Add CheckoutPR.java (#13184)

Author: koppor

.jbang/CheckoutPR.java

@@ -0,0 +1,110 @@
+import java.io.File;
+import java.util.List;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.storage.file.FileRepositoryBuilder;
+import org.eclipse.jgit.transport.RemoteConfig;
+import org.eclipse.jgit.transport.URIish;
+import org.kohsuke.github.GHIssueState;
+import org.kohsuke.github.GHPullRequest;
+import org.kohsuke.github.GHRepository;
+import org.kohsuke.github.GitHub;
+import org.kohsuke.github.GitHubBuilder;
+
+///usr/bin/env jbang "$0" "$@" ; exit $?
+
+//JAVA 21+
+//RUNTIME_OPTIONS --enable-native-access=ALL-UNNAMED
+
+//DEPS org.kohsuke:github-api:2.0-rc.3
+//DEPS org.eclipse.jgit:org.eclipse.jgit.pgm:7.2.1.202505142326-r
+
+public class CheckoutPR {
+    public static void main(String[] args) throws Exception {
+        GitHub github = new GitHubBuilder().build();
+        GHRepository repo = github.getRepository("JabRef/jabref");
+
+        if (args.length != 1) {
+            System.err.println("Usage: java CheckoutPR <pull-request-number>|<contributor:branch-name>");
+            System.exit(1);
+        }
+
+        String arg = args[0];
+        GHPullRequest pr;
+        if (arg.contains(":")) {
+            String[] parts = arg.split(":");
+            String contributor = parts[0];
+            String branchName = parts[1];
+            pr = repo.getPullRequests(GHIssueState.OPEN)
+                                   .stream()
+                                   .filter(p -> p.getHead().getUser().getLogin().equals(contributor))
+                                   .filter(p -> p.getHead().getRef().equals(branchName))
+                                   .findFirst()
+                                   .orElseThrow(() -> new IllegalArgumentException("Pull request not found for branch: " + branchName));
+        } else {
+            pr = repo.getPullRequest(Integer.parseInt(args[0]));
+        }
+
+        String headRef = pr.getHead().getRef();
+        String headRepoCloneUrl = pr.getHead().getRepository().getHttpTransportUrl();
+
+        final String remoteName = "tmp-remote";
+        final String localBranchName = "pr--" + pr.getNumber() + "--" + pr.getUser().getLogin() + "--" + headRef;
+
+        // Open the repository in the current directory (".")
+        File repoDir = new File(".");
+        Repository repository = new FileRepositoryBuilder()
+                .setGitDir(new File(repoDir, ".git"))
+                .readEnvironment()
+                .findGitDir()
+                .build();
+
+        try (Git git = new Git(repository)) {
+            // If current branch is "tmp-branch", checkout "main"
+            String currentBranch = repository.getBranch();
+            if (localBranchName.equals(currentBranch)) {
+                System.out.println("Checking out 'main' branch");
+                git.checkout().setName("main").call();
+            }
+
+            // Check if branch "tmp-branch" exists and remove it if present
+            List<org.eclipse.jgit.lib.Ref> branches = git.branchList().call();
+            boolean branchExists = branches.stream().anyMatch(branch -> branch.getName().endsWith(localBranchName));
+            if (branchExists) {
+                System.out.println("Deleting branch 'tmp-branch'");
+                git.branchDelete().setBranchNames(localBranchName).setForce(true).call();
+            }
+
+            // Check if the remote "tmp-remote" exists and remove it if present
+            List<RemoteConfig> remotes = git.remoteList().call();
+            boolean remoteExists = remotes.stream().anyMatch(remote -> remote.getName().equals(remoteName));
+            if (remoteExists) {
+                System.out.println("Removing remote 'tmp-remote'");
+                git.remoteRemove().setRemoteName(remoteName).call();
+            }
+
+            System.out.println("Adding remote 'tmp-remote'");
+            git.remoteAdd()
+               .setName(remoteName)
+               .setUri(new URIish(headRepoCloneUrl))
+               .call();
+        }
+
+        // Has nice output, therefore we use pgm
+        System.out.println("Fetching...");
+        String[] jGitArgsFetch = {"fetch", remoteName};
+        org.eclipse.jgit.pgm.Main.main(jGitArgsFetch);
+
+        try (Git git = new Git(repository)) {
+            System.out.println("Checking out...");
+            git.checkout()
+               .setCreateBranch(true)
+               .setName(localBranchName)
+               .setStartPoint(remoteName + "/" + headRef)
+               .call();
+        }
+
+        System.out.println("Checked out PR #" + pr.getNumber() + " (" + pr.getTitle() + ") to branch '" + localBranchName + "'.");
+    }
+}

.jbang/CloneJabRef.java

@@ -3,7 +3,7 @@
 
 ///usr/bin/env jbang "$0" "$@" ; exit $?
 
-//JAVA 24
+//JAVA 21+
 //RUNTIME_OPTIONS --enable-native-access=ALL-UNNAMED
 
 //DEPS org.eclipse.jgit:org.eclipse.jgit.pgm:7.2.1.202505142326-r