Add funcorder linter (#5630)

Author: manuelarte

.golangci.next.reference.yml

@@ -43,6 +43,7 @@ linters:
     - fatcontext
     - forbidigo
     - forcetypeassert
+    - funcorder
     - funlen
     - ginkgolinter
     - gocheckcompilerdirectives
@@ -150,6 +151,7 @@ linters:
     - fatcontext
     - forbidigo
     - forcetypeassert
+    - funcorder
     - funlen
     - ginkgolinter
     - gocheckcompilerdirectives
@@ -530,6 +532,14 @@ linters:
       # Default: false
       analyze-types: true
 
+    funcorder:
+      # Checks that constructors are placed after the structure declaration.
+      # Default: true
+      constructor: false
+      # Checks if the exported methods of a structure are placed before the non-exported ones.
+      # Default: true
+      struct-method: false
+
     funlen:
       # Checks the number of lines in a function.
       # If lower than 0, disable the check.

go.mod

@@ -74,6 +74,7 @@ require (
 	github.com/ldez/usetesting v0.4.2
 	github.com/leonklingele/grouper v1.1.2
 	github.com/macabu/inamedparam v0.2.0
+	github.com/manuelarte/funcorder v0.2.1
 	github.com/maratori/testableexamples v1.0.0
 	github.com/maratori/testpackage v1.1.1
 	github.com/matoous/godox v1.1.0

go.sum

@@ -741,6 +741,7 @@
             "fatcontext",
             "forbidigo",
             "forcetypeassert",
+            "funcorder",
             "funlen",
             "ginkgolinter",
             "gocheckcompilerdirectives",
@@ -1302,6 +1303,22 @@
             }
           }
         },
+        "funcorderSettings": {
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "constructor": {
+              "description": "Checks that constructors are placed after the structure declaration.",
+              "type": "boolean",
+              "default": true
+            },
+            "struct-method": {
+              "description": "Checks if the exported methods of a structure are placed before the non-exported ones.",
+              "type": "boolean",
+              "default": true
+            }
+          }
+        },
         "funlenSettings": {
           "type": "object",
           "additionalProperties": false,
@@ -4345,6 +4362,9 @@
             "forbidigo": {
               "$ref": "#/definitions/settings/definitions/forbidigoSettings"
             },
+            "funcorder": {
+              "$ref": "#/definitions/settings/definitions/funcorderSettings"
+            },
             "funlen": {
               "$ref": "#/definitions/settings/definitions/funlenSettings"
             },

jsonschema/golangci.next.jsonschema.json

@@ -41,6 +41,10 @@ var defaultLintersSettings = LintersSettings{
 	Forbidigo: ForbidigoSettings{
 		ExcludeGodocExamples: true,
 	},
+	FuncOrder: FuncOrderSettings{
+		Constructor:  true,
+		StructMethod: true,
+	},
 	Funlen: FunlenSettings{
 		IgnoreComments: true,
 	},
@@ -217,6 +221,7 @@ type LintersSettings struct {
 	Exhaustruct     ExhaustructSettings     `mapstructure:"exhaustruct"`
 	Fatcontext      FatcontextSettings      `mapstructure:"fatcontext"`
 	Forbidigo       ForbidigoSettings       `mapstructure:"forbidigo"`
+	FuncOrder       FuncOrderSettings       `mapstructure:"funcorder"`
 	Funlen          FunlenSettings          `mapstructure:"funlen"`
 	GinkgoLinter    GinkgoLinterSettings    `mapstructure:"ginkgolinter"`
 	Gocognit        GocognitSettings        `mapstructure:"gocognit"`
@@ -420,6 +425,11 @@ type ForbidigoPattern struct {
 	Msg     string `yaml:"msg,omitempty" mapstructure:"msg,omitempty"`
 }
 
+type FuncOrderSettings struct {
+	Constructor  bool `mapstructure:"constructor,omitempty"`
+	StructMethod bool `mapstructure:"struct-method,omitempty"`
+}
+
 type FunlenSettings struct {
 	Lines          int  `mapstructure:"lines"`
 	Statements     int  `mapstructure:"statements"`

pkg/config/linters_settings.go

@@ -0,0 +1,29 @@
+package funcorder
+
+import (
+	"github.com/manuelarte/funcorder/analyzer"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/v2/pkg/config"
+	"github.com/golangci/golangci-lint/v2/pkg/goanalysis"
+)
+
+func New(settings *config.FuncOrderSettings) *goanalysis.Linter {
+	a := analyzer.NewAnalyzer()
+
+	cfg := map[string]map[string]any{}
+
+	if settings != nil {
+		cfg[a.Name] = map[string]any{
+			analyzer.ConstructorCheckName:  settings.Constructor,
+			analyzer.StructMethodCheckName: settings.StructMethod,
+		}
+	}
+
+	return goanalysis.NewLinter(
+		a.Name,
+		a.Doc,
+		[]*analysis.Analyzer{a},
+		cfg,
+	).WithLoadMode(goanalysis.LoadModeSyntax)
+}

pkg/golinters/funcorder/funcorder.go

@@ -0,0 +1,11 @@
+package funcorder
+
+import (
+	"testing"
+
+	"github.com/golangci/golangci-lint/v2/test/testshared/integration"
+)
+
+func TestFromTestdata(t *testing.T) {
+	integration.RunTestdata(t)
+}

pkg/golinters/funcorder/funcorder_integration_test.go

@@ -0,0 +1,40 @@
+//golangcitest:args -Efuncorder
+package testdata
+
+import "time"
+
+type MyStruct struct {
+	Name string
+}
+
+func (m MyStruct) lenName() int { // want `unexported method "lenName" for struct "MyStruct" should be placed after the exported method "SetName"`
+	return len(m.Name)
+}
+
+func (m MyStruct) GetName() string {
+	return m.Name
+}
+
+func (m *MyStruct) SetName(name string) {
+	m.Name = name
+}
+
+type MyStruct2 struct {
+	Name string
+}
+
+func (m MyStruct2) GetName() string {
+	return m.Name
+}
+
+func (m *MyStruct2) SetName(name string) {
+	m.Name = name
+}
+
+func NewMyStruct2() *MyStruct2 { // want `constructor "NewMyStruct2" for struct "MyStruct2" should be placed before struct method "GetName"`
+	return &MyStruct2{Name: "John"}
+}
+
+func NewTime() time.Time {
+	return time.Now()
+}

pkg/golinters/funcorder/testdata/funcorder.go

@@ -0,0 +1,41 @@
+//golangcitest:args -Efuncorder
+//golangcitest:config_path testdata/funcorder_disable_constructor.yml
+package testdata
+
+import "time"
+
+type MyStruct struct {
+	Name string
+}
+
+func (m MyStruct) lenName() int { // want `unexported method "lenName" for struct "MyStruct" should be placed after the exported method "SetName"`
+	return len(m.Name)
+}
+
+func (m MyStruct) GetName() string {
+	return m.Name
+}
+
+func (m *MyStruct) SetName(name string) {
+	m.Name = name
+}
+
+type MyStruct2 struct {
+	Name string
+}
+
+func (m MyStruct2) GetName() string {
+	return m.Name
+}
+
+func (m *MyStruct2) SetName(name string) {
+	m.Name = name
+}
+
+func NewMyStruct2() *MyStruct2 {
+	return &MyStruct2{Name: "John"}
+}
+
+func NewTime() time.Time {
+	return time.Now()
+}

pkg/golinters/funcorder/testdata/funcorder_disable_constructor.go

@@ -0,0 +1,6 @@
+version: "2"
+
+linters:
+  settings:
+    funcorder:
+      constructor: false