Refactor collectors

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

pkg/perflib/utils_test.go

@@ -0,0 +1,127 @@
+package perflib
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/go-kit/log"
+)
+
+type simple struct {
+	ValA float64 `perflib:"Something"`
+	ValB float64 `perflib:"Something Else"`
+	ValC float64 `perflib:"Something Else,secondvalue"`
+}
+
+func TestUnmarshalPerflib(t *testing.T) {
+	cases := []struct {
+		name string
+		obj  *PerfObject
+
+		expectedOutput []simple
+		expectError    bool
+	}{
+		{
+			name:           "nil check",
+			obj:            nil,
+			expectedOutput: []simple{},
+			expectError:    true,
+		},
+		{
+			name: "Simple",
+			obj: &PerfObject{
+				Instances: []*PerfInstance{
+					{
+						Counters: []*PerfCounter{
+							{
+								Def: &PerfCounterDef{
+									Name:        "Something",
+									CounterType: PERF_COUNTER_COUNTER,
+								},
+								Value: 123,
+							},
+						},
+					},
+				},
+			},
+			expectedOutput: []simple{{ValA: 123}},
+			expectError:    false,
+		},
+		{
+			name: "Multiple properties",
+			obj: &PerfObject{
+				Instances: []*PerfInstance{
+					{
+						Counters: []*PerfCounter{
+							{
+								Def: &PerfCounterDef{
+									Name:        "Something",
+									CounterType: PERF_COUNTER_COUNTER,
+								},
+								Value: 123,
+							},
+							{
+								Def: &PerfCounterDef{
+									Name:           "Something Else",
+									CounterType:    PERF_COUNTER_COUNTER,
+									HasSecondValue: true,
+								},
+								Value:       256,
+								SecondValue: 222,
+							},
+						},
+					},
+				},
+			},
+			expectedOutput: []simple{{ValA: 123, ValB: 256, ValC: 222}},
+			expectError:    false,
+		},
+		{
+			name: "Multiple instances",
+			obj: &PerfObject{
+				Instances: []*PerfInstance{
+					{
+						Counters: []*PerfCounter{
+							{
+								Def: &PerfCounterDef{
+									Name:        "Something",
+									CounterType: PERF_COUNTER_COUNTER,
+								},
+								Value: 321,
+							},
+						},
+					},
+					{
+						Counters: []*PerfCounter{
+							{
+								Def: &PerfCounterDef{
+									Name:        "Something",
+									CounterType: PERF_COUNTER_COUNTER,
+								},
+								Value: 231,
+							},
+						},
+					},
+				},
+			},
+			expectedOutput: []simple{{ValA: 321}, {ValA: 231}},
+			expectError:    false,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			output := make([]simple, 0)
+			err := UnmarshalObject(c.obj, &output, log.NewNopLogger())
+			if err != nil && !c.expectError {
+				t.Errorf("Did not expect error, got %q", err)
+			}
+			if err == nil && c.expectError {
+				t.Errorf("Expected an error, but got ok")
+			}
+
+			if err == nil && !reflect.DeepEqual(output, c.expectedOutput) {
+				t.Errorf("Output mismatch, expected %+v, got %+v", c.expectedOutput, output)
+			}
+		})
+	}
+}