Avoid running resolve logic with no transport version name (elastic#135379)

When resolving transport version conflicts we must lookup the definition
that is being added by the current branch. We do this by detecting the
resource file that has been added. When no files are added, we should
not do anything. This commit moves the logic that detects branches
closer to where it is needed so that we don't possibly run it with an
empty transport version name.

Author: rjernst

build-tools-internal/src/integTest/groovy/org/elasticsearch/gradle/internal/transport/ResolveTransportVersionConflictFuncTest.groovy

@@ -0,0 +1,99 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.gradle.internal.transport
+
+import org.gradle.testkit.runner.BuildResult
+import org.gradle.testkit.runner.GradleRunner
+import org.gradle.testkit.runner.TaskOutcome
+
+class ResolveTransportVersionConflictFuncTest extends AbstractTransportVersionFuncTest {
+
+    GradleRunner runResolveAndValidateTask() {
+        List<String> args = List.of(":myserver:validateTransportVersionResources", ":myserver:resolveTransportVersionConflict")
+        return gradleRunner(args.toArray())
+    }
+
+    void assertResolveAndValidateSuccess(BuildResult result) {
+        assert result.task(":myserver:resolveTransportVersionConflict").outcome == TaskOutcome.SUCCESS
+        assert result.task(":myserver:validateTransportVersionResources").outcome == TaskOutcome.SUCCESS
+    }
+
+    def "update flag works with current"() {
+        given:
+        referableAndReferencedTransportVersion("new_tv", "8123000")
+        file("myserver/src/main/resources/transport/latest/9.2.csv").text =
+            """
+            <<<<<<< HEAD
+            existing_92,8123000
+            =======
+            new_tv,8123000
+            >>>>>> name
+            """.strip()
+
+        when:
+        def result = runResolveAndValidateTask().build()
+
+        then:
+        assertResolveAndValidateSuccess(result)
+        assertReferableDefinition("existing_92", "8123000,8012001")
+        assertReferableDefinition("new_tv", "8124000")
+        assertUpperBound("9.2", "new_tv,8124000")
+    }
+
+    def "update flag works with multiple branches"() {
+        given:
+        referableAndReferencedTransportVersion("new_tv", "8123000,8012001,7123001")
+        file("myserver/src/main/resources/transport/latest/9.2.csv").text =
+            """
+            <<<<<<< HEAD
+            existing_92,8123000
+            =======
+            new_tv,8123000
+            >>>>>> name
+            """.strip()
+        file("myserver/src/main/resources/transport/latest/9.1.csv").text =
+            """
+            <<<<<<< HEAD
+            existing_92,8012001
+            =======
+            new_tv,8012001
+            >>>>>> name
+            """.strip()
+        file("myserver/src/main/resources/transport/latest/8.19.csv").text =
+            """
+            <<<<<<< HEAD
+            initial_8.19.7,7123001
+            =======
+            new_tv,7123001
+            >>>>>> name
+            """.strip()
+
+        when:
+        def result = runResolveAndValidateTask().build()
+
+        then:
+        assertResolveAndValidateSuccess(result)
+        assertReferableDefinition("existing_92", "8123000,8012001")
+        assertUnreferableDefinition("initial_8.19.7", "7123001")
+        assertReferableDefinition("new_tv", "8124000,8012002,7123002")
+        assertUpperBound("9.2", "new_tv,8124000")
+        assertUpperBound("9.1", "new_tv,8012002")
+        assertUpperBound("8.19", "new_tv,7123002")
+    }
+
+    def "no new transport version is idempotent"() {
+        when:
+        def result = runResolveAndValidateTask().build()
+
+        then:
+        assertResolveAndValidateSuccess(result)
+        assertUpperBound("9.2", "existing_92,8123000")
+    }
+}

build-tools-internal/src/integTest/groovy/org/elasticsearch/gradle/internal/transport/TransportVersionGenerationFuncTest.groovy

@@ -499,7 +499,7 @@ class TransportVersionGenerationFuncTest extends AbstractTransportVersionFuncTes
 
     def "upper bounds files must exist for backport branches"() {
         when:
-        def result = runGenerateTask("--backport-branches=9.1,8.13,7.17,6.0").buildAndFail()
+        def result = runGenerateTask("--name", "new_tv", "--backport-branches=9.1,8.13,7.17,6.0").buildAndFail()
 
         then:
         assertGenerateFailure(result, "Missing upper bounds files for branches [6.0, 7.17, 8.13], known branches are [8.19, 9.0, 9.1, 9.2]")

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/transport/GenerateTransportVersionDefinitionTask.java

@@ -102,14 +102,14 @@ public void run() throws IOException {
         List<String> changedDefinitionNames = resources.getChangedReferableDefinitionNames();
         String targetDefinitionName = getTargetDefinitionName(resources, referencedNames, changedDefinitionNames);
 
-        List<TransportVersionUpperBound> upstreamUpperBounds = resources.getUpperBoundsFromUpstream();
-        Set<String> targetUpperBoundNames = getTargetUpperBoundNames(resources, upstreamUpperBounds, targetDefinitionName);
-
         getLogger().lifecycle("Generating transport version name: " + targetDefinitionName);
         if (targetDefinitionName.isEmpty()) {
             // TODO: resetting upper bounds needs to be done locally, otherwise it pulls in some (incomplete) changes from upstream main
             // resetAllUpperBounds(resources);
         } else {
+            List<TransportVersionUpperBound> upstreamUpperBounds = resources.getUpperBoundsFromUpstream();
+            Set<String> targetUpperBoundNames = getTargetUpperBoundNames(resources, upstreamUpperBounds, targetDefinitionName);
+
             List<TransportVersionId> ids = updateUpperBounds(resources, upstreamUpperBounds, targetUpperBoundNames, targetDefinitionName);
             // (Re)write the definition file.
             resources.writeDefinition(new TransportVersionDefinition(targetDefinitionName, ids, true));