(feat) Add method to list instances of code scanning alert

[#1133]

Author: akashRindhe

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

@@ -128,6 +128,15 @@ public GHCodeScanningAlertInstance getMostRecentInstance() {
         return most_recent_instance;
     }
 
+    /**
+     * List all instances of the alert
+     *
+     * @return the paged iterable
+     */
+    public PagedIterable<GHCodeScanningAlertInstance> listAlertInstances() {
+        return new GHCodeScanningAlertInstancesIterable(this, root.createRequest().withUrlPath(instances_url));
+    }
+
     @Override
     public URL getHtmlUrl() throws IOException {
         return GitHubClient.parseURL(html_url);

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

@@ -1,17 +1,12 @@
 package org.kohsuke.github;
 
-import com.fasterxml.jackson.annotation.JsonIgnore;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
 public class GHCodeScanningAlertInstance {
-
-    @JsonIgnore
-    private GHCodeScanningAlert owner;
-
     private String ref;
     private String analysis_key;
     private String environment;
@@ -55,7 +50,6 @@ public Location getLocation() {
 
     @SuppressFBWarnings(value = { "UWF_UNWRITTEN_FIELD" }, justification = "JSON API")
     static class Message {
-
         private String text;
 
         public String getText() {

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

@@ -0,0 +1,46 @@
+package org.kohsuke.github;
+
+import java.net.MalformedURLException;
+import java.util.Iterator;
+
+import javax.annotation.Nonnull;
+
+public class GHCodeScanningAlertInstancesIterable extends PagedIterable<GHCodeScanningAlertInstance> {
+    private final GHCodeScanningAlert owner;
+    private final GitHubRequest request;
+    private GHCodeScanningAlertInstance[] result;
+
+    public GHCodeScanningAlertInstancesIterable(GHCodeScanningAlert owner, GitHubRequest.Builder<?> requestBuilder) {
+        this.owner = owner;
+        try {
+            this.request = requestBuilder.build();
+        } catch (MalformedURLException e) {
+            throw new GHException("Malformed URL", e);
+        }
+    }
+
+    @Nonnull
+    @Override
+    public PagedIterator<GHCodeScanningAlertInstance> _iterator(int pageSize) {
+        return new PagedIterator<>(
+                adapt(GitHubPageIterator
+                        .create(owner.getRoot().getClient(), GHCodeScanningAlertInstance[].class, request, pageSize)),
+                null);
+    }
+
+    protected Iterator<GHCodeScanningAlertInstance[]> adapt(final Iterator<GHCodeScanningAlertInstance[]> base) {
+        return new Iterator<GHCodeScanningAlertInstance[]>() {
+            public boolean hasNext() {
+                return base.hasNext();
+            }
+
+            public GHCodeScanningAlertInstance[] next() {
+                GHCodeScanningAlertInstance[] v = base.next();
+                if (result == null) {
+                    result = v;
+                }
+                return result;
+            }
+        };
+    }
+}

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

@@ -0,0 +1,65 @@
+package org.kohsuke.github;
+
+import org.junit.Assume;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.List;
+
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.hamcrest.Matchers.not;
+
+/**
+ * <p>
+ * Note : As the code scanning alerts cannot be tailored as part of test setup, lot of the test cases are dependent on
+ * manual setup of the mock repo. Assertions and verifications will often simply check that the values are non-null
+ * rather than depending on hard-coded values, to prevent making the tests flimsy
+ * </p>
+ */
+public class GHCodeScanningAlertInstanceTest extends AbstractGitHubWireMockTest {
+    private static final String REPO_NAME = "Pixi";
+    private GHCodeScanningAlert alert;
+
+    @Before
+    public void setUp() throws Exception {
+        GHRepository repo = gitHub.getRepository(GITHUB_API_TEST_ORG + "/" + REPO_NAME);
+        alert = getAlertFromRepo(repo);
+    }
+
+    private GHCodeScanningAlert getAlertFromRepo(GHRepository repo) {
+        List<GHCodeScanningAlert> dismissedAlerts = repo.listCodeScanningAlerts(GHCodeScanningAlertState.DISMISSED)
+                ._iterator(1)
+                .nextPage();
+        Assume.assumeThat(dismissedAlerts.size(), greaterThanOrEqualTo(1));
+        return dismissedAlerts.get(0);
+    }
+
+    @Test
+    public void testListAlertInstances() throws IOException {
+        // Arrange
+
+        // Act
+        List<GHCodeScanningAlertInstance> results = alert.listAlertInstances().toList();
+
+        // Assert
+        assertThat(results.size(), greaterThanOrEqualTo(1));
+        GHCodeScanningAlertInstance instance = results.get(0);
+        // Can't assert on exact values with having to hardcode values from
+        // json file, hence making the assertions generics
+        assertThat(instance.getRef(), not((Object) null));
+        assertThat(instance.getCommitSha(), not((Object) null));
+        assertThat(instance.getState(), not((Object) null));
+        assertThat(instance.getMessage(), not((Object) null));
+        assertThat(instance.getLocation(), not((Object) null));
+
+        GHCodeScanningAlertInstance.Location location = instance.getLocation();
+        // Can't assert on exact values with having to hardcode values from
+        // json file, hence making the assertions generics
+        assertThat(location.getPath(), not((Object) null));
+        assertThat(location.getStartLine(), greaterThanOrEqualTo(0L));
+        assertThat(location.getEndLine(), greaterThanOrEqualTo(0L));
+        assertThat(location.getStartColumn(), greaterThanOrEqualTo(0L));
+        assertThat(location.getStartColumn(), greaterThanOrEqualTo(0L));
+    }
+}