From 40e125053bc2ddaf20d6bce14fa026cdb3131ca1 Mon Sep 17 00:00:00 2001
From: Eduard Urbach <eduard@urbach.dev>
Date: Fri, 18 Sep 2026 09:38:38 +0200
Subject: [PATCH] Improved linter to recognize copies as identical values

---
 src/linter/isIdentical.go  | 30 ++++++++++++++++++++++++++++++
 src/linter/lintBinaryOp.go |  2 +-
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 src/linter/isIdentical.go

diff --git a/src/linter/isIdentical.go b/src/linter/isIdentical.go
new file mode 100644
index 0000000..7fd7790
--- /dev/null
+++ b/src/linter/isIdentical.go
@@ -0,0 +1,30 @@
+package linter
+
+import (
+	"git.urbach.dev/cli/q/src/ssa"
+)
+
+// isIdentical returns true if the values are identical or copies of identical values.
+func isIdentical(left ssa.Value, right ssa.Value) bool {
+	if left == right {
+		return true
+	}
+
+	leftCopy, leftIsCopy := left.(*ssa.Copy)
+
+	if leftIsCopy && leftCopy.Value == right {
+		return true
+	}
+
+	rightCopy, rightIsCopy := right.(*ssa.Copy)
+
+	if rightIsCopy && rightCopy.Value == left {
+		return true
+	}
+
+	if leftIsCopy && rightIsCopy && leftCopy.Value == rightCopy.Value {
+		return true
+	}
+
+	return false
+}
\ No newline at end of file
diff --git a/src/linter/lintBinaryOp.go b/src/linter/lintBinaryOp.go
index 0b45dad..49acc7b 100644
--- a/src/linter/lintBinaryOp.go
+++ b/src/linter/lintBinaryOp.go
@@ -16,7 +16,7 @@ func lintBinaryOp(binOp *ssa.BinaryOp, file *fs.File) error {
 		return nil
 	}
 
-	if binOp.Left == binOp.Right {
+	if isIdentical(binOp.Left, binOp.Right) {
 		switch binOp.Op {
 		case token.Sub, token.Div, token.Mod, token.And, token.Or, token.Xor, token.Equal, token.NotEqual, token.Less, token.LessEqual, token.Greater, token.GreaterEqual:
 			return errors.New(&IdenticalExpressions{Operator: binOp.Op.String()}, file, binOp.Source)
-- 
2.51.2