feat: add support for loading features from a filesystem

Signed-off-by: Mark Sagi-Kazar <mark.sagikazar@gmail.com>

features/features.go

@@ -0,0 +1,17 @@
+//go:build go1.16
+// +build go1.16
+
+package features
+
+import (
+	"embed"
+	"io/fs"
+)
+
+//go:embed *.feature
+var features embed.FS
+
+// Features returns a filesystem that contains feature files.
+func Features() fs.FS {
+  return features
+}

go.mod

@@ -1,6 +1,6 @@
 module github.com/go-bdd/gobdd
 
-go 1.12
+go 1.16
 
 require (
 	github.com/cucumber/gherkin-go/v13 v13.0.0

gobdd_go1_16.go

@@ -0,0 +1,63 @@
+//go:build go1.16
+// +build go1.16
+
+package gobdd
+
+import (
+	"fmt"
+	"io"
+	"io/fs"
+)
+
+// WithFeaturesFS configures a filesystem and a pattern (regexp) where features can be found.
+// An empty path defaults to "*.feature"
+func WithFeaturesFS(fs fs.FS, pattern string) func(*SuiteOptions) {
+	return func(options *SuiteOptions) {
+		options.featureSource = fsFeatureSource{
+      fs: fs,
+      pattern: pattern,
+    }
+	}
+}
+
+type fsFeatureSource struct {
+	fs      fs.FS
+	pattern string
+}
+
+func (s fsFeatureSource) loadFeatures() ([]feature, error) {
+	pattern := s.pattern
+	if pattern == "" {
+		pattern = "*.feature"
+	}
+
+	files, err := fs.Glob(s.fs, pattern)
+	if err != nil {
+		return nil, fmt.Errorf("loading features: %w", err)
+	}
+
+	features := make([]feature, 0, len(files))
+
+	for _, f := range files {
+		features = append(features, fsFeature{
+			fs:   s.fs,
+			file: f,
+		})
+	}
+
+	return features, nil
+}
+
+type fsFeature struct {
+	fs   fs.FS
+	file string
+}
+
+func (f fsFeature) Open() (io.Reader, error) {
+	file, err := f.fs.Open(string(f.file))
+	if err != nil {
+		return nil, fmt.Errorf("opening feature: %w", err)
+	}
+
+	return file, nil
+}

gobdd_go1_16_test.go

@@ -0,0 +1,21 @@
+//go:build go1.16
+// +build go1.16
+
+package gobdd
+
+import (
+	"regexp"
+	"testing"
+
+	"github.com/go-bdd/gobdd/features"
+)
+
+func TestWithFeaturesFS(t *testing.T) {
+	suite := NewSuite(t, WithFeaturesFS(features.Features(), "example.feature"))
+	compiled := regexp.MustCompile(`I add (\d+) and (\d+)`)
+	suite.AddRegexStep(compiled, add)
+	compiled = regexp.MustCompile(`the result should equal (\d+)`)
+	suite.AddRegexStep(compiled, check)
+
+	suite.Run()
+}