feat: add reassign linter

Author: chokoswitch

.golangci.reference.yml

@@ -1221,6 +1221,12 @@ linters-settings:
      - CamelCase
      - UnitAbbreviations
 
+  reassign:
+    # Pattern for variables that are checked for reassignment.
+    # See https://github.com/curioswitch/go-reassign#usage
+    # Defaults to "^(EOF|Err.*)$"
+    pattern: ".*"
+
   revive:
     # Maximum number of open files at the same time.
     # See https://github.com/mgechev/revive#command-line-flags
@@ -1941,6 +1947,7 @@ linters:
     - prealloc
     - predeclared
     - promlinter
+    - reassign
     - revive
     - rowserrcheck
     - scopelint

go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/breml/errchkjson v0.3.0
 	github.com/butuzov/ireturn v0.1.1
 	github.com/charithe/durationcheck v0.0.9
+	github.com/curioswitch/go-reassign v0.1.0
 	github.com/daixiang0/gci v0.6.2
 	github.com/denis-tingaikin/go-header v0.4.3
 	github.com/esimonov/ifshort v1.0.4

go.sum

@@ -167,6 +167,7 @@ type LintersSettings struct {
 	Prealloc         PreallocSettings
 	Predeclared      PredeclaredSettings
 	Promlinter       PromlinterSettings
+	Reassign         ReassignSettings
 	Revive           ReviveSettings
 	RowsErrCheck     RowsErrCheckSettings
 	Staticcheck      StaticCheckSettings
@@ -517,6 +518,10 @@ type PromlinterSettings struct {
 	DisabledLinters []string `mapstructure:"disabled-linters"`
 }
 
+type ReassignSettings struct {
+	Pattern string `mapstructure:"pattern"`
+}
+
 type ReviveSettings struct {
 	MaxOpenFiles          int  `mapstructure:"max-open-files"`
 	IgnoreGeneratedHeader bool `mapstructure:"ignore-generated-header"`

pkg/config/linters_settings.go

@@ -0,0 +1,29 @@
+package golinters
+
+import (
+	"github.com/curioswitch/go-reassign"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/config"
+	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
+)
+
+func NewReassign(settings *config.ReassignSettings) *goanalysis.Linter {
+	a := reassign.NewAnalyzer()
+
+	var cfg map[string]map[string]interface{}
+	if settings != nil {
+		cfg = map[string]map[string]interface{}{
+			a.Name: {
+				reassign.FlagPattern: settings.Pattern,
+			},
+		}
+	}
+
+	return goanalysis.NewLinter(
+		a.Name,
+		a.Doc,
+		[]*analysis.Analyzer{a},
+		cfg,
+	).WithLoadMode(goanalysis.LoadModeSyntax)
+}

pkg/golinters/reassign.go

@@ -153,6 +153,7 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 		preallocCfg         *config.PreallocSettings
 		predeclaredCfg      *config.PredeclaredSettings
 		promlinterCfg       *config.PromlinterSettings
+		reassignCfg         *config.ReassignSettings
 		reviveCfg           *config.ReviveSettings
 		rowserrcheckCfg     *config.RowsErrCheckSettings
 		staticcheckCfg      *config.StaticCheckSettings
@@ -225,6 +226,7 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 		parallelTestCfg = &m.cfg.LintersSettings.ParallelTest
 		predeclaredCfg = &m.cfg.LintersSettings.Predeclared
 		promlinterCfg = &m.cfg.LintersSettings.Promlinter
+		reassignCfg = &m.cfg.LintersSettings.Reassign
 		reviveCfg = &m.cfg.LintersSettings.Revive
 		rowserrcheckCfg = &m.cfg.LintersSettings.RowsErrCheck
 		staticcheckCfg = &m.cfg.LintersSettings.Staticcheck
@@ -668,6 +670,11 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 			WithPresets(linter.PresetStyle).
 			WithURL("https://github.com/yeya24/promlinter"),
 
+		linter.NewConfig(golinters.NewReassign(reassignCfg)).
+			WithSince("1.49.0").
+			WithPresets(linter.PresetBugs).
+			WithURL("https://github.com/curioswitch/go-reassign"),
+
 		linter.NewConfig(golinters.NewRevive(reviveCfg)).
 			WithSince("v1.37.0").
 			WithPresets(linter.PresetStyle, linter.PresetMetaLinter).

pkg/lint/lintersdb/manager.go

@@ -0,0 +1,8 @@
+//golangcitest:args -Ereassign
+package testdata
+
+import "io"
+
+func breakIO() {
+	io.EOF = nil // ERROR `reassigning variable EOF in other package io`
+}