Export Analyzer interface

.circleci/config.yml

@@ -3,10 +3,10 @@ version: 2
 jobs:
   build:
     docker:
-      - image: circleci/golang:1.12
+      - image: cimg/go:1.17.7
     steps:
       - checkout
-      - run: sudo apt-get -y -qq install python python-pip
+      - run: sudo apt-get update && sudo apt-get -y -qq install python pip
       - run: pip install pre-commit
       - run: SKIP=no-commit-to-branch pre-commit run -a
       - run: go test ./...

.golangci.yml

@@ -1,2 +1 @@
-linters:
-  enable-all: true
+linters: {}

.pre-commit-config.yaml

@@ -1,5 +1,9 @@
 repos:
   - repo: https://github.com/golangci/golangci-lint
-    rev: v1.17.1
+    rev: v1.44.2
     hooks:
       - id: golangci-lint
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.1.0
+    hooks:
+      - id: trailing-whitespace

README.md

@@ -1,5 +1,7 @@
 # makezero
 
+[![CircleCI](https://circleci.com/gh/ashanbrown/makezero/tree/master.svg?style=svg)](https://circleci.com/gh/ashanbrown/makezero/tree/master)
+
 makezero is a Go static analysis tool to find slice declarations that are not initialized with zero length and are later
 used with append.
 

go.mod

@@ -4,5 +4,5 @@ go 1.12
 
 require (
 	github.com/stretchr/testify v1.4.0
-	golang.org/x/tools v0.0.0-20190916130336-e45ffcd953cc
+	golang.org/x/tools v0.1.9
 )

go.sum

@@ -2,24 +2,37 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90PveolxSbWFaJdECFbxSq0Mqo2M=
+github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/net v0.0.0-20190620200207-3b0461eec859 h1:R/3boaszxrf1GEUWTVDzSKVwLmSJpwZ1yqXm8j0v2QI=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.5.1 h1:OJxoQ/rynoF0dcCdI7cLPktw/hR2cueqYfjm43oqK38=
+golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58 h1:8gQV6CLnAEikrhgkHFbMAEhagSSnXWGV915qUMm9mrU=
+golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a h1:1BGLXjeY4akVXGgbC9HugT3Jv3hCI0z56oJR5vAMgBU=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654 h1:id054HUawV2/6IGm2IV8KZQjqtwAOo2CYlOToYqa0d0=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/tools v0.0.0-20190916130336-e45ffcd953cc h1:+GB9/q0gCzmtaIl6WdoJFMS3lPwrR6rpcMyY6jfQHAw=
-golang.org/x/tools v0.0.0-20190916130336-e45ffcd953cc/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7 h1:9zdDQZ7Thm29KFXgAX/+yaf3eVbP7djjWp/dXAppNCc=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.9 h1:j9KsMiaP1c3B0OTQGth0/k+miLGTgLsAFUCrF2vLcF8=
+golang.org/x/tools v0.1.9/go.mod h1:nABZi5QlRsZVlzPpHl034qft6wpY4eDcsTt5AaioBiU=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=

main.go

@@ -29,7 +29,7 @@ func main() {
 	}
 	linter := makezero.NewLinter(*always)
 
-	var issues []makezero.Issue // nolint:prealloc // don't know how many there will be
+	var issues []makezero.Issue
 	for _, p := range pkgs {
 		nodes := make([]ast.Node, 0, len(p.Syntax))
 		for _, n := range p.Syntax {

makezero/makezero.go

@@ -1,4 +1,4 @@
-// makezero provides a linter for appends to slices initialized with non-zero length.
+// Package makezero provides a linter for appends to slices initialized with non-zero length.
 package makezero
 
 import (
@@ -13,27 +13,33 @@ import (
 )
 
 // a decl might include multiple var,
-// so var name with decl make final uniq obj
+// so var name with decl make final uniq obj.
 type uniqDecl struct {
 	varName string
 	decl    interface{}
 }
 
 type Issue interface {
 	Details() string
+	Pos() token.Pos
 	Position() token.Position
 	String() string
 }
 
 type AppendIssue struct {
 	name     string
+	pos      token.Pos
 	position token.Position
 }
 
 func (a AppendIssue) Details() string {
 	return fmt.Sprintf("append to slice `%s` with non-zero initialized length", a.name)
 }
 
+func (a AppendIssue) Pos() token.Pos {
+	return a.pos
+}
+
 func (a AppendIssue) Position() token.Position {
 	return a.position
 }
@@ -42,13 +48,18 @@ func (a AppendIssue) String() string { return toString(a) }
 
 type MustHaveNonZeroInitLenIssue struct {
 	name     string
+	pos      token.Pos
 	position token.Position
 }
 
 func (i MustHaveNonZeroInitLenIssue) Details() string {
 	return fmt.Sprintf("slice `%s` does not have non-zero initial length", i.name)
 }
 
+func (i MustHaveNonZeroInitLenIssue) Pos() token.Pos {
+	return i.pos
+}
+
 func (i MustHaveNonZeroInitLenIssue) Position() token.Position {
 	return i.position
 }
@@ -81,7 +92,7 @@ func NewLinter(initialLengthMustBeZero bool) *Linter {
 }
 
 func (l Linter) Run(fset *token.FileSet, info *types.Info, nodes ...ast.Node) ([]Issue, error) {
-	var issues []Issue // nolint:prealloc // don't know how many there will be
+	var issues []Issue
 	for _, node := range nodes {
 		var comments []*ast.CommentGroup
 		if file, ok := node.(*ast.File); ok {
@@ -110,7 +121,12 @@ func (v *visitor) Visit(node ast.Node) ast.Visitor {
 		if sliceIdent, ok := node.Args[0].(*ast.Ident); ok &&
 			v.hasNonZeroInitialLength(sliceIdent) &&
 			!v.hasNoLintOnSameLine(fun) {
-			v.issues = append(v.issues, AppendIssue{name: sliceIdent.Name, position: v.fset.Position(fun.Pos())})
+			v.issues = append(v.issues,
+				AppendIssue{
+					name:     sliceIdent.Name,
+					pos:      fun.Pos(),
+					position: v.fset.Position(fun.Pos()),
+				})
 		}
 	case *ast.AssignStmt:
 		for i, right := range node.Rhs {
@@ -130,6 +146,7 @@ func (v *visitor) Visit(node ast.Node) ast.Visitor {
 					if v.initLenMustBeZero && !v.hasNoLintOnSameLine(fun) {
 						v.issues = append(v.issues, MustHaveNonZeroInitLenIssue{
 							name:     v.textFor(left),
+							pos:      node.Pos(),
 							position: v.fset.Position(node.Pos()),
 						})
 					}
@@ -201,7 +218,7 @@ func (v *visitor) isSlice(node ast.Node) bool {
 }
 
 func (v *visitor) hasNoLintOnSameLine(node ast.Node) bool {
-	var nolint = regexp.MustCompile(`^\s*nozero\b`)
+	nolint := regexp.MustCompile(`^\s*nozero\b`)
 	nodePos := v.fset.Position(node.Pos())
 	for _, c := range v.comments {
 		commentPos := v.fset.Position(c.Pos())

makezero/makezero_test.go

@@ -64,7 +64,6 @@ func foo() {
   append(x, 1) //nozeroxxx
 }`, "append to slice `x` with non-zero initialized length at testing.go:7:3")
 		})
-
 	})
 
 	t.Run("ignores more complex constructs than basic variables", func(t *testing.T) {

pkg/analyzer/analyzer.go

@@ -0,0 +1,52 @@
+package analyzer
+
+import (
+	"flag"
+	"go/ast"
+
+	"github.com/ashanbrown/makezero/makezero"
+	"golang.org/x/tools/go/analysis"
+)
+
+type analyzer struct {
+	always bool
+}
+
+// NewAnalyzer returns a go/analysis-compatible analyzer
+// Set "-always" to report any non-empty slice initialization.
+func NewAnalyzer() *analysis.Analyzer {
+	var flags flag.FlagSet
+	a := analyzer{}
+	flags.BoolVar(&a.always, "always", false, "report any non-empty slice initializations, regardless of intention")
+	return &analysis.Analyzer{
+		Name:  "makezero",
+		Doc:   "detect unintended non-empty slice initializations",
+		Run:   a.runAnalysis,
+		Flags: flags,
+	}
+}
+
+func (a *analyzer) runAnalysis(pass *analysis.Pass) (interface{}, error) {
+	linter := makezero.NewLinter(a.always)
+	nodes := make([]ast.Node, 0, len(pass.Files))
+	for _, f := range pass.Files {
+		nodes = append(nodes, f)
+	}
+	issues, err := linter.Run(pass.Fset, pass.TypesInfo, nodes...)
+	if err != nil {
+		return nil, err
+	}
+	reportIssues(pass, issues)
+	return nil, nil
+}
+
+func reportIssues(pass *analysis.Pass, issues []makezero.Issue) {
+	for _, i := range issues {
+		diag := analysis.Diagnostic{
+			Pos:      i.Pos(),
+			Message:  i.Details(),
+			Category: "restriction",
+		}
+		pass.Report(diag)
+	}
+}

pkg/analyzer/analyzer_test.go

@@ -0,0 +1,24 @@
+package analyzer_test
+
+import (
+	"testing"
+
+	"github.com/ashanbrown/makezero/pkg/analyzer"
+	"golang.org/x/tools/go/analysis/analysistest"
+)
+
+func TestAppend(t *testing.T) {
+	testdata := analysistest.TestData()
+	a := analyzer.NewAnalyzer()
+	analysistest.Run(t, testdata, a, "./append")
+}
+
+func TestAlways(t *testing.T) {
+	testdata := analysistest.TestData()
+	a := analyzer.NewAnalyzer()
+	err := a.Flags.Set("always", "true")
+	if err != nil {
+		t.Fatalf("expected no error but got %q", err)
+	}
+	analysistest.Run(t, testdata, a, "./always")
+}

pkg/analyzer/testdata/always/append.go

@@ -0,0 +1,8 @@
+package always
+
+import "fmt"
+
+func Foo() {
+	x := make([]int, 5) // want "slice `x` does not have non-zero initial length"
+	fmt.Println(x)
+}

pkg/analyzer/testdata/append/append.go

@@ -0,0 +1,9 @@
+package append
+
+import "fmt"
+
+func Foo() {
+	x := make([]int, 5)
+	x = append(x, 1) // want "append to slice `x` with non-zero initialized length"
+	fmt.Println(x)
+}