Allow unit tests defined anywhere in mbed-os

[LDong-Arm]

Summary of changes

Currently unit tests are inside the top-level UNITTESTS. But in our new directory structure proposal, unit tests will be moved into libraries. To make it possible, this PR is to allow unittest.cmake to sit anywhere inside Mbed OS.

Before:

• UNITTESTS/foo/test_A/unittest.cmake -> BUILD/unittests/foo-test_A
• bar/UNITTESTS/test_B/unittest.cmake -> not built

After:

• UNITTESTS/foo/test_A/unittest.cmake -> BUILD/unittests/UNITTESTS-foo-test_A
• bar/UNITTESTS/test_B/unittest.cmake -> BUILD/unittests/bar-UNITTESTS-test_B

IMO we can fine tune the test binary names in the future, but they don't really matter in my opinion.

Impact of changes

Migration actions required

Documentation

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Pull request type

[x] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results

[] No Tests required for this change (E.g docs only update)
[x] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

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Reviewers

@0xc0170 @jamesbeyond @ARMmbed/mbed-os-core

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[LDong-Arm]

@jamesbeyond @0xc0170 We will need this for the directory structure work. Any suggestions?

[jamesbeyond]

after the change, is the unit-test still required to be is a UNITTESTS folder ?
e.g.

foo/bar/UNITTESTS/test_A/unittest.cmake

[LDong-Arm]

after the change, is the unit-test still required to be is a UNITTESTS folder ?
e.g.

foo/bar/UNITTESTS/test_A/unittest.cmake

For a test to compile & run, the directory does not have to be named UNITTESTS - it's not a magic keyword, unlike TESTS for Greentea. Hopefully our CI scripts don't look for UNITTESTS as a magic name?

[ciarmcom]

@LDong-Arm, thank you for your changes.
@jamesbeyond @0xc0170 @ARMmbed/mbed-os-maintainers please review.

[LDong-Arm]

The relative path (to mbed-os) is the binary name of a test case. ${PROJECT_SOURCE_DIR} is UNITTESTS.

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 1 of 1 test jobs passed
Build number : 1
Build artifacts

[jamesbeyond]

after the change, is the unit-test still required to be is a UNITTESTS folder ?
e.g.

foo/bar/UNITTESTS/test_A/unittest.cmake

For a test to compile & run, the directory does not have to be named UNITTESTS - it's not a magic keyword, unlike TESTS for Greentea. Hopefully our CI scripts don't look for UNITTESTS as a magic name?

I see, Shall we keep the consistency of keeping the UNITTESTS folder to identify these are the unit tests?

[LDong-Arm]

As we can see, the test case names have changed: https://mbed-os.mbedcloudtesting.com/blue/organizations/jenkins/mbed-os-ci_unittests/detail/mbed-os-ci_unittests/6431/tests
Names (i.e. paths) used to be relative to UNITTESTS but now to the top directory of mbed-os. This is needed so that tests outside the top-level UNITTESTS (to be created in the future) won't start with .. in their names.

[LDong-Arm]

I see, Shall we keep the consistency of keeping the UNITTESTS folder to identify these are the unit tests?

I agree personally. We keep the name UNITTESTS for now as we re-structure some libraries, and plan to change it once we switch to a new build tool.

[ladislas]

will that work for unit tests outside of mbed-os directory?

[LDong-Arm]

will that work for unit tests outside of mbed-os directory?

Not yet with this change, which is part of our refactoring work with fairly minimal impact.

[ladislas]

Not yet with this change, which is part of our refactoring work with fairly minimal impact.

Thanks @LDong-Arm! So does that mean it will be worked on in the future? Would be glad to help as it is something we're looking for doing ourselves anyway.

[0xc0170]

CI restarted (old results here)

[mbed-ci]

Test run: SUCCESS

Summary: 1 of 1 test jobs passed
Build number : 2
Build artifacts