Less temperamental bwc artifacts check when between versions

buildSrc/src/main/java/org/opensearch/gradle/internal/InternalDistributionBwcSetupPlugin.java

@@ -52,6 +52,8 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
+import java.util.Optional;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import static java.util.Arrays.asList;
@@ -106,6 +108,7 @@ private void configureBwcProject(Project project, BwcVersions.UnreleasedVersionI
                 distributionProject.name,
                 distributionProject.getProjectPath(),
                 distributionProject.getDistFile(),
+                distributionProject.getAlternativeDistFiles(),
                 buildBwcTaskProvider
             );
 
@@ -200,6 +203,7 @@ static void createBuildBwcTask(
         String projectName,
         String projectPath,
         File projectArtifact,
+        List<File> alternativeProjectArtifacts,
         TaskProvider<Task> bwcTaskProvider
     ) {
         String bwcTaskName = buildBwcTaskName(projectName);
@@ -220,8 +224,27 @@ public void execute(LoggedExec c) {
                     @Override
                     public void execute(Task task) {
                         if (projectArtifact.exists() == false) {
+                            Optional<String> foundAlternative = alternativeProjectArtifacts.stream()
+                                .filter(File::exists)
+                                .map(File::getName)
+                                .findFirst();
+                            if (foundAlternative.isPresent()) {
+                                project.getLogger()
+                                    .warn(
+                                        "Building " + bwcVersion.get() + " found acceptable alternative artifact " + foundAlternative.get()
+                                    );
+                                return;
+                            }
+                            String foundArtifacts = stream(projectArtifact.getParentFile().listFiles()).map(f -> f.getName())
+                                .map(s -> "   - " + s)
+                                .collect(Collectors.joining("\r\n"));
                             throw new InvalidUserDataException(
-                                "Building " + bwcVersion.get() + " didn't generate expected file " + projectArtifact
+                                "Building "
+                                    + bwcVersion.get()
+                                    + " didn't generate expected file "
+                                    + projectArtifact
+                                    + "\r\nFound the following artifacts:\r\n"
+                                    + foundArtifacts
                             );
                         }
                     }
@@ -239,22 +262,35 @@ private static class DistributionProject {
         private final String name;
         private String projectPath;
         private File distFile;
+        private List<File> alternativeDistFiles;
         private File expandedDistDir;
 
         DistributionProject(String name, String baseDir, Version version, String classifier, String extension, File checkoutDir) {
             this.name = name;
             this.projectPath = baseDir + "/" + name;
-            if (version.onOrAfter("1.1.0")) {
-                this.distFile = new File(
-                    checkoutDir,
-                    baseDir + "/" + name + "/build/distributions/opensearch-min-" + version + "-SNAPSHOT" + classifier + "." + extension
-                );
-            } else {
-                this.distFile = new File(
-                    checkoutDir,
-                    baseDir + "/" + name + "/build/distributions/opensearch-" + version + "-SNAPSHOT" + classifier + "." + extension
-                );
-            }
+            final String minDesignation = version.onOrAfter("1.1.0") ? "min-" : "";
+            final Function<Version, String> generateName = (Version ver) -> {
+                return baseDir
+                    + "/"
+                    + name
+                    + "/build/distributions/opensearch-"
+                    + minDesignation
+                    + ver
+                    + "-SNAPSHOT"
+                    + classifier
+                    + "."
+                    + extension;
+            };
+            this.distFile = new File(checkoutDir, generateName.apply(version));
+
+            final Version nextPatchVersion = new Version(version.getMajor(), version.getMinor(), version.getRevision() + 1);
+            final Version nextMinorVersion = new Version(version.getMajor(), version.getMinor() + 1, 0);
+            this.alternativeDistFiles = List.of(nextPatchVersion, nextMinorVersion)
+                .stream()
+                .map(generateName)
+                .map(n -> new File(checkoutDir, n))
+                .collect(Collectors.toList());
+
             // we only ported this down to the 7.x branch.
             if (version.onOrAfter("7.10.0") && (name.endsWith("zip") || name.endsWith("tar"))) {
                 this.expandedDistDir = new File(checkoutDir, baseDir + "/" + name + "/build/install");
@@ -269,6 +305,10 @@ public File getDistFile() {
             return distFile;
         }
 
+        public List<File> getAlternativeDistFiles() {
+            return alternativeDistFiles;
+        }
+
         public File getExpandedDistDirectory() {
             return expandedDistDir;
         }