Allow custom api writers to mock the http environment

tdrules-store-loader/src/main/java/giis/tdrules/store/loader/oa/ApiWriter.java

@@ -24,6 +24,11 @@ public class ApiWriter {
 	// Headers to sent (in addition to Content-type: application/json)
 	private List<String[]> headers = new ArrayList<>();
 
+	public ApiWriter reset() {
+		headers = new ArrayList<>();
+		return this;
+	}
+
 	public ApiWriter addHeader(String key, String value) {
 		headers.add(new String[] { key, value });
 		return this;

tdrules-store-loader/src/main/java/giis/tdrules/store/loader/oa/IPathResolver.java

@@ -9,6 +9,17 @@ public interface IPathResolver {
 	 * Sets the url (without path) of the service
 	 */
 	IPathResolver setServerUrl(String url);
+
+	/**
+	 * Sets an alternative ApiWriter used to send requests
+	 */
+	IPathResolver setApiWriter(ApiWriter writer);
+
+	/**
+	 * Geths the ApiWriter used to send requests
+	 * (this is the default ApiWriter if none has been set)
+	 */
+	ApiWriter getApiWriter();
 
 	/**
 	 * Determines the url where a POST to create an object must be sent.

tdrules-store-loader/src/main/java/giis/tdrules/store/loader/oa/OaLiveAdapter.java

@@ -66,7 +66,7 @@ public void endWrite() {
 		boolean usePut = resolver.usePut(this.currentEntity);
 		log.trace("endWrite: {} to url {}", usePut ? "PUT" : "POST", url);
 
-		ApiWriter writer = new ApiWriter();
+		ApiWriter writer = resolver.getApiWriter().reset();
 		if (authStore != null) // Store or set credentials, if applicable
 			authStore.processAuthentication(this.currentEntity, json, writer);
 		ApiResponse response = writer.post(url, json, usePut);

tdrules-store-loader/src/main/java/giis/tdrules/store/loader/oa/OaPathResolver.java

@@ -23,12 +23,26 @@ public class OaPathResolver implements IPathResolver {
 
 	private String url = "";
 	private TdSchema model = null;
+	// To send api requests, uses this default ApiWriter to send requests to a server,
+	// unless another is set
+	private ApiWriter writer = new ApiWriter();
 
 	@Override
 	public IPathResolver setServerUrl(String url) {
 		this.url = url;
 		return this;
 	}
+
+	@Override 
+	public IPathResolver setApiWriter(ApiWriter writer) {
+		this.writer = writer;
+		return this;
+	}
+
+	@Override
+	public ApiWriter getApiWriter() {
+		return this.writer;
+	}
 
 	@Override
 	public String getEndpointPath(String entityName) {

tdrules-store-loader/src/test/java/test4giis/tdrules/store/loader/oa/TestApiClientMock.java

@@ -0,0 +1,86 @@
+package test4giis.tdrules.store.loader.oa;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+
+import org.junit.Test;
+
+import giis.tdrules.model.ModelException;
+import giis.tdrules.openapi.model.TdAttribute;
+import giis.tdrules.openapi.model.TdEntity;
+import giis.tdrules.openapi.model.TdSchema;
+import giis.tdrules.store.loader.DataLoader;
+import giis.tdrules.store.loader.IDataAdapter;
+import giis.tdrules.store.loader.oa.ApiResponse;
+import giis.tdrules.store.loader.oa.ApiWriter;
+import giis.tdrules.store.loader.oa.IPathResolver;
+import giis.tdrules.store.loader.oa.OaLiveAdapter;
+import giis.tdrules.store.loader.oa.OaLiveUidGen;
+import giis.tdrules.store.loader.oa.OaPathResolver;
+
+/**
+ * Test a custom ApiClient to mock the servlet environment. This is used to test
+ * the HTTP controller endpoints without the need to launch a servlet container
+ */
+public class TestApiClientMock {
+
+	protected TdSchema getModel() {
+		TdEntity master = new TdEntity().name("Master")
+				.addAttributesItem(new TdAttribute().name("pk1").datatype("integer").uid("true"))
+				.addAttributesItem(new TdAttribute().name("i1").datatype("int32"));
+		TdEntity detail = new TdEntity().name("Detail")
+				.addAttributesItem(new TdAttribute().name("pk1").datatype("integer").uid("true"))
+				.addAttributesItem(new TdAttribute().name("fk1").datatype("integer").rid("Master.pk1"));
+		return new TdSchema().storetype("openapi").addEntitiesItem(master).addEntitiesItem(detail);
+	}
+
+	// Data generator with a path resolver that uses a custom api writer
+	protected DataLoader getLiveGenerator() {
+		ApiWriter writer = new CustomApiWriter(); // this mocks the servlet environment and the server
+		IPathResolver resolver = new OaPathResolver().setServerUrl("").setApiWriter(writer);
+		IDataAdapter dataAdapter = new OaLiveAdapter(resolver);
+		return new DataLoader(getModel(), dataAdapter).setUidGen(new OaLiveUidGen());
+	}
+
+	// This custom api writer returns the content of the body request
+	// and simulates a server generated uid by adding it to the response
+	public class CustomApiWriter extends ApiWriter {
+		public ApiResponse post(String url, String requestBody, boolean usePut) {
+			if ("/master".equals(url) && "{\"i1\":2}".equals(requestBody))
+				return new ApiResponse(200, "OK", "{\"pk1\":99,\"i1\":2}");
+			else if ("/detail".equals(url))
+				return new ApiResponse(200, "OK", requestBody);
+			else
+				return new ApiResponse(404, "NotFound", "");
+		}
+	}
+
+	// Checks that the custom api writer works fine integrated with the data loading
+	// - request sent
+	// - response received
+	// - a symbolic generated key for master that is recovered and sent to the detail
+	@Test
+	public void testGenerateMockOk() {
+		DataLoader dtg = getLiveGenerator();
+		String json1 = dtg.load("master", "pk1=@generatedpk");
+		assertEquals("{\"i1\":2}", json1);
+		assertEquals("{\"pk1\":99,\"i1\":2}", dtg.getDataAdapter().getLastResponse());
+
+		String json2 = dtg.load("detail", "fk1=@generatedpk");
+		assertEquals("{\"pk1\":101,\"fk1\":99}", json2);
+		assertEquals("{\"pk1\":101,\"fk1\":99}", dtg.getDataAdapter().getLastResponse());
+
+		assertEquals("\"master\":{\"i1\":2}\n" + "\"detail\":{\"pk1\":101,\"fk1\":99}",
+				dtg.getDataAdapter().getAllAsString());
+	}
+
+	@Test
+	public void testGenerateMockError() {
+		DataLoader dtg = getLiveGenerator();
+		ModelException exception = assertThrows(ModelException.class, () -> {
+			dtg.load("notexists", "");
+		});
+		assertEquals("Can't find any entity in the schema with name notexists", exception.getMessage());
+	}
+
+}