Adding a unittest.

Author: Paul-Ferrell

stackinator/mirror.py

@@ -54,11 +54,16 @@ def _load_mirrors(self, cmdline_cache: Optional[str]) -> Dict[str, Dict]:
         else:
             mirrors = {}
 
+        try:
+            schema.MirrorsValidator.validate(mirrors)
+        except ValueError as err:
+            raise MirrorError("Mirror config does not comply with schema.\n{err}")
+
         # Add or set the cache given on the command line as the buildcache destination
         if cmdline_cache is not None:
             # If the mirror name given on the command line isn't in the config, assume it 
             # is the URL to a build cache.
-            if cmdline_cache in mirrors:
+            if cmdline_cache not in mirrors:
                 mirrors['cmdline_cache'] = {
                         'url': cmdline_cache,
                         'description': "Cache configured via command line.",
@@ -74,16 +79,10 @@ def _load_mirrors(self, cmdline_cache: Optional[str]) -> Dict[str, Dict]:
                 mirror['cache'] = True
 
         # Load the cache as defined by the deprecated 'cache.yaml' file.
-        mirrors['legacy_cache_cfg'] = self._load_legacy_cache()
-
+        legacy_cache = self._load_legacy_cache()
+        if legacy_cache is not None:
+            mirrors['legacy_cache_cfg'] = legacy_cache
 
-        try:
-            # validate the yaml, including anything we added
-            schema.MirrorsValidator.validate(mirrors)
-        except ValueError as err:
-            raise MirrorError(
-                "Mirror config does not comply with schema.\n{err}"
-            )
 
         caches = [mirror for mirror in mirrors.values() if mirror['cache']]
         if len(caches) > 1:
@@ -92,7 +91,7 @@ def _load_mirrors(self, cmdline_cache: Optional[str]) -> Dict[str, Dict]:
                 "Some of these may have come from a legacy 'cache.yaml' or the '--cache' option.\n"
                 f"{self._pp_yaml(caches)}")
 
-        return {name: mirror for name, mirror in raw.items() if mirror["enabled"]}
+        return {name: mirror for name, mirror in mirrors.items() if mirror["enabled"]}
 
     @staticmethod 
     def _pp_yaml(object):

unittests/test_mirrors.py

@@ -30,11 +30,19 @@ def test_mirror_init(systems_path, valid_mirrors):
         assert mir["enabled"]
     # test that cmdline_cache gets added to mirrors?
 
+def test_command_line_cache(systems_path):
+    """Check that adding a cache from the command line works."""
+
+    mirrors = mirror.Mirrors(systems_path/'mirror-ok', cmdline_cache=systems_path.as_posix())
+
+    assert len(mirrors.mirrors) == 4
+    
+
 def test_create_spack_mirrors_yaml(systems_path):
     pass
 
 def test_create_bootstrap_configs():
     pass
 
 def test_key_setup():
-    pass
+    pass