httphandlers/GetRecords: handle context expiry and cancellation

internal/httphandlers/getrecords.go

@@ -68,6 +68,7 @@ func GetRecords(log logger.Logger, s RecordsGetter) http.HandlerFunc {
 			WithField("max-records", maxRecords).
 			WithField("timeout", timeout)
 
+		var errIsContext bool
 		records, err := s.GetRecords(ctx, topicName, offset, maxRecords, softMaxBytes)
 		if err != nil {
 			if errors.Is(err, seb.ErrTopicNotFound) {
@@ -84,23 +85,26 @@ func GetRecords(log logger.Logger, s RecordsGetter) http.HandlerFunc {
 				return
 			}
 
-			if errors.Is(err, context.DeadlineExceeded) {
-				// there was no error, there is just no content
-				w.Header().Add("Content-Type", multipartFormData)
-
-				log.Debugf("deadline exceeded: %s", err)
-				w.WriteHeader(http.StatusPartialContent)
-				fmt.Fprintf(w, "deadline exceeded")
+			errIsContext = errors.Is(err, context.DeadlineExceeded) || errors.Is(err, context.Canceled)
+			if !errIsContext {
+				log.Errorf("reading record: %s", err.Error())
+				w.WriteHeader(http.StatusInternalServerError)
+				fmt.Fprintf(w, "failed to read record '%d': %s", offset, err)
 				return
 			}
 
-			log.Errorf("reading record: %s", err.Error())
-			w.WriteHeader(http.StatusInternalServerError)
-			fmt.Fprintf(w, "failed to read record '%d': %s", offset, err)
+			// NOTE: continues from here!
 		}
 
 		mw := multipart.NewWriter(w)
 		w.Header().Set("Content-Type", mw.FormDataContentType())
+
+		if errIsContext {
+			log.Debugf("context ended: %s", err)
+			w.WriteHeader(http.StatusPartialContent)
+			return
+		}
+
 		for localOffset, record := range records {
 			fw, err := mw.CreateFormField(fmt.Sprintf("%d", offset+uint64(localOffset)))
 			if err != nil {

internal/httphandlers/getrecords_test.go

@@ -1,6 +1,7 @@
 package httphandlers_test
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"mime"
@@ -10,6 +11,8 @@ import (
 	"testing"
 
 	"github.com/micvbang/go-helpy/uint64y"
+	seb "github.com/micvbang/simple-event-broker"
+	"github.com/micvbang/simple-event-broker/internal/httphandlers"
 	"github.com/micvbang/simple-event-broker/internal/infrastructure/httphelpers"
 	"github.com/micvbang/simple-event-broker/internal/infrastructure/tester"
 	"github.com/micvbang/simple-event-broker/internal/sebrecords"
@@ -290,3 +293,60 @@ func TestGetRecordsMultipartFormData(t *testing.T) {
 		})
 	}
 }
+
+// TestGetRecordsErrors verifies that the expected status codes are returned
+// when GetRecords() returns certain errors.
+func TestGetRecordsErrors(t *testing.T) {
+	deps := &httphandlers.MockDependencies{}
+
+	server := tester.HTTPServer(t, tester.HTTPDependencies(deps))
+	defer server.Close()
+
+	tests := map[string]struct {
+		getRecordsErr error
+		statusCode    int
+	}{
+		"deadline exceeded": {
+			getRecordsErr: context.DeadlineExceeded,
+			statusCode:    http.StatusPartialContent,
+		},
+		"deadline cancelled": {
+			getRecordsErr: context.DeadlineExceeded,
+			statusCode:    http.StatusPartialContent,
+		},
+		"topic not found": {
+			getRecordsErr: seb.ErrTopicNotFound,
+			statusCode:    http.StatusNotFound,
+		},
+		"out of bounds": {
+			getRecordsErr: seb.ErrOutOfBounds,
+			statusCode:    http.StatusNotFound,
+		},
+		"nil": {
+			getRecordsErr: nil,
+			statusCode:    http.StatusOK,
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			deps.GetRecordsMock = func(ctx context.Context, topicName string, offset uint64, maxRecords, softMaxBytes int) ([]sebrecords.Record, error) {
+				return nil, test.getRecordsErr
+			}
+
+			r := httptest.NewRequest("GET", "/records", nil)
+			r.Header.Add("Accept", "multipart/form-data")
+			httphelpers.AddQueryParams(r, map[string]string{
+				"topic-name": "some-topic",
+				"offset":     "0",
+				"timeout":    "5s",
+			})
+
+			// Act
+			response := server.DoWithAuth(r)
+
+			// Assert
+			require.Equal(t, test.statusCode, response.StatusCode)
+		})
+	}
+}