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

@@ -4700,17 +4700,11 @@ 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  # Reset at and of loop
-                if not os.path.exists(test_cmd):
-                    raise EasyBuildError(f"Test specifies non-existing path: {test_cmd}")
+                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}")
 
             try:
-                self.log.debug(f"Running test {test_cmd}")
                 run_shell_cmd(test_cmd)
             except EasyBuildError as err:
                 raise EasyBuildError(f"Running test {test_cmd} failed: {err}")

test/framework/easyblock.py

@@ -1344,6 +1344,23 @@ def test_test_cases_step(self):
         eb.test_cases_step()
         self.assertIn("test passed", read_file(eb.logfile))
 
+        # Test is found when put next to easyconfig file, and preferred
+        test_file = os.path.join(os.path.dirname(self.eb_file), os.path.basename(test_file))
+        write_file(test_file, '#!/bin/bash\necho "new test passed"')
+        test_file2 = os.path.join(os.path.dirname(self.eb_file), 'example_test2')
+        write_file(test_file2, '#!/bin/bash\necho "additional test passed"')
+        adjust_permissions(test_file, stat.S_IXUSR, add=True)
+        adjust_permissions(test_file2, stat.S_IXUSR, add=True)
+        self.contents += "\ntests = ['example_test', 'example_test2']"
+        self.writeEC()
+        eb = EasyBlock(EasyConfig(self.eb_file))
+
+        write_file(eb.logfile, '')  # reset log file
+        eb.test_cases_step()
+        logtxt = read_file(eb.logfile)
+        self.assertIn("new test passed", logtxt)
+        self.assertIn("additional test passed", logtxt)
+
     def test_extensions_step(self):
         """Test the extensions_step"""
         init_config(build_options={'silent': True})