Hackaton 12: Add some unit tests, take 1 (#101457)

* tsdb/graphite: add happy path test for QueryData

* infra/httpclient/httpclientprovider: add tests for RedirectLimitMiddleware

pkg/infra/httpclient/httpclientprovider/host_redirect_validation_middleware_test.go

@@ -0,0 +1,117 @@
+package httpclientprovider
+
+import (
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend/httpclient"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRedirectLimitMiddleware(t *testing.T) {
+	t.Parallel()
+
+	t.Run("when the server responds with a status code 3xx", func(t *testing.T) {
+		t.Parallel()
+
+		t.Run("but there is no Location header in the response, then the response is not validated", func(t *testing.T) {
+			t.Parallel()
+
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(http.StatusTemporaryRedirect)
+			}))
+			t.Cleanup(server.Close)
+
+			mw := RedirectLimitMiddleware(&fakeValidator{err: errors.New("this wont be called")})
+			rt := mw.CreateMiddleware(httpclient.Options{}, http.DefaultTransport)
+			require.NotNil(t, rt)
+
+			middlewareName, ok := mw.(httpclient.MiddlewareName)
+			require.True(t, ok)
+			require.Equal(t, HostRedirectValidationMiddlewareName, middlewareName.MiddlewareName())
+
+			req, err := http.NewRequest(http.MethodGet, server.URL, nil)
+			require.NoError(t, err)
+
+			res, err := rt.RoundTrip(req)
+			require.NoError(t, err)
+			require.NotNil(t, res)
+
+			if res.Body != nil {
+				require.NoError(t, res.Body.Close())
+			}
+		})
+
+		t.Run("and there is a Location header in the response", func(t *testing.T) {
+			t.Parallel()
+
+			t.Run("but the validation function fails, it returns the validation error", func(t *testing.T) {
+				t.Parallel()
+
+				server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					w.Header().Set("Location", "http://www.example.com")
+					w.WriteHeader(http.StatusTemporaryRedirect)
+				}))
+				t.Cleanup(server.Close)
+
+				fakeErr := errors.New("fake error")
+
+				mw := RedirectLimitMiddleware(&fakeValidator{err: fakeErr})
+				rt := mw.CreateMiddleware(httpclient.Options{}, http.DefaultTransport)
+				require.NotNil(t, rt)
+
+				middlewareName, ok := mw.(httpclient.MiddlewareName)
+				require.True(t, ok)
+				require.Equal(t, HostRedirectValidationMiddlewareName, middlewareName.MiddlewareName())
+
+				req, err := http.NewRequest(http.MethodGet, server.URL, nil)
+				require.NoError(t, err)
+
+				res, err := rt.RoundTrip(req)
+				require.ErrorIs(t, err, fakeErr)
+				require.Nil(t, res)
+
+				if res != nil && res.Body != nil {
+					require.NoError(t, res.Body.Close())
+				}
+			})
+
+			t.Run("and the validation function succeeds, it returns the response", func(t *testing.T) {
+				t.Parallel()
+
+				server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					w.Header().Set("Location", "http://www.example.com")
+					w.WriteHeader(http.StatusTemporaryRedirect)
+				}))
+				t.Cleanup(server.Close)
+
+				mw := RedirectLimitMiddleware(&fakeValidator{})
+				rt := mw.CreateMiddleware(httpclient.Options{}, http.DefaultTransport)
+				require.NotNil(t, rt)
+
+				middlewareName, ok := mw.(httpclient.MiddlewareName)
+				require.True(t, ok)
+				require.Equal(t, HostRedirectValidationMiddlewareName, middlewareName.MiddlewareName())
+
+				req, err := http.NewRequest(http.MethodGet, server.URL, nil)
+				require.NoError(t, err)
+
+				res, err := rt.RoundTrip(req)
+				require.NoError(t, err)
+				require.NotNil(t, res)
+
+				if res.Body != nil {
+					require.NoError(t, res.Body.Close())
+				}
+			})
+		})
+	})
+}
+
+type fakeValidator struct {
+	err error
+}
+
+func (v *fakeValidator) Validate(_ string) error { return v.err }

pkg/tsdb/graphite/graphite_test.go

@@ -6,18 +6,20 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/http/httptest"
 	"reflect"
 	"strings"
 	"testing"
 	"time"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
-	"github.com/grafana/grafana-plugin-sdk-go/backend/instancemgmt"
 	"github.com/grafana/grafana-plugin-sdk-go/data"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"github.com/grafana/grafana/pkg/components/simplejson"
+	"github.com/grafana/grafana/pkg/infra/httpclient"
+	"github.com/grafana/grafana/pkg/infra/tracing"
 )
 
 func TestFixIntervalFormat(t *testing.T) {
@@ -141,14 +143,71 @@ func TestProcessQueries(t *testing.T) {
 			},
 		}
 
-		service.im = fakeInstanceManager{}
+		service := ProvideService(httpclient.NewProvider(), tracing.NewNoopTracerService())
+
 		rsp, err := service.QueryData(context.Background(), &backend.QueryDataRequest{
+			PluginContext: backend.PluginContext{
+				DataSourceInstanceSettings: &backend.DataSourceInstanceSettings{
+					ID:  0,
+					URL: "http://localhost",
+				},
+			},
 			Queries: queries,
 		})
 		assert.NoError(t, err)
 		expectedResponse := backend.ErrDataResponseWithSource(400, backend.ErrorSourceDownstream, "no query target found for the alert rule")
 		assert.Equal(t, expectedResponse, rsp.Responses["A"])
 	})
+
+	t.Run("QueryData with no queries returns an error", func(t *testing.T) {
+		service := &Service{}
+
+		rsp, err := service.QueryData(context.Background(), &backend.QueryDataRequest{})
+		assert.Nil(t, rsp)
+		assert.Error(t, err)
+	})
+
+	t.Run("QueryData happy path with service provider and plugin context", func(t *testing.T) {
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			_, _ = w.Write([]byte(`[
+				{
+					"target": "target A",
+					"tags": { "fooTag": "fooValue", "barTag": "barValue", "int": 100, "float": 3.14 },
+					"datapoints": [[50, 1], [null, 2], [100, 3]]
+				}	
+			]`))
+		}))
+		t.Cleanup(server.Close)
+
+		service := ProvideService(httpclient.NewProvider(), tracing.NewNoopTracerService())
+
+		queries := []backend.DataQuery{
+			{
+				RefID: "A",
+				JSON: []byte(`{
+					"target": "app.grafana.*.dashboards.views.1M.count"
+				}`),
+			},
+			{
+				RefID: "B",
+				JSON: []byte(`{
+					"query": "app.grafana.*.dashboards.views.1M.count"
+				}`),
+			},
+		}
+
+		rsp, err := service.QueryData(context.Background(), &backend.QueryDataRequest{
+			PluginContext: backend.PluginContext{
+				DataSourceInstanceSettings: &backend.DataSourceInstanceSettings{
+					ID:  0,
+					URL: server.URL,
+				},
+			},
+			Queries: queries,
+		})
+		assert.NoError(t, err)
+		assert.NotNil(t, rsp)
+	})
 }
 
 func TestConvertResponses(t *testing.T) {
@@ -289,13 +348,3 @@ func TestConvertResponses(t *testing.T) {
 		require.Error(t, err)
 	})
 }
-
-type fakeInstanceManager struct{}
-
-func (f fakeInstanceManager) Get(_ context.Context, _ backend.PluginContext) (instancemgmt.Instance, error) {
-	return datasourceInfo{}, nil
-}
-
-func (f fakeInstanceManager) Do(_ context.Context, _ backend.PluginContext, _ instancemgmt.InstanceCallbackFunc) error {
-	return nil
-}