Add filesys.FileSystem to ignoreFileMatcher (#3994)

kyaml/kio/ignorefilesmatcher.go

@@ -4,12 +4,14 @@
 package kio
 
 import (
+	"errors"
 	"os"
 	"path/filepath"
 	"strings"
 
-	"github.com/monochromegane/go-gitignore"
+	gitignore "github.com/monochromegane/go-gitignore"
 	"sigs.k8s.io/kustomize/kyaml/ext"
+	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
 
 // ignoreFilesMatcher handles `.krmignore` files, which allows for ignoring
@@ -32,16 +34,17 @@ import (
 //   is set to true
 type ignoreFilesMatcher struct {
 	matchers []matcher
+	fs       filesys.FileSystemOrOnDisk
 }
 
 // readIgnoreFile checks whether there is a .krmignore file in the path, and
 // if it is, reads it in and turns it into a matcher. If we can't find a file,
 // we just add a matcher that match nothing.
 func (i *ignoreFilesMatcher) readIgnoreFile(path string) error {
 	i.verifyPath(path)
-	m, err := gitignore.NewGitIgnore(filepath.Join(path, ext.IgnoreFileName()))
+	f, err := i.fs.Open(filepath.Join(path, ext.IgnoreFileName()))
 	if err != nil {
-		if os.IsNotExist(err) {
+		if errors.Is(err, os.ErrNotExist) {
 			i.matchers = append(i.matchers, matcher{
 				matcher:  gitignore.DummyIgnoreMatcher(false),
 				basePath: path,
@@ -50,8 +53,10 @@ func (i *ignoreFilesMatcher) readIgnoreFile(path string) error {
 		}
 		return err
 	}
+	defer f.Close()
+
 	i.matchers = append(i.matchers, matcher{
-		matcher:  m,
+		matcher:  gitignore.NewGitIgnoreFromReader(path, f),
 		basePath: path,
 	})
 	return nil

kyaml/kio/ignorefilesmatcher_test.go

@@ -10,6 +10,8 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
 
 func TestIgnoreFilesMatcher_readIgnoreFile(t *testing.T) {
@@ -30,35 +32,52 @@ func TestIgnoreFilesMatcher_readIgnoreFile(t *testing.T) {
 		},
 	}
 
-	for i := range testCases {
-		test := testCases[i]
-		t.Run(test.name, func(t *testing.T) {
+	const (
+		ignoreFileName = ".krmignore"
+		testFileName   = "testfile.yaml"
+		ignoreFileBody = "\n" + testFileName + "\n"
+	)
+
+	fsMakers := map[string]func(bool) (string, filesys.FileSystem){
+		// onDisk creates a temp directory and returns a nil FileSystem, testing
+		// the normal conditions under which ignoreFileMatcher is used.
+		"onDisk": func(writeIgnoreFile bool) (string, filesys.FileSystem) {
 			dir, err := ioutil.TempDir("", "kyaml-test")
-			if !assert.NoError(t, err) {
-				assert.FailNow(t, err.Error())
-			}
+			require.NoError(t, err)
 
-			if test.writeIgnoreFile {
-				ignoreFilePath := filepath.Join(dir, ".krmignore")
-				err = ioutil.WriteFile(ignoreFilePath, []byte(`
-testfile.yaml
-`), 0600)
-				if !assert.NoError(t, err) {
-					assert.FailNow(t, err.Error())
-				}
+			if writeIgnoreFile {
+				ignoreFilePath := filepath.Join(dir, ignoreFileName)
+				require.NoError(t, ioutil.WriteFile(ignoreFilePath, []byte(ignoreFileBody), 0600))
 			}
-			testFilePath := filepath.Join(dir, "testfile.yaml")
-			err = ioutil.WriteFile(testFilePath, []byte{}, 0600)
-			if !assert.NoError(t, err) {
-				assert.FailNow(t, err.Error())
+			testFilePath := filepath.Join(dir, testFileName)
+			require.NoError(t, ioutil.WriteFile(testFilePath, []byte{}, 0600))
+			return dir, nil
+		},
+
+		// inMem creates an in-memory FileSystem and returns it.
+		"inMem": func(writeIgnoreFile bool) (string, filesys.FileSystem) {
+			fs := filesys.MakeEmptyDirInMemory()
+			if writeIgnoreFile {
+				require.NoError(t, fs.WriteFile(ignoreFileName, []byte(ignoreFileBody)))
 			}
+			require.NoError(t, fs.WriteFile(testFileName, nil))
+			return ".", fs
+		},
+	}
 
-			ignoreFilesMatcher := ignoreFilesMatcher{}
-			err = ignoreFilesMatcher.readIgnoreFile(dir)
-			if !assert.NoError(t, err) {
-				t.FailNow()
+	for name, fsMaker := range fsMakers {
+		t.Run(name, func(t *testing.T) {
+			fsMaker := fsMaker
+			for i := range testCases {
+				test := testCases[i]
+				dir, fs := fsMaker(test.writeIgnoreFile)
+				t.Run(test.name, func(t *testing.T) {
+					m := ignoreFilesMatcher{}
+					m.fs.Set(fs)
+					require.NoError(t, m.readIgnoreFile(dir))
+					require.Equal(t, test.isMatch, m.matchFile(filepath.Join(dir, testFileName)))
+				})
 			}
-			assert.Equal(t, test.isMatch, ignoreFilesMatcher.matchFile(testFilePath))
 		})
 	}
 }