Add tests showing cache performance

src/main/java/org/kohsuke/github/GitHubBuilder.java

@@ -19,7 +19,7 @@
  *
  * @since 1.59
  */
-public class GitHubBuilder {
+public class GitHubBuilder implements Cloneable {
 
     // default scoped so unit tests can read them.
     /* private */ String endpoint = GitHub.GITHUB_URL;
@@ -206,4 +206,13 @@ public HttpURLConnection connect(URL url) throws IOException {
     public GitHub build() throws IOException {
         return new GitHub(endpoint, user, oauthToken, password, connector, rateLimitHandler, abuseLimitHandler);
     }
+
+    @Override
+    public GitHubBuilder clone() {
+        try {
+            return (GitHubBuilder) super.clone();
+        } catch (CloneNotSupportedException e) {
+            throw new RuntimeException("Clone should be supported", e);
+        }
+    }
 }

src/main/java/org/kohsuke/github/extras/OkHttpConnector.java

@@ -34,22 +34,41 @@
 public class OkHttpConnector implements HttpConnector {
     private final OkUrlFactory urlFactory;
 
+    private final String maxAgeHeaderValue;
+
     public OkHttpConnector(OkUrlFactory urlFactory) {
+        this(urlFactory, 0);
+    }
+
+    /**
+     * package private for tests to be able to change max-age for cache.
+     * @param urlFactory
+     * @param cacheMaxAge
+     */
+    OkHttpConnector(OkUrlFactory urlFactory, int cacheMaxAge) {
         urlFactory.client().setSslSocketFactory(TlsSocketFactory());
         urlFactory.client().setConnectionSpecs(TlsConnectionSpecs());
         this.urlFactory = urlFactory;
+
+        if (cacheMaxAge >= 0 && urlFactory.client() != null) {
+            maxAgeHeaderValue = "max-age=" + cacheMaxAge;
+        } else {
+            maxAgeHeaderValue = null;
+        }
     }
 
+
     public HttpURLConnection connect(URL url) throws IOException {
         HttpURLConnection urlConnection = urlFactory.open(url);
-        if (urlFactory.client() != null && urlFactory.client().getCache() != null) {
+        // Cache can be added after client is created so we have to check it for each call
+        if (maxAgeHeaderValue != null && urlFactory.client().getCache() != null) {
             // By default OkHttp honors max-age, meaning it will use local cache
             // without checking the network within that time frame.
             // However, that can result in stale data being returned during that time so
             // we force network-based checking no matter how often the query is made.
             // OkHttp still automatically does ETag checking and returns cached data when
             // GitHub reports 304, but those do not count against rate limit.
-            urlConnection.setRequestProperty("Cache-Control", "max-age=0");
+            urlConnection.setRequestProperty("Cache-Control", maxAgeHeaderValue);
         }
 
         return urlConnection;

src/test/java/org/kohsuke/github/AbstractGitHubApiWireMockTest.java

@@ -83,12 +83,7 @@ private static GitHubBuilder createGitHubBuilder() {
     }
 
     protected GitHubBuilder getGitHubBuilder() {
-        return githubBuilder;
-    }
-
-    @Before
-    public void wireMockSetup() throws Exception {
-        GitHubBuilder builder = getGitHubBuilder();
+        GitHubBuilder builder = githubBuilder.clone();
 
         if (!githubApi.isUseProxy()) {
             // This sets the user and password to a placeholder for wiremock testing
@@ -97,12 +92,19 @@ public void wireMockSetup() throws Exception {
             builder.withPassword(STUBBED_USER_LOGIN, STUBBED_USER_PASSWORD);
         }
 
+        return builder;
+    }
+
+    @Before
+    public void wireMockSetup() throws Exception {
+        GitHubBuilder builder = getGitHubBuilder()
+            .withEndpoint(githubApi.baseUrl());
+
         gitHub = builder
-            .withEndpoint("http://localhost:" + githubApi.port())
             .build();
 
         if (githubApi.isUseProxy()) {
-            gitHubBeforeAfter = builder
+            gitHubBeforeAfter = getGitHubBuilder()
                 .withEndpoint("https://api.github.com/")
                 .build();
         } else {