fix for branch create in empty repo, minor config changes for err shadow

.golangci.yml

@@ -297,6 +297,8 @@ issues:
   max-same-issues: 50
 
   exclude-rules:
+    - text: 'shadow: declaration of "err" shadows declaration at'
+      linters: [ govet ]
     - source: "^//\\s*go:generate\\s"
       linters: [ lll ]
     - source: "(noinspection|TODO)"

.vscode/launch.json

@@ -18,7 +18,7 @@
             "type": "go",
             "request": "launch",
             "mode": "auto",
-            "program": "${workspaceFolder}",
+            "program": "cmd/gitness",
             "args": ["server", "../../.local.env"]
         }
     ]

gitrpc/blame.go

@@ -7,7 +7,6 @@ package gitrpc
 import (
 	"context"
 	"errors"
-	"fmt"
 	"io"
 
 	"github.com/harness/gitness/gitrpc/rpc"
@@ -31,19 +30,19 @@ func (params *BlameParams) Validate() error {
 	}
 
 	if params.GitRef == "" {
-		return fmt.Errorf("git ref needs to be provided: %w", ErrInvalidArgument)
+		return Errorf(StatusInvalidArgument, "git ref needs to be provided")
 	}
 
 	if params.Path == "" {
-		return fmt.Errorf("file path needs to be provided: %w", ErrInvalidArgument)
+		return Errorf(StatusInvalidArgument, "file path needs to be provided")
 	}
 
 	if params.LineFrom < 0 || params.LineTo < 0 {
-		return fmt.Errorf("line from and line to can't be negative: %w", ErrInvalidArgument)
+		return Errorf(StatusInvalidArgument, "line from and line to can't be negative")
 	}
 
 	if params.LineTo > 0 && params.LineFrom > params.LineTo {
-		return fmt.Errorf("line from can't be after line after: %w", ErrInvalidArgument)
+		return Errorf(StatusInvalidArgument, "line from can't be after line after")
 	}
 
 	return nil

gitrpc/internal/service/branch.go

@@ -36,6 +36,10 @@ func (s ReferenceService) CreateBranch(ctx context.Context,
 		return nil, processGitErrorf(err, "failed to open repo")
 	}
 
+	if ok, err := repo.IsEmpty(); ok {
+		return nil, ErrInvalidArgumentf("branch cannot be created on empty repository", err)
+	}
+
 	sharedRepo, err := NewSharedRepo(s.tmpDir, base.GetRepoUid(), repo)
 	if err != nil {
 		return nil, processGitErrorf(err, "failed to create new shared repo")

gitrpc/internal/service/errors.go

@@ -64,6 +64,9 @@ func Errorf(code codes.Code, format string, args ...any) (err error) {
 	newargs := make([]any, 0, len(args))
 
 	for _, arg := range args {
+		if arg == nil {
+			continue
+		}
 		switch t := arg.(type) {
 		case error:
 			err = t