From e9379aee8bc899563e934c7ed5823a39298b7257 Mon Sep 17 00:00:00 2001
From: Tommy Muehle <tommy.muehle@lovoo.com>
Date: Wed, 23 Sep 2020 14:14:35 +0200
Subject: [PATCH] Check also binary expressions in return statement, fixes #11

---
 checks/return.go              | 18 ++++++++++++++++++
 testdata/src/return/return.go | 16 ++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/checks/return.go b/checks/return.go
index be7f546..84974f1 100644
--- a/checks/return.go
+++ b/checks/return.go
@@ -41,6 +41,24 @@ func (a *ReturnAnalyzer) Check(n ast.Node) {
 			if a.isMagicNumber(x) {
 				a.pass.Reportf(x.Pos(), reportMsg, x.Value, ReturnCheck)
 			}
+		case *ast.BinaryExpr:
+			a.checkBinaryExpr(x)
+		}
+	}
+}
+
+func (a *ReturnAnalyzer) checkBinaryExpr(expr *ast.BinaryExpr) {
+	switch x := expr.X.(type) {
+	case *ast.BasicLit:
+		if a.isMagicNumber(x) {
+			a.pass.Reportf(x.Pos(), reportMsg, x.Value, ReturnCheck)
+		}
+	}
+
+	switch y := expr.Y.(type) {
+	case *ast.BasicLit:
+		if a.isMagicNumber(y) {
+			a.pass.Reportf(y.Pos(), reportMsg, y.Value, ReturnCheck)
 		}
 	}
 }
diff --git a/testdata/src/return/return.go b/testdata/src/return/return.go
index 0b28adb..54584b1 100644
--- a/testdata/src/return/return.go
+++ b/testdata/src/return/return.go
@@ -11,3 +11,19 @@ func example2() string {
 func example3() float64 {
 	return 2.0 // want "Magic number: 2.0"
 }
+
+func example4(x int32) int32 {
+	return x + 42 // want "Magic number: 42"
+}
+
+func example5(x int32) int32 {
+	return 42 + x // want "Magic number: 42"
+}
+
+func example6(x int32) int32 {
+	return x + (42 * 10) // want "Magic number: 42" "Magic number: 10"
+}
+
+func example7(x int32) int32 {
+	return (42 * x) + 10 // want "Magic number: 42" "Magic number: 10"
+}