Add UseTesting linter (#5170)

.golangci.next.reference.yml

@@ -114,6 +114,7 @@ linters:
     - unparam
     - unused
     - usestdlibvars
+    - usetesting
     - varnamelen
     - wastedassign
     - whitespace
@@ -230,6 +231,7 @@ linters:
     - unparam
     - unused
     - usestdlibvars
+    - usetesting
     - varnamelen
     - wastedassign
     - whitespace
@@ -3533,6 +3535,38 @@ linters-settings:
     # Default: false
     constant-kind: true
 
+  usetesting:
+    # Enable/disable `os.CreateTemp("", ...)` detections.
+    # Default: true
+    os-create-temp: false
+
+    # Enable/disable `os.MkdirTemp()` detections.
+    # Default: true
+    os-mkdir-temp: false
+
+    # Enable/disable `os.Setenv()` detections.
+    # Default: false
+    os-setenv: true
+
+    # Enable/disable `os.TempDir()` detections.
+    # Default: false
+    os-temp-dir: true
+
+    # Enable/disable `os.Chdir()` detections.
+    # Disabled if Go < 1.24.
+    # Default: true
+    os-chdir: false
+
+    # Enable/disable `context.Background()` detections.
+    # Disabled if Go < 1.24.
+    # Default: true
+    context-background: false
+
+    # Enable/disable `context.TODO()` detections.
+    # Disabled if Go < 1.24.
+    # Default: true
+    context-todo: false
+
   unconvert:
     # Remove conversions that force intermediate rounding.
     # Default: false

go.mod

@@ -68,6 +68,7 @@ require (
 	github.com/lasiar/canonicalheader v1.1.2
 	github.com/ldez/gomoddirectives v0.2.4
 	github.com/ldez/tagliatelle v0.6.0
+	github.com/ldez/usetesting v0.2.0
 	github.com/leonklingele/grouper v1.1.2
 	github.com/macabu/inamedparam v0.1.3
 	github.com/maratori/testableexamples v1.0.0

jsonschema/golangci.next.jsonschema.json

@@ -428,6 +428,7 @@
             "unparam",
             "unused",
             "usestdlibvars",
+            "usetesting",
             "varnamelen",
             "wastedassign",
             "whitespace",
@@ -3325,6 +3326,40 @@
             }
           }
         },
+        "usetesting": {
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "context-background": {
+              "type": "boolean",
+              "default": true
+            },
+            "context-todo": {
+              "type": "boolean",
+              "default": true
+            },
+            "os-chdir": {
+              "type": "boolean",
+              "default": true
+            },
+            "os-mkdir-temp": {
+              "type": "boolean",
+              "default": true
+            },
+            "os-setenv": {
+              "type": "boolean",
+              "default": false
+            },
+            "os-create-temp": {
+              "type": "boolean",
+              "default": true
+            },
+            "os-temp-dir": {
+              "type": "boolean",
+              "default": false
+            }
+          }
+        },
         "unconvert": {
           "type": "object",
           "additionalProperties": false,

pkg/config/linters_settings.go

@@ -179,6 +179,15 @@ var defaultLintersSettings = LintersSettings{
 		HTTPMethod:     true,
 		HTTPStatusCode: true,
 	},
+	UseTesting: UseTestingSettings{
+		ContextBackground: true,
+		ContextTodo:       true,
+		OSChdir:           true,
+		OSMkdirTemp:       true,
+		OSSetenv:          false,
+		OSTempDir:         false,
+		OSCreateTemp:      true,
+	},
 	Varnamelen: VarnamelenSettings{
 		MaxDistance:   5,
 		MinNameLength: 3,
@@ -278,6 +287,7 @@ type LintersSettings struct {
 	Unparam         UnparamSettings
 	Unused          UnusedSettings
 	UseStdlibVars   UseStdlibVarsSettings
+	UseTesting      UseTestingSettings
 	Varnamelen      VarnamelenSettings
 	Whitespace      WhitespaceSettings
 	Wrapcheck       WrapcheckSettings
@@ -959,6 +969,16 @@ type UseStdlibVarsSettings struct {
 	SyslogPriority     bool `mapstructure:"syslog-priority"` // Deprecated
 }
 
+type UseTestingSettings struct {
+	ContextBackground bool `mapstructure:"context-background"`
+	ContextTodo       bool `mapstructure:"context-todo"`
+	OSChdir           bool `mapstructure:"os-chdir"`
+	OSMkdirTemp       bool `mapstructure:"os-mkdir-temp"`
+	OSSetenv          bool `mapstructure:"os-setenv"`
+	OSTempDir         bool `mapstructure:"os-temp-dir"`
+	OSCreateTemp      bool `mapstructure:"os-create-temp"`
+}
+
 type UnconvertSettings struct {
 	FastMath bool `mapstructure:"fast-math"`
 	Safe     bool `mapstructure:"safe"`

pkg/golinters/usetesting/testdata/usetesting.go

@@ -0,0 +1,26 @@
+//golangcitest:args -Eusetesting
+package testdata
+
+import (
+	"os"
+	"testing"
+)
+
+func Test_osMkdirTemp(t *testing.T) {
+	os.MkdirTemp("", "") // want `os\.MkdirTemp\(\) could be replaced by t\.TempDir\(\) in .+`
+}
+
+func Test_osSetenv(t *testing.T) {
+	os.Setenv("", "")
+}
+
+func Test_osTempDir(t *testing.T) {
+	os.TempDir()
+}
+
+func Test_osCreateTemp(t *testing.T) {
+	os.CreateTemp("", "")   // want `os\.CreateTemp\("", \.\.\.\) could be replaced by os\.CreateTemp\(t\.TempDir\(\), \.\.\.\) in .+`
+	os.CreateTemp("", "xx") // want `os\.CreateTemp\("", \.\.\.\) could be replaced by os\.CreateTemp\(t\.TempDir\(\), \.\.\.\) in .+`
+	os.CreateTemp(os.TempDir(), "xx")
+	os.CreateTemp(t.TempDir(), "xx")
+}

pkg/golinters/usetesting/testdata/usetesting_configuration.go

@@ -0,0 +1,27 @@
+//golangcitest:args -Eusetesting
+//golangcitest:config_path testdata/usetesting_configuration.yml
+package testdata
+
+import (
+	"os"
+	"testing"
+)
+
+func Test_osMkdirTemp(t *testing.T) {
+	os.MkdirTemp("", "")
+}
+
+func Test_osTempDir(t *testing.T) {
+	os.TempDir() // want `os\.TempDir\(\) could be replaced by t\.TempDir\(\) in .+`
+}
+
+func Test_osSetenv(t *testing.T) {
+	os.Setenv("", "") // want `os\.Setenv\(\) could be replaced by t\.Setenv\(\) in .+`
+}
+
+func Test_osCreateTemp(t *testing.T) {
+	os.CreateTemp("", "")
+	os.CreateTemp("", "xx")
+	os.CreateTemp(os.TempDir(), "xx") // want `os\.TempDir\(\) could be replaced by t\.TempDir\(\) in .+`
+	os.CreateTemp(t.TempDir(), "xx")
+}

pkg/golinters/usetesting/testdata/usetesting_configuration.yml

@@ -0,0 +1,9 @@
+linters-settings:
+  usetesting:
+    os-create-temp: false
+    os-mkdir-temp: false
+    os-setenv: true
+    os-temp-dir: true
+    os-chdir: false
+    context-background: false
+    context-todo: false

pkg/golinters/usetesting/testdata/usetesting_go124.go

@@ -0,0 +1,41 @@
+//go:build go1.24
+
+//golangcitest:args -Eusetesting
+package testdata
+
+import (
+	"context"
+	"os"
+	"testing"
+)
+
+func Test_contextBackground(t *testing.T) {
+	context.Background() // want `context\.Background\(\) could be replaced by t\.Context\(\) in .+`
+}
+
+func Test_contextTODO(t *testing.T) {
+	context.TODO() // want `context\.TODO\(\) could be replaced by t\.Context\(\) in .+`
+}
+
+func Test_osChdir(t *testing.T) {
+	os.Chdir("") // want `os\.Chdir\(\) could be replaced by t\.Chdir\(\) in .+`
+}
+
+func Test_osMkdirTemp(t *testing.T) {
+	os.MkdirTemp("", "") // want `os\.MkdirTemp\(\) could be replaced by t\.TempDir\(\) in .+`
+}
+
+func Test_osSetenv(t *testing.T) {
+	os.Setenv("", "")
+}
+
+func Test_osTempDir(t *testing.T) {
+	os.TempDir()
+}
+
+func Test_osCreateTemp(t *testing.T) {
+	os.CreateTemp("", "")   // want `os\.CreateTemp\("", \.\.\.\) could be replaced by os\.CreateTemp\(t\.TempDir\(\), \.\.\.\) in .+`
+	os.CreateTemp("", "xx") // want `os\.CreateTemp\("", \.\.\.\) could be replaced by os\.CreateTemp\(t\.TempDir\(\), \.\.\.\) in .+`
+	os.CreateTemp(os.TempDir(), "xx")
+	os.CreateTemp(t.TempDir(), "xx")
+}

pkg/golinters/usetesting/testdata/usetesting_go124_configuration.go

@@ -0,0 +1,42 @@
+//go:build go1.24
+
+//golangcitest:args -Eusetesting
+//golangcitest:config_path testdata/usetesting_go124_configuration.yml
+package testdata
+
+import (
+	"context"
+	"os"
+	"testing"
+)
+
+func Test_contextBackground(t *testing.T) {
+	context.Background()
+}
+
+func Test_contextTODO(t *testing.T) {
+	context.TODO()
+}
+
+func Test_osChdir(t *testing.T) {
+	os.Chdir("")
+}
+
+func Test_osMkdirTemp(t *testing.T) {
+	os.MkdirTemp("", "")
+}
+
+func Test_osSetenv(t *testing.T) {
+	os.Setenv("", "") // want `os\.Setenv\(\) could be replaced by t\.Setenv\(\) in .+`
+}
+
+func Test_osTempDir(t *testing.T) {
+	os.TempDir() // want `os\.TempDir\(\) could be replaced by t\.TempDir\(\) in .+`
+}
+
+func Test_osCreateTemp(t *testing.T) {
+	os.CreateTemp("", "")
+	os.CreateTemp("", "xx")
+	os.CreateTemp(os.TempDir(), "xx") // want `os\.TempDir\(\) could be replaced by t\.TempDir\(\) in .+`
+	os.CreateTemp(t.TempDir(), "xx")
+}

pkg/golinters/usetesting/testdata/usetesting_go124_configuration.yml

@@ -0,0 +1,9 @@
+linters-settings:
+  usetesting:
+    os-create-temp: false
+    os-mkdir-temp: false
+    os-setenv: true
+    os-temp-dir: true
+    os-chdir: false
+    context-background: false
+    context-todo: false

pkg/golinters/usetesting/usetesting.go

@@ -0,0 +1,33 @@
+package usetesting
+
+import (
+	"github.com/ldez/usetesting"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/config"
+	"github.com/golangci/golangci-lint/pkg/goanalysis"
+)
+
+func New(settings *config.UseTestingSettings) *goanalysis.Linter {
+	a := usetesting.NewAnalyzer()
+
+	cfg := make(map[string]map[string]any)
+	if settings != nil {
+		cfg[a.Name] = map[string]any{
+			"contextbackground": settings.ContextBackground,
+			"contexttodo":       settings.ContextTodo,
+			"oschdir":           settings.OSChdir,
+			"osmkdirtemp":       settings.OSMkdirTemp,
+			"ossetenv":          settings.OSSetenv,
+			"ostempdir":         settings.OSTempDir,
+			"oscreatetemp":      settings.OSCreateTemp,
+		}
+	}
+
+	return goanalysis.NewLinter(
+		a.Name,
+		a.Doc,
+		[]*analysis.Analyzer{a},
+		cfg,
+	).WithLoadMode(goanalysis.LoadModeTypesInfo)
+}

pkg/golinters/usetesting/usetesting_integration_test.go

@@ -0,0 +1,11 @@
+package usetesting
+
+import (
+	"testing"
+
+	"github.com/golangci/golangci-lint/test/testshared/integration"
+)
+
+func TestFromTestdata(t *testing.T) {
+	integration.RunTestdata(t)
+}

pkg/lint/linter/config.go

@@ -164,12 +164,20 @@ func (lc *Config) WithNoopFallback(cfg *config.Config, cond func(cfg *config.Con
 }
 
 func IsGoLowerThanGo122() func(cfg *config.Config) error {
+	return isGoLowerThanGo("1.22")
+}
+
+func IsGoLowerThanGo124() func(cfg *config.Config) error {
+	return isGoLowerThanGo("1.24")
+}
+
+func isGoLowerThanGo(v string) func(cfg *config.Config) error {
 	return func(cfg *config.Config) error {
-		if cfg == nil || config.IsGoGreaterThanOrEqual(cfg.Run.Go, "1.22") {
+		if cfg == nil || config.IsGoGreaterThanOrEqual(cfg.Run.Go, v) {
 			return nil
 		}
 
-		return fmt.Errorf("this linter is disabled because the Go version (%s) of your project is lower than Go 1.22", cfg.Run.Go)
+		return fmt.Errorf("this linter is disabled because the Go version (%s) of your project is lower than Go %s", cfg.Run.Go, v)
 	}
 }