mtest: Add support for rust unit tests

Rust has it's own built in unit test format, which is invoked by
compiling a rust executable with the `--test` flag to rustc. The tests
are then run by simply invoking that binary. They output a custom test
format, which this patch adds parsing support for. This means that we
can report each subtest in the junit we generate correctly, which should
be helpful for orchestration systems like gitlab and jenkins which can
parse junit XML.

1 files changed, 39 insertions, 0 deletions

diff --git a/mesonbuild/mtest.py b/mesonbuild/mtest.py
index c31ad1a..9db271e 100644
--- a/mesonbuild/mtest.py
+++ b/mesonbuild/mtest.py
@@ -666,6 +666,28 @@ class JunitBuilder(TestLogger):
             tree.write(f, encoding='utf-8', xml_declaration=True)
 
 
+def parse_rust_test(stdout: str) -> T.Dict[str, TestResult]:
+    """Parse the output of rust tests."""
+    res = {}  # type; T.Dict[str, TestResult]
+
+    def parse_res(res: str) -> TestResult:
+        if res == 'ok':
+            return TestResult.OK
+        elif res == 'ignored':
+            return TestResult.SKIP
+        elif res == 'FAILED':
+            return TestResult.FAIL
+        raise MesonException('Unsupported output from rust test: {}'.format(res))
+
+    for line in stdout.splitlines():
+        if line.startswith('test ') and not line.startswith('test result'):
+            _, name, _, result = line.split(' ')
+            name = name.replace('::', '.')
+            res[name] = parse_res(result)
+
+    return res
+
+
 class TestRun:
     TEST_NUM = 0
 
@@ -749,6 +771,21 @@ class TestRun:
 
         self.complete(res, results, returncode, stdo, stde, cmd)
 
+    def complete_rust(self, returncode: int, stdo: str, stde: str, cmd: T.List[str]) -> None:
+        results = parse_rust_test(stdo)
+
+        failed = TestResult.FAIL in results.values()
+        # Now determine the overall result of the test based on the outcome of the subcases
+        if all(t is TestResult.SKIP for t in results.values()):
+            # This includes the case where num_tests is zero
+            res = TestResult.SKIP
+        elif self.should_fail:
+            res = TestResult.EXPECTEDFAIL if failed else TestResult.UNEXPECTEDPASS
+        else:
+            res = TestResult.FAIL if failed else TestResult.OK
+
+        self.complete(res, results, returncode, stdo, stde, cmd)
+
     @property
     def num(self) -> int:
         if self._num is None:
@@ -1069,6 +1106,8 @@ class SingleTestRunner:
                 self.runobj.complete_exitcode(returncode, stdo, stde, cmd)
             elif self.test.protocol is TestProtocol.GTEST:
                 self.runobj.complete_gtest(returncode, stdo, stde, cmd)
+            elif self.test.protocol is TestProtocol.RUST:
+                return self.runobj.complete_rust(returncode, stdo, stde, cmd)
             else:
                 if self.options.verbose:
                     print(stdo, end='')