feat(config): Add config Provider (#164)

Signed-off-by: Flc゛ <[email protected]>

config/config.go

@@ -0,0 +1,20 @@
+package config
+
+import "context"
+
+type configKey struct{}
+
+func NewContext[T any](ctx context.Context, config T) (context.Context, error) {
+	return context.WithValue(ctx, configKey{}, config), nil
+}
+
+func FromContext[T any](ctx context.Context) (T, bool) {
+	config, ok := ctx.Value(configKey{}).(T)
+	return config, ok
+}
+
+func Provider[T any](config T) func(ctx context.Context) (context.Context, error) {
+	return func(ctx context.Context) (context.Context, error) {
+		return NewContext(ctx, config)
+	}
+}

config/config_test.go

@@ -0,0 +1,35 @@
+package config
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type config struct {
+	Host string
+	Port int
+}
+
+type config2 struct {
+	Host string
+	Port int
+}
+
+func TestConfig(t *testing.T) {
+	ctx, err := Provider(&config{
+		Host: "localhost",
+		Port: 8080,
+	})(context.Background())
+	assert.NoError(t, err)
+
+	cfg, ok := FromContext[*config](ctx)
+	assert.True(t, ok)
+	assert.Equal(t, "localhost", cfg.Host)
+	assert.Equal(t, 8080, cfg.Port)
+
+	cfg2, ok := FromContext[*config2](ctx)
+	assert.False(t, ok)
+	assert.Nil(t, cfg2)
+}