CCNxTestrig

CCNxTestrig is an application to perform functional tests for CCNx forwarders. It treats the forwarder as a black box and assesses its packet forwarding functionality for correctness. Tests are prescriptive in nature and are built using compile-time test scripts.

For example, the following test script creates a random Interest with the name prefix "ccnx:/test/b", a matching Content Object, and then ensures that the forwarder-under-test will forward these packets correctly. That is, the Interest and Content Object will be routed to the correct links.

// Create the test packets
CCNxName *testName = _createRandomName("ccnx:/test/c");
assertNotNull(testName, "The name must not be NULL");

// Create the protocol messages
CCNxInterest *interest = ccnxInterest_Create(testName, 1000, NULL, NULL);
PARCBuffer *testPayload = parcBuffer_Allocate(1024);
CCNxContentObject *content = ccnxContentObject_CreateWithNameAndPayload(testName, testPayload);

// Build the script
CCNxTestrigScript *script = ccnxTestrigScript_Create(testCaseName);
CCNxTestrigScriptStep *step1 = ccnxTestrigScript_AddSendStep(script, interest, CCNxTestrigLinkID_LinkA);
CCNxTestrigScriptStep *step2 = ccnxTestrigScript_AddReceiveOneStep(script, step1, 
  ccnxTestrig_GetLinkVector(rig, CCNxTestrigLinkID_LinkC));
CCNxTestrigScriptStep *step3 = ccnxTestrigScript_AddSendStep(script, content, CCNxTestrigLinkID_LinkC);
CCNxTestrigScriptStep *step4 = ccnxTestrigScript_AddReceiveOneStep(script, step3, 
  ccnxTestrig_GetLinkVector(rig, CCNxTestrigLinkID_LinkA));

// Execute it
CCNxTestrigSuiteTestResult *testCaseResult = ccnxTestrigScript_Execute(script, rig);

CCNxTestrig design

The CCNxTestrig application is composed of five primary elements:

1. Testrig: The main application that creates and configures links to the forwarder and then executes (part of or the entirety of) the test suite.

2. Link: An abstraction of a forwarder link connection. Currently, UDP and TCP links are supported.

3. Test suite: A collection of compiled test scripts that are executed.

4. Test script: A set of steps to interact with the forwarder to send and receive packets on specific links.

5. Reporter: A module that produces the test results.

These modules are composed as follows:

                      +---------+  uses  +------------+
                      |   link  <--------+ testscript |
                      +----^----+        +------^-----+
                           |                    |
                           |creates             |executes
                           |                    |
+------------+  uses  +----+----+        +------+-----+
|  reporter  <--------+ testrig +--------> testsuite  |
+------------+        +---------+        +------------+
                                configures

CCNxTestrig scripts

Test scripts are a prescriptive set of steps that are executed in sequence to send and receive packets to interact with a forwarder. Scripts are created by providing packets to send verifying that they are received correctly. For example, a script step might be to send an Interest to link A attached to the forwarder. To verify receipt, the subsequent step might be a receive step that expects the packet which was sent to be that which was received.

Currently, test scripts must be written in C code. A future extension would be to implement a custom DSL to write these tests and have them compile to their C code equivalents.