chore: import upstream snapshot with attribution

config/source/file/format_test.go

@@ -0,0 +1,30 @@
+package file
+
+import (
+	"testing"
+
+	"go-micro.dev/v6/config/source"
+)
+
+func TestFormat(t *testing.T) {
+	opts := source.NewOptions()
+	e := opts.Encoder
+
+	testCases := []struct {
+		p string
+		f string
+	}{
+		{"/foo/bar.json", "json"},
+		{"/foo/bar.yaml", "yaml"},
+		{"/foo/bar.xml", "xml"},
+		{"/foo/bar.conf.ini", "ini"},
+		{"conf", e.String()},
+	}
+
+	for _, d := range testCases {
+		f := format(d.p, e)
+		if f != d.f {
+			t.Fatalf("%s: expected %s got %s", d.p, d.f, f)
+		}
+	}
+}