NFD

# Unit Testing

NFD requires unit testing for most modules.

NFD uses the [Boost Unit Test Framework](https://www.boost.org/doc/libs/1_65_1/libs/test/doc/html/index.html).

## Learning Resources for Boost Unit Test Framework

* Boost Unit Test Framework [documentation](https://www.boost.org/doc/libs/1_65_1/libs/test/doc/html/index.html)

* After compiling the test binary (or binaries), it is possible at run time to select which tests to run and what kind of output is desired.  

  Use the `--help` command line option to get more information about the available options.

## Testing Code Guidelines

* The test suite for `.../folder/module-name.hpp` should be placed in `tests/.../folder/module-name.t.cpp`.

    * For example, test suite for `daemon/fw/forwarder.hpp` should be place in `tests/daemon/fw/forwarder.t.cpp`.

* The test suite should be named `TestModuleName`, and nested under test suites named after directories.

    * For example, test suite for `security/transform/base64-decode.hpp` is named `Security/Transform/TestBase64Decode`.

* The test suite should be declared inside the same namespace of the tested type plus additional `tests` namespace.

    * For example, test suite for `nfd::Forwarder` is declared in `nfd::tests`, test suite for `nfd::cs::Cs` is declared in `nfd::cs`.

    * If needed, parent `tests` sub-namespace can be imported with `using namespace` directive.

* All test suites for the `nfd` binary itself (i.e., for translation units located under `daemon/` subdir) should use the `GlobalIoFixture` fixture, to get automatic setup and teardown of the global `io_service` instance. Other test suites (e.g., for translation units under `tools/` subdir) must not use `GlobalIoFixture`.

    * Similarly, if a custom fixture is needed for a test suite or test case in `daemon/`, that fixture should derive, directly or indirectly, from `GlobalIoFixture`.

    * `KeyChainFixture` should be used if a test case needs to create identities in KeyChain.

    * `ClockFixture` or `GlobalIoTimeFixture` can be used if mocked clocks are desired.

## Testing Helpers

* `tests/daemon/limited-io.hpp` provides operation count and time limit

* `tests/daemon/face/dummy-face.hpp` provides a `Face` that doesn't depend on a socket

* `tests/daemon/fw/strategy-tester.hpp` provides a facade to test a forwarding strategy

* `tests/daemon/fw/topology-tester.hpp` provides facilities to test forwarder and strategy in a virtual topology