Add framework to allow test-specific assertions on HTTP response.

Motivation:

Individual tests may expect IDS to respond in a specific fashion.
Currently there is no way for tests that execise IDS request that return
content to assert the HTTP response.  This is because, for these
interactions, the test client returns the content from IDS and not the
HTTP response.

Modification:

Add the ability for a test to make an HTTP request that includes an
assertion on the HTTP response.  This is done by providing the
assertions as a `Consumer` object.  Lambdas provides a light-weight
mechanism for writing such assertions.

An interceptor is used to create a custom client that asserts the
response.  The existing code is refactored to take advantage of this.

To keep code DRY, two new static methods are introduced that provide
lambdas that assert that the response is chunked or is not chunked.

Some existing tests are updated to take advantage of this framework.

Result:

It is now possible to write tests that make test-specific assertions on
the HTTP response from IDS, even for interactions where IDS returns
content.

pom.xml

@@ -129,6 +129,12 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest</artifactId>
+            <version>2.2</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

src/test/java/org/icatproject/ids/integration/BaseTest.java

@@ -6,6 +6,7 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -20,6 +21,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.UUID;
 import java.util.zip.CRC32;
@@ -369,6 +371,16 @@ protected void checkStream(InputStream stream, long id) throws IOException {
         assertTrue(found);
     }
 
+    protected long fileLength(long id) {
+        for (Entry<String, Long> e : ids.entrySet()) {
+            if (id == e.getValue()) {
+                var fileContents = contents.get(e.getKey());
+                return fileContents.getBytes(StandardCharsets.UTF_8).length;
+            }
+        }
+        throw new NoSuchElementException("No file with id " + id);
+    }
+
     protected void writeToFile(Datafile df, String content, String key)
             throws IOException, IcatException_Exception, NoSuchAlgorithmException {
         Path path = setup.getStorageDir().resolve(df.getLocation());

src/test/java/org/icatproject/ids/integration/one/GetDataExplicitTest.java

@@ -2,6 +2,8 @@
 
 import java.io.InputStream;
 import java.util.Arrays;
+import static org.hamcrest.Matchers.*;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 import static org.junit.Assert.assertEquals;
 import org.junit.BeforeClass;
@@ -15,6 +17,7 @@
 import org.icatproject.ids.integration.util.client.InsufficientPrivilegesException;
 import org.icatproject.ids.integration.util.client.NotFoundException;
 import org.icatproject.ids.integration.util.client.TestingClient.Flag;
+import static org.icatproject.ids.integration.util.client.TestingClient.isNotChunkedEncoded;
 
 public class GetDataExplicitTest extends BaseTest {
 
@@ -98,52 +101,75 @@ public void forbiddenTest() throws Exception {
 
     @Test
     public void correctBehaviourTestNone() throws Exception {
-        try (InputStream stream = testingClient.getData(sessionId, new DataSelection().addDatafiles(datafileIds),
-                Flag.NONE, 0, 200)) {
+        try (InputStream stream = testingClient
+                .assertingHttpResponse(isNotChunkedEncoded()) // assumes caching
+                .getData(sessionId, new DataSelection().addDatafiles(datafileIds),
+                    Flag.NONE, 0, 200)) {
             checkZipStream(stream, datafileIds, 57L, 0);
         }
 
-        try (InputStream stream = testingClient.getData(sessionId, new DataSelection().addDatafile(datafileIds.get(0)),
-                Flag.NONE, 0, 200)) {
+        var datafileId = datafileIds.get(0);
+        var fileLength = fileLength(datafileId);
+        try (InputStream stream = testingClient
+                .assertingHttpResponse(isNotChunkedEncoded()) // assumes caching
+                .assertingHttpResponse(r -> {
+                        var contentLength = r.getFirstHeader("Content-Length");
+                        var entitySize = Long.valueOf(contentLength.getValue());
+                        assertThat(entitySize, equalTo(fileLength));
+                })
+                .getData(sessionId, new DataSelection().addDatafile(datafileId),
+                    Flag.NONE, 0, 200)) {
             checkStream(stream, datafileIds.get(0));
         }
     }
 
     @Test
     public void correctBehaviourTestCompress() throws Exception {
-        try (InputStream stream = testingClient.getData(sessionId, new DataSelection().addDatafiles(datafileIds),
-                Flag.COMPRESS, 0, 200)) {
+        try (InputStream stream = testingClient
+                .assertingHttpResponse(isNotChunkedEncoded()) // assumes caching
+                .getData(sessionId, new DataSelection().addDatafiles(datafileIds),
+                    Flag.COMPRESS, 0, 200)) {
             checkZipStream(stream, datafileIds, 36L, 0);
         }
 
-        try (InputStream stream = testingClient.getData(sessionId, new DataSelection().addDatafile(datafileIds.get(0)),
+        try (InputStream stream = testingClient
+                .assertingHttpResponse(isNotChunkedEncoded()) // assumes caching
+                .getData(sessionId, new DataSelection().addDatafile(datafileIds.get(0)),
                 Flag.COMPRESS, 0, 200)) {
             checkStream(stream, datafileIds.get(0));
         }
     }
 
     @Test
     public void correctBehaviourTestZip() throws Exception {
-        try (InputStream stream = testingClient.getData(sessionId, new DataSelection().addDatafiles(datafileIds),
-                Flag.ZIP, 0, 200)) {
+        try (InputStream stream = testingClient
+                .assertingHttpResponse(isNotChunkedEncoded()) // assumes caching
+                .getData(sessionId, new DataSelection().addDatafiles(datafileIds),
+                    Flag.ZIP, 0, 200)) {
             checkZipStream(stream, datafileIds, 57L, 0);
         }
 
-        try (InputStream stream = testingClient.getData(sessionId, new DataSelection().addDatafile(datafileIds.get(0)),
-                Flag.ZIP, 0, 200)) {
+        try (InputStream stream = testingClient
+                .assertingHttpResponse(isNotChunkedEncoded()) // assumes caching
+                .getData(sessionId, new DataSelection().addDatafile(datafileIds.get(0)),
+                    Flag.ZIP, 0, 200)) {
             checkZipStream(stream, datafileIds.subList(0, 1), 57L, 0);
         }
     }
 
     @Test
     public void correctBehaviourTestZipAndCompress() throws Exception {
-        try (InputStream stream = testingClient.getData(sessionId, new DataSelection().addDatafiles(datafileIds),
-                Flag.ZIP_AND_COMPRESS, 0, 200)) {
+        try (InputStream stream = testingClient
+                .assertingHttpResponse(isNotChunkedEncoded()) // assumes caching
+                .getData(sessionId, new DataSelection().addDatafiles(datafileIds),
+                    Flag.ZIP_AND_COMPRESS, 0, 200)) {
             checkZipStream(stream, datafileIds, 36L, 0);
         }
 
-        try (InputStream stream = testingClient.getData(sessionId, new DataSelection().addDatafile(datafileIds.get(0)),
-                Flag.ZIP_AND_COMPRESS, 0, 200)) {
+        try (InputStream stream = testingClient
+                .assertingHttpResponse(isNotChunkedEncoded()) // assumes caching
+                .getData(sessionId, new DataSelection().addDatafile(datafileIds.get(0)),
+                    Flag.ZIP_AND_COMPRESS, 0, 200)) {
             checkZipStream(stream, datafileIds.subList(0, 1), 36L, 0);
         }
     }

src/test/java/org/icatproject/ids/integration/util/LongValue.java

@@ -0,0 +1,33 @@
+package org.icatproject.ids.integration.util;
+
+import org.hamcrest.Description;
+import org.hamcrest.Matcher;
+import org.hamcrest.TypeSafeMatcher;
+
+/**
+ * A Matcher that checks whether a String argument is a Long value.  The code is
+ * heavily based on an answer from Ezequiel to
+ * <a href="https://stackoverflow.com/questions/58099695/is-there-a-way-in-hamcrest-to-test-for-a-value-to-be-a-number">
+ * a stack overview question</a>.
+ */
+public class LongValue extends TypeSafeMatcher<String> {
+
+    @Override
+    protected boolean matchesSafely(String s) {
+        try {
+            Long.valueOf(s);
+        } catch (NumberFormatException nfe) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public void describeTo(Description description) {
+        description.appendText("is long");
+    }
+
+    public static Matcher<String> longValue() {
+        return new LongValue();
+    }
+}