Introduce Helmfile's own filesystem abstraction to correctly unit test some components (#307)

Use abstracted FS

Signed-off-by: Arkaitz Jimenez <arkaitzj@gmail.com>

Signed-off-by: Arkaitz Jimenez <arkaitzj@gmail.com>

pkg/app/app.go

@@ -17,6 +17,7 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/helmfile/helmfile/pkg/argparser"
+	"github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/plugins"
 	"github.com/helmfile/helmfile/pkg/remote"
@@ -39,16 +40,7 @@ type App struct {
 
 	FileOrDir string
 
-	readFile          func(string) ([]byte, error)
-	deleteFile        func(string) error
-	fileExists        func(string) (bool, error)
-	glob              func(string) ([]string, error)
-	abs               func(string) (string, error)
-	fileExistsAt      func(string) bool
-	directoryExistsAt func(string) bool
-
-	getwd func() (string, error)
-	chdir func(string) error
+	fs *filesystem.FileSystem
 
 	remote *remote.Remote
 
@@ -81,20 +73,11 @@ func New(conf ConfigProvider) *App {
 		FileOrDir:           conf.FileOrDir(),
 		ValuesFiles:         conf.StateValuesFiles(),
 		Set:                 conf.StateValuesSet(),
+		fs:                  filesystem.DefaultFileSystem(),
 	})
 }
 
 func Init(app *App) *App {
-	app.readFile = os.ReadFile
-	app.deleteFile = os.Remove
-	app.glob = filepath.Glob
-	app.abs = filepath.Abs
-	app.getwd = os.Getwd
-	app.chdir = os.Chdir
-	app.fileExistsAt = fileExistsAt
-	app.fileExists = fileExists
-	app.directoryExistsAt = directoryExistsAt
-
 	var err error
 	app.valsRuntime, err = plugins.ValsInstance()
 	if err != nil {
@@ -619,19 +602,19 @@ func (a *App) within(dir string, do func() error) error {
 		return do()
 	}
 
-	prev, err := a.getwd()
+	prev, err := a.fs.Getwd()
 	if err != nil {
 		return fmt.Errorf("failed getting current working direcotyr: %v", err)
 	}
 
-	absDir, err := a.abs(dir)
+	absDir, err := a.fs.Abs(dir)
 	if err != nil {
 		return err
 	}
 
 	a.Logger.Debugf("changing working directory to \"%s\"", absDir)
 
-	if err := a.chdir(absDir); err != nil {
+	if err := a.fs.Chdir(absDir); err != nil {
 		return fmt.Errorf("failed changing working directory to \"%s\": %v", absDir, err)
 	}
 
@@ -639,7 +622,7 @@ func (a *App) within(dir string, do func() error) error {
 
 	a.Logger.Debugf("changing working directory back to \"%s\"", prev)
 
-	if chdirBackErr := a.chdir(prev); chdirBackErr != nil {
+	if chdirBackErr := a.fs.Chdir(prev); chdirBackErr != nil {
 		if appErr != nil {
 			a.Logger.Warnf("%v", appErr)
 		}
@@ -658,7 +641,7 @@ func (a *App) visitStateFiles(fileOrDir string, opts LoadOpts, do func(string, s
 	for _, relPath := range desiredStateFiles {
 		var file string
 		var dir string
-		if a.directoryExistsAt(relPath) {
+		if a.fs.DirectoryExistsAt(relPath) {
 			file = relPath
 			dir = relPath
 		} else {
@@ -668,7 +651,7 @@ func (a *App) visitStateFiles(fileOrDir string, opts LoadOpts, do func(string, s
 
 		a.Logger.Debugf("processing file \"%s\" in directory \"%s\"", file, dir)
 
-		absd, errAbsDir := a.abs(dir)
+		absd, errAbsDir := a.fs.Abs(dir)
 		if errAbsDir != nil {
 			return errAbsDir
 		}
@@ -690,20 +673,15 @@ func (a *App) loadDesiredStateFromYaml(file string, opts ...LoadOpts) (*state.He
 	}
 
 	ld := &desiredStateLoader{
-		readFile:          a.readFile,
-		deleteFile:        a.deleteFile,
-		fileExists:        a.fileExists,
-		directoryExistsAt: a.directoryExistsAt,
-		env:               a.Env,
-		namespace:         a.Namespace,
-		chart:             a.Chart,
-		logger:            a.Logger,
-		abs:               a.abs,
-		remote:            a.remote,
+		fs:        a.fs,
+		env:       a.Env,
+		namespace: a.Namespace,
+		chart:     a.Chart,
+		logger:    a.Logger,
+		remote:    a.remote,
 
 		overrideKubeContext: a.OverrideKubeContext,
 		overrideHelmBinary:  a.OverrideHelmBinary,
-		glob:                a.glob,
 		getHelm:             a.getHelm,
 		valsRuntime:         a.valsRuntime,
 	}
@@ -995,7 +973,7 @@ func (a *App) visitStatesWithSelectorsAndRemoteSupport(fileOrDir string, converg
 		opts.Environment.OverrideValues = envvals
 	}
 
-	a.remote = remote.NewRemote(a.Logger, "", a.readFile, a.directoryExistsAt, a.fileExistsAt)
+	a.remote = remote.NewRemote(a.Logger, "", a.fs)
 
 	f := converge
 	if opts.Filter {
@@ -1095,18 +1073,18 @@ func (a *App) findDesiredStateFiles(specifiedPath string, opts LoadOpts) ([]stri
 	var helmfileDir string
 	if specifiedPath != "" {
 		switch {
-		case a.fileExistsAt(specifiedPath):
+		case a.fs.FileExistsAt(specifiedPath):
 			return []string{specifiedPath}, nil
-		case a.directoryExistsAt(specifiedPath):
+		case a.fs.DirectoryExistsAt(specifiedPath):
 			helmfileDir = specifiedPath
 		default:
 			return []string{}, fmt.Errorf("specified state file %s is not found", specifiedPath)
 		}
 	} else {
 		var defaultFile string
-		if a.fileExistsAt(DefaultHelmfile) {
+		if a.fs.FileExistsAt(DefaultHelmfile) {
 			defaultFile = DefaultHelmfile
-		} else if a.fileExistsAt(DeprecatedHelmfile) {
+		} else if a.fs.FileExistsAt(DeprecatedHelmfile) {
 			log.Printf(
 				"warn: %s is being loaded: %s is deprecated in favor of %s. See https://github.com/roboll/helmfile/issues/25 for more information",
 				DeprecatedHelmfile,
@@ -1117,7 +1095,7 @@ func (a *App) findDesiredStateFiles(specifiedPath string, opts LoadOpts) ([]stri
 		}
 
 		switch {
-		case a.directoryExistsAt(DefaultHelmfileDirectory):
+		case a.fs.DirectoryExistsAt(DefaultHelmfileDirectory):
 			if defaultFile != "" {
 				return []string{}, fmt.Errorf("configuration conlict error: you can have either %s or %s, but not both", defaultFile, DefaultHelmfileDirectory)
 			}
@@ -1130,7 +1108,7 @@ func (a *App) findDesiredStateFiles(specifiedPath string, opts LoadOpts) ([]stri
 		}
 	}
 
-	files, err := a.glob(filepath.Join(helmfileDir, "*.y*ml"))
+	files, err := a.fs.Glob(filepath.Join(helmfileDir, "*.y*ml"))
 	if err != nil {
 		return []string{}, err
 	}
@@ -1926,28 +1904,6 @@ func (a *App) writeValues(r *Run, c WriteValuesConfigProvider) (bool, []error) {
 	return true, errs
 }
 
-func fileExistsAt(path string) bool {
-	fileInfo, err := os.Stat(path)
-	return err == nil && fileInfo.Mode().IsRegular()
-}
-
-func fileExists(path string) (bool, error) {
-	_, err := os.Stat(path)
-
-	if err != nil {
-		if os.IsNotExist(err) {
-			return false, nil
-		}
-		return false, err
-	}
-	return true, nil
-}
-
-func directoryExistsAt(path string) bool {
-	fileInfo, err := os.Stat(path)
-	return err == nil && fileInfo.Mode().IsDir()
-}
-
 // Error is a wrapper around an error that adds context to the error.
 type Error struct {
 	msg string
@@ -2064,10 +2020,10 @@ func (c context) wrapErrs(errs ...error) error {
 func (a *App) ShowCacheDir(c CacheConfigProvider) error {
 	fmt.Printf("Cache directory: %s\n", remote.CacheDir())
 
-	if !directoryExistsAt(remote.CacheDir()) {
+	if !a.fs.DirectoryExistsAt(remote.CacheDir()) {
 		return nil
 	}
-	dirs, err := os.ReadDir(remote.CacheDir())
+	dirs, err := a.fs.ReadDir(remote.CacheDir())
 	if err != nil {
 		return err
 	}
@@ -2079,7 +2035,7 @@ func (a *App) ShowCacheDir(c CacheConfigProvider) error {
 }
 
 func (a *App) CleanCacheDir(c CacheConfigProvider) error {
-	if !directoryExistsAt(remote.CacheDir()) {
+	if !a.fs.DirectoryExistsAt(remote.CacheDir()) {
 		return nil
 	}
 	fmt.Printf("Cleaning up cache directory: %s\n", remote.CacheDir())

pkg/app/app_apply_nokubectx_test.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
@@ -12,6 +11,7 @@ import (
 	"github.com/variantdev/vals"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	"github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -90,8 +90,7 @@ func TestApply_3(t *testing.T) {
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  filesystem.DefaultFileSystem(),
 				OverrideKubeContext: "",
 				Env:                 "default",
 				Logger:              logger,

pkg/app/app_apply_test.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
@@ -12,6 +11,7 @@ import (
 	"github.com/variantdev/vals"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	"github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -90,8 +90,7 @@ func TestApply_2(t *testing.T) {
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  filesystem.DefaultFileSystem(),
 				OverrideKubeContext: "default",
 				Env:                 "default",
 				Logger:              logger,

pkg/app/app_diff_test.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
@@ -13,6 +12,7 @@ import (
 	"github.com/variantdev/vals"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	"github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -129,8 +129,7 @@ releases:
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  filesystem.DefaultFileSystem(),
 				OverrideKubeContext: "default",
 				Env:                 "default",
 				Logger:              logger,

pkg/app/app_lint_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/variantdev/vals"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -131,8 +132,7 @@ releases:
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  ffs.DefaultFileSystem(),
 				OverrideKubeContext: "default",
 				Env:                 "default",
 				Logger:              logger,

pkg/app/app_list_test.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
@@ -12,6 +11,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/variantdev/vals"
 
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 	"github.com/helmfile/helmfile/pkg/testutil"
@@ -145,8 +145,7 @@ releases:
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  ffs.DefaultFileSystem(),
 				OverrideKubeContext: "default",
 				Env:                 tc.environment,
 				Logger:              logger,

pkg/app/app_sync_test.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
@@ -12,6 +11,7 @@ import (
 	"github.com/variantdev/vals"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -88,8 +88,7 @@ func TestSync(t *testing.T) {
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  ffs.DefaultFileSystem(),
 				OverrideKubeContext: "default",
 				Env:                 "default",
 				Logger:              logger,

pkg/app/app_template_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/variantdev/vals"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -131,8 +132,7 @@ releases:
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  &ffs.FileSystem{Glob: filepath.Glob},
 				OverrideKubeContext: "default",
 				Env:                 "default",
 				Logger:              logger,

pkg/app/app_test.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/helmfile/helmfile/pkg/envvar"
 	"github.com/helmfile/helmfile/pkg/exectest"
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/remote"
 	"github.com/helmfile/helmfile/pkg/state"
@@ -40,14 +41,7 @@ func injectFs(app *App, fs *testhelper.TestFs) *App {
 		app.Set = make(map[string]interface{})
 	}
 
-	app.readFile = fs.ReadFile
-	app.glob = fs.Glob
-	app.abs = fs.Abs
-	app.getwd = fs.Getwd
-	app.chdir = fs.Chdir
-	app.fileExistsAt = fs.FileExistsAt
-	app.fileExists = fs.FileExists
-	app.directoryExistsAt = fs.DirectoryExistsAt
+	app.fs = fs.ToFileSystem()
 	return app
 }
 
@@ -1529,12 +1523,11 @@ func TestLoadDesiredStateFromYaml_DuplicateReleaseName(t *testing.T) {
 		}
 		return yamlContent, nil
 	}
+	fs := ffs.FromFileSystem(ffs.FileSystem{ReadFile: readFile})
 	app := &App{
 		OverrideHelmBinary:  DefaultHelmBinary,
 		OverrideKubeContext: "default",
-		readFile:            readFile,
-		glob:                filepath.Glob,
-		abs:                 filepath.Abs,
+		fs:                  fs,
 		Env:                 "default",
 		Logger:              helmexec.NewLogger(os.Stderr, "debug"),
 	}
@@ -1593,16 +1586,11 @@ helmDefaults:
 	app := &App{
 		OverrideHelmBinary:  DefaultHelmBinary,
 		OverrideKubeContext: "default",
-		readFile:            testFs.ReadFile,
-		glob:                testFs.Glob,
-		abs:                 testFs.Abs,
-		directoryExistsAt:   testFs.DirectoryExistsAt,
-		fileExistsAt:        testFs.FileExistsAt,
-		fileExists:          testFs.FileExists,
+		fs:                  testFs.ToFileSystem(),
 		Env:                 "default",
 		Logger:              helmexec.NewLogger(os.Stderr, "debug"),
 	}
-	app.remote = remote.NewRemote(app.Logger, "", app.readFile, app.directoryExistsAt, app.fileExistsAt)
+	app.remote = remote.NewRemote(app.Logger, "", app.fs)
 
 	expectNoCallsToHelm(app)
 
@@ -1683,14 +1671,11 @@ helmDefaults:
 	})
 	app := &App{
 		OverrideHelmBinary: DefaultHelmBinary,
-		readFile:           testFs.ReadFile,
-		fileExists:         testFs.FileExists,
-		glob:               testFs.Glob,
-		abs:                testFs.Abs,
+		fs:                 testFs.ToFileSystem(),
 		Env:                "default",
 		Logger:             helmexec.NewLogger(os.Stderr, "debug"),
 	}
-	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, testFs.ReadFile, testFs.DirectoryExistsAt, testFs.FileExistsAt)
+	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, app.fs)
 
 	expectNoCallsToHelm(app)
 
@@ -1762,14 +1747,11 @@ foo: FOO
 	})
 	app := &App{
 		OverrideHelmBinary: DefaultHelmBinary,
-		readFile:           testFs.ReadFile,
-		fileExists:         testFs.FileExists,
-		glob:               testFs.Glob,
-		abs:                testFs.Abs,
+		fs:                 testFs.ToFileSystem(),
 		Env:                "default",
 		Logger:             helmexec.NewLogger(os.Stderr, "debug"),
 	}
-	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, testFs.ReadFile, testFs.DirectoryExistsAt, testFs.FileExistsAt)
+	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, app.fs)
 
 	expectNoCallsToHelm(app)
 
@@ -1828,14 +1810,11 @@ foo: FOO
 	})
 	app := &App{
 		OverrideHelmBinary: DefaultHelmBinary,
-		readFile:           testFs.ReadFile,
-		fileExists:         testFs.FileExists,
-		glob:               testFs.Glob,
-		abs:                testFs.Abs,
+		fs:                 testFs.ToFileSystem(),
 		Env:                "default",
 		Logger:             helmexec.NewLogger(os.Stderr, "debug"),
 	}
-	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, testFs.ReadFile, testFs.DirectoryExistsAt, testFs.FileExistsAt)
+	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, app.fs)
 
 	expectNoCallsToHelm(app)
 
@@ -1912,14 +1891,11 @@ helmDefaults:
 	})
 	app := &App{
 		OverrideHelmBinary: DefaultHelmBinary,
-		readFile:           testFs.ReadFile,
-		fileExists:         testFs.FileExists,
-		glob:               testFs.Glob,
-		abs:                testFs.Abs,
+		fs:                 testFs.ToFileSystem(),
 		Env:                "test",
 		Logger:             helmexec.NewLogger(os.Stderr, "debug"),
 	}
-	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, testFs.ReadFile, testFs.DirectoryExistsAt, testFs.FileExistsAt)
+	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, app.fs)
 
 	expectNoCallsToHelm(app)
 
@@ -1988,13 +1964,11 @@ releases:
 	})
 	app := &App{
 		OverrideHelmBinary: DefaultHelmBinary,
-		readFile:           testFs.ReadFile,
-		glob:               testFs.Glob,
-		abs:                testFs.Abs,
+		fs:                 testFs.ToFileSystem(),
 		Env:                "default",
 		Logger:             helmexec.NewLogger(os.Stderr, "debug"),
 	}
-	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, testFs.ReadFile, testFs.DirectoryExistsAt, testFs.FileExistsAt)
+	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, app.fs)
 
 	expectNoCallsToHelm(app)
 
@@ -2046,14 +2020,12 @@ releases:
 	})
 	app := &App{
 		OverrideHelmBinary: DefaultHelmBinary,
-		readFile:           testFs.ReadFile,
-		glob:               testFs.Glob,
-		abs:                testFs.Abs,
+		fs:                 testFs.ToFileSystem(),
 		Env:                "default",
 		Logger:             helmexec.NewLogger(os.Stderr, "debug"),
 	}
 
-	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, testFs.ReadFile, testFs.DirectoryExistsAt, testFs.FileExistsAt)
+	app.remote = remote.NewRemote(app.Logger, testFs.Cwd, app.fs)
 	expectNoCallsToHelm(app)
 
 	st, err := app.loadDesiredStateFromYaml(statePath, LoadOpts{Reverse: true})
@@ -2103,13 +2075,11 @@ releases:
 		})
 		app := &App{
 			OverrideHelmBinary: DefaultHelmBinary,
-			readFile:           testFs.ReadFile,
-			glob:               testFs.Glob,
-			abs:                testFs.Abs,
+			fs:                 testFs.ToFileSystem(),
 			Env:                "default",
 			Logger:             helmexec.NewLogger(os.Stderr, "debug"),
 		}
-		app.remote = remote.NewRemote(app.Logger, testFs.Cwd, testFs.ReadFile, testFs.DirectoryExistsAt, testFs.FileExistsAt)
+		app.remote = remote.NewRemote(app.Logger, testFs.Cwd, app.fs)
 
 		opts := LoadOpts{
 			CalleePath: statePath,
@@ -2217,13 +2187,11 @@ services:
 		})
 		app := &App{
 			OverrideHelmBinary: DefaultHelmBinary,
-			readFile:           testFs.ReadFile,
-			glob:               testFs.Glob,
-			abs:                testFs.Abs,
+			fs:                 testFs.ToFileSystem(),
 			Env:                "default",
 			Logger:             helmexec.NewLogger(os.Stderr, "debug"),
 		}
-		app.remote = remote.NewRemote(app.Logger, testFs.Cwd, testFs.ReadFile, testFs.DirectoryExistsAt, testFs.FileExistsAt)
+		app.remote = remote.NewRemote(app.Logger, testFs.Cwd, app.fs)
 
 		expectNoCallsToHelm(app)
 
@@ -2656,8 +2624,7 @@ releases:
 
 	app := appWithFs(&App{
 		OverrideHelmBinary:  DefaultHelmBinary,
-		glob:                filepath.Glob,
-		abs:                 filepath.Abs,
+		fs:                  ffs.DefaultFileSystem(),
 		OverrideKubeContext: "default",
 		Env:                 "default",
 		Logger:              logger,
@@ -2729,8 +2696,6 @@ releases:
 
 	app := appWithFs(&App{
 		OverrideHelmBinary:  DefaultHelmBinary,
-		glob:                filepath.Glob,
-		abs:                 filepath.Abs,
 		OverrideKubeContext: "default",
 		Env:                 "default",
 		Logger:              logger,
@@ -2741,6 +2706,8 @@ releases:
 		valsRuntime: valsRuntime,
 	}, files)
 
+	fmt.Printf("CRAFTED APP WITH %p\n", app.fs.DirectoryExistsAt)
+
 	if err := app.Template(configImpl{}); err != nil {
 		t.Fatalf("%v", err)
 	}
@@ -4282,8 +4249,7 @@ changing working directory back to "/path/to"
 
 				app := appWithFs(&App{
 					OverrideHelmBinary:  DefaultHelmBinary,
-					glob:                filepath.Glob,
-					abs:                 filepath.Abs,
+					fs:                  ffs.DefaultFileSystem(),
 					OverrideKubeContext: "default",
 					Env:                 "default",
 					Logger:              logger,
@@ -4465,8 +4431,7 @@ changing working directory back to "/path/to"
 
 				app := appWithFs(&App{
 					OverrideHelmBinary:  DefaultHelmBinary,
-					glob:                filepath.Glob,
-					abs:                 filepath.Abs,
+					fs:                  ffs.DefaultFileSystem(),
 					OverrideKubeContext: "default",
 					Env:                 "default",
 					Logger:              logger,
@@ -4523,8 +4488,7 @@ releases:
 
 	app := appWithFs(&App{
 		OverrideHelmBinary:  DefaultHelmBinary,
-		glob:                filepath.Glob,
-		abs:                 filepath.Abs,
+		fs:                  ffs.DefaultFileSystem(),
 		OverrideKubeContext: "default",
 		Env:                 "default",
 		Logger:              logger,
@@ -4570,8 +4534,7 @@ releases:
 
 	app := appWithFs(&App{
 		OverrideHelmBinary:  DefaultHelmBinary,
-		glob:                filepath.Glob,
-		abs:                 filepath.Abs,
+		fs:                  ffs.DefaultFileSystem(),
 		OverrideKubeContext: "default",
 		Env:                 "default",
 		Logger:              logger,
@@ -4631,8 +4594,7 @@ releases:
 
 	app := appWithFs(&App{
 		OverrideHelmBinary:  DefaultHelmBinary,
-		glob:                filepath.Glob,
-		abs:                 filepath.Abs,
+		fs:                  ffs.DefaultFileSystem(),
 		OverrideKubeContext: "default",
 		Env:                 "default",
 		Logger:              logger,
@@ -4693,8 +4655,7 @@ releases:
 
 	app := appWithFs(&App{
 		OverrideHelmBinary:  DefaultHelmBinary,
-		glob:                filepath.Glob,
-		abs:                 filepath.Abs,
+		fs:                  ffs.DefaultFileSystem(),
 		OverrideKubeContext: "default",
 		Env:                 "default",
 		Logger:              logger,

pkg/app/desired_state_file_loader.go

@@ -11,6 +11,7 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/helmfile/helmfile/pkg/environment"
+	"github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/remote"
 	"github.com/helmfile/helmfile/pkg/state"
@@ -27,14 +28,9 @@ type desiredStateLoader struct {
 	env       string
 	namespace string
 	chart     string
+	fs        *filesystem.FileSystem
 
-	readFile          func(string) ([]byte, error)
-	deleteFile        func(string) error
-	fileExists        func(string) (bool, error)
-	abs               func(string) (string, error)
-	glob              func(string) ([]string, error)
-	directoryExistsAt func(string) bool
-	getHelm           func(*state.HelmState) helmexec.Interface
+	getHelm func(*state.HelmState) helmexec.Interface
 
 	remote      *remote.Remote
 	logger      *zap.SugaredLogger
@@ -50,8 +46,8 @@ func (ld *desiredStateLoader) Load(f string, opts LoadOpts) (*state.HelmState, e
 		if opts.CalleePath == "" {
 			return nil, fmt.Errorf("bug: opts.CalleePath was nil: f=%s, opts=%v", f, opts)
 		}
-		storage := state.NewStorage(opts.CalleePath, ld.logger, ld.glob)
-		envld := state.NewEnvironmentValuesLoader(storage, ld.readFile, ld.logger, ld.remote)
+		storage := state.NewStorage(opts.CalleePath, ld.logger, ld.fs)
+		envld := state.NewEnvironmentValuesLoader(storage, ld.fs, ld.logger, ld.remote)
 		handler := state.MissingFileHandlerError
 		vals, err := envld.LoadEnvironmentValues(&handler, args, &environment.EmptyEnvironment)
 		if err != nil {
@@ -120,7 +116,7 @@ func (ld *desiredStateLoader) loadFileWithOverrides(inheritedEnv, overrodeEnv *e
 		f = filepath.Join(baseDir, file)
 	}
 
-	fileBytes, err := ld.readFile(f)
+	fileBytes, err := ld.fs.ReadFile(f)
 	if err != nil {
 		return nil, err
 	}
@@ -166,8 +162,7 @@ func (ld *desiredStateLoader) loadFileWithOverrides(inheritedEnv, overrodeEnv *e
 }
 
 func (a *desiredStateLoader) underlying() *state.StateCreator {
-	c := state.NewCreator(a.logger, a.readFile, a.fileExists, a.abs, a.glob, a.directoryExistsAt, a.valsRuntime, a.getHelm, a.overrideHelmBinary, a.remote)
-	c.DeleteFile = a.deleteFile
+	c := state.NewCreator(a.logger, a.fs, a.valsRuntime, a.getHelm, a.overrideHelmBinary, a.remote)
 	c.LoadFile = a.loadFile
 	return c
 }

pkg/app/destroy_nokubectx_test.go

@@ -4,13 +4,13 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
 	"github.com/variantdev/vals"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -83,8 +83,7 @@ func TestDestroy_2(t *testing.T) {
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  ffs.DefaultFileSystem(),
 				OverrideKubeContext: "",
 				Env:                 "default",
 				Logger:              logger,

pkg/app/destroy_test.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
@@ -12,6 +11,7 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -124,8 +124,7 @@ func TestDestroy(t *testing.T) {
 
 			app := appWithFs(&App{
 				OverrideHelmBinary:  DefaultHelmBinary,
-				glob:                filepath.Glob,
-				abs:                 filepath.Abs,
+				fs:                  ffs.DefaultFileSystem(),
 				OverrideKubeContext: "default",
 				Env:                 "default",
 				Logger:              logger,

pkg/app/diff_nokubectx_test.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
@@ -12,6 +11,7 @@ import (
 	"github.com/variantdev/vals"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -1060,8 +1060,7 @@ changing working directory back to "/path/to"
 
 				app := appWithFs(&App{
 					OverrideHelmBinary:  DefaultHelmBinary,
-					glob:                filepath.Glob,
-					abs:                 filepath.Abs,
+					fs:                  ffs.DefaultFileSystem(),
 					OverrideKubeContext: "",
 					Env:                 "default",
 					Logger:              logger,

pkg/app/diff_test.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"path/filepath"
 	"sync"
 	"testing"
 
@@ -13,6 +12,7 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/helmfile/helmfile/pkg/exectest"
+	ffs "github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/testhelper"
 )
@@ -1352,8 +1352,7 @@ changing working directory back to "/path/to"
 
 				app := appWithFs(&App{
 					OverrideHelmBinary:  DefaultHelmBinary,
-					glob:                filepath.Glob,
-					abs:                 filepath.Abs,
+					fs:                  ffs.DefaultFileSystem(),
 					OverrideKubeContext: overrideKubeContext,
 					Env:                 "default",
 					Logger:              logger,

pkg/app/two_pass_renderer.go

@@ -124,7 +124,7 @@ func (r *desiredStateLoader) twoPassRenderTemplateToYaml(inherited, overrode *en
 	}
 
 	tmplData := state.NewEnvironmentTemplateData(*finalEnv, r.namespace, vals)
-	secondPassRenderer := tmpl.NewFileRenderer(r.readFile, baseDir, tmplData)
+	secondPassRenderer := tmpl.NewFileRenderer(r.fs, baseDir, tmplData)
 	yamlBuf, err := secondPassRenderer.RenderTemplateContentToBuffer(content)
 	if err != nil {
 		if r.logger != nil {

pkg/app/two_pass_renderer_test.go

@@ -17,16 +17,13 @@ import (
 func makeLoader(files map[string]string, env string) (*desiredStateLoader, *testhelper.TestFs) {
 	testfs := testhelper.NewTestFs(files)
 	logger := helmexec.NewLogger(os.Stdout, "debug")
-	r := remote.NewRemote(logger, testfs.Cwd, testfs.ReadFile, testfs.DirectoryExistsAt, testfs.FileExistsAt)
+	r := remote.NewRemote(logger, testfs.Cwd, testfs.ToFileSystem())
 	return &desiredStateLoader{
-		env:        env,
-		namespace:  "namespace",
-		logger:     helmexec.NewLogger(os.Stdout, "debug"),
-		readFile:   testfs.ReadFile,
-		fileExists: testfs.FileExists,
-		abs:        testfs.Abs,
-		glob:       testfs.Glob,
-		remote:     r,
+		env:       env,
+		namespace: "namespace",
+		logger:    helmexec.NewLogger(os.Stdout, "debug"),
+		fs:        testfs.ToFileSystem(),
+		remote:    r,
 	}, testfs
 }