[chore][connector/routing] Refactor trace and metric routing by resource (#36098)

Author: djaglowski

connector/routingconnector/internal/pmetricutil/metrics.go

@@ -0,0 +1,18 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package pmetricutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/connector/routingconnector/internal/pmetricutil"
+
+import "go.opentelemetry.io/collector/pdata/pmetric"
+
+// MoveResourcesIf calls f sequentially for each ResourceSpans present in the first pmetric.Metrics.
+// If f returns true, the element is removed from the first pmetric.Metrics and added to the second pmetric.Metrics.
+func MoveResourcesIf(from, to pmetric.Metrics, f func(pmetric.ResourceMetrics) bool) {
+	from.ResourceMetrics().RemoveIf(func(rs pmetric.ResourceMetrics) bool {
+		if !f(rs) {
+			return false
+		}
+		rs.CopyTo(to.ResourceMetrics().AppendEmpty())
+		return true
+	})
+}

connector/routingconnector/internal/pmetricutil/metrics_test.go

@@ -0,0 +1,73 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package pmetricutil_test
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/connector/routingconnector/internal/pmetricutil"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest/pmetrictest"
+)
+
+func TestMoveResourcesIf(t *testing.T) {
+	testCases := []struct {
+		name      string
+		condition func(pmetric.ResourceMetrics) bool
+	}{
+		{
+			name: "move_none",
+			condition: func(pmetric.ResourceMetrics) bool {
+				return false
+			},
+		},
+		{
+			name: "move_all",
+			condition: func(pmetric.ResourceMetrics) bool {
+				return true
+			},
+		},
+		{
+			name: "move_one",
+			condition: func(rl pmetric.ResourceMetrics) bool {
+				rname, ok := rl.Resource().Attributes().Get("resourceName")
+				return ok && rname.AsString() == "resourceA"
+			},
+		},
+		{
+			name: "move_to_preexisting",
+			condition: func(rl pmetric.ResourceMetrics) bool {
+				rname, ok := rl.Resource().Attributes().Get("resourceName")
+				return ok && rname.AsString() == "resourceB"
+			},
+		},
+	}
+
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			// Load up a fresh copy of the input for each test, since it may be modified in place.
+			from, err := golden.ReadMetrics(filepath.Join("testdata", "resource", tt.name, "from.yaml"))
+			require.NoError(t, err)
+
+			to, err := golden.ReadMetrics(filepath.Join("testdata", "resource", tt.name, "to.yaml"))
+			require.NoError(t, err)
+
+			fromModifed, err := golden.ReadMetrics(filepath.Join("testdata", "resource", tt.name, "from_modified.yaml"))
+			require.NoError(t, err)
+
+			toModified, err := golden.ReadMetrics(filepath.Join("testdata", "resource", tt.name, "to_modified.yaml"))
+			require.NoError(t, err)
+
+			pmetricutil.MoveResourcesIf(from, to, tt.condition)
+
+			assert.NoError(t, pmetrictest.CompareMetrics(fromModifed, from), "from not modified as expected")
+			assert.NoError(t, pmetrictest.CompareMetrics(toModified, to), "to not as expected")
+		})
+	}
+}