From 0b4b007603a00a806d3a69faa810e8307c85991d Mon Sep 17 00:00:00 2001
From: "R. Aidan Campbell" <aidan.campbell@gmail.com>
Date: Sat, 17 Aug 2024 13:18:34 -0700
Subject: [PATCH] add scancheck linter
---
.golangci.next.reference.yml | 2 +
go.mod | 1 +
go.sum | 2 +
jsonschema/golangci.next.jsonschema.json | 1 +
pkg/golinters/scancheck/scancheck.go | 18 ++
pkg/golinters/scancheck/testdata/scancheck.go | 179 ++++++++++++++++++
pkg/lint/lintersdb/builder_linter.go | 6 +
7 files changed, 209 insertions(+)
create mode 100644 pkg/golinters/scancheck/scancheck.go
create mode 100644 pkg/golinters/scancheck/testdata/scancheck.go
diff --git a/.golangci.next.reference.yml b/.golangci.next.reference.yml
index 2d4c9e10e009..0ff9ba331c2c 100644
--- a/.golangci.next.reference.yml
+++ b/.golangci.next.reference.yml
@@ -2674,6 +2674,7 @@ linters:
- reassign
- revive
- rowserrcheck
+ - scancheck
- sloglint
- spancheck
- sqlclosecheck
@@ -2789,6 +2790,7 @@ linters:
- reassign
- revive
- rowserrcheck
+ - scancheck
- sloglint
- spancheck
- sqlclosecheck
diff --git a/go.mod b/go.mod
index ecb2b9612bc8..45824ff16f01 100644
--- a/go.mod
+++ b/go.mod
@@ -86,6 +86,7 @@ require (
github.com/pelletier/go-toml/v2 v2.2.2
github.com/polyfloyd/go-errorlint v1.6.0
github.com/quasilyte/go-ruleguard/dsl v0.3.22
+ github.com/raidancampbell/scancheck v1.0.2
github.com/ryancurrah/gomodguard v1.3.3
github.com/ryanrolds/sqlclosecheck v0.5.1
github.com/sanposhiho/wastedassign/v2 v2.0.7
diff --git a/go.sum b/go.sum
index 73a0cc77faab..7cce242b492e 100644
--- a/go.sum
+++ b/go.sum
@@ -458,6 +458,8 @@ github.com/quasilyte/regex/syntax v0.0.0-20210819130434-b3f0c404a727 h1:TCg2WBOl
github.com/quasilyte/regex/syntax v0.0.0-20210819130434-b3f0c404a727/go.mod h1:rlzQ04UMyJXu/aOvhd8qT+hvDrFpiwqp8MRXDY9szc0=
github.com/quasilyte/stdinfo v0.0.0-20220114132959-f7386bf02567 h1:M8mH9eK4OUR4lu7Gd+PU1fV2/qnDNfzT635KRSObncs=
github.com/quasilyte/stdinfo v0.0.0-20220114132959-f7386bf02567/go.mod h1:DWNGW8A4Y+GyBgPuaQJuWiy0XYftx4Xm/y5Jqk9I6VQ=
+github.com/raidancampbell/scancheck v1.0.2 h1:7ZZAB/ogNlmqLwNyV6UgJ/Hn+1BeuIWZ8m/WYGCI+hE=
+github.com/raidancampbell/scancheck v1.0.2/go.mod h1:tDBwTPKt6IvDRCCPAjh2zNRzVeh1zQm2tRMzVf8RAt4=
github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
diff --git a/jsonschema/golangci.next.jsonschema.json b/jsonschema/golangci.next.jsonschema.json
index 510740d61660..f01ff07379a0 100644
--- a/jsonschema/golangci.next.jsonschema.json
+++ b/jsonschema/golangci.next.jsonschema.json
@@ -384,6 +384,7 @@
"reassign",
"revive",
"rowserrcheck",
+ "scancheck",
"scopelint",
"sloglint",
"sqlclosecheck",
diff --git a/pkg/golinters/scancheck/scancheck.go b/pkg/golinters/scancheck/scancheck.go
new file mode 100644
index 000000000000..847ed6e41e22
--- /dev/null
+++ b/pkg/golinters/scancheck/scancheck.go
@@ -0,0 +1,18 @@
+package scancheck
+
+import (
+ "github.com/golangci/golangci-lint/pkg/goanalysis"
+ "github.com/raidancampbell/scancheck/pkg/scancheck"
+ "golang.org/x/tools/go/analysis"
+)
+
+func New() *goanalysis.Linter {
+ a := scancheck.Analyzer
+
+ return goanalysis.NewLinter(
+ a.Name,
+ a.Doc,
+ []*analysis.Analyzer{a},
+ nil,
+ ).WithLoadMode(goanalysis.LoadModeTypesInfo)
+}
diff --git a/pkg/golinters/scancheck/testdata/scancheck.go b/pkg/golinters/scancheck/testdata/scancheck.go
new file mode 100644
index 000000000000..bdcfd24f84bf
--- /dev/null
+++ b/pkg/golinters/scancheck/testdata/scancheck.go
@@ -0,0 +1,179 @@
+//golangcitest:args -Escancheck
+package testdata
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+)
+
+func incorrectErrorScanner(reader io.Reader) {
+ scanner := bufio.NewScanner(reader)
+
+ for scanner.Scan() {
+ _ = scanner.Bytes()
+
+ // this is incorrect behavior: if scanner.Scan() returns false, scanner.Err() should be checked.
+ // meaning that scanner.Err() should only be checked outside the loop.
+ if err := scanner.Err(); err != nil { // want "scanner.Err\\(\\) called inside a Scan\\(\\) loop"
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+}
+
+func bufioRawScanner(reader io.Reader) {
+ var scanner = bufio.Scanner{}
+
+ for scanner.Scan() {
+ _ = scanner.Bytes()
+ if err := scanner.Err(); err != nil { // want "scanner.Err\\(\\) called inside a Scan\\(\\) loop"
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+}
+
+func bufioRawNewScanner(reader io.Reader) {
+ scanner := new(bufio.Scanner)
+
+ for scanner.Scan() {
+ _ = scanner.Bytes()
+ if err := scanner.Err(); err != nil { // want "scanner.Err\\(\\) called inside a Scan\\(\\) loop"
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+}
+
+func multipleAssignment(reader io.Reader) {
+ _, scanner := bufio.NewReader(reader), bufio.NewScanner(reader)
+
+ for scanner.Scan() {
+ _ = scanner.Bytes()
+ if err := scanner.Err(); err != nil { // want "scanner.Err\\(\\) called inside a Scan\\(\\) loop"
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+}
+
+func unrelatedBufioScanner(reader io.Reader) {
+ x := func(_ bufio.Scanner) *notABufioScanner {
+ return newNotBufioScanner()
+ }
+ scanner := x(bufio.Scanner{})
+
+ for scanner.Scan() {
+ if err := scanner.Err(); err != nil {
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+
+}
+
+func correctErrorScanner(reader io.Reader) {
+ scanner := bufio.NewScanner(reader)
+
+ for scanner.Scan() {
+ _ = scanner.Bytes()
+
+ // this is incorrect behavior: if scanner.Scan() returns false, scanner.Err() should be checked.
+ // meaning that scanner.Err() should only be checked outside the loop.
+ }
+
+ if err := scanner.Err(); err != nil {
+ fmt.Printf("oh no! %v", err)
+ }
+}
+
+func hasNoScanner() {}
+
+func scannerIsNotScanned(reader io.Reader) {
+ scanner := bufio.NewScanner(reader)
+ _ = scanner.Bytes()
+}
+
+func scannerScannedOutsideForLoop(reader io.Reader) {
+ scanner := bufio.NewScanner(reader)
+ _ = scanner.Scan()
+ if err := scanner.Err(); err != nil {
+ fmt.Printf("oh no! %v", err)
+ }
+ _ = scanner.Bytes()
+}
+
+func bufioNotScanner(reader io.Reader) {
+ r := bufio.NewReader(reader)
+
+ for _, err := r.ReadByte(); err != nil; {
+ }
+}
+
+func scannerNotBufio(reader io.Reader) {
+ sg := scannerGenerator{}
+ scanner := sg.NewScanner()
+
+ for scanner.Scan() {
+ if err := scanner.Err(); err != nil {
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+}
+
+func scannerShadowingBufio(reader io.Reader) {
+ bufio := scannerGenerator{}
+ scanner := bufio.NewScanner()
+
+ for scanner.Scan() {
+ if err := scanner.Err(); err != nil {
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+}
+
+func scannerAlmostShadowingBufio(reader io.Reader) {
+ bufio := scannerGenerator{}
+ scanner := bufio.NewScannerWithDifferentName()
+
+ for scanner.Scan() {
+ if err := scanner.Err(); err != nil {
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+}
+
+func scanNotScanner(reader io.Reader) {
+ b := new(boolScanner)
+ for b.Scan() {
+ if err := newNotBufioScanner().Err(); err != nil {
+ fmt.Printf("oh no! %v", err)
+ }
+ }
+}
+
+func newNotBufioScanner() *notABufioScanner {
+ return new(notABufioScanner)
+}
+
+type notABufioScanner struct{}
+
+func (n notABufioScanner) Scan() bool {
+ return true
+}
+
+func (n notABufioScanner) Err() error {
+ return nil
+}
+
+type scannerGenerator struct{}
+
+func (s scannerGenerator) NewScanner() *notABufioScanner {
+ return newNotBufioScanner()
+}
+
+func (s scannerGenerator) NewScannerWithDifferentName() *notABufioScanner {
+ return newNotBufioScanner()
+}
+
+type boolScanner struct{}
+
+func (b boolScanner) Scan() bool {
+ return false
+}
diff --git a/pkg/lint/lintersdb/builder_linter.go b/pkg/lint/lintersdb/builder_linter.go
index 2e6c148e329c..1a257ec199d4 100644
--- a/pkg/lint/lintersdb/builder_linter.go
+++ b/pkg/lint/lintersdb/builder_linter.go
@@ -87,6 +87,7 @@ import (
"github.com/golangci/golangci-lint/pkg/golinters/reassign"
"github.com/golangci/golangci-lint/pkg/golinters/revive"
"github.com/golangci/golangci-lint/pkg/golinters/rowserrcheck"
+ "github.com/golangci/golangci-lint/pkg/golinters/scancheck"
"github.com/golangci/golangci-lint/pkg/golinters/sloglint"
"github.com/golangci/golangci-lint/pkg/golinters/spancheck"
"github.com/golangci/golangci-lint/pkg/golinters/sqlclosecheck"
@@ -668,6 +669,11 @@ func (LinterBuilder) Build(cfg *config.Config) ([]*linter.Config, error) {
WithPresets(linter.PresetBugs, linter.PresetSQL).
WithURL("https://github.com/jingyugao/rowserrcheck"),
+ linter.NewConfig(scancheck.New()).
+ WithSince("v1.61.0").
+ WithPresets(linter.PresetBugs, linter.PresetError).
+ WithURL("https://github.com/raidancampbell/scancheck"),
+
linter.NewConfig(sloglint.New(&cfg.LintersSettings.SlogLint)).
WithSince("v1.55.0").
WithLoadForGoAnalysis().