Refactor datastore.GetSubject() to report not found errors. (Velocide…

…x#990)

.github/workflows/windows.yml

@@ -5,10 +5,10 @@ jobs:
     name: Windows Test
     runs-on: windows-latest
     steps:
-    - name: Set up Go 1.14
+    - name: Set up Go 1.16
       uses: actions/setup-go@v2
       with:
-        go-version: 1.14
+        go-version: 1.16
       id: go
 
     - name: Check out code into the Go module directory

api/api.go

@@ -613,23 +613,6 @@ func (self *ApiServer) SetGUIOptions(
 	return &empty.Empty{}, users.SetUserOptions(self.config, user_info.Name, in)
 }
 
-func (self *ApiServer) GetUserNotifications(
-	ctx context.Context,
-	in *api_proto.GetUserNotificationsRequest) (
-	*api_proto.GetUserNotificationsResponse, error) {
-	result, err := users.GetUserNotifications(
-		self.config, GetGRPCUserInfo(self.config, ctx).Name, in.ClearPending)
-	return result, err
-}
-
-func (self *ApiServer) GetUserNotificationCount(
-	ctx context.Context,
-	in *empty.Empty) (*api_proto.UserNotificationCount, error) {
-	n, err := users.GetUserNotificationCount(
-		self.config, GetGRPCUserInfo(self.config, ctx).Name)
-	return &api_proto.UserNotificationCount{Count: n}, err
-}
-
 func (self *ApiServer) VFSListDirectory(
 	ctx context.Context,
 	in *flows_proto.VFSListRequest) (*flows_proto.VFSListResponse, error) {

api/clients.go

@@ -19,7 +19,7 @@ package api
 
 import (
 	"errors"
-	"io"
+	"io/fs"
 	"net"
 	"regexp"
 	"strings"
@@ -74,8 +74,7 @@ func GetApiClient(
 	result.Labels = services.GetLabeler().GetClientLabels(config_obj, client_id)
 
 	client_info := &actions_proto.ClientInfo{}
-	err = db.GetSubject(config_obj,
-		client_path_manager.Path(), client_info)
+	err = db.GetSubject(config_obj, client_path_manager.Path(), client_info)
 	if err != nil {
 		return nil, err
 	}
@@ -169,7 +168,7 @@ func (self *ApiServer) GetClientMetadata(
 
 	result := &api_proto.ClientMetadata{}
 	err = db.GetSubject(self.config, client_path_manager.Metadata(), result)
-	if err != nil && err == io.EOF {
+	if errors.Is(err, fs.ErrNotExist) {
 		// Metadata not set, start with empty set.
 		err = nil
 	}

api/download.go

@@ -28,6 +28,7 @@ package api
 import (
 	"archive/zip"
 	"io"
+	"io/fs"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -434,7 +435,7 @@ func vfsGetBuffer(
 	}
 
 	n, err := reader_at.ReadAt(result.Data, int64(offset))
-	if err != nil && errors.Cause(err) != io.EOF &&
+	if err != nil && errors.Is(err, fs.ErrNotExist) &&
 		errors.Cause(err) != io.ErrUnexpectedEOF {
 		return nil, err
 	}

api/notebooks.go

@@ -6,7 +6,7 @@ import (
 	"encoding/base64"
 	"encoding/binary"
 	"fmt"
-	"io"
+	"io/fs"
 	"path"
 	"strings"
 	"time"
@@ -78,7 +78,7 @@ func (self *ApiServer) GetNotebooks(
 
 		// Handle the EOF especially: it means there is no such
 		// notebook and return an empty result set.
-		if errors.Cause(err) == io.EOF {
+		if errors.Is(err, fs.ErrNotExist) || notebook.NotebookId == "" {
 			return result, nil
 		}
 		if err != nil {
@@ -443,12 +443,12 @@ func (self *ApiServer) GetNotebookCell(
 		notebook)
 
 	// Cell does not exist, make it a default cell.
-	if err == io.EOF {
+	if errors.Is(err, fs.ErrNotExist) {
 		return &api_proto.NotebookCell{
 			Input:  "",
 			Output: "",
 			Data:   "{}",
-			CellId: notebook.CellId,
+			CellId: in.CellId,
 			Type:   "Markdown",
 		}, nil
 	}