middleware tests

backend/httpclient/error_source_middleware_test.go

@@ -0,0 +1,51 @@
+package httpclient
+
+import (
+	"errors"
+	"net"
+	"net/http"
+	"testing"
+
+	"github.com/grafana/grafana-plugin-sdk-go/experimental/status"
+	"github.com/stretchr/testify/require"
+)
+
+func TestErrorSourceMiddleware(t *testing.T) {
+	t.Run("With non-downstream HTTP error returned from http.RoundTripper should not be wrapped in a downstream error", func(t *testing.T) {
+		ctx := &testContext{}
+		someErr := errors.New("some error")
+		finalRoundTripper := ctx.createRoundTripperWithError(someErr)
+		mw := ErrorSourceMiddleware()
+		rt := mw.CreateMiddleware(Options{}, finalRoundTripper)
+		require.NotNil(t, rt)
+		middlewareName, ok := mw.(MiddlewareName)
+		require.True(t, ok)
+		require.Equal(t, ErrorSourceMiddlewareName, middlewareName.MiddlewareName())
+
+		req, err := http.NewRequest(http.MethodGet, "http://", nil)
+		require.NoError(t, err)
+		_, err = rt.RoundTrip(req)
+		require.Error(t, err)
+		require.False(t, status.IsDownstreamError(err))
+		require.ErrorIs(t, err, someErr)
+	})
+
+	t.Run("With downstream HTTP error returned from http.RoundTripper should be wrapped in a downstream error", func(t *testing.T) {
+		ctx := &testContext{}
+		someErr := &net.DNSError{IsNotFound: true}
+		finalRoundTripper := ctx.createRoundTripperWithError(someErr)
+		mw := ErrorSourceMiddleware()
+		rt := mw.CreateMiddleware(Options{}, finalRoundTripper)
+		require.NotNil(t, rt)
+		middlewareName, ok := mw.(MiddlewareName)
+		require.True(t, ok)
+		require.Equal(t, ErrorSourceMiddlewareName, middlewareName.MiddlewareName())
+
+		req, err := http.NewRequest(http.MethodGet, "http://", nil)
+		require.NoError(t, err)
+		_, err = rt.RoundTrip(req)
+		require.Error(t, err)
+		require.True(t, status.IsDownstreamError(err))
+		require.ErrorIs(t, err, someErr)
+	})
+}

backend/httpclient/http_client_test.go

@@ -170,6 +170,12 @@ func (c *testContext) createRoundTripper(name string) http.RoundTripper {
 	})
 }
 
+func (c *testContext) createRoundTripperWithError(err error) http.RoundTripper {
+	return RoundTripperFunc(func(_ *http.Request) (*http.Response, error) {
+		return nil, err
+	})
+}
+
 func (c *testContext) createMiddleware(name string) Middleware {
 	return NamedMiddlewareFunc(name, func(_ Options, next http.RoundTripper) http.RoundTripper {
 		return RoundTripperFunc(func(req *http.Request) (*http.Response, error) {