Added (*Dropbox).LatestCursor() call and tests

See: https://www.dropbox.com/developers/core/docs#delta-latest-cursor

dropbox.go

@@ -68,7 +68,7 @@ type CopyRef struct {
 type DeltaPage struct {
 	Reset   bool         // if true the local state must be cleared.
 	HasMore bool         // if true an other call to delta should be made.
-	Cursor  string       // Tag of the current state.
+	Cursor               // Tag of the current state.
 	Entries []DeltaEntry // List of changed entries.
 }
 
@@ -91,6 +91,10 @@ type ChunkUploadResponse struct {
 	Expires  DBTime `json:"expires"`   // Expiration time of this upload.
 }
 
+type Cursor struct {
+	Cursor string `json:"cursor"`
+}
+
 // Format of reply when http error code is not 200.
 // Format may be:
 // {"error": "reason"}
@@ -684,7 +688,7 @@ func (db *Dropbox) Delta(cursor, pathPrefix string) (*DeltaPage, error) {
 	type deltaPageParser struct {
 		Reset   bool                `json:"reset"`    // if true the local state must be cleared.
 		HasMore bool                `json:"has_more"` // if true an other call to delta should be made.
-		Cursor  string              `json:"cursor"`   // Tag of the current state.
+		Cursor                      // Tag of the current state.
 		Entries [][]json.RawMessage `json:"entries"` // List of changed entries.
 	}
 	var dpp deltaPageParser
@@ -854,3 +858,21 @@ func (db *Dropbox) Move(src, dst string) (*Entry, error) {
 			"to_path":   {dst}}, &rv)
 	return &rv, err
 }
+
+func (db *Dropbox) LatestCursor(prefix string, mediaInfo bool) (*Cursor, error) {
+	var (
+		params = &url.Values{}
+		cur    Cursor
+	)
+
+	if prefix != "" {
+		params.Set("path_prefix", prefix)
+	}
+
+	if mediaInfo {
+		params.Set("include_media_info", "true")
+	}
+
+	err := db.doRequest("POST", "delta/latest_cursor", params, &cur)
+	return &cur, err
+}

dropbox_test.go

@@ -719,3 +719,65 @@ func TestShares(t *testing.T) {
 		t.Errorf("got %#v expected %#v", *received, expected)
 	}
 }
+
+func TestLatestCursor(t *testing.T) {
+	tab := []struct {
+		prefix    string
+		mediaInfo bool
+	}{
+		{
+			prefix:    "",
+			mediaInfo: false,
+		},
+		{
+			prefix:    "/some",
+			mediaInfo: false,
+		},
+		{
+			prefix:    "",
+			mediaInfo: true,
+		},
+		{
+			prefix:    "/some",
+			mediaInfo: true,
+		},
+	}
+
+	expected := Cursor{Cursor: "some"}
+	cur, err := json.Marshal(expected)
+	if err != nil {
+		t.Fatal("Failed to JSON encode Cursor")
+	}
+
+	for _, testCase := range tab {
+		db := newDropbox(t)
+		fake := FakeHTTP{
+			Method: "POST",
+			Host:   "api.dropbox.com",
+			Path:   "/1/delta/latest_cursor",
+			t:      t,
+			Params: map[string]string{
+				"locale": "en",
+			},
+			ResponseData: cur,
+		}
+
+		if testCase.prefix != "" {
+			fake.Params["path_prefix"] = testCase.prefix
+		}
+
+		if testCase.mediaInfo {
+			fake.Params["include_media_info"] = "true"
+		}
+
+		http.DefaultClient = &http.Client{
+			Transport: fake,
+		}
+
+		if received, err := db.LatestCursor(testCase.prefix, testCase.mediaInfo); err != nil {
+			t.Errorf("API error: %s", err)
+		} else if !reflect.DeepEqual(expected, *received) {
+			t.Errorf("got %#v expected %#v", *received, expected)
+		}
+	}
+}