From 020378affad4f1a8ae0cd6ac4ba3711ffd399e52 Mon Sep 17 00:00:00 2001
From: Vyacheslav Pryimak <vyacheslavpryimak@gmail.com>
Date: Mon, 5 Apr 2021 23:10:19 +0300
Subject: [PATCH] #42 Combine multiple import tokens to single (#48)

#42 combine multiple import tokens to single
---
 go.sum                  |  2 --
 reviser/reviser.go      | 54 ++++++++++++++++++++++++++++++++++++++++-
 reviser/reviser_test.go | 31 ++++++++++++++++++++++-
 3 files changed, 83 insertions(+), 4 deletions(-)

diff --git a/go.sum b/go.sum
index b4a94c4..fbac785 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,3 @@
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -34,7 +33,6 @@ golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
diff --git a/reviser/reviser.go b/reviser/reviser.go
index 32c25b6..096dd29 100644
--- a/reviser/reviser.go
+++ b/reviser/reviser.go
@@ -80,6 +80,11 @@ func Execute(projectName, filePath, localPkgPrefixes string, options ...Option)
 		importsWithMetadata,
 	)
 
+	decls, ok := hasMultipleImportTokens(pf)
+	if ok {
+		pf.Decls = decls
+	}
+
 	fixImports(pf, stdImports, generalImports, projectLocalPkgs, projectImports, importsWithMetadata)
 
 	fixedImportsContent, err := generateFile(fset, pf)
@@ -188,7 +193,6 @@ func fixImports(
 	commentsMetadata map[string]*commentsMetadata,
 ) {
 	var importsPositions []*importPosition
-
 	for _, decl := range f.Decls {
 		dd, ok := decl.(*ast.GenDecl)
 		if !ok {
@@ -213,6 +217,54 @@ func fixImports(
 	removeEmptyImportNode(f)
 }
 
+// hasMultipleImportTokens will return combined import tokens to single declaration
+//
+// Ex.:
+// import "fmt"
+// import "io"
+// -----
+// to
+// -----
+// import (
+// 	"fmt"
+//	"io"
+// )
+func hasMultipleImportTokens(f *ast.File) ([]ast.Decl, bool) {
+	importSpecs := make([]ast.Spec, 0, len(f.Imports))
+	for _, importSpec := range f.Imports {
+		importSpecs = append(importSpecs, importSpec)
+	}
+
+	var hasMultipleImportTokens bool
+	decls := make([]ast.Decl, 0, len(f.Decls))
+	for _, decl := range f.Decls {
+		dd, ok := decl.(*ast.GenDecl)
+		if !ok {
+			decls = append(decls, decl)
+			continue
+		}
+
+		if dd.Tok != token.IMPORT {
+			decls = append(decls, dd)
+			continue
+		}
+
+		if hasMultipleImportTokens {
+			storedGenDecl := decls[len(decls)-1].(*ast.GenDecl)
+			if storedGenDecl.Tok == token.IMPORT {
+				storedGenDecl.Rparen = dd.End()
+			}
+			continue
+		}
+
+		dd.Specs = importSpecs
+		decls = append(decls, dd)
+		hasMultipleImportTokens = true
+	}
+
+	return decls, hasMultipleImportTokens
+}
+
 func removeEmptyImportNode(f *ast.File) {
 	var (
 		decls      []ast.Decl
diff --git a/reviser/reviser_test.go b/reviser/reviser_test.go
index 1bd7039..b135ced 100644
--- a/reviser/reviser_test.go
+++ b/reviser/reviser_test.go
@@ -298,7 +298,6 @@ import (
 			wantChange: false,
 			wantErr:    false,
 		},
-
 		{
 			name: "success no changes by imports and comments",
 			args: args{
@@ -336,6 +335,36 @@ import (
 			wantChange: false,
 			wantErr:    false,
 		},
+		{
+			name: "success with multiple import statements",
+			args: args{
+				projectName: "github.com/incu6us/goimports-reviser",
+				filePath:    "./testdata/example.go",
+				fileContent: `package testdata
+
+	import "sync"
+	import "testing"
+
+	// yolo
+	import "fmt"
+
+
+	// not sure why this is here but we shall find out soon enough
+	import "io"
+`,
+			},
+			want: `package testdata
+
+import (
+	"fmt"
+	"io"
+	"sync"
+	"testing"
+)
+`,
+			wantChange: true,
+			wantErr:    false,
+		},
 	}
 	for _, tt := range tests {
 		if err := ioutil.WriteFile(tt.args.filePath, []byte(tt.args.fileContent), 0644); err != nil {