Evaluate and return submit requirements with ChangeInfo

This change implements evaluating submit requirements in ChangeData, and
also adds submit requirements as an additional field in ChangeInfo,
hence returned with the 'Get Change' rest endpoint.

Submit requirements should always be evaluated for open changes. In a
follow-up change, we will handle returning submit requirements for
merged changes, and the plan is to store submit requirements for changes
in NoteDb upon merge and load them when requested.

Note: I added additional bindings to BatchProgramModule for
ChangeQueryBuilder and ConflictsCache since these implementations are
needed by the ReindexIT tests.

Change-Id: I416bb9c2e98240de269cda115725f554f84dd2ed
diff --git a/Documentation/rest-api-changes.txt b/Documentation/rest-api-changes.txt
index 9c3c8b6..724436f 100644
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -239,6 +239,12 @@
   current user.
 --
 
+[[submit-requirements]]
+--
+* `SUBMIT_REQUIREMENTS`: detailed result of the evaluated submit requirements
+  for this change.
+--
+
 [[current-revision]]
 --
 * `CURRENT_REVISION`: describe the current revision (patch set)
@@ -6510,7 +6516,11 @@
 entities.
 |`requirements`             |optional|
 List of the link:rest-api-changes.html#requirement[requirements] to be met before this change
-can be submitted.
+can be submitted. This field is deprecated in favour of `submit_requirements`.
+|`submit_requirements`      |optional|
+List of the link:#submit-requirement-result-info[SubmitRequirementResultInfo]
+containing the evaluated submit requirements for the change.
+Only set if link:#submit-requirements[`SUBMIT_REQUIREMENTS`] is requested.
 |`labels`             |optional|
 The labels of the change as a map that maps the label names to
 link:#label-info[LabelInfo] entries. +
@@ -8137,6 +8147,56 @@
 the failure of the rule predicate.
 |===========================
 
+[[submit-requirement-expression-info]]
+=== SubmitRequirementExpressionInfo
+The `SubmitRequirementExpressionInfo` describes the result of evaluating a
+single submit requirement expression, for example `label:code-review=+2`.
+
+[options="header",cols="1,6"]
+|===========================
+|Field Name      |Description
+|`expression`|
+The submit requirement expression as a string, for example
+`branch:refs/heads/foo and label:verified=+1`.
+|`fulfilled`|
+True if the submit requirement is fulfilled for the change.
+|`passing_atoms`|
+A list of passing atoms as strings. For the above expression,
+`passing_atoms` can contain ["branch:refs/heads/foo"] if the branch predicate is
+fulfilled for the change.
+|`failing_atoms`|
+A list of failing atoms. This is similar to `passing_atoms` except that it
+contains the list of predicates that are not fulfilled for the change.
+|===========================
+
+[[submit-requirement-result-info]]
+=== SubmitRequirementResultInfo
+The `SubmitRequirementResultInfo` describes the result of evaluating a
+submit requirement on a change.
+
+[options="header",cols="1,^1,5"]
+|===========================
+|Field Name      ||Description
+|`name`||
+The submit requirement name.
+|`description`|optional|
+Description of the submit requirement.
+|`status`||
+Status describing the result of evaluating the submit requirement. The status
+is one of (`SATISFIED`, `UNSATISFED`, `OVERRIDDEN`, `NOT_APPLICABLE`).
+|`applicability_expression_result`|optional|
+A link:#submit-requirement-expression-info[SubmitRequirementExpressionInfo]
+containing the result of evaluating the applicability expression. Not set if the
+submit requirement did not define an applicability expression.
+|`submittability_expression_result`||
+A link:#submit-requirement-expression-info[SubmitRequirementExpressionInfo]
+containing the result of evaluating the submittability expression.
+|`override_expression_result`|optional|
+A link:#submit-requirement-expression-info[SubmitRequirementExpressionInfo]
+containing the result of evaluating the override expression. Not set if the
+submit requirement did not define an override expression.
+|===========================
+
 [[submitted-together-info]]
 === SubmittedTogetherInfo
 The `SubmittedTogetherInfo` entity contains information about a
diff --git a/java/com/google/gerrit/acceptance/AbstractDaemonTest.java b/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
index fd78bd8..7ddf2ba 100644
--- a/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
+++ b/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
@@ -71,6 +71,7 @@
 import com.google.gerrit.entities.PermissionRule.Action;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.entities.RefNames;
+import com.google.gerrit.entities.SubmitRequirement;
 import com.google.gerrit.extensions.api.GerritApi;
 import com.google.gerrit.extensions.api.changes.ChangeApi;
 import com.google.gerrit.extensions.api.changes.ReviewInput;
@@ -1595,6 +1596,14 @@
         ObjectId.fromString(get(changeId, ListChangesOption.CURRENT_REVISION).currentRevision));
   }
 
+  protected void configSubmitRequirement(
+      Project.NameKey project, SubmitRequirement submitRequirement) throws Exception {
+    try (ProjectConfigUpdate u = updateProject(project)) {
+      u.getConfig().upsertSubmitRequirement(submitRequirement);
+      u.save();
+    }
+  }
+
   protected void configLabel(String label, LabelFunction func) throws Exception {
     configLabel(label, func, ImmutableList.of());
   }
diff --git a/java/com/google/gerrit/entities/SubmitRequirementExpressionResult.java b/java/com/google/gerrit/entities/SubmitRequirementExpressionResult.java
index 94c0e91..f7a883e 100644
--- a/java/com/google/gerrit/entities/SubmitRequirementExpressionResult.java
+++ b/java/com/google/gerrit/entities/SubmitRequirementExpressionResult.java
@@ -98,7 +98,7 @@
   public abstract static class PredicateResult {
     abstract ImmutableList<PredicateResult> childPredicateResults();
 
-    abstract String predicateString();
+    public abstract String predicateString();
 
     /** true if the predicate is passing for a given change. */
     abstract boolean status();
diff --git a/java/com/google/gerrit/extensions/client/ListChangesOption.java b/java/com/google/gerrit/extensions/client/ListChangesOption.java
index 6071cc7..f1f7831 100644
--- a/java/com/google/gerrit/extensions/client/ListChangesOption.java
+++ b/java/com/google/gerrit/extensions/client/ListChangesOption.java
@@ -85,7 +85,10 @@
    * Skip diffstat computation that compute the insertions field (number of lines inserted) and
    * deletions field (number of lines deleted)
    */
-  SKIP_DIFFSTAT(23);
+  SKIP_DIFFSTAT(23),
+
+  /** Include the evaluated submit requirements for the caller. */
+  SUBMIT_REQUIREMENTS(24);
 
   private final int value;
 
diff --git a/java/com/google/gerrit/extensions/common/ChangeInfo.java b/java/com/google/gerrit/extensions/common/ChangeInfo.java
index 9e915f5..6afe8ac 100644
--- a/java/com/google/gerrit/extensions/common/ChangeInfo.java
+++ b/java/com/google/gerrit/extensions/common/ChangeInfo.java
@@ -112,6 +112,7 @@
   public List<PluginDefinedInfo> plugins;
   public Collection<TrackingIdInfo> trackingIds;
   public Collection<LegacySubmitRequirementInfo> requirements;
+  public Collection<SubmitRequirementResultInfo> submitRequirements;
 
   public ChangeInfo() {}
 
diff --git a/java/com/google/gerrit/extensions/common/SubmitRequirementExpressionInfo.java b/java/com/google/gerrit/extensions/common/SubmitRequirementExpressionInfo.java
new file mode 100644
index 0000000..4d1fce2
--- /dev/null
+++ b/java/com/google/gerrit/extensions/common/SubmitRequirementExpressionInfo.java
@@ -0,0 +1,39 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.extensions.common;
+
+import java.util.List;
+
+/** Result of evaluating a single submit requirement expression. */
+public class SubmitRequirementExpressionInfo {
+
+  /** Submit requirement expression as a String. */
+  public String expression;
+
+  /** A boolean indicating if the expression is fulfilled on a change. */
+  public boolean fulfilled;
+
+  /**
+   * A list of all atoms that are passing, for example query "branch:refs/heads/foo and project:bar"
+   * has two atoms: ["branch:refs/heads/foo", "project:bar"].
+   */
+  public List<String> passingAtoms;
+
+  /**
+   * A list of all atoms that are failing, for example query "branch:refs/heads/foo and project:bar"
+   * has two atoms: ["branch:refs/heads/foo", "project:bar"].
+   */
+  public List<String> failingAtoms;
+}
diff --git a/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java b/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java
new file mode 100644
index 0000000..685e81a
--- /dev/null
+++ b/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java
@@ -0,0 +1,58 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.extensions.common;
+
+/** Result of evaluating a submit requirement on a change. */
+public class SubmitRequirementResultInfo {
+  public enum Status {
+    /** Submit requirement is fulfilled. */
+    SATISFIED,
+
+    /**
+     * Submit requirement is not satisfied. Happens when {@code submittabilityExpressionResult} is
+     * not fulfilled.
+     */
+    UNSATISFIED,
+
+    /**
+     * Submit requirement is overridden. Happens when {@code overrideExpressionResult} is fulfilled.
+     */
+    OVERRIDDEN,
+
+    /**
+     * Submit requirement is not applicable for the change. Happens when {@code
+     * applicabilityExpressionResult} is not fulfilled.
+     */
+    NOT_APPLICABLE
+  }
+
+  /** Submit requirement name. */
+  public String name;
+
+  /** Submit requirement description. */
+  public String description;
+
+  /** Overall result (status) of evaluating this submit requirement. */
+  public Status status;
+
+  /** Result of evaluating the applicability expression. */
+  public SubmitRequirementExpressionInfo applicabilityExpressionResult;
+
+  /** Result of evaluating the submittability expression. */
+  public SubmitRequirementExpressionInfo submittabilityExpressionResult;
+
+  /** Result of evaluating the override expression. */
+  public SubmitRequirementExpressionInfo overrideExpressionResult;
+}
diff --git a/java/com/google/gerrit/pgm/util/BatchProgramModule.java b/java/com/google/gerrit/pgm/util/BatchProgramModule.java
index 30de2f5..4db657d 100644
--- a/java/com/google/gerrit/pgm/util/BatchProgramModule.java
+++ b/java/com/google/gerrit/pgm/util/BatchProgramModule.java
@@ -83,6 +83,8 @@
 import com.google.gerrit.server.query.approval.ApprovalModule;
 import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gerrit.server.query.change.ChangeIsVisibleToPredicate;
+import com.google.gerrit.server.query.change.ChangeQueryBuilder;
+import com.google.gerrit.server.query.change.ConflictsCacheImpl;
 import com.google.gerrit.server.restapi.group.GroupModule;
 import com.google.gerrit.server.rules.DefaultSubmitRule;
 import com.google.gerrit.server.rules.IgnoreSelfApprovalRule;
@@ -174,6 +176,7 @@
     modules.add(new NoteDbModule());
     modules.add(AccountCacheImpl.module());
     modules.add(ApprovalCacheImpl.module());
+    modules.add(ConflictsCacheImpl.module());
     modules.add(DefaultPreferencesCacheImpl.module());
     modules.add(GroupCacheImpl.module());
     modules.add(GroupIncludeCacheImpl.module());
@@ -190,6 +193,10 @@
     factory(ChangeIsVisibleToPredicate.Factory.class);
     factory(ProjectState.Factory.class);
 
+    DynamicMap.mapOf(binder(), ChangeQueryBuilder.ChangeOperatorFactory.class);
+    DynamicMap.mapOf(binder(), ChangeQueryBuilder.ChangeHasOperandFactory.class);
+    DynamicMap.mapOf(binder(), ChangeQueryBuilder.ChangeIsOperandFactory.class);
+
     // Submit rules
     DynamicSet.setOf(binder(), SubmitRule.class);
     factory(SubmitRuleEvaluator.Factory.class);
diff --git a/java/com/google/gerrit/server/change/ChangeJson.java b/java/com/google/gerrit/server/change/ChangeJson.java
index 029f231..e9c9946 100644
--- a/java/com/google/gerrit/server/change/ChangeJson.java
+++ b/java/com/google/gerrit/server/change/ChangeJson.java
@@ -31,6 +31,7 @@
 import static com.google.gerrit.extensions.client.ListChangesOption.REVIEWER_UPDATES;
 import static com.google.gerrit.extensions.client.ListChangesOption.SKIP_DIFFSTAT;
 import static com.google.gerrit.extensions.client.ListChangesOption.SUBMITTABLE;
+import static com.google.gerrit.extensions.client.ListChangesOption.SUBMIT_REQUIREMENTS;
 import static com.google.gerrit.extensions.client.ListChangesOption.TRACKING_IDS;
 import static com.google.gerrit.server.ChangeMessagesUtil.createChangeMessageInfo;
 import static com.google.gerrit.server.util.AttentionSetUtil.additionsOnly;
@@ -59,6 +60,11 @@
 import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.entities.SubmitRecord;
 import com.google.gerrit.entities.SubmitRecord.Status;
+import com.google.gerrit.entities.SubmitRequirement;
+import com.google.gerrit.entities.SubmitRequirementExpression;
+import com.google.gerrit.entities.SubmitRequirementExpressionResult;
+import com.google.gerrit.entities.SubmitRequirementExpressionResult.PredicateResult;
+import com.google.gerrit.entities.SubmitRequirementResult;
 import com.google.gerrit.entities.SubmitTypeRecord;
 import com.google.gerrit.exceptions.StorageException;
 import com.google.gerrit.extensions.api.changes.FixInput;
@@ -75,6 +81,8 @@
 import com.google.gerrit.extensions.common.ProblemInfo;
 import com.google.gerrit.extensions.common.ReviewerUpdateInfo;
 import com.google.gerrit.extensions.common.RevisionInfo;
+import com.google.gerrit.extensions.common.SubmitRequirementExpressionInfo;
+import com.google.gerrit.extensions.common.SubmitRequirementResultInfo;
 import com.google.gerrit.extensions.common.TrackingIdInfo;
 import com.google.gerrit.extensions.restapi.Url;
 import com.google.gerrit.index.RefState;
@@ -362,11 +370,54 @@
     return reqInfos;
   }
 
+  private static Collection<SubmitRequirementResultInfo> submitRequirementsFor(ChangeData cd) {
+    Collection<SubmitRequirementResultInfo> reqInfos = new ArrayList<>();
+    Map<SubmitRequirement, SubmitRequirementResult> requirements = cd.submitRequirements();
+    for (Map.Entry<SubmitRequirement, SubmitRequirementResult> entry : requirements.entrySet()) {
+      reqInfos.add(submitRequirementToInfo(entry.getKey(), entry.getValue()));
+    }
+    return reqInfos;
+  }
+
   private static LegacySubmitRequirementInfo requirementToInfo(
       LegacySubmitRequirement req, Status status) {
     return new LegacySubmitRequirementInfo(status.name(), req.fallbackText(), req.type());
   }
 
+  private static SubmitRequirementResultInfo submitRequirementToInfo(
+      SubmitRequirement req, SubmitRequirementResult result) {
+    SubmitRequirementResultInfo info = new SubmitRequirementResultInfo();
+    info.name = req.name();
+    info.description = req.description().orElse(null);
+    if (req.applicabilityExpression().isPresent()) {
+      info.applicabilityExpressionResult =
+          submitRequirementExpressionToInfo(
+              req.applicabilityExpression().get(), result.applicabilityExpressionResult().get());
+    }
+    if (req.overrideExpression().isPresent()) {
+      info.overrideExpressionResult =
+          submitRequirementExpressionToInfo(
+              req.overrideExpression().get(), result.overrideExpressionResult().get());
+    }
+    info.submittabilityExpressionResult =
+        submitRequirementExpressionToInfo(
+            req.submittabilityExpression(), result.submittabilityExpressionResult());
+    info.status = SubmitRequirementResultInfo.Status.valueOf(result.status().toString());
+    return info;
+  }
+
+  private static SubmitRequirementExpressionInfo submitRequirementExpressionToInfo(
+      SubmitRequirementExpression expression, SubmitRequirementExpressionResult result) {
+    SubmitRequirementExpressionInfo info = new SubmitRequirementExpressionInfo();
+    info.expression = expression.expressionString();
+    info.fulfilled = result.status().equals(SubmitRequirementExpressionResult.Status.PASS);
+    info.passingAtoms =
+        result.getPassingAtoms().stream().map(PredicateResult::predicateString).collect(toList());
+    info.failingAtoms =
+        result.getFailingAtoms().stream().map(PredicateResult::predicateString).collect(toList());
+    return info;
+  }
+
   private static void finish(ChangeInfo info) {
     info.id =
         Joiner.on('~')
@@ -612,6 +663,9 @@
 
     out.labels = labelsJson.labelsFor(accountLoader, cd, has(LABELS), has(DETAILED_LABELS));
     out.requirements = requirementsFor(cd);
+    if (has(SUBMIT_REQUIREMENTS)) {
+      out.submitRequirements = submitRequirementsFor(cd);
+    }
 
     if (out.labels != null && has(DETAILED_LABELS)) {
       // If limited to specific patch sets but not the current patch set, don't
diff --git a/java/com/google/gerrit/server/project/ProjectConfig.java b/java/com/google/gerrit/server/project/ProjectConfig.java
index 9f898d9..3253282 100644
--- a/java/com/google/gerrit/server/project/ProjectConfig.java
+++ b/java/com/google/gerrit/server/project/ProjectConfig.java
@@ -529,6 +529,10 @@
     return submitRequirementSections;
   }
 
+  public void upsertSubmitRequirement(SubmitRequirement requirement) {
+    submitRequirementSections.put(requirement.name(), requirement);
+  }
+
   /** Adds or replaces the given {@link LabelType} in this config. */
   public void upsertLabelType(LabelType labelType) {
     labelSections.put(labelType.getName(), labelType);
diff --git a/java/com/google/gerrit/server/project/ProjectState.java b/java/com/google/gerrit/server/project/ProjectState.java
index 03d38b3..4569027 100644
--- a/java/com/google/gerrit/server/project/ProjectState.java
+++ b/java/com/google/gerrit/server/project/ProjectState.java
@@ -22,6 +22,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.entities.AccessSection;
@@ -37,6 +38,7 @@
 import com.google.gerrit.entities.PermissionRule;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.entities.StoredCommentLinkInfo;
+import com.google.gerrit.entities.SubmitRequirement;
 import com.google.gerrit.entities.SubscribeSection;
 import com.google.gerrit.extensions.api.projects.CommentLinkInfo;
 import com.google.gerrit.extensions.client.SubmitType;
@@ -392,6 +394,21 @@
     return false;
   }
 
+  /** Get all submit requirements for a project, including those from parent projects. */
+  public Map<String, SubmitRequirement> getSubmitRequirements() {
+    Map<String, SubmitRequirement> requirements = new LinkedHashMap<>();
+    for (ProjectState s : treeInOrder()) {
+      for (SubmitRequirement requirement : s.getConfig().getSubmitRequirementSections().values()) {
+        String lowerName = requirement.name().toLowerCase();
+        SubmitRequirement old = requirements.get(lowerName);
+        if (old == null || old.allowOverrideInChildProjects()) {
+          requirements.put(lowerName, requirement);
+        }
+      }
+    }
+    return ImmutableMap.copyOf(requirements);
+  }
+
   /** All available label types. */
   public LabelTypes getLabelTypes() {
     Map<String, LabelType> types = new LinkedHashMap<>();
diff --git a/java/com/google/gerrit/server/query/change/ChangeData.java b/java/com/google/gerrit/server/query/change/ChangeData.java
index 6f8b097..ac28342 100644
--- a/java/com/google/gerrit/server/query/change/ChangeData.java
+++ b/java/com/google/gerrit/server/query/change/ChangeData.java
@@ -53,6 +53,8 @@
 import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.entities.RobotComment;
 import com.google.gerrit.entities.SubmitRecord;
+import com.google.gerrit.entities.SubmitRequirement;
+import com.google.gerrit.entities.SubmitRequirementResult;
 import com.google.gerrit.entities.SubmitTypeRecord;
 import com.google.gerrit.exceptions.StorageException;
 import com.google.gerrit.extensions.restapi.BadRequestException;
@@ -86,6 +88,7 @@
 import com.google.gerrit.server.project.NoSuchChangeException;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectState;
+import com.google.gerrit.server.project.SubmitRequirementsEvaluator;
 import com.google.gerrit.server.project.SubmitRuleEvaluator;
 import com.google.gerrit.server.project.SubmitRuleOptions;
 import com.google.gerrit.server.util.time.TimeUtil;
@@ -265,7 +268,7 @@
     ChangeData cd =
         new ChangeData(
             null, null, null, null, null, null, null, null, null, null, null, null, null, null,
-            null, project, id, null, null);
+            null, null, project, id, null, null);
     cd.currentPatchSet =
         PatchSet.builder()
             .id(PatchSet.id(id, currentPatchSetId))
@@ -291,6 +294,7 @@
   private final ProjectCache projectCache;
   private final TrackingFooters trackingFooters;
   private final PureRevert pureRevert;
+  private final SubmitRequirementsEvaluator submitRequirementsEvaluator;
   private final SubmitRuleEvaluator.Factory submitRuleEvaluatorFactory;
 
   // Required assisted injected fields.
@@ -302,6 +306,8 @@
   private final Map<SubmitRuleOptions, List<SubmitRecord>> submitRecords =
       Maps.newLinkedHashMapWithExpectedSize(1);
 
+  private Map<SubmitRequirement, SubmitRequirementResult> submitRequirements;
+
   private StorageConstraint storageConstraint = StorageConstraint.NOTEDB_ONLY;
   private Change change;
   private ChangeNotes notes;
@@ -365,6 +371,7 @@
       ProjectCache projectCache,
       TrackingFooters trackingFooters,
       PureRevert pureRevert,
+      SubmitRequirementsEvaluator submitRequirementsEvaluator,
       SubmitRuleEvaluator.Factory submitRuleEvaluatorFactory,
       @Assisted Project.NameKey project,
       @Assisted Change.Id id,
@@ -384,6 +391,7 @@
     this.starredChangesUtil = starredChangesUtil;
     this.trackingFooters = trackingFooters;
     this.pureRevert = pureRevert;
+    this.submitRequirementsEvaluator = submitRequirementsEvaluator;
     this.submitRuleEvaluatorFactory = submitRuleEvaluatorFactory;
 
     this.project = project;
@@ -920,6 +928,21 @@
     return messages;
   }
 
+  /** Get all submit requirements for this change, including those from parent projects. */
+  public Map<SubmitRequirement, SubmitRequirementResult> submitRequirements() {
+    if (submitRequirements == null) {
+      ProjectState state = projectCache.get(project()).orElseThrow(illegalState(project()));
+      Map<String, SubmitRequirement> requirements = state.getSubmitRequirements();
+      ImmutableMap.Builder<SubmitRequirement, SubmitRequirementResult> result =
+          ImmutableMap.builderWithExpectedSize(requirements.size());
+      for (SubmitRequirement requirement : requirements.values()) {
+        result.put(requirement, submitRequirementsEvaluator.evaluate(requirement, this));
+      }
+      submitRequirements = result.build();
+    }
+    return submitRequirements;
+  }
+
   public List<SubmitRecord> submitRecords(SubmitRuleOptions options) {
     // If the change is not submitted yet, 'strict' and 'lenient' both have the same result. If the
     // change is submitted, SubmitRecord requested with 'strict' will contain just a single entry
diff --git a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
index 529ce73..22a727a 100644
--- a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
@@ -100,6 +100,8 @@
 import com.google.gerrit.entities.Permission;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.entities.RefNames;
+import com.google.gerrit.entities.SubmitRequirement;
+import com.google.gerrit.entities.SubmitRequirementExpression;
 import com.google.gerrit.exceptions.StorageException;
 import com.google.gerrit.extensions.annotations.Exports;
 import com.google.gerrit.extensions.api.accounts.DeleteDraftCommentsInput;
@@ -142,6 +144,8 @@
 import com.google.gerrit.extensions.common.GitPerson;
 import com.google.gerrit.extensions.common.LabelInfo;
 import com.google.gerrit.extensions.common.RevisionInfo;
+import com.google.gerrit.extensions.common.SubmitRequirementResultInfo;
+import com.google.gerrit.extensions.common.SubmitRequirementResultInfo.Status;
 import com.google.gerrit.extensions.common.TrackingIdInfo;
 import com.google.gerrit.extensions.events.WorkInProgressStateChangedListener;
 import com.google.gerrit.extensions.restapi.AuthException;
@@ -3990,6 +3994,192 @@
   }
 
   @Test
+  public void submitRequirementIsSatisfied_whenSubmittabilityExpressionIsFulfilled()
+      throws Exception {
+    configSubmitRequirement(
+        project,
+        SubmitRequirement.builder()
+            .setName("code-review")
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:code-review=+2"))
+            .setAllowOverrideInChildProjects(false)
+            .build());
+    configSubmitRequirement(
+        project,
+        SubmitRequirement.builder()
+            .setName("verified")
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:verified=+1"))
+            .setAllowOverrideInChildProjects(false)
+            .build());
+
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+
+    ChangeInfo change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(2);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.UNSATISFIED);
+    assertSubmitRequirementStatus(change.submitRequirements, "verified", Status.UNSATISFIED);
+
+    voteLabel(changeId, "code-review", 2);
+
+    change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(2);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.SATISFIED);
+    assertSubmitRequirementStatus(change.submitRequirements, "verified", Status.UNSATISFIED);
+  }
+
+  @Test
+  public void submitRequirementIsNotApplicable_whenApplicabilityExpressionIsNotFulfilled()
+      throws Exception {
+    configSubmitRequirement(
+        project,
+        SubmitRequirement.builder()
+            .setName("code-review")
+            .setApplicabilityExpression(SubmitRequirementExpression.of("project:foo"))
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:code-review=+2"))
+            .setAllowOverrideInChildProjects(false)
+            .build());
+
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+
+    ChangeInfo change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.NOT_APPLICABLE);
+  }
+
+  @Test
+  public void submitRequirementIsOverridden_whenOverrideExpressionIsFulfilled() throws Exception {
+    configLabel("build-cop-override", LabelFunction.MAX_WITH_BLOCK);
+    projectOperations
+        .project(project)
+        .forUpdate()
+        .add(
+            allowLabel("build-cop-override")
+                .ref("refs/heads/master")
+                .group(REGISTERED_USERS)
+                .range(-1, 1))
+        .update();
+
+    configSubmitRequirement(
+        project,
+        SubmitRequirement.builder()
+            .setName("code-review")
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:code-review=+2"))
+            .setOverrideExpression(SubmitRequirementExpression.of("label:build-cop-override=+1"))
+            .setAllowOverrideInChildProjects(false)
+            .build());
+
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+    ChangeInfo change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.UNSATISFIED);
+
+    voteLabel(changeId, "build-cop-override", 1);
+
+    change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.OVERRIDDEN);
+  }
+
+  @Test
+  public void submitRequirement_overriddenInChildProject() throws Exception {
+    configSubmitRequirement(
+        allProjects,
+        SubmitRequirement.builder()
+            .setName("code-review")
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:code-review=+1"))
+            .setOverrideExpression(SubmitRequirementExpression.of("label:build-cop-override=+1"))
+            .setAllowOverrideInChildProjects(true)
+            .build());
+
+    // Override submit requirement in child project (requires code-review=+2 instead of +1)
+    configSubmitRequirement(
+        project,
+        SubmitRequirement.builder()
+            .setName("code-review")
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:code-review=+2"))
+            .setOverrideExpression(SubmitRequirementExpression.of("label:build-cop-override=+1"))
+            .setAllowOverrideInChildProjects(false)
+            .build());
+
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+    ChangeInfo change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.UNSATISFIED);
+
+    voteLabel(changeId, "code-review", 1);
+    change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.UNSATISFIED);
+
+    voteLabel(changeId, "code-review", 2);
+    change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.SATISFIED);
+  }
+
+  @Test
+  public void submitRequirement_inheritedFromParentProject() throws Exception {
+    configSubmitRequirement(
+        allProjects,
+        SubmitRequirement.builder()
+            .setName("code-review")
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:code-review=+1"))
+            .setOverrideExpression(SubmitRequirementExpression.of("label:build-cop-override=+1"))
+            .setAllowOverrideInChildProjects(false)
+            .build());
+
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+    ChangeInfo change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.UNSATISFIED);
+
+    voteLabel(changeId, "code-review", 1);
+    change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.SATISFIED);
+  }
+
+  @Test
+  public void submitRequirement_ignoredInChildProject_ifParentDoesNotAllowOverride()
+      throws Exception {
+    configSubmitRequirement(
+        allProjects,
+        SubmitRequirement.builder()
+            .setName("code-review")
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:code-review=+1"))
+            .setOverrideExpression(SubmitRequirementExpression.of("label:build-cop-override=+1"))
+            .setAllowOverrideInChildProjects(false)
+            .build());
+
+    // Override submit requirement in child project (requires code-review=+2 instead of +1).
+    // Will have no effect since parent does not allow override.
+    configSubmitRequirement(
+        project,
+        SubmitRequirement.builder()
+            .setName("code-review")
+            .setSubmittabilityExpression(SubmitRequirementExpression.create("label:code-review=+2"))
+            .setOverrideExpression(SubmitRequirementExpression.of("label:build-cop-override=+1"))
+            .setAllowOverrideInChildProjects(false)
+            .build());
+
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+    ChangeInfo change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.UNSATISFIED);
+
+    voteLabel(changeId, "code-review", 1);
+    change = gApi.changes().id(changeId).get();
+    assertThat(change.submitRequirements).hasSize(1);
+    // +1 was enough to fulfill the requirement: override in child project was ignored
+    assertSubmitRequirementStatus(change.submitRequirements, "code-review", Status.SATISFIED);
+  }
+
+  @Test
   public void fourByteEmoji() throws Exception {
     // U+1F601 GRINNING FACE WITH SMILING EYES
     String smile = new String(Character.toChars(0x1f601));
@@ -4630,4 +4820,21 @@
           event.getChange().workInProgress != null ? event.getChange().workInProgress : false;
     }
   }
+
+  private void voteLabel(String changeId, String labelName, int score) throws RestApiException {
+    gApi.changes().id(changeId).current().review(new ReviewInput().label(labelName, score));
+  }
+
+  private void assertSubmitRequirementStatus(
+      Collection<SubmitRequirementResultInfo> results,
+      String requirementName,
+      SubmitRequirementResultInfo.Status status) {
+    for (SubmitRequirementResultInfo result : results) {
+      if (result.name.equals(requirementName) && result.status == status) {
+        return;
+      }
+    }
+    throw new AssertionError(
+        "Could not find submit requirement  " + requirementName + " with status " + status);
+  }
 }