Use obtain_file to get file for test_cases_step

Searching only `source_paths` is inconsistent with how patches etc. are
located making it impossible to place tests e.g. next to easyconfigs or
in software-specific source folders.

Author: Flamefire

easybuild/framework/easyblock.py

@@ -4707,14 +4707,9 @@ def test_cases_step(self):
             if os.path.isabs(test):
                 test_cmd = test
             else:
-                for source_path in source_paths():
-                    test_cmd = os.path.join(source_path, self.name, test)
-                    if os.path.exists(test_cmd):
-                        break
-                else:
-                    test_cmd = test
+                test_cmd = self.obtain_file(test, no_download=True, warning_only=True) or test
             if not os.path.exists(test_cmd):
-                raise EasyBuildError(f"Test specifies non-existing path: {test_cmd}")
+                raise EasyBuildError(f"Test specifies non-existing path: {test}")
 
             if os.path.isfile(test_cmd):
                 original_perms = os.lstat(test_cmd).st_mode
@@ -4724,8 +4719,8 @@ def test_cases_step(self):
                     adjust_permissions(test_cmd, stat.S_IEXEC, add=True, recursive=False)
             else:
                 original_perms = None
+            self.log.debug(f"Running test {test_cmd}")
             try:
-                self.log.debug(f"Running test {test_cmd}")
                 run_shell_cmd(test_cmd)
             except RunShellCmdError:
                 raise  # Let that propagate which will report more information

test/framework/easyblock.py

@@ -1338,6 +1338,21 @@ def test_test_cases_step(self):
         self.assertIn('Test case success', log_txt)
         self.assertIn('Test case failure', log_txt)
 
+        # Test is found when put next to easyconfig file, and preferred
+        new_mock_test_bin = os.path.join(os.path.dirname(self.eb_file), os.path.basename(mock_test_bin))
+        write_file(new_mock_test_bin, '#!/bin/bash\necho "new test passed"')
+        new_mock_test_bin2 = os.path.join(os.path.dirname(self.eb_file), 'example_test2')
+        write_file(new_mock_test_bin2, '#!/bin/bash\necho "additional test passed"')
+        eb.cfg['tests'] = [os.path.basename(new_mock_test_bin), os.path.basename(new_mock_test_bin2)]
+
+        write_file(eb.logfile, '')  # reset log file
+        eb.test_cases_step()
+        logtxt = read_file(eb.logfile)
+        self.assertIn(f'Running test {new_mock_test_bin}', logtxt)
+        self.assertIn(f'Running test {new_mock_test_bin2}', logtxt)
+        self.assertIn("new test passed", logtxt)
+        self.assertIn("additional test passed", logtxt)
+
     def test_post_processing_step(self):
         """Test post_processing_step and deprecated post_install_step."""
         init_config(build_options={'silent': True})