run_project_tests: Fix it to actually work

This move the sorting logic into the TestDef class itself, which
simplifies sorting them.

Additionally it remove overcomplicated sort logic, because python
strings are compared character by character, we don't need to do the
split and cast to int, we know that realistically a maximum of 4
characters (the first 4 numbers) are going to be compared in most cases.

run_project_tests.py

@@ -15,6 +15,7 @@
 # limitations under the License.
 
 import typing as T
+import functools
 import itertools
 import os
 import subprocess
@@ -76,6 +77,7 @@ class TestResult:
         self.testtime = testtime
 
 
+@functools.total_ordering
 class TestDef:
     def __init__(self, path: Path, name: T.Optional[str], args: T.List[str], skip: bool = False):
         self.path = path
@@ -91,6 +93,12 @@ class TestDef:
             return '{}   ({})'.format(self.path.as_posix(), self.name)
         return self.path.as_posix()
 
+    def __lt__(self, other: T.Any) -> T.Union[bool, type(NotImplemented)]:
+        if isinstance(other, TestDef):
+            # None is not sortable, so replace it with an empty string
+            return (self.path, self.name or '') < (other.path, other.name or '')
+        return NotImplemented
+
 class AutoDeletedDir:
     def __init__(self, d):
         self.dir = d
@@ -492,7 +500,7 @@ def _run_test(testdir, test_build_dir, install_dir, extra_args, compiler, backen
     return TestResult(validate_install(testdir, install_dir, compiler, builddata.environment),
                       BuildStep.validate, stdo, stde, mesonlog, cicmds, gen_time, build_time, test_time)
 
-def gather_tests(testdir: Path) -> T.List[TestDef]:
+def gather_tests(testdir: Path) -> T.Iterator[TestDef]:
     tests = [t.name for t in testdir.glob('*') if t.is_dir()]
     tests = [t for t in tests if not t.startswith('.')]  # Filter non-tests files (dot files, etc)
     tests = [TestDef(testdir / t, None, []) for t in tests]
@@ -538,10 +546,7 @@ def gather_tests(testdir: Path) -> T.List[TestDef]:
             skip = any([x[1] for x in i])
             all_tests += [TestDef(t.path, name, opts, skip)]
 
-    all_tests = [(int(t.path.name.split()[0]), t.name or '', t) for t in all_tests]
-    all_tests.sort()
-    all_tests = [t[2] for t in all_tests]
-    return all_tests
+    return sorted(all_tests)
 
 def have_d_compiler():
     if shutil.which("ldc2"):