checkers: fix reflect.Value suggestion in redundantSprint

checkers/checkers_test.go

@@ -12,6 +12,12 @@ import (
 	"github.com/google/go-cmp/cmp"
 )
 
+func init() {
+	if err := InitEmbeddedRules(); err != nil {
+		panic(err) // Should never happen
+	}
+}
+
 func TestCheckers(t *testing.T) {
 	allParams := map[string]map[string]interface{}{
 		"captLocal": {"paramsOnly": false},

checkers/rules/rules.go

@@ -10,7 +10,7 @@ import (
 //doc:after   x.String()
 func redundantSprint(m dsl.Matcher) {
 	m.Match(`fmt.Sprint($x)`, `fmt.Sprintf("%s", $x)`, `fmt.Sprintf("%v", $x)`).
-		Where(m["x"].Type.Implements(`fmt.Stringer`)).
+		Where(!m["x"].Type.Is(`reflect.Value`) && m["x"].Type.Implements(`fmt.Stringer`)).
 		Suggest(`$x.String()`).
 		Report(`use $x.String() instead`)
 

checkers/testdata/redundantSprint/negative_tests.go

@@ -1,5 +1,10 @@
 package checker_test
 
+import (
+	"fmt"
+	"reflect"
+)
+
 func _() {
 	{
 		var foo withStringer
@@ -17,4 +22,11 @@ func _() {
 
 		_ = "x"
 	}
+
+	{
+		var rv reflect.Value
+		_ = fmt.Sprint(rv)
+		_ = fmt.Sprintf("%s", rv)
+		_ = fmt.Sprintf("%v", rv)
+	}
 }