Add unittest for HTTPServe

Author: brian-brazil

simpleclient_httpserver/src/test/java/io/prometheus/client/exporter/TestHTTPServer.java

@@ -0,0 +1,83 @@
+package io.prometheus.client.exporter;
+
+import io.prometheus.client.Gauge;
+import io.prometheus.client.CollectorRegistry;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.URL;
+import java.net.URLConnection;
+import java.util.Scanner;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class TestHTTPServer {
+
+  HTTPServer s;
+
+  @Before
+  public void init() throws IOException {
+    CollectorRegistry registry = new CollectorRegistry();
+    Gauge.build("a", "a help").register(registry);
+    Gauge.build("b", "a help").register(registry);
+    Gauge.build("c", "a help").register(registry);
+    s = new HTTPServer(new InetSocketAddress(0), registry);
+  }
+
+  @After
+  public void cleanup() {
+    s.stop();
+  }
+
+  String request(String suffix) throws IOException {
+    String url = "http://localhost:" + s.server.getAddress().getPort() + "/metrics" + suffix;
+    URLConnection connection = new URL(url).openConnection();
+    connection.setDoOutput(true);
+    connection.connect();
+    Scanner s = new Scanner(connection.getInputStream(), "UTF-8").useDelimiter("\\A");
+    return s.hasNext() ? s.next() : "";
+  }
+
+  @Test
+  public void testSimpleRequest() throws IOException {
+    String response = request("");
+    assertThat(response).contains("a 0.0");
+    assertThat(response).contains("b 0.0");
+    assertThat(response).contains("c 0.0");
+  }
+
+  @Test
+  public void testBadParams() throws IOException {
+    String response = request("?x");
+    assertThat(response).contains("a 0.0");
+    assertThat(response).contains("b 0.0");
+    assertThat(response).contains("c 0.0");
+  }
+
+  @Test
+  public void testSingleName() throws IOException {
+    String response = request("?name[]=a");
+    assertThat(response).contains("a 0.0");
+    assertThat(response).doesNotContain("b 0.0");
+    assertThat(response).doesNotContain("c 0.0");
+  }
+
+  @Test
+  public void testMultiName() throws IOException {
+    String response = request("?name[]=a&name[]=b");
+    assertThat(response).contains("a 0.0");
+    assertThat(response).contains("b 0.0");
+    assertThat(response).doesNotContain("c 0.0");
+  }
+
+  @Test
+  public void testDecoding() throws IOException {
+    String response = request("?n%61me[]=%61");
+    assertThat(response).contains("a 0.0");
+    assertThat(response).doesNotContain("b 0.0");
+    assertThat(response).doesNotContain("c 0.0");
+  }
+
+}