feat: add errchkjson linter

.golangci.example.yml

@@ -103,6 +103,13 @@ linters-settings:
     # should ignore tests (default false)
     skip-tests: false
 
+  errchkjson:
+    # with omit-safe set to true, errchkjson does not warn about errors from json encoding functions that are safe
+    # to be ignored, because they are not possible to happen (default false)
+    omit-safe: false
+    # if report-no-exported is true, encoding a struct without exported fields is reported as issue (default false)
+    report-no-exported: false
+
   dogsled:
     # checks assignments with too many blank identifiers; default is 2
     max-blank-identifiers: 2

go.mod

@@ -16,6 +16,7 @@ require (
 	github.com/blizzy78/varnamelen v0.4.0
 	github.com/bombsimon/wsl/v3 v3.3.0
 	github.com/breml/bidichk v0.2.1
+	github.com/breml/errchkjson v0.2.0
 	github.com/butuzov/ireturn v0.1.1
 	github.com/charithe/durationcheck v0.0.9
 	github.com/daixiang0/gci v0.2.9

pkg/config/linters_settings.go

@@ -89,6 +89,7 @@ type LintersSettings struct {
 	Dogsled          DogsledSettings
 	Dupl             DuplSettings
 	Errcheck         ErrcheckSettings
+	ErrChkJSON       ErrChkJSONSettings
 	ErrorLint        ErrorLintSettings
 	Exhaustive       ExhaustiveSettings
 	ExhaustiveStruct ExhaustiveStructSettings
@@ -165,6 +166,11 @@ type Cyclop struct {
 	SkipTests      bool    `mapstructure:"skip-tests"`
 }
 
+type ErrChkJSONSettings struct {
+	OmitSafe         bool `mapstructure:"omit-safe"`
+	ReportNoExported bool `mapstructure:"report-no-exported"`
+}
+
 type DepGuardSettings struct {
 	ListType                 string `mapstructure:"list-type"`
 	Packages                 []string

pkg/golinters/errchkjson.go

@@ -0,0 +1,80 @@
+package golinters
+
+import (
+	"github.com/breml/errchkjson"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/config"
+	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
+	"github.com/golangci/golangci-lint/pkg/lint/linter"
+)
+
+func NewErrChkJSONFuncName(linters *config.Linters,
+	cfg *config.ErrChkJSONSettings,
+	errcheckCfg *config.ErrcheckSettings,
+) *goanalysis.Linter {
+	a := errchkjson.NewAnalyzer()
+
+	var omitSafe bool
+	var reportNoExported bool
+	if cfg != nil {
+		omitSafe = cfg.OmitSafe
+		reportNoExported = cfg.ReportNoExported
+	}
+
+	// Modify errcheck config if this linter is enabled and OmitSafe is false
+	if isEnabled(linters, a.Name) && !omitSafe {
+		if errcheckCfg == nil {
+			errcheckCfg = &config.ErrcheckSettings{}
+		}
+		errcheckCfg.ExcludeFunctions = append(errcheckCfg.ExcludeFunctions,
+			"encoding/json.Marshal",
+			"encoding/json.MarshalIndent",
+			"(*encoding/json.Encoder).Encode",
+		)
+	}
+
+	cfgMap := map[string]map[string]interface{}{}
+	cfgMap[a.Name] = map[string]interface{}{
+		"omit-safe":          omitSafe,
+		"report-no-exported": reportNoExported,
+	}
+
+	return goanalysis.NewLinter(
+		"errchkjson",
+		"Checks types passed to the json encoding functions. "+
+			"Reports unsupported types and reports occations, where the check for the returned error can be omitted.",
+		[]*analysis.Analyzer{a},
+		cfgMap,
+	).WithLoadMode(goanalysis.LoadModeTypesInfo)
+}
+
+func isEnabled(linters *config.Linters, linterName string) bool {
+	if linters != nil {
+		var enabled bool
+		for _, linter := range linters.Enable {
+			if linter == linterName {
+				enabled = true
+				break
+			}
+		}
+		var disabled bool
+		for _, linter := range linters.Disable {
+			if linter == linterName {
+				disabled = true
+				break
+			}
+		}
+		var presetEnabled bool
+		for _, preset := range linters.Presets {
+			if preset == linter.PresetBugs || preset == linter.PresetUnused {
+				presetEnabled = true
+				break
+			}
+		}
+		return enabled ||
+			linters.EnableAll && !disabled ||
+			presetEnabled && !disabled
+	}
+	return false
+}

pkg/lint/lintersdb/manager.go

@@ -100,8 +100,12 @@ func enableLinterConfigs(lcs []*linter.Config, isEnabled func(lc *linter.Config)
 
 //nolint:funlen
 func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
+	var linters *config.Linters
+
 	var bidichkCfg *config.BiDiChkSettings
 	var cyclopCfg *config.Cyclop
+	var errcheckCfg *config.ErrcheckSettings
+	var errchkjsonCfg *config.ErrChkJSONSettings
 	var errorlintCfg *config.ErrorLintSettings
 	var exhaustiveCfg *config.ExhaustiveSettings
 	var exhaustiveStructCfg *config.ExhaustiveStructSettings
@@ -127,8 +131,11 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 	var nlreturnCfg *config.NlreturnSettings
 
 	if m.cfg != nil {
+		linters = &m.cfg.Linters
 		bidichkCfg = &m.cfg.LintersSettings.BiDiChk
 		cyclopCfg = &m.cfg.LintersSettings.Cyclop
+		errcheckCfg = &m.cfg.LintersSettings.Errcheck
+		errchkjsonCfg = &m.cfg.LintersSettings.ErrChkJSON
 		errorlintCfg = &m.cfg.LintersSettings.ErrorLint
 		exhaustiveCfg = &m.cfg.LintersSettings.Exhaustive
 		exhaustiveStructCfg = &m.cfg.LintersSettings.ExhaustiveStruct
@@ -173,6 +180,11 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 			WithLoadForGoAnalysis().
 			WithPresets(linter.PresetPerformance, linter.PresetBugs).
 			WithURL("https://github.com/sonatard/noctx"),
+		linter.NewConfig(golinters.NewErrChkJSONFuncName(linters, errchkjsonCfg, errcheckCfg)).
+			WithSince("1.44.0").
+			WithPresets(linter.PresetBugs, linter.PresetUnused).
+			WithLoadForGoAnalysis().
+			WithURL("https://github.com/breml/errchkjson"),
 		linter.NewConfig(golinters.NewErrcheck()).
 			WithSince("v1.0.0").
 			WithLoadForGoAnalysis().

test/testdata/configs/errchkjson.yml

@@ -0,0 +1,2 @@
+issues:
+  max-issues-per-linter: 100

test/testdata/configs/errchkjson_no_exported.yml

@@ -0,0 +1,3 @@
+linters-settings:
+  errchkjson:
+    report-no-exported: true

test/testdata/configs/errchkjson_omit_safe.yml

@@ -0,0 +1,5 @@
+issues:
+  max-issues-per-linter: 100
+linters-settings:
+  errchkjson:
+    omit-safe: true