Allow additional mergeable statuses to skip upload

We have some statuses that we know are safe to skip to upload when
the git diff would be empty for github_pr_destination. But there
might be other statuses where we want to skip too. This allows
users to add additional statuses to skip. The inmediate usage
is to skip when "BLOCKED". We think this would make sense in
general when this GitHub destination is not the SoT, but we want
to have the flexibility to enable it for individual use cases.

Update update docs script to use java 11 (otherwise it fails)

Change-Id: Ie21d0b1b46a2d28f930f834de0f2b1e93099ec3b

Author: mikelalcon

docs/reference.md

@@ -2535,7 +2535,7 @@ primary_branch_migration | `bool`<br><p>When enabled, copybara will ignore the '
 
 Creates changes in a new pull request in the destination.
 
-`destination` `git.github_pr_destination(url, destination_ref='master', pr_branch=None, partial_fetch=False, allow_empty_diff=True, title=None, body=None, integrates=None, api_checker=None, update_description=False, primary_branch_migration=False, checker=None, draft=False)`
+`destination` `git.github_pr_destination(url, destination_ref='master', pr_branch=None, partial_fetch=False, allow_empty_diff=True, empty_diff_merge_statuses=[], title=None, body=None, integrates=None, api_checker=None, update_description=False, primary_branch_migration=False, checker=None, draft=False)`
 
 
 #### Parameters:
@@ -2547,6 +2547,7 @@ destination_ref | `string`<br><p>Destination reference for the change.</p>
 pr_branch | `string` or `NoneType`<br><p>Customize the pull request branch. Any variable present in the message in the form of ${CONTEXT_REFERENCE} will be replaced by the corresponding stable reference (head, PR number, Gerrit change number, etc.).</p>
 partial_fetch | `bool`<br><p>This is an experimental feature that only works for certain origin globs.</p>
 allow_empty_diff | `bool`<br><p>By default, copybara migrates changes without checking existing PRs. If set, copybara will skip pushing a change to an existing PR only if the git three of the pending migrating change is the same as the existing PR.</p>
+empty_diff_merge_statuses | `sequence of string`<br><p>By default, if `allow_empty_diff = False` is set, Copybara will also check the **experimental** GitHub field `mergeable status` to decide if it uploads or not. For example if status is 'CLEAN', 'DRAFT', 'HAS_HOOKS' or 'BEHIND', it assumes that the uploaded content is up to date. This field allows to add additional states that the PR could be in where we skip uploading, for example 'BLOCKED'. The statuses values are described at: https://docs.github.com/en/github-ae@latest/graphql/reference/enums#mergestatestatus. **Note that this field is experimental and is subject to change by GitHub without notice**. Please consult Copybara team before using this field</p>
 title | `string` or `NoneType`<br><p>When creating (or updating if `update_description` is set) a pull request, use this title. By default it uses the change first line. This field accepts a template with labels. For example: `"Change ${CONTEXT_REFERENCE}"`</p>
 body | `string` or `NoneType`<br><p>When creating (or updating if `update_description` is set) a pull request, use this body. By default it uses the change summary. This field accepts a template with labels. For example: `"Change ${CONTEXT_REFERENCE}"`</p>
 integrates | `sequence of git_integrate` or `NoneType`<br><p>Integrate changes from a url present in the migrated change label. Defaults to a semi-fake merge if COPYBARA_INTEGRATE_REVIEW label is present in the message</p>

java/com/google/copybara/git/GitHubPrWriteHook.java

@@ -18,7 +18,9 @@
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import com.google.copybara.GeneralOptions;
+import com.google.copybara.config.SkylarkUtil;
 import com.google.copybara.exception.RedundantChangeException;
 import com.google.copybara.exception.RepoException;
 import com.google.copybara.exception.ValidationException;
@@ -42,6 +44,7 @@ public class GitHubPrWriteHook extends DefaultWriteHook {
   private final GeneralOptions generalOptions;
   private final GitHubOptions gitHubOptions;
   private final boolean partialFetch;
+  private final ImmutableSet<String> emptyDiffMergeStatuses;
   private final Console console;
   private GitHubHost ghHost;
   @Nullable private final String prBranchToUpdate;
@@ -54,14 +57,15 @@ public class GitHubPrWriteHook extends DefaultWriteHook {
       @Nullable String prBranchToUpdate,
       boolean partialFetch,
       boolean allowEmptyDiff,
-      Console console,
+      ImmutableSet<String> emptyDiffMergeStatuses, Console console,
       GitHubHost ghHost) {
     this.generalOptions = Preconditions.checkNotNull(generalOptions);
     this.repoUrl = Preconditions.checkNotNull(repoUrl);
     this.gitHubOptions = Preconditions.checkNotNull(gitHubOptions);
     this.prBranchToUpdate = prBranchToUpdate;
     this.partialFetch = partialFetch;
     this.allowEmptyDiff = allowEmptyDiff;
+    this.emptyDiffMergeStatuses = emptyDiffMergeStatuses;
     this.console = Preconditions.checkNotNull(console);
     this.ghHost = Preconditions.checkNotNull(ghHost);
   }
@@ -146,6 +150,11 @@ private boolean skipUploadBasedOnPrStatus(String configProjectName, GitHubApi ap
         console.verboseFmt("Skipping upload because mergeable status is %s", mergeableState);
         return true;
       default:
+        if (emptyDiffMergeStatuses.contains(mergeableState.toUpperCase())) {
+          console.infoFmt("Skipping upload because mergeable status is %s,"
+              + " that is configured in users config.", mergeableState);
+          return true;
+        }
         console.verboseFmt("Not skipping upload because mergeable status is %s", mergeableState);
         return false;
     }
@@ -159,6 +168,7 @@ protected GitHubPrWriteHook withUpdatedPrBranch(String prBranchToUpdate) {
         prBranchToUpdate,
         this.partialFetch,
         this.allowEmptyDiff,
+        this.emptyDiffMergeStatuses,
         this.console,
         this.ghHost);
   }

java/com/google/copybara/git/GitModule.java

@@ -1688,7 +1688,24 @@ public GitDestination gitHubDestination(
                     + "If set, copybara will skip pushing a change to an existing PR "
                     + "only if the git three of the pending migrating change is the same "
                     + "as the existing PR."),
-        @Param(
+          @Param(
+              name = "empty_diff_merge_statuses",
+              allowedTypes = {
+                  @ParamType(type = Sequence.class, generic1 = String.class)
+              },
+              defaultValue = "[]",
+              named = true,
+              positional = false,
+              doc = "By default, if `allow_empty_diff = False` is set, Copybara will also check"
+                  + " the **experimental** GitHub field `mergeable status` to decide if it uploads"
+                  + " or not. For example if status is 'CLEAN', 'DRAFT', 'HAS_HOOKS' or 'BEHIND',"
+                  + " it assumes that the uploaded content is up to date. This field allows to"
+                  + " add additional states that the PR could be in where we skip uploading, for"
+                  + " example 'BLOCKED'. The statuses values are described at:"
+                  + " https://docs.github.com/en/github-ae@latest/graphql/reference/enums#mergestatestatus."
+                  + " **Note that this field is experimental and is subject to change by GitHub"
+                  + " without notice**. Please consult Copybara team before using this field"),
+          @Param(
             name = "title",
             allowedTypes = {
               @ParamType(type = String.class),
@@ -1778,7 +1795,7 @@ public GitDestination gitHubDestination(
             defaultValue = "False",
             named = true,
             positional = false,
-            doc = "Flag create pull request as draft or not."),
+            doc = "Flag create pull request as draft or not.")
       },
       useStarlarkThread = true)
   @UsesFlags({GitDestinationOptions.class, GitHubDestinationOptions.class})
@@ -1814,6 +1831,7 @@ public GitHubPrDestination githubPrDestination(
       Object prBranch,
       Boolean partialFetch,
       Boolean allowEmptyDiff,
+      Sequence<?> emptyDiffMergeStatuses,
       Object title,
       Object body,
       Object integrates,
@@ -1853,6 +1871,9 @@ public GitHubPrDestination githubPrDestination(
             destinationPrBranch,
             partialFetch,
             allowEmptyDiff,
+            ImmutableSet.copyOf(
+                SkylarkUtil.convertStringList(emptyDiffMergeStatuses,
+                    "empty_diff_merge_statuses")),
             getGeneralConsole(),
             GITHUB_COM),
         Starlark.isNullOrNone(integrates)

javatests/com/google/copybara/git/GitHubPrDestinationTest.java

@@ -43,6 +43,7 @@
 import com.google.copybara.WriterContext;
 import com.google.copybara.authoring.Author;
 import com.google.copybara.effect.DestinationEffect;
+import com.google.copybara.exception.CannotResolveRevisionException;
 import com.google.copybara.exception.RedundantChangeException;
 import com.google.copybara.exception.RepoException;
 import com.google.copybara.exception.ValidationException;
@@ -67,6 +68,7 @@
 import java.nio.file.Path;
 import java.util.Map;
 import java.util.Map.Entry;
+import javax.annotation.Nullable;
 import net.starlark.java.eval.StarlarkList;
 import org.junit.Before;
 import org.junit.Test;
@@ -84,6 +86,7 @@ public class GitHubPrDestinationTest {
 
   private Path workdir;
   private String primaryBranchMigration;
+  @Nullable private String emptyDiffMergeStatus;
 
   @Before
   public void setup() throws Exception {
@@ -636,6 +639,18 @@ public void testWriteNomain() throws ValidationException, IOException, RepoExcep
   @Test
   public void emptyChange() throws Exception {
     Writer<GitRevision> writer = getWriterForTestEmptyDiff();
+    runEmptyChange(writer, "clean");
+  }
+
+  @Test
+  public void emptyChangeBecauseUserConfigureStatus() throws Exception {
+    emptyDiffMergeStatus = "BLOCKED";
+    Writer<GitRevision> writer = getWriterForTestEmptyDiff();
+    runEmptyChange(writer, "blocked");
+  }
+
+  private void runEmptyChange(Writer<GitRevision> writer, String prMergeableState)
+      throws RepoException, IOException, CannotResolveRevisionException {
     GitRepository remote = gitUtil.mockRemoteRepo("github.com/foo");
     addFiles(
         remote,
@@ -665,7 +680,7 @@ public void emptyChange() throws Exception {
             + "  \"state\": \"closed\",\n"
             + "  \"title\": \"test summary\",\n"
             + "  \"mergeable\": true,\n"
-            + "  \"mergeable_state\": \"clean\",\n"
+            + "  \"mergeable_state\": \"" + prMergeableState + "\",\n"
             + "  \"body\": \"test summary\","
             + "  \"head\": {\"sha\": \"" + changeHead + "\"},"
             + "  \"base\": {\"sha\": \"" + baseline + "\"}"
@@ -813,6 +828,9 @@ private Writer<GitRevision> getWriterForTestEmptyDiff() throws Exception {
         + "    allow_empty_diff = False,\n"
         + "    destination_ref = 'main',\n"
         + "    pr_branch = 'test_${CONTEXT_REFERENCE}',\n"
+        + (emptyDiffMergeStatus != null
+           ? "empty_diff_merge_statuses = ['" + emptyDiffMergeStatus + "'],\n"
+           : "")
         + "    primary_branch_migration = " +  primaryBranchMigration + ",\n"
         + ")");
     WriterContext writerContext =

scripts/update_docs

@@ -1,5 +1,5 @@
 #!/bin/bash
-bazel build java/com/google/copybara:generate_reference
+bazel build --java_language_version=11 --tool_java_language_version=11 --java_runtime_version=remotejdk_11  java/com/google/copybara:generate_reference
 mkdir -p docs
 cp bazel-bin/java/com/google/copybara/reference.md docs/reference.md
 git add docs/reference.md