chore: add back file-delete test (#1694)

Adds back a test that was inappropriately removed (as explained [here](https://github.com/beeme1mr/flagd/pull/16/files#r2223712589)). Also fixes some typos. Signed-off-by: Todd Baert <todd.baert@dynatrace.com>

Author: toddbaert

CONTRIBUTING.md

@@ -42,7 +42,7 @@ export GOPRIVATE=buf.build/gen/go
 
 ### Manual testing
 
-flagd has a number of interfaces (you can read more about than at [flagd.dev](https://flagd.dev/)) which can be used to evaluate flags, or deliver flag configurations so that they can be evaluated by _in-process_ providers.
+flagd has a number of interfaces (you can read more about them at [flagd.dev](https://flagd.dev/)) which can be used to evaluate flags, or deliver flag configurations so that they can be evaluated by _in-process_ providers.
 
 You can manually test this functionality by starting flagd (from the flagd/ directory) with `go run main.go start -f file:../config/samples/example_flags.flagd.json`.
 
@@ -69,7 +69,7 @@ curl -X POST -d '{"context":{}}' 'http://localhost:8016/ofrep/v1/evaluate/flags
 grpcurl -import-path schemas/protobuf/flagd/evaluation/v1/ -proto evaluation.proto -plaintext -d '{"flagKey":"myBoolFlag"}' localhost:8013 flagd.evaluation.v1.Service/ResolveBoolean | jq
 ```
 
-#### Remote bulk evaluation via via HTTP1.1/OFREP
+#### Remote bulk evaluation via HTTP1.1/OFREP
 
 ```sh
 # evaluates flags in bulk
@@ -93,7 +93,7 @@ grpcurl -import-path schemas/protobuf/flagd/sync/v1/ -proto sync.proto -plaintex
 #### Flag synchronization stream via gRPC
 
 ```sh
-# will open a persistent stream which sends flag changes when the watched source is modified 
+# will open a persistent stream which sends flag changes when the watched source is modified
 grpcurl -import-path schemas/protobuf/flagd/sync/v1/ -proto sync.proto -plaintext localhost:8015 flagd.sync.v1.FlagSyncService/SyncFlags | jq
 ```
 

core/pkg/sync/file/filepath_sync_test.go

@@ -58,6 +58,7 @@ func TestSimpleReSync(t *testing.T) {
 func TestSimpleSync(t *testing.T) {
 readDirName := t.TempDir()
 updateDirName := t.TempDir()
+deleteDirName := t.TempDir()
 tests := map[string]struct {
 manipulationFuncs []func(t *testing.T)
 expectedDataSync []sync.DataSync
@@ -98,6 +99,27 @@ func TestSimpleSync(t *testing.T) {
 },
 },
 },
+"delete-event": {
+fetchDirName: deleteDirName,
+manipulationFuncs: []func(t *testing.T){
+func(t *testing.T) {
+writeToFile(t, deleteDirName, fetchFileContents)
+},
+func(t *testing.T) {
+deleteFile(t, deleteDirName, fetchFileName)
+},
+},
+expectedDataSync: []sync.DataSync{
+{
+FlagData: fetchFileContents,
+Source: fmt.Sprintf("%s/%s", deleteDirName, fetchFileName),
+},
+{
+FlagData: defaultState,
+Source: fmt.Sprintf("%s/%s", deleteDirName, fetchFileName),
+},
+},
+},
 }
 
 for test, tt := range tests {

core/pkg/sync/http/http_sync_test.go

@@ -290,16 +290,16 @@ func TestHTTPSync_Fetch(t *testing.T) {
 newETag := `"c2e01ce63d90109c4c7f4f6dcea97ed1bb2b51e3647f36caf5acbe27413a24bb"`
 
 return &http.Response{
-Header:  map[string][]string{
+Header: map[string][]string{
 "Content-Type": {"application/json"},
-"Etag": {newETag},
+"Etag":  {newETag},
 },
 Body: io.NopCloser(strings.NewReader(newContent)),
 StatusCode: http.StatusOK,
 }, nil
 })
 },
-uri:  "http://localhost",
+uri: "http://localhost",
 eTagHeader: `"1af17a664e3fa8e419b8ba05c2a173169df76162a5a286e0c405b460d478f7ef"`,
 handleResponse: func(t *testing.T, httpSync Sync, _ string, err error) {
 if err != nil {
@@ -370,7 +370,7 @@ func TestSync_Init(t *testing.T) {
 func TestHTTPSync_Resync(t *testing.T) {
 ctrl := gomock.NewController(t)
 source := "http://localhost"
-emptyeFlagData := "{}"
+emptyFlagData := "{}"
 
 tests := map[string]struct {
 setup func(t *testing.T, client *syncmock.MockClient)
@@ -385,7 +385,7 @@ func TestHTTPSync_Resync(t *testing.T) {
 setup: func(_ *testing.T, client *syncmock.MockClient) {
 client.EXPECT().Do(gomock.Any()).Return(&http.Response{
 Header: map[string][]string{"Content-Type": {"application/json"}},
-Body: io.NopCloser(strings.NewReader(emptyeFlagData)),
+Body: io.NopCloser(strings.NewReader(emptyFlagData)),
 StatusCode: http.StatusOK,
 }, nil)
 },
@@ -402,7 +402,7 @@ func TestHTTPSync_Resync(t *testing.T) {
 wantErr: false,
 wantNotifications: []sync.DataSync{
 {
-FlagData: emptyeFlagData,
+FlagData: emptyFlagData,
 Source: source,
 },
 },