From d200c33105dbd5ee12b97ac9a474b33c04131930 Mon Sep 17 00:00:00 2001
From: alwx <alwxsin@gmail.com>
Date: Sun, 20 Jul 2025 14:46:38 +0300
Subject: [PATCH] fix false positive case when error is not handling in
 condition

fixes #5
---
 noinlineerr.go                | 24 ++++++++++++++++++++++--
 testdata/src/a/main.go        |  5 +++++
 testdata/src/a/main.go.golden |  5 +++++
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/noinlineerr.go b/noinlineerr.go
index ecafcd9..9bf5623 100644
--- a/noinlineerr.go
+++ b/noinlineerr.go
@@ -57,9 +57,9 @@ func inlineErrorInspector(pass *analysis.Pass) func(n ast.Node) {
 				continue
 			}
 
-			// confirm type is error
+			// confirm type is error and it is used in condition
 			obj := pass.TypesInfo.ObjectOf(ident)
-			if !isError(obj) || ident.Name == "_" {
+			if !isError(obj) || ident.Name == "_" || !errorUsedInCondition(ifStmt.Cond, ident.Name) {
 				continue
 			}
 
@@ -132,3 +132,23 @@ func shadowVarsExists(name string, scope *types.Scope) bool {
 
 	return parentScope.Lookup(name) != nil
 }
+
+func errorUsedInCondition(cond ast.Expr, errIdentName string) bool {
+	used := false
+
+	ast.Inspect(cond, func(n ast.Node) bool {
+		ident, ok := n.(*ast.Ident)
+		if !ok {
+			return true
+		}
+
+		if ident.Name == errIdentName {
+			used = true
+			return false
+		}
+
+		return true
+	})
+
+	return used
+}
diff --git a/testdata/src/a/main.go b/testdata/src/a/main.go
index 832c02a..de02284 100644
--- a/testdata/src/a/main.go
+++ b/testdata/src/a/main.go
@@ -52,6 +52,11 @@ func valid() error {
 	if ok, _ := strconv.ParseBool("1"); ok {
 		fmt.Println("ok")
 	}
+	
+	var myErr MyAliasErr
+	if err, ok := myErr.(error); ok {
+		fmt.Println("ok", err)
+	}
 
 	return nil
 }
diff --git a/testdata/src/a/main.go.golden b/testdata/src/a/main.go.golden
index d8a52d1..8e65c8b 100644
--- a/testdata/src/a/main.go.golden
+++ b/testdata/src/a/main.go.golden
@@ -54,6 +54,11 @@ func valid() error {
 		fmt.Println("ok")
 	}
 
+    var myErr MyAliasErr
+	if err, ok := myErr.(error); ok {
+		fmt.Println("ok", err)
+	}
+
 	return nil
 }