UUID,
         GroupQueryBuilder.FIELD_UUID, uuid.get());

gerrit-server/src/main/java/com/google/gerrit/server/query/group/GroupQueryBuilder.java

@@ -83,6 +83,11 @@ public class GroupQueryBuilder extends QueryBuilder<AccountGroup> {
     throw error("Invalid query");
   }
 
+  @Override
+  protected Predicate<AccountGroup> defaultField(String query) {
+    return GroupPredicates.defaultPredicate(query);
+  }
+
   @Operator
   public Predicate<AccountGroup> limit(String query)
       throws QueryParseException {
@@ -92,4 +97,5 @@ public class GroupQueryBuilder extends QueryBuilder<AccountGroup> {
     }
     return new LimitPredicate<>(FIELD_LIMIT, limit);
   }
+
 }

gerrit-server/src/test/java/com/google/gerrit/server/query/group/AbstractQueryGroupsTest.java

@@ -252,6 +252,18 @@ public abstract class AbstractQueryGroupsTest extends GerritServerTests {
     assertQuery("is:visibleToAll", groupThatIsVisibleToAll);
   }
 
+  @Test
+  public void byDefaultField() throws Exception {
+    GroupInfo group1 = createGroup(name("foo-group"));
+    GroupInfo group2 = createGroup(name("group2"));
+    GroupInfo group3 = createGroupWithDescription(name("group3"),
+        "decription that contains foo and the UUID of group2: " + group2.id);
+
+    assertQuery("non-existing");
+    assertQuery("foo", group1, group3);
+    assertQuery(group2.id, group2, group3);
+  }
+
   @Test
   public void withLimit() throws Exception {
     GroupInfo group1 = createGroup(name("group1"));