Add Command For Unsetting Custom Claims

Adds the ability to remove custom claims from the user. It is not
perfect yet, as it replaces key with null.

#20

cmd/unsetCustomClaims.go

@@ -0,0 +1,44 @@
+package cmd
+
+import (
+	"context"
+	"os"
+
+	"github.com/mainawycliffe/kamanda/firebase/auth"
+	"github.com/mainawycliffe/kamanda/utils"
+	"github.com/spf13/cobra"
+)
+
+// unsetCustomClaimsCmd represents the unsetCustomClaims command
+var unsetCustomClaimsCmd = &cobra.Command{
+	Use:     "custom-claims",
+	Aliases: []string{"customClaims"},
+	Short:   "Unset custom claims from a firebase user account",
+	Example: "kamanda users unset custom-claims --keys \"role\"",
+	Run: func(cmd *cobra.Command, args []string) {
+		keys, _ := cmd.Flags().GetStringArray("keys")
+		hasError := false
+		for _, v := range args {
+			user, err := auth.RemoveCustomClaimFromUser(context.Background(), v, keys)
+			if err != nil {
+				hasError = true
+				utils.StdOutError(os.Stderr, "Error removing custom claims for %s (%s)\n", v, user.Email)
+				continue
+			}
+			utils.StdOutSuccess(os.Stdout, "Successfully remove custom claims for %s (%s)\n", v, user.Email)
+		}
+		if hasError {
+			os.Exit(1)
+		}
+		os.Exit(0)
+	},
+}
+
+func init() {
+	unsetCmd.AddCommand(unsetCustomClaimsCmd)
+	unsetCustomClaimsCmd.Flags().StringArray("keys", nil, "Custom claims keys to remove")
+	if err := unsetCustomClaimsCmd.MarkFlagRequired("keys"); err != nil {
+		utils.StdOutError(os.Stderr, "%s\n", err.Error())
+		os.Exit(1)
+	}
+}

firebase/auth/auth.go

@@ -105,6 +105,26 @@ func AddCustomClaimToFirebaseUser(ctx context.Context, uid string, customClaims
 	return nil
 }
 
+// RemoveCustomClaimFromUser remove a custom claim or custom claims from a users
+// account
+func RemoveCustomClaimFromUser(ctx context.Context, UID string, keys []string) (*auth.UserRecord, error) {
+	customClaimsToUnset := map[string]interface{}{}
+	for _, v := range keys {
+		customClaimsToUnset[v] = nil
+	}
+	client, err := firebase.Auth(ctx, "", "")
+	if err != nil {
+		return nil, fmt.Errorf("Error authenticating firebase account: %w", err)
+	}
+	params := &auth.UserToUpdate{}
+	params.CustomClaims(customClaimsToUnset)
+	user, err := client.UpdateUser(ctx, UID, params)
+	if err != nil {
+		return nil, firebase.NewError(err)
+	}
+	return user, nil
+}
+
 func DeleteFirebaseUser(ctx context.Context, uid string) error {
 	if uid == "" {
 		return fmt.Errorf("The UID of the user can not be empty")