diff --git a/.golangci.example.yml b/.golangci.example.yml
index 49e1d9a5..3dba1f05 100644
--- a/.golangci.example.yml
+++ b/.golangci.example.yml
@@ -201,6 +201,9 @@ linters-settings:
- NOTE
- OPTIMIZE # marks code that should be optimized before merging
- HACK # marks hack-arounds that should be removed before merging
+ dogsled:
+ # checks assignments with too many blank identifiers; default is 2
+ max-blank-identifiers: 2
linters:
enable:
diff --git a/.golangci.yml b/.golangci.yml
index 670992d3..f70a1af9 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -49,6 +49,7 @@ linters:
- bodyclose
- deadcode
- depguard
+ # - dogsled - TODO: enable it when golangci.com will support it.
- dupl
- errcheck
# - funlen - TODO: enable it when golangci.com will support it.
diff --git a/README.md b/README.md
index 5e5b7e53..09da2852 100644
--- a/README.md
+++ b/README.md
@@ -195,6 +195,7 @@ $ golangci-lint help linters
Disabled by default linters:
bodyclose: checks whether HTTP response body is closed successfully [fast: false, auto-fix: false]
depguard: Go linter that checks if package imports are in a list of acceptable packages [fast: true, auto-fix: false]
+dogsled: Checks assignments with too many blank identifiers (e.g. x, _, _, _, := f()) [fast: true, auto-fix: false]
dupl: Tool for code clone detection [fast: true, auto-fix: false]
funlen: Tool for detection of long functions [fast: true, auto-fix: false]
gochecknoglobals: Checks that no globals are present in Go code [fast: true, auto-fix: false]
@@ -454,6 +455,7 @@ golangci-lint help linters
- [misspell](https://github.com/client9/misspell) - Finds commonly misspelled English words in comments
- [lll](https://github.com/walle/lll) - Reports long lines
- [unparam](https://github.com/mvdan/unparam) - Reports unused function parameters
+- [dogsled](https://github.com/alexkohler/dogsled) - Checks assignments with too many blank identifiers (e.g. x, _, _, _, := f())
- [nakedret](https://github.com/alexkohler/nakedret) - Finds naked returns in functions greater than a specified function length
- [prealloc](https://github.com/alexkohler/prealloc) - Finds slice declarations that could potentially be preallocated
- [scopelint](https://github.com/kyoh86/scopelint) - Scopelint checks for unpinned variables in go programs
@@ -783,6 +785,9 @@ linters-settings:
- NOTE
- OPTIMIZE # marks code that should be optimized before merging
- HACK # marks hack-arounds that should be removed before merging
+ dogsled:
+ # checks assignments with too many blank identifiers; default is 2
+ max-blank-identifiers: 2
linters:
enable:
@@ -916,6 +921,7 @@ linters:
- bodyclose
- deadcode
- depguard
+ # - dogsled - TODO: enable it when golangci.com will support it.
- dupl
- errcheck
# - funlen - TODO: enable it when golangci.com will support it.
diff --git a/pkg/config/config.go b/pkg/config/config.go
index 4edccfa3..4b7bf7fb 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -178,6 +178,7 @@ type LintersSettings struct {
Errcheck ErrcheckSettings
Gocritic GocriticSettings
Godox GodoxSettings
+ Dogsled DogsledSettings
}
type GovetSettings struct {
@@ -234,6 +235,10 @@ type GodoxSettings struct {
Keywords []string
}
+type DogsledSettings struct {
+ MaxBlankIdentifiers int `mapstructure:"max-blank-identifiers"`
+}
+
var defaultLintersSettings = LintersSettings{
Lll: LllSettings{
LineLength: 120,
@@ -256,6 +261,9 @@ var defaultLintersSettings = LintersSettings{
Godox: GodoxSettings{
Keywords: []string{},
},
+ Dogsled: DogsledSettings{
+ MaxBlankIdentifiers: 2,
+ },
}
type Linters struct {
diff --git a/pkg/golinters/dogsled.go b/pkg/golinters/dogsled.go
new file mode 100644
index 00000000..68237cc0
--- /dev/null
+++ b/pkg/golinters/dogsled.go
@@ -0,0 +1,79 @@
+package golinters
+
+import (
+ "context"
+ "fmt"
+ "go/ast"
+ "go/token"
+
+ "github.com/golangci/golangci-lint/pkg/lint/linter"
+ "github.com/golangci/golangci-lint/pkg/result"
+)
+
+type Dogsled struct{}
+
+func (Dogsled) Name() string {
+ return "dogsled"
+}
+
+func (Dogsled) Desc() string {
+ return "Checks assignments with too many blank identifiers (e.g. x, _, _, _, := f())"
+}
+
+func (d Dogsled) Run(ctx context.Context, lintCtx *linter.Context) ([]result.Issue, error) {
+
+ var res []result.Issue
+ for _, f := range lintCtx.ASTCache.GetAllValidFiles() {
+ v := returnsVisitor{
+ maxBlanks: lintCtx.Settings().Dogsled.MaxBlankIdentifiers,
+ f: f.Fset,
+ }
+ ast.Walk(&v, f.F)
+ res = append(res, v.issues...)
+ }
+
+ return res, nil
+}
+
+type returnsVisitor struct {
+ f *token.FileSet
+ maxBlanks int
+ issues []result.Issue
+}
+
+func (v *returnsVisitor) Visit(node ast.Node) ast.Visitor {
+ funcDecl, ok := node.(*ast.FuncDecl)
+ if !ok {
+ return v
+ }
+ if funcDecl.Body == nil {
+ return v
+ }
+
+ for _, expr := range funcDecl.Body.List {
+ assgnStmt, ok := expr.(*ast.AssignStmt)
+ if !ok {
+ continue
+ }
+
+ numBlank := 0
+ for _, left := range assgnStmt.Lhs {
+ ident, ok := left.(*ast.Ident)
+ if !ok {
+ continue
+ }
+ if ident.Name == "_" {
+ numBlank++
+ }
+ }
+
+ if numBlank > v.maxBlanks {
+ v.issues = append(v.issues, result.Issue{
+ FromLinter: Dogsled{}.Name(),
+ Text: fmt.Sprintf("declaration has %v blank identifiers", numBlank),
+ Pos: v.f.Position(assgnStmt.Pos()),
+ })
+ }
+ }
+ return v
+}
diff --git a/pkg/lint/lintersdb/manager.go b/pkg/lint/lintersdb/manager.go
index 5a2a5788..27862a7b 100644
--- a/pkg/lint/lintersdb/manager.go
+++ b/pkg/lint/lintersdb/manager.go
@@ -215,6 +215,10 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
WithLoadDepsTypeInfo().
WithSSA().
WithURL("https://github.com/mvdan/unparam"),
+ linter.NewConfig(golinters.Dogsled{}).
+ WithPresets(linter.PresetStyle).
+ WithSpeed(10).
+ WithURL("https://github.com/alexkohler/dogsled"),
linter.NewConfig(golinters.Nakedret{}).
WithPresets(linter.PresetComplexity).
WithSpeed(10).
diff --git a/test/testdata/dogsled.go b/test/testdata/dogsled.go
new file mode 100644
index 00000000..8604a2d7
--- /dev/null
+++ b/test/testdata/dogsled.go
@@ -0,0 +1,25 @@
+//args: -Edogsled
+package testdata
+
+func Dogsled() {
+ _ = ret1()
+ _, _ = ret2()
+ _, _, _ = ret3() // ERROR "declaration has 3 blank identifiers"
+ _, _, _, _ = ret4() // ERROR "declaration has 4 blank identifiers"
+}
+
+func ret1() (a int) {
+ return 1
+}
+
+func ret2() (a, b int) {
+ return 1, 2
+}
+
+func ret3() (a, b, c int) {
+ return 1, 2, 3
+}
+
+func ret4() (a, b, c, d int) {
+ return 1, 2, 3, 4
+}
diff --git a/third_party/dogsled/LICENSE b/third_party/dogsled/LICENSE
new file mode 100644
index 00000000..bc3ffbd4
--- /dev/null
+++ b/third_party/dogsled/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Alex Kohler
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.