FAB-4454 Increase IT coverage for HFCAClient

. Added more tests to increase coverage
. Changed the existing tests to use the "thrown" pattern
. Added MockHFCAClient to help test coverage
. Added mechanism to generate unique users for each run
(allows the tests to be run repeatedly without needing to restart CA)
. Minor change to HFCAClient to prevent NPEs

Change-Id: I920213f1bd7d372ba9200d5de68ca0c0e3344bb7
Signed-off-by: Chris Murphy <chrism@fast.au.fujitsu.com>

src/main/java/org/hyperledger/fabric_ca/sdk/HFCAClient.java

@@ -320,7 +320,12 @@ public Enrollment enroll(String user, String secret, EnrollmentRequest req) thro
             }
 
             JsonObject result = jsonst.getJsonObject("result");
+            if (result == null) {
+                throw new EnrollmentException(format("FabricCA failed enrollment for user %s - response did not contain a result", user));
+            }
+
             Base64.Decoder b64dec = Base64.getDecoder();
+
             String signedPem = new String(b64dec.decode(result.getString("Cert").getBytes(UTF_8)));
             logger.debug(format("[HFCAClient] enroll returned pem:[%s]", signedPem));
 
@@ -525,8 +530,7 @@ public void revoke(User revoker, String revokee, String reason) throws Revocatio
      * @return Body of post returned.
      * @throws Exception
      */
-
-    private String httpPost(String url, String body, UsernamePasswordCredentials credentials) throws Exception {
+    String httpPost(String url, String body, UsernamePasswordCredentials credentials) throws Exception {
         logger.debug(format("httpPost %s, body:%s", url, body));
         CredentialsProvider provider = new BasicCredentialsProvider();
 
@@ -578,7 +582,7 @@ private String httpPost(String url, String body, UsernamePasswordCredentials cre
         return responseBody;
     }
 
-    private JsonObject httpPost(String url, String body, String authHTTPCert) throws Exception {
+    JsonObject httpPost(String url, String body, String authHTTPCert) throws Exception {
 
         HttpPost httpPost = new HttpPost(url);
         logger.debug(format("httpPost %s, body:%s, authHTTPCert: %s", url, body, authHTTPCert));

src/test/java/org/hyperledger/fabric_ca/sdk/MockHFCAClient.java

@@ -0,0 +1,95 @@
+/*
+ *  Copyright 2017 DTCC, Fujitsu Australia Software Technology, IBM - All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+ package org.hyperledger.fabric_ca.sdk;
+
+import java.io.StringReader;
+import java.net.MalformedURLException;
+import java.util.Properties;
+
+import javax.json.Json;
+import javax.json.JsonObject;
+import javax.json.JsonReader;
+
+import org.apache.http.auth.UsernamePasswordCredentials;
+import org.hyperledger.fabric_ca.sdk.exception.EnrollmentException;
+import org.hyperledger.fabric_ca.sdk.exception.InvalidArgumentException;
+
+import static java.lang.String.format;
+
+/**
+ * A Mock class for testing HFCAClient.java
+ *
+ */
+
+public class MockHFCAClient extends HFCAClient {
+
+    private String httpPostResponse = null;
+
+    MockHFCAClient(String name, String url, Properties properties) throws MalformedURLException {
+        super(name, url, properties);
+    }
+
+    @Override
+    String httpPost(String url, String body, UsernamePasswordCredentials credentials) throws Exception {
+        return httpPostResponse == null ? super.httpPost(url, body, credentials) : httpPostResponse;
+    }
+
+    @Override
+    JsonObject httpPost(String url, String body, String authHTTPCert) throws Exception {
+
+        JsonObject response;
+
+        if (httpPostResponse == null) {
+            response = super.httpPost(url, body, authHTTPCert);
+        } else {
+            JsonReader reader = Json.createReader(new StringReader(httpPostResponse));
+            response = (JsonObject) reader.read();
+
+            // TODO: HFCAClient could do with some minor refactoring to avoid duplicating this code here!!
+            JsonObject result = response.getJsonObject("result");
+            if (result == null) {
+                EnrollmentException e = new EnrollmentException(
+                        format("POST request to %s failed request body %s " + "Body of response did not contain result",
+                                url, body),
+                        new Exception());
+                throw e;
+            }
+        }
+        return response;
+    }
+
+    public static MockHFCAClient createNewInstance(String url, Properties properties) throws MalformedURLException {
+
+        return new MockHFCAClient(null, url, properties);
+    }
+
+    public static MockHFCAClient createNewInstance(String name, String url, Properties properties)
+            throws MalformedURLException, InvalidArgumentException {
+
+        if (name == null || name.isEmpty()) {
+
+            throw new InvalidArgumentException("name must not be null or an empty string.");
+        }
+
+        return new MockHFCAClient(name, url, properties);
+    }
+
+    // Sets the test string to be returned from httpPost
+    // If null, it returns the actual response
+    public void setHttpPostResponse(String httpPostResponse) {
+        this.httpPostResponse = httpPostResponse;
+    }
+
+}