Use tag as fallback in api requests if no branch is available

dd-java-agent/agent-ci-visibility/src/main/java/datadog/trace/civisibility/config/ExecutionSettingsFactoryImpl.java

@@ -106,6 +106,7 @@ private TracerEnvironment buildTracerEnvironment(JvmInfo jvmInfo, @Nullable Stri
         .env(config.getEnv())
         .repositoryUrl(gitInfo.getRepositoryURL())
         .branch(gitInfo.getBranch())
+        .tag(gitInfo.getTag())
         .sha(gitInfo.getCommit().getSha())
         .commitMessage(gitInfo.getCommit().getFullMessage())
         .osPlatform(wellKnownTags.getOsPlatform().toString())

dd-java-agent/agent-ci-visibility/src/main/java/datadog/trace/civisibility/config/TracerEnvironment.java

@@ -2,6 +2,7 @@
 
 import com.squareup.moshi.Json;
 import datadog.trace.api.civisibility.config.Configurations;
+import datadog.trace.util.Strings;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -111,6 +112,7 @@ public static final class Builder {
     private String env;
     private String repositoryUrl;
     private String branch;
+    private String tag; // will act as fallback if no branch is provided
     private String sha;
     private String commitMessage;
     private String osPlatform;
@@ -143,6 +145,11 @@ public Builder branch(String branch) {
       return this;
     }
 
+    public Builder tag(String tag) {
+      this.tag = tag;
+      return this;
+    }
+
     public Builder sha(String sha) {
       this.sha = sha;
       return this;
@@ -203,7 +210,7 @@ public TracerEnvironment build() {
           service,
           env,
           repositoryUrl,
-          branch,
+          Strings.isNotBlank(branch) ? branch : tag,
           sha,
           commitMessage,
           new Configurations(

dd-java-agent/agent-ci-visibility/src/test/groovy/datadog/trace/civisibility/config/TracerEnvironmentTest.groovy

@@ -0,0 +1,21 @@
+package datadog.trace.civisibility.config
+
+import spock.lang.Specification
+
+class TracerEnvironmentTest extends Specification {
+  def "test fallback to tag on no branch"() {
+    setup:
+    def builder = TracerEnvironment.builder()
+    def environment = builder.branch(branch).tag(tag).build()
+
+    expect:
+    environment.branch == environmentBranch
+
+    where:
+    branch | tag       | environmentBranch
+    "main" | "v.1.0.0" | "main"
+    "main" | null      | "main"
+    null   | "v.1.0.0" | "v.1.0.0"
+    null   | null      | null
+  }
+}