Add ContinueOnError (#161)

so watcher can continue watching even the loader fails to load the
configuration

.github/workflows/release.yml

@@ -45,24 +45,16 @@ jobs:
               name: "v${{ steps.query-release-info.outputs.version }}",
               body: `${{ steps.query-release-info.outputs.release-notes }}`
             })
-
-  tag:
-    strategy:
-      matrix:
-        module: [ 'provider/file', 'provider/pflag', 'provider/appconfig', 'provider/azappconfig', 'provider/secretmanager' ]
-    name: Submodules
-    needs: release
-    if: ${{ needs.release.steps.create-release.outcome == 'success' }}
-    runs-on: ubuntu-latest
-    steps:
-      - name: Create tag
+      - name: Tag Submodules
         uses: actions/github-script@v7
         with:
           script: |
-            ref = "refs/tags/${{ matrix.module }}/v${{ needs.release.steps.query-release-info.outputs.version }}"
-            github.rest.git.createRef({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              ref: ref,
-              sha: context.sha
-            })
+            const modules = [ 'provider/file', 'provider/pflag', 'provider/appconfig', 'provider/azappconfig', 'provider/secretmanager' ]
+            for (const module of modules) {
+              github.rest.git.createRef({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                ref: "refs/tags/${{ module }}/v${{ steps.query-release-info.outputs.version }}",
+                sha: context.sha
+              })
+            }

CHANGELOG.md

@@ -7,9 +7,16 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+## [0.6.2] - 2024-02-21
+
+### Fixed
+
+- Add ContinueOnError so watcher can continue watching even the loader fails to load the configuration (#161).
+
 ## [0.6.1] - 2024-02-21
 
 ### Changed
+
 - merge loader into providers even it fails the loading. Developers can ignore the loading error
   and wait for the watching to get latest configuration (#159).
 

config.go

@@ -82,13 +82,25 @@ func New(opts ...Option) Config {
 //
 // This method can be called multiple times but it is not concurrency-safe.
 // It panics if loader is nil.
-func (c Config) Load(loader Loader) error {
+func (c Config) Load(loader Loader, opts ...LoadOption) error {
 	if loader == nil {
 		panic("cannot load config from nil loader")
 	}
 
+	loadOption := &loadOptions{}
+	for _, opt := range opts {
+		opt(loadOption)
+	}
+
 	values, err := loader.Load()
+	if err != nil {
+		if !loadOption.continueOnError {
+			return fmt.Errorf("load configuration: %w", err)
+		}
+		c.logger.Warn("failed to load configuration", "loader", loader, "error", err)
+	}
 	maps.Merge(c.values, values)
+
 	// Merged to empty map to convert to lower case.
 	providerValues := make(map[string]any)
 	maps.Merge(providerValues, values)
@@ -97,10 +109,6 @@ func (c Config) Load(loader Loader) error {
 		values: providerValues,
 	})
 
-	if err != nil {
-		return fmt.Errorf("load configuration: %w", err)
-	}
-
 	return nil
 }
 

config_test.go

@@ -15,6 +15,41 @@ import (
 	"github.com/nil-go/konf/provider/env"
 )
 
+func TestConfig_Load_error(t *testing.T) {
+	t.Parallel()
+
+	testcases := []struct {
+		description string
+		opts        []konf.LoadOption
+		err         string
+	}{
+		{
+			description: "error",
+			err:         "load configuration: load error",
+		},
+		{
+			description: "continue on error",
+			opts:        []konf.LoadOption{konf.ContinueOnError()},
+		},
+	}
+
+	for _, testcase := range testcases {
+		testcase := testcase
+
+		t.Run(testcase.description, func(t *testing.T) {
+			t.Parallel()
+
+			config := konf.New()
+			err := config.Load(&errorLoader{}, testcase.opts...)
+			if testcase.err == "" {
+				assert.NoError(t, err)
+			} else {
+				assert.Equal(t, testcase.err, err.Error())
+			}
+		})
+	}
+}
+
 func TestConfig_Load_panic(t *testing.T) {
 	t.Parallel()
 

go.mod

@@ -3,3 +3,5 @@ module github.com/nil-go/konf
 go 1.21
 
 require github.com/go-viper/mapstructure/v2 v2.0.0-alpha.1
+
+retract v0.6.1 // It does not work while file is not exist

option.go

@@ -56,6 +56,20 @@ type (
 	options Config
 )
 
+func ContinueOnError() LoadOption {
+	return func(options *loadOptions) {
+		options.continueOnError = true
+	}
+}
+
+type (
+	// LoadOption configures Config.Load with specific options.
+	LoadOption  func(*loadOptions)
+	loadOptions struct {
+		continueOnError bool
+	}
+)
+
 // WithValueFormatter provides the value formatter for Config.Explain.
 // It's for hiding sensitive information (e.g. password, secret) which should not be exposed.
 //