add processor to filter out unique values

internal/processor/filter-unique.go

@@ -0,0 +1,39 @@
+package processor
+
+import (
+	"context"
+	"reflect"
+
+	"github.com/jwetzell/showbridge-go/internal/common"
+	"github.com/jwetzell/showbridge-go/internal/config"
+)
+
+type FilterUnique struct {
+	config   config.ProcessorConfig
+	previous any
+}
+
+func (fr *FilterUnique) Process(ctx context.Context, wrappedPayload common.WrappedPayload) (common.WrappedPayload, error) {
+	payload := wrappedPayload.Payload
+
+	if reflect.DeepEqual(payload, fr.previous) {
+		wrappedPayload.End = true
+		return wrappedPayload, nil
+	}
+	fr.previous = payload
+
+	return wrappedPayload, nil
+}
+
+func (fr *FilterUnique) Type() string {
+	return fr.config.Type
+}
+
+func init() {
+	RegisterProcessor(ProcessorRegistration{
+		Type: "filter.unique",
+		New: func(config config.ProcessorConfig) (Processor, error) {
+			return &FilterUnique{config: config}, nil
+		},
+	})
+}

internal/processor/test/filter-unique_test.go

@@ -0,0 +1,124 @@
+package processor_test
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/jwetzell/showbridge-go/internal/common"
+	"github.com/jwetzell/showbridge-go/internal/config"
+	"github.com/jwetzell/showbridge-go/internal/processor"
+)
+
+func TestFilterUniqueFromRegistry(t *testing.T) {
+	registration, ok := processor.ProcessorRegistry["filter.unique"]
+	if !ok {
+		t.Fatalf("filter.unique processor not registered")
+	}
+
+	processorInstance, err := registration.New(config.ProcessorConfig{
+		Type: "filter.unique",
+	})
+	if err != nil {
+		t.Fatalf("failed to create filter.unique processor: %s", err)
+	}
+
+	if processorInstance.Type() != "filter.unique" {
+		t.Fatalf("filter.unique processor has wrong type: %s", processorInstance.Type())
+	}
+
+	payload := "hello"
+	expected := "hello"
+
+	got, err := processorInstance.Process(t.Context(), common.GetWrappedPayload(t.Context(), payload))
+	if err != nil {
+		t.Fatalf("filter.unique processing failed: %s", err)
+	}
+
+	if !reflect.DeepEqual(got.Payload, expected) {
+		t.Fatalf("filter.unique got %+v, expected %+v", got.Payload, expected)
+	}
+}
+
+func TestGoodFilterUnique(t *testing.T) {
+	tests := []struct {
+		name    string
+		params  map[string]any
+		payload string
+		match   bool
+	}{
+		{
+			name:    "basic",
+			payload: "hello",
+			params:  nil,
+			match:   true,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			registration, ok := processor.ProcessorRegistry["filter.unique"]
+			if !ok {
+				t.Fatalf("filter.unique processor not registered")
+			}
+
+			processorInstance, err := registration.New(config.ProcessorConfig{
+				Type:   "filter.unique",
+				Params: test.params,
+			})
+
+			if err != nil {
+				t.Fatalf("filter.unique failed to create processor: %s", err)
+			}
+
+			got, err := processorInstance.Process(t.Context(), common.GetWrappedPayload(t.Context(), test.payload))
+
+			if err != nil {
+				t.Fatalf("filter.unique processing failed: %s", err)
+			}
+
+			if got.End != !test.match {
+				t.Fatalf("filter.unique did not filter properly %+v, expected %+v", got, test.match)
+			}
+		})
+	}
+}
+
+func TestBadFilterUnique(t *testing.T) {
+	tests := []struct {
+		name        string
+		params      map[string]any
+		payload     any
+		errorString string
+	}{}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			registration, ok := processor.ProcessorRegistry["filter.unique"]
+			if !ok {
+				t.Fatalf("filter.unique processor not registered")
+			}
+
+			processorInstance, err := registration.New(config.ProcessorConfig{
+				Type:   "filter.unique",
+				Params: test.params,
+			})
+
+			if err != nil {
+				if test.errorString != err.Error() {
+					t.Fatalf("filter.unique got error '%s', expected '%s'", err.Error(), test.errorString)
+				}
+				return
+			}
+
+			got, err := processorInstance.Process(t.Context(), common.GetWrappedPayload(t.Context(), test.payload))
+
+			if err == nil {
+				t.Fatalf("filter.unique expected to fail but got payload: %+v", got)
+			}
+
+			if err.Error() != test.errorString {
+				t.Fatalf("filter.unique got error '%s', expected '%s'", err.Error(), test.errorString)
+			}
+		})
+	}
+}