Merge pull request #145 from bananaumai/skip-generated-code-proto

skip processing generated code

Author: kisielk

internal/errcheck/errcheck.go

@@ -17,6 +17,7 @@ import (
 	"strings"
 	"sync"
 
+	"go/parser"
 	"golang.org/x/tools/go/loader"
 )
 
@@ -108,6 +109,9 @@ type Checker struct {
 	// If true, checking of _test.go files is disabled
 	WithoutTests bool
 
+	// If true, checking of files with generated code is disabled
+	WithoutGeneratedCode bool
+
 	exclude map[string]bool
 }
 
@@ -169,6 +173,11 @@ func (c *Checker) load(paths ...string) (*loader.Program, error) {
 	loadcfg := loader.Config{
 		Build: &ctx,
 	}
+
+	if c.WithoutGeneratedCode {
+		loadcfg.ParserMode = parser.ParseComments
+	}
+
 	rest, err := loadcfg.FromArgs(paths, !c.WithoutTests)
 	if err != nil {
 		return nil, fmt.Errorf("could not parse arguments: %s", err)
@@ -180,6 +189,24 @@ func (c *Checker) load(paths ...string) (*loader.Program, error) {
 	return loadcfg.Load()
 }
 
+var generatedCodeRegexp = regexp.MustCompile("^// Code generated .* DO NOT EDIT\\.$")
+
+func (c *Checker) shouldSkipFile(file *ast.File) bool {
+	if !c.WithoutGeneratedCode {
+		return false
+	}
+
+	for _, cg := range file.Comments {
+		for _, comment := range cg.List {
+			if generatedCodeRegexp.MatchString(comment.Text) {
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
 // CheckPackages checks packages for errors.
 func (c *Checker) CheckPackages(paths ...string) error {
 	program, err := c.load(paths...)
@@ -212,6 +239,9 @@ func (c *Checker) CheckPackages(paths ...string) error {
 			}
 
 			for _, astFile := range v.pkg.Files {
+				if c.shouldSkipFile(astFile) {
+					continue
+				}
 				ast.Walk(v, astFile)
 			}
 			u.Append(v.errors...)

internal/errcheck/errcheck_test.go

@@ -93,7 +93,8 @@ func TestWhitelist(t *testing.T) {
 
 }
 
-const testVendorMain = `
+func TestIgnore(t *testing.T) {
+	const testVendorMain = `
 	package main
 
 	import "github.com/testlog"
@@ -102,14 +103,13 @@ const testVendorMain = `
 		// returns an error that is not checked
 		testlog.Info()
 	}`
-const testLog = `
+	const testLog = `
 	package testlog
 
 	func Info() error {
 		return nil
 	}`
 
-func TestIgnore(t *testing.T) {
 	if strings.HasPrefix(runtime.Version(), "go1.5") && os.Getenv("GO15VENDOREXPERIMENT") != "1" {
 		// skip tests if running in go1.5 and vendoring is not enabled
 		t.SkipNow()
@@ -179,6 +179,86 @@ func TestIgnore(t *testing.T) {
 	}
 }
 
+func TestWithoutGeneratedCode(t *testing.T) {
+	const testVendorMain = `
+	// Code generated by protoc-gen-go. DO NOT EDIT.
+	package main
+
+	import "github.com/testlog"
+
+	func main() {
+		// returns an error that is not checked
+		testlog.Info()
+	}`
+	const testLog = `
+	package testlog
+
+	func Info() error {
+		return nil
+	}`
+
+	if strings.HasPrefix(runtime.Version(), "go1.5") && os.Getenv("GO15VENDOREXPERIMENT") != "1" {
+		// skip tests if running in go1.5 and vendoring is not enabled
+		t.SkipNow()
+	}
+
+	// copy testvendor directory into current directory for test
+	testVendorDir, err := ioutil.TempDir(".", "testvendor")
+	if err != nil {
+		t.Fatalf("unable to create testvendor directory: %v", err)
+	}
+	defer os.RemoveAll(testVendorDir)
+
+	if err := ioutil.WriteFile(path.Join(testVendorDir, "main.go"), []byte(testVendorMain), 0755); err != nil {
+		t.Fatalf("Failed to write testvendor main: %v", err)
+	}
+	if err := os.MkdirAll(path.Join(testVendorDir, "vendor/github.com/testlog"), 0755); err != nil {
+		t.Fatalf("MkdirAll failed: %v", err)
+	}
+	if err := ioutil.WriteFile(path.Join(testVendorDir, "vendor/github.com/testlog/testlog.go"), []byte(testLog), 0755); err != nil {
+		t.Fatalf("Failed to write testlog: %v", err)
+	}
+
+	cases := []struct {
+		withoutGeneratedCode bool
+		numExpectedErrs      int
+	}{
+		// basic case has one error
+		{
+			withoutGeneratedCode: false,
+			numExpectedErrs:      1,
+		},
+		// ignoring vendored import works
+		{
+			withoutGeneratedCode: true,
+			numExpectedErrs:      0,
+		},
+	}
+
+	for i, currCase := range cases {
+		checker := NewChecker()
+		checker.WithoutGeneratedCode = currCase.withoutGeneratedCode
+		err := checker.CheckPackages(path.Join("github.com/kisielk/errcheck/internal/errcheck", testVendorDir))
+
+		if currCase.numExpectedErrs == 0 {
+			if err != nil {
+				t.Errorf("Case %d: expected no errors, but got: %v", i, err)
+			}
+			continue
+		}
+
+		uerr, ok := err.(*UncheckedErrors)
+		if !ok {
+			t.Errorf("Case %d: wrong error type returned", i)
+			continue
+		}
+
+		if currCase.numExpectedErrs != len(uerr.Errors) {
+			t.Errorf("Case %d:\nExpected: %d errors\nActual:   %d errors", i, currCase.numExpectedErrs, len(uerr.Errors))
+		}
+	}
+}
+
 func test(t *testing.T, f flags) {
 	var (
 		asserts bool = f&CheckAsserts != 0

main.go

@@ -133,6 +133,7 @@ func parseFlags(checker *errcheck.Checker, args []string) ([]string, int) {
 	flags.BoolVar(&checker.Blank, "blank", false, "if true, check for errors assigned to blank identifier")
 	flags.BoolVar(&checker.Asserts, "asserts", false, "if true, check for ignored type assertion results")
 	flags.BoolVar(&checker.WithoutTests, "ignoretests", false, "if true, checking of _test.go files is disabled")
+	flags.BoolVar(&checker.WithoutGeneratedCode,  "ignoregenerated", false, "if true, checking of files with generated code is disabled")
 	flags.BoolVar(&checker.Verbose, "verbose", false, "produce more verbose logging")
 
 	flags.BoolVar(&abspath, "abspath", false, "print absolute paths to files")