test: add unit tests for @resources vs @kubernetes precedence

6 tests covering the merge logic when both decorators specify
memory/cpu: default override, explicit max, both-at-default.

Author: Nissan Pow

test/unit/test_resources_override.py

@@ -1,54 +1,78 @@
-"""Tests for @resources vs @kubernetes decorator precedence logic.
+"""Tests for @resources vs @kubernetes precedence logic.
 
-The merge logic in KubernetesDecorator.step_init works as follows:
-- If @kubernetes attribute is at its default AND @resources explicitly sets a value
-  → use the @resources value (even if lower than the @kubernetes default).
-- If both explicitly set → take max.
-- If both at default → take max (which equals default).
+The merge logic in KubernetesDecorator.step_init determines which value
+wins when both @resources and @kubernetes set the same attribute (e.g. memory).
+
+Rules:
+- If @kubernetes is at its default and @resources explicitly sets a value,
+  @resources wins (even if lower).
+- If both are explicitly set, the larger value wins.
+- If both are at default, the default is kept.
 """
 
-K8S_DEFAULTS = {"cpu": "1", "memory": "4096", "disk": "10240"}
-RESOURCES_DEFAULTS = {"cpu": "1", "memory": "4096"}
+from metaflow.plugins.kubernetes.kubernetes_decorator import KubernetesDecorator
+from metaflow.plugins.resources_decorator import ResourcesDecorator
+
+
+def _merge_resource(k8s_val, resources_val, attr="memory"):
+    """Simulate the merge logic from step_init for a single attribute.
+
+    Returns the resolved value as a string (matching self.attributes format).
+    """
+    k8s_default = KubernetesDecorator.defaults[attr]
+    res_default = ResourcesDecorator.defaults.get(attr)
 
+    my_val = k8s_val
+    v = resources_val
 
-def _merge(k, k8s_val, resources_val):
-    """Replicate the merge logic from KubernetesDecorator.step_init."""
-    k8s_is_default = float(k8s_val or 0) == float(K8S_DEFAULTS.get(k) or 0)
-    resources_is_default = k in RESOURCES_DEFAULTS and float(
-        resources_val or 0
-    ) == float(RESOURCES_DEFAULTS.get(k) or 0)
+    if my_val is None and v is None:
+        return str(my_val)
+
+    k8s_is_default = float(my_val or 0) == float(k8s_default or 0)
+    resources_is_default = attr in ResourcesDecorator.defaults and float(
+        v or 0
+    ) == float(res_default or 0)
 
     if k8s_is_default and not resources_is_default:
-        return str(float(resources_val or 0))
+        return str(float(v or 0))
     else:
-        return str(max(float(k8s_val or 0), float(resources_val or 0)))
+        return str(max(float(my_val or 0), float(v or 0)))
 
 
-def test_resources_lower_than_k8s_default():
-    """@resources(memory=256) with @kubernetes default (4096) → resources wins."""
-    result = _merge("memory", K8S_DEFAULTS["memory"], "256")
-    assert result == "256.0"
+def test_resources_lower_than_k8s_default_wins():
+    """@resources(memory=256) should override @kubernetes default (4096)."""
+    result = _merge_resource("4096", "256")
+    assert float(result) == 256.0
 
 
-def test_resources_higher_than_k8s_default():
-    """@resources(memory=8192) with @kubernetes default (4096) → resources wins."""
-    result = _merge("memory", K8S_DEFAULTS["memory"], "8192")
-    assert result == "8192.0"
+def test_resources_higher_than_k8s_default_wins():
+    """@resources(memory=8192) overrides @kubernetes default (4096)."""
+    result = _merge_resource("4096", "8192")
+    assert float(result) == 8192.0
 
 
-def test_both_explicit_resources_higher():
-    """@kubernetes(memory=2048) explicit with @resources(memory=8192) → max wins."""
-    result = _merge("memory", "2048", "8192")
-    assert result == "8192.0"
+def test_both_explicit_takes_max():
+    """@kubernetes(memory=2048) + @resources(memory=8192) → max wins."""
+    result = _merge_resource("2048", "8192")
+    # k8s is not at default (2048 != 4096), so max(2048, 8192) = 8192
+    assert float(result) == 8192.0
 
 
 def test_both_explicit_k8s_higher():
-    """@kubernetes(memory=8192) explicit with @resources(memory=2048) → max wins."""
-    result = _merge("memory", "8192", "2048")
-    assert result == "8192.0"
+    """@kubernetes(memory=8192) + @resources(memory=2048) → k8s wins."""
+    result = _merge_resource("8192", "2048")
+    assert float(result) == 8192.0
 
 
 def test_both_at_default():
-    """Both at default → stays at default (4096)."""
-    result = _merge("memory", K8S_DEFAULTS["memory"], RESOURCES_DEFAULTS["memory"])
-    assert result == "4096.0"
+    """Both at default → stays at default."""
+    k8s_default = KubernetesDecorator.defaults["memory"]
+    res_default = ResourcesDecorator.defaults["memory"]
+    result = _merge_resource(k8s_default, res_default)
+    assert float(result) == float(k8s_default)
+
+
+def test_cpu_resources_overrides_k8s_default():
+    """@resources(cpu=2) should override @kubernetes default cpu (1)."""
+    result = _merge_resource("1", "2", attr="cpu")
+    assert float(result) == 2.0