Clarify config code and add a few test cases. Fixes #123. Thanks @ecebuzz!

Author: sylvinus

mrq/config.py

@@ -438,12 +438,15 @@ def get_config(
 
             # We only keep variables starting with an uppercase character.
             if k[0].isupper():
-                default_config[k.lower()] = v
+                from_file[k.lower()] = v
 
     # Merge the config in the order given by the user
     merged_config = default_config
+
+    config_keys = set(default_config.keys() + from_file.keys())
+
     for part in sources:
-        for name in merged_config:
+        for name in config_keys:
 
             if part == "env":
                 value = os.environ.get(env_prefix + name.upper())

tests/fixtures/config2.py

@@ -2,3 +2,5 @@
 
 # There configs should be added transparently.
 ADDITIONAL_UNEXPECTED_CONFIG = "1"
+
+MONGODB_JOBS = "mongodb://127.0.0.1:27017/mrq?connectTimeoutMS=4242"

tests/test_config.py

@@ -4,27 +4,31 @@
 def test_config(worker):
     """ Test different config passing options. """
 
+    # Default config values
     worker.start()
 
     cfg = json.loads(
         worker.send_task("tests.tasks.general.GetConfig", {}, block=True))
 
-    assert "mongodb_jobs" in cfg
+    assert cfg["mongodb_jobs"] == "mongodb://127.0.0.1:27017/mrq"
     assert cfg.get("additional_unexpected_config") is None
 
     worker.stop()
 
+    # Values from config file
     worker.start(flags="--config tests/fixtures/config2.py")
 
     cfg = json.loads(
         worker.send_task("tests.tasks.general.GetConfig", {}, block=True))
 
+    assert cfg["mongodb_jobs"] == "mongodb://127.0.0.1:27017/mrq?connectTimeoutMS=4242"
     assert cfg["name"] == "testworker"
     assert cfg.get("additional_unexpected_config") == "1"
 
     worker.stop()
 
-    worker.start(flags="--config tests/fixtures/config2.py --name xxx")
+    # CLI > Config file && CLI > ENV
+    worker.start(flags="--config tests/fixtures/config2.py --name xxx", env={"MRQ_NAME": "yyy"})
 
     cfg = json.loads(
         worker.send_task("tests.tasks.general.GetConfig", {}, block=True))
@@ -33,3 +37,14 @@ def test_config(worker):
     assert cfg.get("additional_unexpected_config") == "1"
 
     worker.stop()
+
+    # ENV > Config file
+    worker.start(flags="--config tests/fixtures/config2.py", env={"MRQ_NAME": "yyy"})
+
+    cfg = json.loads(
+        worker.send_task("tests.tasks.general.GetConfig", {}, block=True))
+
+    assert cfg["name"] == "yyy"
+    assert cfg.get("additional_unexpected_config") == "1"
+
+    worker.stop()