Merge remote-tracking branch 'upstream/master'

README.md

@@ -26,11 +26,15 @@ Here's how `revive` is different from `golint`:
 ## Who uses Revive
 
 - [`tidb`](https://github.com/pingcap/tidb) - TiDB is a distributed HTAP database compatible with the MySQL protocol
+- [`grafana`](https://github.com/grafana/grafana) - The tool for beautiful monitoring and metric analytics & dashboards for Graphite, InfluxDB & Prometheus & More
+- [`etcd`](https://github.com/etcd-io/etcd) - Distributed reliable key-value store for the most critical data of a distributed system
 - [`ferret`](https://github.com/MontFerret/ferret) - Declarative web scraping
 - [`gopass`](https://github.com/gopasspw/gopass) - The slightly more awesome standard unix password manager for teams
 - [`gitea`](https://github.com/go-gitea/gitea) - Git with a cup of tea, painless self-hosted git service
 - [`excelize`](https://github.com/360EntSecGroup-Skylar/excelize) - Go library for reading and writing Microsoft Excel™ (XLSX) files
 - [`aurora`](https://github.com/xuri/aurora) - aurora is a web-based Beanstalk queue server console written in Go
+- [`soar`](https://github.com/XiaoMi/soar) - SQL Optimizer And Rewriter
+- [`gorush`](https://github.com/appleboy/gorush) - A push notification server written in Go (Golang)
 
 *Open a PR to add your project*.
 
@@ -294,6 +298,8 @@ List of all available rules. The rules ported from `golint` are left unchanged a
 | [`call-to-gc`](./RULES_DESCRIPTIONS.md#call-to-gc)   | n/a    | Warns on explicit call to the garbage collector    |    no    |  no   |
 | [`duplicated-imports`](./RULES_DESCRIPTIONS#duplicated-imports) | n/a  | Looks for packages that are imported two or more times   |    no    |  no   |
 | [`import-shadowing`](./RULES_DESCRIPTIONS.md#import-shadowing)   | n/a    | Spots identifiers that shadow an import    |    no    |  no   |
+| [`bare-return`](./RULES_DESCRIPTIONS#bare-return) | n/a  | Warns on bare returns   |    no    |  no   |
+| [`unused-receiver`](./RULES_DESCRIPTIONS.md#unused-receiver)   | n/a    | Suggests to rename or remove unused method receivers    |    no    |  no   |
 
 ## Configurable rules
 
@@ -434,13 +440,13 @@ Currently, type checking is enabled by default. If you want to run the linter wi
 :---: |:---: |:---: |:---: |:---: |:---: |
 [mgechev](https://github.com/mgechev) |[chavacava](https://github.com/chavacava) |[xuri](https://github.com/xuri) |[gsamokovarov](https://github.com/gsamokovarov) |[morphy2k](https://github.com/morphy2k) |[tamird](https://github.com/tamird) |
 
-[<img alt="AragurDEV" src="https://avatars0.githubusercontent.com/u/11004008?v=4&s=117" width="117">](https://github.com/AragurDEV) |[<img alt="yangdiangzb" src="https://avatars3.githubusercontent.com/u/16643665?v=4&s=117" width="117">](https://github.com/yangdiangzb) |[<img alt="jamesmaidment" src="https://avatars3.githubusercontent.com/u/2050324?v=4&s=117" width="117">](https://github.com/jamesmaidment) |[<img alt="mapreal19" src="https://avatars2.githubusercontent.com/u/3055997?v=4&s=117" width="117">](https://github.com/mapreal19) |[<img alt="paul-at-start" src="https://avatars2.githubusercontent.com/u/5486775?v=4&s=117" width="117">](https://github.com/paul-at-start) |[<img alt="psapezhko" src="https://avatars3.githubusercontent.com/u/10865586?v=4&s=117" width="117">](https://github.com/psapezhko) |
+[<img alt="AragurDEV" src="https://avatars0.githubusercontent.com/u/11004008?v=4&s=117" width="117">](https://github.com/AragurDEV) |[<img alt="yangdiangzb" src="https://avatars3.githubusercontent.com/u/16643665?v=4&s=117" width="117">](https://github.com/yangdiangzb) |[<img alt="jamesmaidment" src="https://avatars3.githubusercontent.com/u/2050324?v=4&s=117" width="117">](https://github.com/jamesmaidment) |[<img alt="mapreal19" src="https://avatars2.githubusercontent.com/u/3055997?v=4&s=117" width="117">](https://github.com/mapreal19) |[<img alt="markelog" src="https://avatars0.githubusercontent.com/u/945528?v=4&s=117" width="117">](https://github.com/markelog) |[<img alt="paul-at-start" src="https://avatars2.githubusercontent.com/u/5486775?v=4&s=117" width="117">](https://github.com/paul-at-start) |
 :---: |:---: |:---: |:---: |:---: |:---: |
-[AragurDEV](https://github.com/AragurDEV) |[yangdiangzb](https://github.com/yangdiangzb) |[jamesmaidment](https://github.com/jamesmaidment) |[mapreal19](https://github.com/mapreal19) |[paul-at-start](https://github.com/paul-at-start) |[psapezhko](https://github.com/psapezhko) |
+[AragurDEV](https://github.com/AragurDEV) |[yangdiangzb](https://github.com/yangdiangzb) |[jamesmaidment](https://github.com/jamesmaidment) |[mapreal19](https://github.com/mapreal19) |[markelog](https://github.com/markelog) |[paul-at-start](https://github.com/paul-at-start) |
 
-[<img alt="ridvansumset" src="https://avatars2.githubusercontent.com/u/26631560?v=4&s=117" width="117">](https://github.com/ridvansumset) |[<img alt="Jarema" src="https://avatars0.githubusercontent.com/u/7369771?v=4&s=117" width="117">](https://github.com/Jarema) |[<img alt="vkrol" src="https://avatars3.githubusercontent.com/u/153412?v=4&s=117" width="117">](https://github.com/vkrol) |[<img alt="haya14busa" src="https://avatars0.githubusercontent.com/u/3797062?v=4&s=117" width="117">](https://github.com/haya14busa) |
-:---: |:---: |:---: |:---: |
-[ridvansumset](https://github.com/ridvansumset) |[Jarema](https://github.com/Jarema) |[vkrol](https://github.com/vkrol) |[haya14busa](https://github.com/haya14busa) |
+[<img alt="psapezhko" src="https://avatars3.githubusercontent.com/u/10865586?v=4&s=117" width="117">](https://github.com/psapezhko) |[<img alt="ridvansumset" src="https://avatars2.githubusercontent.com/u/26631560?v=4&s=117" width="117">](https://github.com/ridvansumset) |[<img alt="Jarema" src="https://avatars0.githubusercontent.com/u/7369771?v=4&s=117" width="117">](https://github.com/Jarema) |[<img alt="vkrol" src="https://avatars3.githubusercontent.com/u/153412?v=4&s=117" width="117">](https://github.com/vkrol) |[<img alt="haya14busa" src="https://avatars0.githubusercontent.com/u/3797062?v=4&s=117" width="117">](https://github.com/haya14busa) |
+:---: |:---: |:---: |:---: |:---: |
+[psapezhko](https://github.com/psapezhko) |[ridvansumset](https://github.com/ridvansumset) |[Jarema](https://github.com/Jarema) |[vkrol](https://github.com/vkrol) |[haya14busa](https://github.com/haya14busa) |
 
 ## License
 

RULES_DESCRIPTIONS.md

@@ -7,6 +7,7 @@ List of all available rules.
   - [add-constant](#add-constant)
   - [argument-limit](#argument-limit)
   - [atomic](#atomic)
+  - [bare-return](#bare-return)
   - [blank-imports](#blank-imports)
   - [bool-literal-in-expr](#bool-literal-in-expr)
   - [call-to-gc](#call-to-gc)
@@ -53,6 +54,7 @@ List of all available rules.
   - [unnecessary-stmt](#unnecessary-stmt)
   - [unreachable-code](#unreachable-code)
   - [unused-parameter](#unused-parameter)
+  - [unused-receiver](#unused-receiver)
   - [waitgroup-by-value](#waitgroup-by-value)
 
 ## add-constant
@@ -93,6 +95,12 @@ _Description_: Check for commonly mistaken usages of the `sync/atomic` package
 
 _Configuration_: N/A
 
+## bare-return
+
+_Description_: Warns on bare (a.k.a. naked) returns
+
+_Configuration_: N/A
+
 ## blank-imports
 
 _Description_: Blank import should be only in a main or test package, or have a comment justifying it.
@@ -444,6 +452,12 @@ _Description_: This rule warns on unused parameters. Functions or methods with u
 
 _Configuration_: N/A
 
+## unused-receiver
+
+_Description_: This rule warns on unused method receivers. Methods with unused receivers can be a symptom of an unfinished refactoring or a bug.
+
+_Configuration_: N/A
+
 ## waitgroup-by-value
 
 _Description_: Function parameters that are passed by value, are in fact a copy of the original argument. Passing a copy of a `sync.WaitGroup` is usually not what the developer wants to do.

config.go

@@ -75,6 +75,8 @@ var allRules = append([]lint.Rule{
 	&rule.CallToGCRule{},
 	&rule.DuplicatedImportsRule{},
 	&rule.ImportShadowingRule{},
+	&rule.BareReturnRule{},
+	&rule.UnusedReceiverRule{},
 }, defaultRules...)
 
 var allFormatters = []lint.Formatter{

fixtures/bare-return.go

@@ -0,0 +1,33 @@
+package fixtures
+
+func bare1() (int, int, error) {
+	go func() (a int) {
+		return // MATCH /avoid using bare returns, please add return expressions/
+	}(5)
+}
+
+func bare2(a, b int) (int, error, int) {
+	defer func() (a int) {
+		return // MATCH /avoid using bare returns, please add return expressions/
+	}(5)
+}
+
+func bare3(a string, b int) (a int, b float32, c string, d string) {
+	go func() (a int, b int) {
+		return a, b
+	}(5, 6)
+
+	defer func() (a int) {
+		return a
+	}(5)
+
+	return // MATCH /avoid using bare returns, please add return expressions/
+}
+
+func bare4(a string, b int) string {
+	return a
+}
+
+func bare5(a string, b int) {
+	return
+}

fixtures/unused-receiver.go

@@ -0,0 +1,43 @@
+package fixtures
+
+import (
+	"fmt"
+
+	"github.com/mgechev/revive/lint"
+)
+
+func (f *Unix) Name() string { // MATCH /method receiver 'f' is not referenced in method's body, consider removing or renaming it as _/
+	return "unix"
+}
+
+func (f *Unix) Format(failures <-chan lint.Failure, _ lint.RulesConfig) (string, error) { // MATCH /method receiver 'f' is not referenced in method's body, consider removing or renaming it as _/
+	for failure := range failures {
+		fmt.Printf("%v: [%s] %s\n", failure.Position.Start, failure.RuleName, failure.Failure)
+	}
+	return "", nil
+}
+
+func (u *Unix) Foo() (string, error) { // MATCH /method receiver 'u' is not referenced in method's body, consider removing or renaming it as _/
+	for failure := range failures {
+		u := 1 // shadowing the receiver
+		fmt.Printf("%v\n", u)
+	}
+	return "", nil
+}
+
+func (u *Unix) Foos() (string, error) {
+	for failure := range failures {
+		u := 1 // shadowing the receiver
+		fmt.Printf("%v\n", u)
+	}
+
+	return u, nil // use of the receiver
+}
+
+func (u *Unix) Bar() (string, error) {
+	for failure := range failures {
+		u.path = nil // modifies the receiver
+		fmt.Printf("%v\n", u)
+	}
+	return "", nil
+}

rule/bare-return.go

@@ -0,0 +1,77 @@
+package rule
+
+import (
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// BareReturnRule lints given else constructs.
+type BareReturnRule struct{}
+
+// Apply applies the rule to given file.
+func (r *BareReturnRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	w := lintBareReturnRule{onFailure: onFailure}
+	ast.Walk(w, file.AST)
+	return failures
+}
+
+// Name returns the rule name.
+func (r *BareReturnRule) Name() string {
+	return "bare-return"
+}
+
+type lintBareReturnRule struct {
+	onFailure func(lint.Failure)
+}
+
+func (w lintBareReturnRule) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		w.checkFunc(n.Type.Results, n.Body)
+	case *ast.FuncLit: // to cope with deferred functions and go-routines
+		w.checkFunc(n.Type.Results, n.Body)
+	}
+
+	return w
+}
+
+// checkFunc will verify if the given function has named result and bare returns
+func (w lintBareReturnRule) checkFunc(results *ast.FieldList, body *ast.BlockStmt) {
+	hasNamedResults := results != nil && len(results.List) > 0 && results.List[0].Names != nil
+	if !hasNamedResults || body == nil {
+		return // nothing to do
+	}
+
+	brf := bareReturnFinder{w.onFailure}
+	ast.Walk(brf, body)
+}
+
+type bareReturnFinder struct {
+	onFailure func(lint.Failure)
+}
+
+func (w bareReturnFinder) Visit(node ast.Node) ast.Visitor {
+	rs, ok := node.(*ast.ReturnStmt)
+	if !ok {
+		return w
+	}
+
+	if len(rs.Results) > 0 {
+		return w
+	}
+
+	w.onFailure(lint.Failure{
+		Confidence: 1,
+		Node:       rs,
+		Failure:    "avoid using bare returns, please add return expressions",
+	})
+
+	return w
+}

rule/unused-receiver.go

@@ -0,0 +1,77 @@
+package rule
+
+import (
+	"fmt"
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// UnusedReceiverRule lints unused params in functions.
+type UnusedReceiverRule struct{}
+
+// Apply applies the rule to given file.
+func (_ *UnusedReceiverRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	w := lintUnusedReceiverRule{onFailure: onFailure}
+
+	ast.Walk(w, file.AST)
+
+	return failures
+}
+
+// Name returns the rule name.
+func (_ *UnusedReceiverRule) Name() string {
+	return "unused-receiver"
+}
+
+type lintUnusedReceiverRule struct {
+	onFailure func(lint.Failure)
+}
+
+func (w lintUnusedReceiverRule) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		if n.Recv == nil {
+			return nil // skip this func decl, not a method
+		}
+
+		rec := n.Recv.List[0] // safe to access only the first (unique) element of the list
+		if len(rec.Names) < 1 {
+			return nil // the receiver is anonymous: func (aType) Foo(...) ...
+		}
+
+		recID := rec.Names[0]
+		if recID.Name == "_" {
+			return nil // the receiver is already named _
+		}
+
+		// inspect the func body looking for references to the receiver id
+		fselect := func(n ast.Node) bool {
+			ident, isAnID := n.(*ast.Ident)
+
+			return isAnID && ident.Obj == recID.Obj
+		}
+		refs2recID := pick(n.Body, fselect, nil)
+
+		if len(refs2recID) > 0 {
+			return nil // the receiver is referenced in the func body
+		}
+
+		w.onFailure(lint.Failure{
+			Confidence: 1,
+			Node:       recID,
+			Category:   "bad practice",
+			Failure:    fmt.Sprintf("method receiver '%s' is not referenced in method's body, consider removing or renaming it as _", recID.Name),
+		})
+
+		return nil // full method body already inspected
+	}
+
+	return w
+}

test/bare-return_test.go

@@ -0,0 +1,11 @@
+package test
+
+import (
+	"testing"
+
+	"github.com/mgechev/revive/rule"
+)
+
+func TestBareReturn(t *testing.T) {
+	testRule(t, "bare-return", &rule.BareReturnRule{})
+}

test/unused-receiver_test.go

@@ -0,0 +1,11 @@
+package test
+
+import (
+	"testing"
+
+	"github.com/mgechev/revive/rule"
+)
+
+func TestUnusedReceiver(t *testing.T) {
+	testRule(t, "unused-receiver", &rule.UnusedReceiverRule{})
+}