split file and fs provider

.github/codecov.yml

@@ -20,6 +20,10 @@ component_management:
     - component_id: konf
       paths:
         - "!provider/pflag/"
+        - "!provider/file/"
+    - component_id: file
+      paths:
+        - "provider/file/"
     - component_id: pflag
       paths:
         - "provider/pflag/"

.github/dependabot.yml

@@ -6,6 +6,11 @@ updates:
     schedule:
       interval: daily
 
+  - package-ecosystem: gomod
+    directory: /provider/file
+    schedule:
+      interval: daily
+
   - package-ecosystem: gomod
     directory: /provider/pflag
     schedule:

.github/workflows/benchmark.yml

@@ -18,6 +18,9 @@ jobs:
           go-version: 'stable'
       - name: Benchmark
         run: go test -v -shuffle=on -bench=. ./...
+      - name: Benchmark (file)
+        run: go test -v -shuffle=on -bench=. ./...
+        working-directory: provider/file
       - name: Benchmark (pflag)
         run: go test -v -shuffle=on -bench=. ./...
         working-directory: provider/pflag

.github/workflows/coverage.yml

@@ -18,6 +18,9 @@ jobs:
           go-version: 'stable'
       - name: Coverage
         run: go test -v -covermode=count -coverprofile=coverage.txt ./...
+      - name: Coverage (file)
+        run: go test -v -covermode=count -coverprofile=coverage.txt ./...
+        working-directory: provider/file
       - name: Coverage (pflag)
         run: go test -v -covermode=count -coverprofile=coverage.txt ./...
         working-directory: provider/pflag

.github/workflows/lint.yml

@@ -18,6 +18,10 @@ jobs:
           go-version: 'stable'
       - name: Lint
         uses: golangci/golangci-lint-action@v3
+      - name: Lint (file)
+        uses: golangci/golangci-lint-action@v3
+        with:
+          working-directory: provider/file
       - name: Lint (pflag)
         uses: golangci/golangci-lint-action@v3
         with:

.github/workflows/test.yml

@@ -24,6 +24,12 @@ jobs:
         run: go test -v -shuffle=on -count=10 -race ./...
       - name: Test
         run: go test -v -shuffle=on ./...
+      - name: Race Test (file)
+        run: go test -v -shuffle=on -count=10 -race ./...
+        working-directory: provider/file
+      - name: Test (file)
+        run: go test -v -shuffle=on ./...
+        working-directory: provider/file
       - name: Race Test (pflag)
         run: go test -v -shuffle=on -count=10 -race ./...
         working-directory: provider/pflag

.golangci.yml

@@ -16,13 +16,6 @@ linters-settings:
     local-prefixes: github.com/ktong/konf
   govet:
     check-shadowing: true
-  ireturn:
-    allow:
-      - anon
-      - error
-      - empty
-      - stdlib
-      - T
   makezero:
     always: true
   misspell:
@@ -86,7 +79,7 @@ linters:
     - govet
     - grouper
     - importas
-    # inamedparam
+    - inamedparam
     - ineffassign
     - interfacebloat
     - ireturn

CHANGELOG.md

@@ -7,6 +7,10 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Changed
+
+- Split file and fs provider (#49).
+
 ### Removed
 
 - Remove konf.Logger in favor of slog (#48).

README.md

@@ -88,6 +88,7 @@ There are providers for the following configuration sources:
 - `env` loads configuration from environment variables.
 - `file` loads configuration from a file.
 - `flag` loads configuration from flags.
+- `fs` loads configuration from fs.FS.
 - `pflag` loads configuration from [spf13/pflag](https://github.com/spf13/pflag).
 
 ## Compatibility

config.go

@@ -20,7 +20,7 @@ import (
 type Config struct {
 	delimiter string
 
-	values    map[string]any
+	values    *provider
 	providers []*provider
 	watchOnce sync.Once
 }
@@ -29,6 +29,7 @@ type Config struct {
 func New(opts ...Option) (*Config, error) {
 	option := apply(opts)
 	config := option.Config
+	config.values = &provider{values: make(map[string]any)}
 	config.providers = make([]*provider, 0, len(option.loaders))
 
 	for _, loader := range option.loaders {
@@ -44,7 +45,7 @@ func New(opts ...Option) (*Config, error) {
 		if err != nil {
 			return nil, fmt.Errorf("[konf] load configuration: %w", err)
 		}
-		maps.Merge(config.values, values)
+		maps.Merge(config.values.values, values)
 		slog.Info(
 			"Configuration has been loaded.",
 			"loader", loader,
@@ -92,10 +93,10 @@ func (c *Config) Unmarshal(path string, target any) error {
 
 func (c *Config) sub(path string) any {
 	if path == "" {
-		return c.values
+		return c.values.values
 	}
 
-	var next any = c.values
+	var next any = c.values.values
 	for _, key := range strings.Split(strings.ToLower(path), c.delimiter) {
 		mp, ok := next.(map[string]any)
 		if !ok {
@@ -142,7 +143,7 @@ func (c *Config) Watch(ctx context.Context, fns ...func(*Config)) error { //noli
 				for _, w := range c.providers {
 					maps.Merge(values, w.values)
 				}
-				c.values = values
+				c.values.values = values
 
 				for _, fn := range fns {
 					fn(c)

config_test.go

@@ -10,7 +10,6 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
-	"golang.org/x/sync/errgroup"
 
 	"github.com/ktong/konf"
 )
@@ -179,26 +178,6 @@ func TestConfig_Watch(t *testing.T) {
 	require.Equal(t, "changed", cfg)
 }
 
-func TestConfig_Watch_twice(t *testing.T) {
-	t.Parallel()
-
-	config, err := konf.New(konf.WithLoader(mapWatcher(make(chan map[string]any))))
-	require.NoError(t, err)
-
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	group, ctx := errgroup.WithContext(ctx)
-	group.Go(func() error {
-		return config.Watch(ctx)
-	})
-	group.Go(func() error {
-		return config.Watch(ctx)
-	})
-
-	require.EqualError(t, group.Wait(), "[konf] Watch only can be called once")
-}
-
 type mapWatcher chan map[string]any
 
 func (m mapWatcher) Load() (map[string]any, error) {

example_test.go

@@ -4,16 +4,12 @@
 package konf_test
 
 import (
-	"context"
 	"embed"
 	"fmt"
-	"time"
-
-	"golang.org/x/sync/errgroup"
 
 	"github.com/ktong/konf"
 	"github.com/ktong/konf/provider/env"
-	"github.com/ktong/konf/provider/file"
+	pfs "github.com/ktong/konf/provider/fs"
 )
 
 func ExampleGet() {
@@ -42,33 +38,13 @@ func ExampleUnmarshal() {
 	// Output: example.com:8080
 }
 
-func ExampleWatch() {
-	ExampleSetGlobal()
-
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
-	defer cancel()
-
-	group, ctx := errgroup.WithContext(ctx)
-	group.Go(func() error {
-		return konf.Watch(ctx, func() {
-			fmt.Print(konf.Get[string]("server.host"))
-		})
-	})
-
-	if err := group.Wait(); err != nil {
-		// Handle error here.
-		panic(err)
-	}
-	// Output:
-}
-
 //go:embed testdata
 var testdata embed.FS
 
 func ExampleSetGlobal() {
 	cfg, err := konf.New(
 		konf.WithLoader(
-			file.New("testdata/config.json", file.WithFS(testdata)),
+			pfs.New(testdata, "testdata/config.json"),
 			env.New(env.WithPrefix("server")),
 		),
 	)

go.mod

@@ -2,21 +2,16 @@ module github.com/ktong/konf
 
 go 1.21
 
-require (
-	github.com/fsnotify/fsnotify v1.7.0
-	github.com/mitchellh/mapstructure v1.5.0
-)
+require github.com/mitchellh/mapstructure v1.5.0
 
 require ( // for test
 	github.com/stretchr/testify v1.8.4
 	go.uber.org/goleak v1.3.0
-	golang.org/x/sync v0.5.0
 )
 
 require ( // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/kr/text v0.2.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	golang.org/x/sys v0.14.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,9 +1,8 @@
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
-github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
@@ -14,11 +13,8 @@ github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcU
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
-golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
-golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
-golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

option.go

@@ -35,7 +35,6 @@ func apply(opts []Option) options {
 	option := &options{
 		Config: &Config{
 			delimiter: ".",
-			values:    make(map[string]any),
 		},
 	}
 	for _, opt := range opts {

provider.go

@@ -7,7 +7,7 @@ import "context"
 
 // Loader is the interface that wraps the Load method.
 //
-// Load loads configuration and returns as a nested map[string]any.
+// Load loads latest configuration and returns as a nested map[string]any.
 // It requires that the string keys should be nested like `{parent: {child: {key: 1}}}`.
 // The key in returned map should be case-insensitive, otherwise random overridden exists.
 type Loader interface {
@@ -16,17 +16,17 @@ type Loader interface {
 
 // Watcher is the interface that wraps the Watch method.
 //
-// Watch watches configuration and triggers a callback with full new configurations
-// as a nested map[string]any when it changes.
-// It blocks until ctx is done, or the service returns an error.
+// Watch watches configuration and triggers onChange callback with latest
+// full configurations as a nested map[string]any when it changes.
+// It blocks until ctx is done, or the watching returns an error.
 type Watcher interface {
-	Watch(context.Context, func(map[string]any)) error
+	Watch(ctx context.Context, onChange func(map[string]any)) error
 }
 
 // ConfigAware is the interface that wraps the WithConfig method.
 //
-// WithConfig enables provider loads configuration from providers before it.
+// WithConfig enables provider uses configuration loaded by providers before it.
 // It ensures the WithConfig is called before executing methods in Loader and Watcher.
 type ConfigAware interface {
-	WithConfig(*Config)
+	WithConfig(config *Config)
 }

provider/file/benchmark_test.go

@@ -5,24 +5,16 @@ package file_test
 
 import (
 	"testing"
-	"testing/fstest"
 
 	"github.com/stretchr/testify/require"
 
 	"github.com/ktong/konf/provider/file"
 )
 
 func BenchmarkNew(b *testing.B) {
-	mapFS := fstest.MapFS{
-		"config.json": {
-			Data: []byte(`{"k":"v"}`),
-		},
-	}
-	b.ResetTimer()
-
 	var loader file.File
 	for i := 0; i < b.N; i++ {
-		loader = file.New("config.json", file.WithFS(mapFS))
+		loader = file.New("testdata/config.json")
 	}
 	b.StopTimer()
 
@@ -32,12 +24,7 @@ func BenchmarkNew(b *testing.B) {
 }
 
 func BenchmarkLoad(b *testing.B) {
-	fs := fstest.MapFS{
-		"config.json": {
-			Data: []byte(`{"k":"v"}`),
-		},
-	}
-	loader := file.New("config.json", file.WithFS(fs))
+	loader := file.New("testdata/config.json")
 	b.ResetTimer()
 
 	var (