[receiver/hostmetrics] Fix processscraper resource attribute test (#3…

…6526)

#### Description
Previously, this test was repeatedly testing the first process resource
in the list. This would usually pass (on non-Mac machines), but is not
testing what it is supposed to. When changing it to test every resource
in the scrape, it came up with issues due to the fact that not all
resource attributes can always be found for every process.

This PR changes the test to look at all process resources in the scrape,
and instead of asserting the presence of every resource attribute, it
checks for one mandatory attribute (the process ID) and ensures that no
unexpected resource attributes are added. This should reduce the
flakiness of this test on other environments, while still asserting this
on every process resource in the list.

#### Link to tracking issue
Fixes #36468

#### Documentation
A comment was added to the assertion helper, and more detailed error
messages are produced on failure.

receiver/hostmetricsreceiver/internal/scraper/processscraper/process_scraper_test.go

@@ -126,7 +126,7 @@ func TestScrape(t *testing.T) {
 			}
 
 			require.Greater(t, md.ResourceMetrics().Len(), 1)
-			assertProcessResourceAttributesExist(t, md.ResourceMetrics())
+			assertValidProcessResourceAttributes(t, md.ResourceMetrics())
 			assertCPUTimeMetricValid(t, md.ResourceMetrics(), expectedStartTime)
 			if metricsBuilderConfig.Metrics.ProcessCPUUtilization.Enabled {
 				assertCPUUtilizationMetricValid(t, md.ResourceMetrics(), expectedStartTime)
@@ -171,16 +171,31 @@ func TestScrape(t *testing.T) {
 	}
 }
 
-func assertProcessResourceAttributesExist(t *testing.T, resourceMetrics pmetric.ResourceMetricsSlice) {
+// assertValidProcessResourceAttributes will assert that each process resource contains at least
+// the most important identifying attribute (the PID attribute) and only contains permissible
+// resource attributes defined by the process scraper metadata.yaml/Process Semantic Conventions.
+func assertValidProcessResourceAttributes(t *testing.T, resourceMetrics pmetric.ResourceMetricsSlice) {
+	requiredResourceAttributes := []string{
+		conventions.AttributeProcessPID,
+	}
+	permissibleResourceAttributes := []string{
+		conventions.AttributeProcessPID,
+		conventions.AttributeProcessExecutableName,
+		conventions.AttributeProcessExecutablePath,
+		conventions.AttributeProcessCommand,
+		conventions.AttributeProcessCommandLine,
+		conventions.AttributeProcessOwner,
+		"process.parent_pid", // TODO: use this from conventions when it is available
+	}
 	for i := 0; i < resourceMetrics.Len(); i++ {
-		attr := resourceMetrics.At(0).Resource().Attributes()
-		internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessPID)
-		internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessExecutableName)
-		internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessExecutablePath)
-		internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessCommand)
-		internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessCommandLine)
-		internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessOwner)
-		internal.AssertContainsAttribute(t, attr, "process.parent_pid")
+		attrs := resourceMetrics.At(i).Resource().Attributes().AsRaw()
+		for _, attr := range requiredResourceAttributes {
+			_, ok := attrs[attr]
+			require.True(t, ok, "resource %s missing required attribute %s", attrs, attr)
+		}
+		for attr := range attrs {
+			require.Contains(t, permissibleResourceAttributes, attr, "resource %s contained unknown attribute %s", attrs, attr)
+		}
 	}
 }
 

receiver/hostmetricsreceiver/internal/testutils.go

@@ -12,11 +12,6 @@ import (
 	"go.opentelemetry.io/collector/pdata/pmetric"
 )
 
-func AssertContainsAttribute(t *testing.T, attr pcommon.Map, key string) {
-	_, ok := attr.Get(key)
-	assert.True(t, ok)
-}
-
 func AssertDescriptorEqual(t *testing.T, expected pmetric.Metric, actual pmetric.Metric) {
 	assert.Equal(t, expected.Name(), actual.Name())
 	assert.Equal(t, expected.Description(), actual.Description())