Added test cases for supporting Nexus based maven metadata

Author: galovics

swagger-brake/src/main/java/io/redskap/swagger/brake/maven/maven2/LatestArtifactVersionResolver.java

@@ -17,7 +17,27 @@ String resolve(DownloadOptions options) {
         String metadataUrl = urlFactory.createLatestArtifactVersionMetadataUrl(options);
         MavenMetadata mavenMetadata = metadataDownloader.download(requestFactory.create(metadataUrl, options));
         MavenVersioning versioning = mavenMetadata.getVersioning();
-        
-        return versioning.getRelease() != null ? versioning.getRelease() : versioning.getLatest();
+        String version = resolveStandardVersioning(versioning);
+        if (version == null) {
+            version = resolveNexusVersioning(versioning);
+        }
+        if (version == null) {
+            throw new IllegalStateException("No version has been found for the metadata");
+        }
+        return version;
+    }
+
+    private String resolveStandardVersioning(MavenVersioning versioning) {
+        if (versioning != null && versioning.getLatest() != null) {
+            return versioning.getLatest();
+        }
+        return null;
+    }
+
+    private String resolveNexusVersioning(MavenVersioning versioning) {
+        if (versioning != null && versioning.getRelease() != null) {
+            return versioning.getRelease();
+        }
+        return null;
     }
 }

swagger-brake/src/test/java/io/redskap/swagger/brake/maven/maven2/LatestArtifactNameResolverTest.java

@@ -38,7 +38,7 @@ public void testResolveSnapshotShouldWorkProperly() {
         String latestBuildNumber = "2";
         String expected = "swagger-brake-example-1.2.0-20181118.221312-2";
         MavenMetadata mavenMetadata = new MavenMetadata("groupId", artifactId,
-            new MavenVersioning(expected, new MavenSnapshot(latestTimestamp, latestBuildNumber)));
+            new MavenVersioning(expected, null, new MavenSnapshot(latestTimestamp, latestBuildNumber)));
 
         String metadataUrl = "url";
         DownloadOptions options = mock(DownloadOptions.class);

swagger-brake/src/test/java/io/redskap/swagger/brake/maven/maven2/LatestArtifactVersionResolverTest.java

@@ -28,12 +28,64 @@ public class LatestArtifactVersionResolverTest {
     @InjectMocks
     private LatestArtifactVersionResolver underTest;
 
+
+    @Test(expected = IllegalStateException.class)
+    public void testResolveShouldThrowExceptionWhenNoVersionCanBeResolved() {
+        // given
+        MavenMetadata mavenMetadata = new MavenMetadata("groupId", "artifactId", new MavenVersioning(null, null, null));
+
+        String metadataUrl = "url";
+        DownloadOptions options = mock(DownloadOptions.class);
+        HttpUriRequest metadataRequest = mock(HttpUriRequest.class);
+        given(urlFactory.createLatestArtifactVersionMetadataUrl(options)).willReturn(metadataUrl);
+        given(requestFactory.create(metadataUrl, options)).willReturn(metadataRequest);
+        given(metadataDownloader.download(metadataRequest)).willReturn(mavenMetadata);
+        // when
+        underTest.resolve(options);
+        // then exception thrown
+    }
+
+    @Test
+    public void testResolveShouldWorkProperlyForStandard() {
+        // given
+        String expected = "latest";
+        MavenMetadata mavenMetadata = new MavenMetadata("groupId", "artifactId", new MavenVersioning(expected, null, null));
+
+        String metadataUrl = "url";
+        DownloadOptions options = mock(DownloadOptions.class);
+        HttpUriRequest metadataRequest = mock(HttpUriRequest.class);
+        given(urlFactory.createLatestArtifactVersionMetadataUrl(options)).willReturn(metadataUrl);
+        given(requestFactory.create(metadataUrl, options)).willReturn(metadataRequest);
+        given(metadataDownloader.download(metadataRequest)).willReturn(mavenMetadata);
+        // when
+        String result = underTest.resolve(options);
+        // then
+        assertThat(result).isEqualTo(expected);
+    }
+
+    @Test
+    public void testResolveShouldWorkProperlyForNexus() {
+        // given
+        String expected = "latest";
+        MavenMetadata mavenMetadata = new MavenMetadata("groupId", "artifactId", new MavenVersioning(null, expected, null));
+
+        String metadataUrl = "url";
+        DownloadOptions options = mock(DownloadOptions.class);
+        HttpUriRequest metadataRequest = mock(HttpUriRequest.class);
+        given(urlFactory.createLatestArtifactVersionMetadataUrl(options)).willReturn(metadataUrl);
+        given(requestFactory.create(metadataUrl, options)).willReturn(metadataRequest);
+        given(metadataDownloader.download(metadataRequest)).willReturn(mavenMetadata);
+        // when
+        String result = underTest.resolve(options);
+        // then
+        assertThat(result).isEqualTo(expected);
+    }
+
     @Test
-    public void testResolveShouldWorkProperly() {
+    public void testResolveShouldPreferStandardVersioningWhenStandardAndNexusSpecificIsPresent() {
         // given
         String expected = "latest";
-        MavenMetadata mavenMetadata = new MavenMetadata("groupId", "artifactId",
-            new MavenVersioning(expected, null));
+        MavenMetadata mavenMetadata = new MavenMetadata("groupId", "artifactId", new MavenVersioning(expected, "nexus", null));
 
         String metadataUrl = "url";
         DownloadOptions options = mock(DownloadOptions.class);