analyzer/testdata: more test rules (#269)

analyzer/testdata/src/extra/file.go

@@ -491,3 +491,19 @@ func _() {
 
 	}
 }
+
+func quotedStringSprint(s string) {
+	_ = fmt.Sprintf(`"%s"`, s)         // want `\Quse %q instead of "%s" for quoted strings`
+	_ = fmt.Sprintf(`foo "%s" bar`, s) // want `\Quse %q instead of "%s" for quoted strings`
+
+	_ = fmt.Sprintf("\"%s\"", s)         // want `\Quse %q instead of "%s" for quoted strings`
+	_ = fmt.Sprintf("foo \"%s\" bar", s) // want `\Quse %q instead of "%s" for quoted strings`
+
+	_ = fmt.Sprintf(`%q`, s)
+	_ = fmt.Sprintf(`foo %q bar`, s)
+
+	_ = fmt.Sprintf("%q", s)
+	_ = fmt.Sprintf("foo %q bar", s)
+
+	_ = fmt.Sprintf("%s", s)
+}

analyzer/testdata/src/extra/rules.go

@@ -182,4 +182,9 @@ func testRules(m dsl.Matcher) {
 	m.Match(`$f($*_)`).
 		Where(m["$$"].Type.Is("error") && m["$$"].Node.Parent().Is("ExprStmt")).
 		Report(`don't ignore the $f result`)
+
+	m.Match(`fmt.Sprintf($s, $*_)`).
+		Where(m["s"].Text.Matches("^`.*\"%s\".*`$") ||
+			m["s"].Text.Matches(`^".*\\"%s\\".*"$`)).
+		Report(`use %q instead of "%s" for quoted strings`)
 }

analyzer/testdata/src/gocritic/f1.go

@@ -1,6 +1,7 @@
 package gocritic
 
 import (
+	"bytes"
 	"flag"
 	"fmt"
 	"io"
@@ -278,6 +279,76 @@ func offBy1(xs []int, ys []string) {
 	var m map[int]int
 	// Not an error. Doesn't panic.
 	_ = m[len(m)]
+
+	var s string
+	var b []byte
+	{
+		start := strings.Index(s, "/")
+		_ = s[start:] // want `\QIndex() can return -1; maybe you wanted to do s[start+1:]`
+	}
+	{
+		start := bytes.Index(b, []byte("/"))
+		_ = b[start:] // want `\QIndex() can return -1; maybe you wanted to do b[start+1:]`
+	}
+	{
+		_ = s[strings.Index(s, "/"):] // want `\QIndex() can return -1; maybe you wanted to do Index()+1`
+	}
+	{
+		_ = b[bytes.Index(b, []byte("/")):] // want `\QIndex() can return -1; maybe you wanted to do Index()+1`
+	}
+	{
+		start := strings.Index(s, "/")
+		res := s[start:] // want `\QIndex() can return -1; maybe you wanted to do s[start+1:]`
+		sink(res)
+	}
+	{
+		start := bytes.Index(b, []byte("/"))
+		res := b[start:] // want `\QIndex() can return -1; maybe you wanted to do b[start+1:]`
+		sink(res)
+	}
+
+	{
+		start := strings.Index(s, "/") + 1
+		_ = s[start:]
+	}
+	{
+		start := bytes.Index(b, []byte("/")) + 1
+		_ = b[start:]
+	}
+	{
+		start := strings.Index(s, "/")
+		_ = s[start+1:]
+	}
+	{
+		start := bytes.Index(b, []byte("/"))
+		_ = b[start+1:]
+	}
+	{
+		_ = s[strings.Index(s, "/")+1:]
+	}
+	{
+		_ = b[bytes.Index(b, []byte("/"))+1:]
+	}
+	{
+		start := strings.Index(s, "/") + 1
+		res := s[start:]
+		sink(res)
+	}
+	{
+		start := bytes.Index(b, []byte("/")) + 1
+		res := b[start:]
+		sink(res)
+	}
+	{
+		start := strings.Index(s, "/")
+		res := s[start+1:]
+		sink(res)
+	}
+	{
+		start := bytes.Index(b, []byte("/"))
+		res := b[start+1:]
+		sink(res)
+	}
 }
 
 func wrapperFunc(s string) {

analyzer/testdata/src/gocritic/rules.go

@@ -115,6 +115,20 @@ func testRules(m dsl.Matcher) {
 		Where(m["s"].Type.Is(`[]$elem`) && m["s"].Pure).
 		Report(`index expr always panics; maybe you wanted $s[len($s)-1]?`)
 
+	m.Match(
+		`$i := strings.Index($s, $_); $_ := $slicing[$i:]`,
+		`$i := strings.Index($s, $_); $_ = $slicing[$i:]`,
+		`$i := bytes.Index($s, $_); $_ := $slicing[$i:]`,
+		`$i := bytes.Index($s, $_); $_ = $slicing[$i:]`).
+		Where(m["s"].Text == m["slicing"].Text).
+		Report(`Index() can return -1; maybe you wanted to do $s[$i+1:]`).
+		At(m["slicing"])
+
+	m.Match(
+		`$s[strings.Index($s, $_):]`,
+		`$s[bytes.Index($s, $_):]`).
+		Report(`Index() can return -1; maybe you wanted to do Index()+1`)
+
 	m.Match(`*flag.Bool($*_)`,
 		`*flag.Float64($*_)`,
 		`*flag.Duration($*_)`,