Minor changes and adding tests

server/handler.go

@@ -8,8 +8,36 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/sirupsen/logrus"
 )
 
+func serviceHandler(l *logrus.Logger, sr ServiceRegistry, validators []Validator) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		name := r.URL.Path[6:]
+		if name == "" {
+			l.Info("no list name defined")
+			w.WriteHeader(400)
+			return
+		}
+
+		if !sr.HasServiceForList(name) {
+			l.Infof("list '%s' not defined", name)
+			w.WriteHeader(404)
+			return
+		}
+
+		svc := sr.GetServiceForList(name)
+		hf := createRequestHandler(
+			l,
+			svc,
+			validators,
+		)
+
+		hf(w, r)
+	}
+}
+
 func defaultHeaderHandler(h http.Handler) http.HandlerFunc {
 
 	type kv struct {
@@ -51,6 +79,8 @@ func createRequestIDHandler(h http.Handler) http.HandlerFunc {
 		lock.Unlock()
 
 		ctx := context.WithValue(r.Context(), CtxRequestID, requestID)
+		w.Header().Set(HeaderRequestID, requestID)
+
 		h.ServeHTTP(w, r.WithContext(ctx))
 	}
 }

server/handler_test.go

@@ -0,0 +1,108 @@
+package server
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"bytes"
+	"encoding/json"
+
+	"github.com/sirupsen/logrus/hooks/test"
+)
+
+func TestServiceHandlerHappyFlow(t *testing.T) {
+	logger, _ := test.NewNullLogger()
+	recorder := httptest.NewRecorder()
+
+	{ // setup
+		payload, _ := json.Marshal(tySugRequest{Input: "baz"})
+		req := httptest.NewRequest(http.MethodPost, "/list/foo", bytes.NewReader(payload))
+		sr := NewServiceRegistry()
+		sr.Register("foo", stubSvc{FindResult: "bar"})
+
+		hf := http.HandlerFunc(serviceHandler(logger, sr, nil))
+		hf.ServeHTTP(recorder, req)
+	}
+
+	t.Run("test status code", func(t *testing.T) {
+		if status := recorder.Code; status != http.StatusOK {
+			t.Errorf("handler returned wrong status code: got %v want %v", status, http.StatusOK)
+		}
+	})
+
+	t.Run("test response result", func(t *testing.T) {
+		expect := tySugResponse{Result: "bar"}
+		var result tySugResponse
+		err := json.Unmarshal(recorder.Body.Bytes(), &result)
+
+		if err != nil {
+			t.Errorf("unexpected error while unmarshalling the response type %s", err)
+		}
+
+		if result.Result != expect.Result {
+			t.Errorf("expected the input to be %s, instead I got %s", expect.Result, result.Result)
+		}
+	})
+}
+
+func TestServiceHandlerInvalidListName(t *testing.T) {
+	logger, _ := test.NewNullLogger()
+
+	t.Run("status code, nonexistent list name", func(t *testing.T) {
+		recorder := httptest.NewRecorder()
+		{ // setup
+			payload, _ := json.Marshal(tySugRequest{Input: "baz"})
+			req := httptest.NewRequest(http.MethodPost, "/list/not-existing", bytes.NewReader(payload))
+
+			sr := NewServiceRegistry()
+			hf := http.HandlerFunc(serviceHandler(logger, sr, nil))
+			hf.ServeHTTP(recorder, req)
+		}
+
+		if status := recorder.Code; status != http.StatusNotFound {
+			t.Errorf("handler returned wrong status code: got %v want %v", status, http.StatusNotFound)
+		}
+	})
+
+	t.Run("status code, unspecified list name", func(t *testing.T) {
+		recorder := httptest.NewRecorder()
+		{ // setup
+			payload, _ := json.Marshal(tySugRequest{Input: "baz"})
+			req := httptest.NewRequest(http.MethodPost, "/list/", bytes.NewReader(payload))
+
+			sr := NewServiceRegistry()
+			hf := http.HandlerFunc(serviceHandler(logger, sr, nil))
+			hf.ServeHTTP(recorder, req)
+		}
+
+		if status := recorder.Code; status != http.StatusBadRequest {
+			t.Errorf("handler returned wrong status code: got %v want %v", status, http.StatusBadRequest)
+		}
+	})
+}
+
+func TestRequestID(t *testing.T) {
+	recorder1 := httptest.NewRecorder()
+	recorder2 := httptest.NewRecorder()
+
+	{ // setup
+		req := httptest.NewRequest(http.MethodPost, "/", nil)
+		h := createRequestIDHandler(http.NewServeMux())
+		hf := http.HandlerFunc(h)
+
+		// Recording two requests
+		hf.ServeHTTP(recorder1, req)
+		hf.ServeHTTP(recorder2, req)
+	}
+
+	rid1 := recorder1.Result().Header.Get(HeaderRequestID)
+	rid2 := recorder2.Result().Header.Get(HeaderRequestID)
+	if rid1 == rid2 {
+		t.Errorf("Did not expect the request ID's to be identical: %s vs %s", rid1, rid2)
+	}
+
+	if rid1 == "" {
+		t.Errorf("Did not expect the request ID to be empty.")
+	}
+}

server/http.go

@@ -34,6 +34,11 @@ const (
 	CtxRequestID contextKey = iota
 )
 
+// Header constants
+const (
+	HeaderRequestID = "X-Request-ID"
+)
+
 type tySugRequest struct {
 	Input string `json:"input"`
 }
@@ -85,29 +90,7 @@ func NewHTTP(sr ServiceRegistry, mux *http.ServeMux, options ...Option) TySugSer
 	}
 
 	mux.HandleFunc("/", http.NotFound)
-	mux.HandleFunc("/list/", func(w http.ResponseWriter, r *http.Request) {
-		name := r.URL.Path[6:]
-		if name == "" {
-			tySug.Logger.Info("no list name defined")
-			w.WriteHeader(400)
-			return
-		}
-
-		if !sr.HasServiceForList(name) {
-			tySug.Logger.Infof("list '%s' not defined", name)
-			w.WriteHeader(404)
-			return
-		}
-
-		svc := sr.GetServiceForList(name)
-		hf := createRequestHandler(
-			tySug.Logger,
-			svc,
-			tySug.validators,
-		)
-
-		hf(w, r)
-	})
+	mux.HandleFunc("/list/", serviceHandler(tySug.Logger, sr, tySug.validators))
 
 	tySug.server = &http.Server{
 		ReadHeaderTimeout: 2 * time.Second,
@@ -217,6 +200,11 @@ func getRequestFromHTTPRequest(r *http.Request) (tySugRequest, error) {
 	var req tySugRequest
 
 	var maxSizePlusOne int64 = maxBodySize + 1
+
+	if r.Body == nil {
+		return req, ErrMissingBody
+	}
+
 	b, err := ioutil.ReadAll(io.LimitReader(r.Body, maxSizePlusOne))
 	if err != nil {
 		if err == io.EOF {

server/option.go

@@ -5,6 +5,8 @@ import (
 
 	"fmt"
 
+	"errors"
+
 	"github.com/NYTimes/gziphandler"
 	"github.com/rs/cors"
 	"github.com/sirupsen/logrus"
@@ -48,6 +50,10 @@ func WithInputLimitValidator(inputMax int) Option {
 				return fmt.Errorf("WithInputLimitValidator input exceeds server specified maximum of %d bytes", inputMax)
 			}
 
+			if len(TSRequest.Input) == 0 {
+				return errors.New("WithInputLimitValidator input may not be empty")
+			}
+
 			return nil
 		})
 	}

server/service_registry_test.go

@@ -6,10 +6,13 @@ import (
 )
 
 type stubSvc struct {
+	FindResult string
+	FindScore  float64
+	FindExact  bool
 }
 
-func (stubSvc) Find(ctx context.Context, input string) (string, float64, bool) {
-	return "", 0, true
+func (svc stubSvc) Find(ctx context.Context, input string) (string, float64, bool) {
+	return svc.FindResult, svc.FindScore, svc.FindExact
 }
 
 func TestHasServiceForList(t *testing.T) {