From 0bdb3335bdaaf0939a3d17813a49780c91dcf0d1 Mon Sep 17 00:00:00 2001
From: Vyacheslav Pryimak <vyacheslavpryimak@gmail.com>
Date: Fri, 5 Feb 2021 19:58:53 +0200
Subject: [PATCH] #35 Remove empty import node if present

---
 reviser/reviser.go      | 35 +++++++++++++++++++++++++++++++++--
 reviser/reviser_test.go | 27 +++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/reviser/reviser.go b/reviser/reviser.go
index 674d79a..32c25b6 100644
--- a/reviser/reviser.go
+++ b/reviser/reviser.go
@@ -172,10 +172,10 @@ func skipPackageAlias(pkg string) string {
 	return strings.Trim(pkg, `"`)
 }
 
-func generateFile(fset *token.FileSet, file *ast.File) ([]byte, error) {
+func generateFile(fset *token.FileSet, f *ast.File) ([]byte, error) {
 	var output []byte
 	buffer := bytes.NewBuffer(output)
-	if err := printer.Fprint(buffer, fset, file); err != nil {
+	if err := printer.Fprint(buffer, fset, f); err != nil {
 		return nil, err
 	}
 
@@ -210,6 +210,37 @@ func fixImports(
 	}
 
 	clearImportDocs(f, importsPositions)
+	removeEmptyImportNode(f)
+}
+
+func removeEmptyImportNode(f *ast.File) {
+	var (
+		decls      []ast.Decl
+		hasImports bool
+	)
+
+	for _, decl := range f.Decls {
+		dd, ok := decl.(*ast.GenDecl)
+		if !ok {
+			decls = append(decls, decl)
+
+			continue
+		}
+
+		if dd.Tok == token.IMPORT && len(dd.Specs) > 0 {
+			hasImports = true
+
+			break
+		}
+
+		if dd.Tok != token.IMPORT {
+			decls = append(decls, decl)
+		}
+	}
+
+	if !hasImports {
+		f.Decls = decls
+	}
 }
 
 func rebuildImports(
diff --git a/reviser/reviser_test.go b/reviser/reviser_test.go
index 249f0ed..1bd7039 100644
--- a/reviser/reviser_test.go
+++ b/reviser/reviser_test.go
@@ -552,6 +552,33 @@ const webDirectory = "web"
 			wantChange: false,
 			wantErr:    false,
 		},
+		{
+			name: "cleanup empty import block",
+			args: args{
+				projectName: "github.com/incu6us/goimports-reviser",
+				filePath:    "./testdata/example.go",
+				fileContent: `// Some comments are here
+package testdata
+
+import (
+	"fmt"
+)
+
+// nolint:gomnd
+func main(){
+}
+`,
+			},
+			want: `// Some comments are here
+package testdata
+
+// nolint:gomnd
+func main() {
+}
+`,
+			wantChange: true,
+			wantErr:    false,
+		},
 	}
 
 	for _, tt := range tests {