testimage: sort modules based on dependencies

TEST_SUITES="auto" is useful to run all suitable tests without
having to hard-code the list. However, it did not take test
dependencies into account, which can be an issue for tests
which really depend on some other test to run first.

To fix this, modules get loaded in the order determined by
TESTS_SUITES, but then get re-ordered based on dependencies
derived from @skipUnlessPassed before running them. The original
order is used to break ties when there are no dependencies, so
reordering only occurs when really necessary.

@skipUnlessPassed gets extended such that it makes the test name
a method depends on available for inspection by the test loader
in oetest.py.

Unfortunately Python's unittest offers no API to inspect tests
in a TestSuite, so the code has to rely on implementation details
to find all tests. The worst that can happen when the implementation
changes is that tests are not found and reordering does not happen.

(From OE-Core rev: 6e4543a35836c572b23b9f8162b19d1e038d3ed2)

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/meta/classes/testimage.bbclass b/meta/classes/testimage.bbclass
index 683173854d..dc163c7313 100644
--- a/meta/classes/testimage.bbclass
+++ b/meta/classes/testimage.bbclass
@@ -16,7 +16,11 @@
 # The test names are the module names in meta/lib/oeqa/runtime.
 # Each name in TEST_SUITES represents a required test for the image. (no skipping allowed)
 # Appending "auto" means that it will try to run all tests that are suitable for the image (each test decides that on it's own).
-# Note that order in TEST_SUITES is important (it's the order tests run) and it influences tests dependencies.
+# Note that order in TEST_SUITES is relevant: tests are run in an order such that
+# tests mentioned in @skipUnlessPassed run before the tests that depend on them,
+# but without such dependencies, tests run in the order in which they are listed
+# in TEST_SUITES.
+#
 # A layer can add its own tests in lib/oeqa/runtime, provided it extends BBPATH as normal in its layer.conf.
 
 # TEST_LOG_DIR contains a command ssh log and may contain infromation about what command is running, output and return codes and for qemu a boot log till login.