From 29854455ffdf6ea839dc1ae73d968e8aaec261fe Mon Sep 17 00:00:00 2001
From: Sean Chittenden <sean@chittenden.org>
Date: Tue, 6 Aug 2024 13:54:37 -0700
Subject: [PATCH 1/3] import: add goimports LocalPrefix support

---
 main.go | 48 +++++++++++++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/main.go b/main.go
index ee59e40..be46b23 100644
--- a/main.go
+++ b/main.go
@@ -43,6 +43,7 @@ var (
 	groupImports = flag.Bool("groupimports", true, "group imports by type")
 	printDiff    = flag.Bool("diff", true, "print diffs")
 	ignore       = flag.String("ignore", "", "regex matching files to skip")
+	localPrefix  = flag.String("local", "", "local imports path")
 	srcDir       = flag.String("srcdir", "", "resolve imports as if the source file is from the given directory (if a file is given, the parent directory is used)")
 )
 
@@ -161,6 +162,10 @@ func checkBuf(path string, src []byte) ([]byte, error) {
 			FormatOnly: false,
 		}
 
+		if localPrefix != nil && *localPrefix != "" {
+			imports.LocalPrefix = *localPrefix
+		}
+
 		pathForImports := path
 		if *srcDir != "" {
 			filename := filepath.Base(path)
@@ -272,6 +277,7 @@ func checkBuf(path string, src []byte) ([]byte, error) {
 			lastPos = typ.End()
 		}
 	}
+
 	output.Write(src[file.Offset(lastPos):])
 	return output.Bytes(), nil
 }
@@ -287,23 +293,39 @@ func checkBuf(path string, src []byte) ([]byte, error) {
 // exception is made for cgo, whose "C" psuedo-imports are extracted into
 // separate import declarations.
 func remapImports(file *parser.File) map[*parser.ImportDecl][]render.ImportBlock {
-	var (
-		stdlibImports []parser.ImportSpec
-		otherImports  []parser.ImportSpec
-	)
-
-	for _, imp := range file.ImportSpecs() {
-		switch impPath := imp.Path(); {
-		case impPath == "C":
-			continue
-		case strings.Contains(impPath, "."):
+	imports := file.ImportSpecs()
+	stdlibImports := make([]parser.ImportSpec, 0, len(imports))
+	otherImports := make([]parser.ImportSpec, 0, len(imports))
+	localImports := make([]parser.ImportSpec, 0, len(imports))
+
+NEXT_IMPORT:
+	for _, imp := range imports {
+		impPath := imp.Path()
+		if impPath == "C" {
+			continue NEXT_IMPORT
+		}
+
+		if localPrefix != nil && *localPrefix != "" {
+			for _, lp := range strings.Split(*localPrefix, ",") {
+				if !strings.HasSuffix(lp, "/") {
+					lp += "/"
+				}
+				if strings.HasPrefix(impPath, lp) {
+					localImports = append(localImports, imp)
+					continue NEXT_IMPORT
+				}
+			}
+		}
+
+		if strings.Contains(impPath, ".") {
 			otherImports = append(otherImports, imp)
-		default:
-			stdlibImports = append(stdlibImports, imp)
+			continue NEXT_IMPORT
 		}
+
+		stdlibImports = append(stdlibImports, imp)
 	}
 
-	mainBlock := render.ImportBlock{stdlibImports, otherImports}
+	mainBlock := render.ImportBlock{stdlibImports, otherImports, localImports}
 	needMainBlock := mainBlock.Size() > 0
 
 	mapping := map[*parser.ImportDecl][]render.ImportBlock{}

From 1c509862fbef2ea4657f0e1d46e3b4578ac5d1ae Mon Sep 17 00:00:00 2001
From: Sean Chittenden <sean@chittenden.org>
Date: Tue, 6 Aug 2024 14:00:21 -0700
Subject: [PATCH 2/3] imports: match goimports help string for the -local flag

---
 main.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main.go b/main.go
index be46b23..a739a59 100644
--- a/main.go
+++ b/main.go
@@ -43,7 +43,7 @@ var (
 	groupImports = flag.Bool("groupimports", true, "group imports by type")
 	printDiff    = flag.Bool("diff", true, "print diffs")
 	ignore       = flag.String("ignore", "", "regex matching files to skip")
-	localPrefix  = flag.String("local", "", "local imports path")
+	localPrefix  = flag.String("local", "", "put imports beginning with this string after 3rd-party packages; comma-separated list")
 	srcDir       = flag.String("srcdir", "", "resolve imports as if the source file is from the given directory (if a file is given, the parent directory is used)")
 )
 

From 7dd5fef4b69869b8b1feeb386205280f077b805b Mon Sep 17 00:00:00 2001
From: Sean Chittenden <sean@chittenden.org>
Date: Tue, 6 Aug 2024 15:36:08 -0700
Subject: [PATCH 3/3] imports: cache the split version of local prefixes

---
 main.go | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/main.go b/main.go
index a739a59..5c856e7 100644
--- a/main.go
+++ b/main.go
@@ -298,6 +298,18 @@ func remapImports(file *parser.File) map[*parser.ImportDecl][]render.ImportBlock
 	otherImports := make([]parser.ImportSpec, 0, len(imports))
 	localImports := make([]parser.ImportSpec, 0, len(imports))
 
+	localPrefixes := []string{}
+	if localPrefix != nil && *localPrefix != "" {
+		lps := strings.Split(*localPrefix, ",")
+		localPrefixes = make([]string, 0, len(lps))
+		for _, lp := range lps {
+			if !strings.HasSuffix(lp, "/") {
+				lp += "/"
+			}
+			localPrefixes = append(localPrefixes, lp)
+		}
+	}
+
 NEXT_IMPORT:
 	for _, imp := range imports {
 		impPath := imp.Path()
@@ -305,15 +317,10 @@ NEXT_IMPORT:
 			continue NEXT_IMPORT
 		}
 
-		if localPrefix != nil && *localPrefix != "" {
-			for _, lp := range strings.Split(*localPrefix, ",") {
-				if !strings.HasSuffix(lp, "/") {
-					lp += "/"
-				}
-				if strings.HasPrefix(impPath, lp) {
-					localImports = append(localImports, imp)
-					continue NEXT_IMPORT
-				}
+		for _, lp := range localPrefixes {
+			if strings.HasPrefix(impPath, lp) {
+				localImports = append(localImports, imp)
+				continue NEXT_IMPORT
 			}
 		}