Moved the mono instantiation from constructor to refresh method

Author: vishal-bihani

api/src/main/java/io/kafbat/ui/service/ApplicationInfoService.java

@@ -73,7 +73,7 @@ private List<EnabledFeaturesEnum> getEnabledFeatures() {
   // updating on startup and every hour
   @Scheduled(fixedRateString = "${github-release-info-update-rate:3600000}")
   public void updateGithubReleaseInfo() {
-    githubReleaseInfo.refresh().subscribe();
+    githubReleaseInfo.refresh();
   }
 
   @VisibleForTesting

api/src/main/java/io/kafbat/ui/util/GithubReleaseInfo.java

@@ -1,6 +1,5 @@
 package io.kafbat.ui.util;
 
-import com.google.common.annotations.VisibleForTesting;
 import java.time.Duration;
 import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
@@ -9,50 +8,48 @@
 @Slf4j
 public class GithubReleaseInfo {
   public static final String GITHUB_RELEASE_INFO_TIMEOUT = "github.release.info.timeout";
-
   private static final String GITHUB_LATEST_RELEASE_RETRIEVAL_URL =
       "https://api.github.com/repos/kafbat/kafka-ui/releases/latest";
 
   public record GithubReleaseDto(String html_url, String tag_name, String published_at) {
-
     static GithubReleaseDto empty() {
       return new GithubReleaseDto(null, null, null);
     }
   }
 
-  private volatile GithubReleaseDto release = GithubReleaseDto.empty();
-
-  private final Mono<Void> refreshMono;
-
   @Getter
   private final int githubApiMaxWaitTime;
+  private volatile GithubReleaseDto release;
 
   public GithubReleaseInfo(int githubApiMaxWaitTime) {
-    this(GITHUB_LATEST_RELEASE_RETRIEVAL_URL, githubApiMaxWaitTime);
+    this.githubApiMaxWaitTime = githubApiMaxWaitTime;
   }
 
-  @VisibleForTesting
-  GithubReleaseInfo(String url, int githubApiMaxWaitTime) {
-    this.githubApiMaxWaitTime = githubApiMaxWaitTime;
-    this.refreshMono = new WebClientConfigurator().build()
+  public GithubReleaseDto get() {
+    if (release != null) {
+      return release;
+    }
+
+    refresh();
+    return release == null ? GithubReleaseDto.empty() : release;
+  }
+
+  public void refresh() {
+    refresh(GITHUB_LATEST_RELEASE_RETRIEVAL_URL);
+  }
+
+  public void refresh(String url) {
+    new WebClientConfigurator().build()
         .get()
         .uri(url)
         .exchangeToMono(resp -> resp.bodyToMono(GithubReleaseDto.class))
-        .timeout(Duration.ofSeconds(this.githubApiMaxWaitTime))
-        .doOnError(th -> log.trace("Error getting latest github release info", th))
+        .timeout(Duration.ofSeconds(githubApiMaxWaitTime))
+        .doOnError(th -> log.error("Failed to retrieve latest release info", th))
         .onErrorResume(th -> true, th -> Mono.just(GithubReleaseDto.empty()))
-        .doOnNext(release -> this.release = release)
-        .then();
-
-    this.refreshMono.block();
+        .doOnNext(r -> this.release = r)
+        .block();
   }
 
-  public GithubReleaseDto get() {
-    return release;
-  }
 
-  public Mono<Void> refresh() {
-    return refreshMono;
-  }
 
 }

api/src/test/java/io/kafbat/ui/util/GithubReleaseInfoTest.java

@@ -25,6 +25,9 @@ void stopMockServer() throws IOException {
 
   @Test
   void test() {
+    var infoHolder = new GithubReleaseInfo(10);
+    var url = mockWebServer.url("repos/kafbat/kafka-ui/releases/latest").toString();
+
     mockWebServer.enqueue(new MockResponse()
         .addHeader("content-type: application/json")
         .setBody("""
@@ -35,10 +38,8 @@ void test() {
               "some_unused_prop": "ololo"
             }
             """));
-    var url = mockWebServer.url("repos/kafbat/kafka-ui/releases/latest").toString();
 
-    var infoHolder = new GithubReleaseInfo(url, 10);
-    infoHolder.refresh().block();
+    infoHolder.refresh(url);
 
     var i = infoHolder.get();
     assertThat(i.html_url())