From 0ef6c878d228bc29801e5fdbd3dc8f57de49595f Mon Sep 17 00:00:00 2001
From: Marcin Federowicz <marcin.federowicz@gmail.com>
Date: Fri, 22 Dec 2023 16:55:36 +0100
Subject: [PATCH] refactor: invert conditions to reduce indent, restore old
 testdata, and change usage of getImportPackageName

---
 rule/redundant-import-alias.go             | 81 +++++++++++++---------
 testdata/redundant-import-alias-ignored.go |  2 +-
 testdata/redundant-import-alias.go         | 19 +++--
 3 files changed, 57 insertions(+), 45 deletions(-)

diff --git a/rule/redundant-import-alias.go b/rule/redundant-import-alias.go
index ce1fbcaa1..99a88a0d2 100644
--- a/rule/redundant-import-alias.go
+++ b/rule/redundant-import-alias.go
@@ -3,6 +3,7 @@ package rule
 import (
 	"fmt"
 	"go/ast"
+	"strings"
 	"sync"
 
 	"github.com/mgechev/revive/lint"
@@ -59,35 +60,39 @@ func (r *RedundantImportAlias) checkRedundantAliases(node ast.Node) map[string]s
 			return true
 		}
 
-		if imp.Name != nil && imp.Path != nil {
-			aliasedPackages[imp.Name.Name] = "redundant"
+		if imp.Name != nil && imp.Path != nil && imp.Name.Name != "_" && getImportPackageName(imp) == imp.Name.Name {
+			aliasedPackages[imp.Name.Name] = "redundant"	
 		}
+
 		return true
 	})
 
-	if r.ignoreUsed {
-		// Second pass: remove one time used aliases
-		ast.Inspect(node, func(n ast.Node) bool {
-			sel, ok := n.(*ast.SelectorExpr)
-			if !ok {
-				return true
-			}
-
-			x, ok := sel.X.(*ast.Ident)
-			if !ok {
-				return true
-			}
+	if !r.ignoreUsed {
+		return aliasedPackages
+	}
 
-			// This alias is being used; it's not redundant
-			if _, exists := aliasedPackages[x.Name]; exists {
-				delete(aliasedPackages, x.Name)
-			}
+	// Second pass: remove one-time used aliases
+	ast.Inspect(node, func(n ast.Node) bool {
+		sel, ok := n.(*ast.SelectorExpr)
+		if !ok {
+			return true
+		}
 
+		x, ok := sel.X.(*ast.Ident)
+		if !ok {
 			return true
-		})
-	}
+		}
+
+		// This alias is being used; it's not redundant
+		if _, exists := aliasedPackages[x.Name]; exists {
+			delete(aliasedPackages, x.Name)
+		}
+
+		return true
+	})
 
 	return aliasedPackages
+
 }
 
 func (r *RedundantImportAlias) configure(arguments lint.Arguments) {
@@ -95,22 +100,32 @@ func (r *RedundantImportAlias) configure(arguments lint.Arguments) {
 	defer r.Unlock()
 
 	r.ignoreUsed = defaultIgnoreUsed
-	if len(arguments) > 0 {
 
-		args, ok := arguments[0].(map[string]any)
-		if !ok {
-			panic(fmt.Sprintf("Invalid argument to the redundant-import-alias rule. Expecting a k,v map, got %T", arguments[0]))
-		}
+	if len(arguments) == 0 {
+		return
+	}
+
+	args, ok := arguments[0].(map[string]any)
+	if !ok {
+		panic(fmt.Sprintf("Invalid argument to the redundant-import-alias rule. Expecting a k,v map, got %T", arguments[0]))
+	}
 
-		for k, v := range args {
-			switch k {
-			case "ignoreUsed":
-				value, ok := v.(bool)
-				if !ok {
-					panic(fmt.Sprintf("Invalid argument to the redundant-import-alias rule, expecting string representation of an bool. Got '%v' (%T)", v, v))
-				}
-				r.ignoreUsed = value
+	for k, v := range args {
+		switch k {
+		case "ignoreUsed":
+			value, ok := v.(bool)
+			if !ok {
+				panic(fmt.Sprintf("Invalid argument to the redundant-import-alias rule, expecting string representation of an bool. Got '%v' (%T)", v, v))
 			}
+			r.ignoreUsed = value
 		}
 	}
+
+}
+
+func getImportPackageName(imp *ast.ImportSpec) string {
+	path := strings.Trim(imp.Path.Value, `"`)
+	parts := strings.Split(path, "/")
+	packageName := parts[len(parts)-1]
+	return packageName
 }
diff --git a/testdata/redundant-import-alias-ignored.go b/testdata/redundant-import-alias-ignored.go
index 57c3acb17..4061d2e96 100644
--- a/testdata/redundant-import-alias-ignored.go
+++ b/testdata/redundant-import-alias-ignored.go
@@ -5,7 +5,7 @@ import (
 	"crypto/md5"
 	md5 "crypto/md5"
 	"strings"
-	str "strings"     // MATCH /Import alias "str" is redundant/
+	str "strings" 
 	strings "strings" // MATCH /Import alias "strings" is redundant/
 )
 
diff --git a/testdata/redundant-import-alias.go b/testdata/redundant-import-alias.go
index 0fc508ac7..c90a26b4d 100644
--- a/testdata/redundant-import-alias.go
+++ b/testdata/redundant-import-alias.go
@@ -1,16 +1,13 @@
 package fixtures
 
-import (
+import(
 	"crypto/md5"
-	md5 "crypto/md5" // MATCH /Import alias "md5" is redundant/
-
-	runpb "cloud.google.com/go/run/apiv2/runpb" // MATCH /Import alias "runpb" is redundant/
+		"strings"
+		_ "crypto/md5"
+		str "strings"
+		strings "strings"  // MATCH /Import alias "strings" is redundant/
+		crypto "crypto/md5"
+        redundant "abc/redundant" // MATCH /Import alias "redundant" is redundant/
+		md5 "crypto/md5"  // MATCH /Import alias "md5" is redundant/
 )
 
-func UseRunpb() {
-	runpb.RegisterTasksServer()
-}
-
-func UseMd5() {
-	fmt.PrintLn(md5.Size)
-}