fs: add --metadata-set flag to specify metadata for uploads

fs/metadata_test.go

@@ -1,6 +1,7 @@
 package fs
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -15,3 +16,81 @@ func TestMetadataSet(t *testing.T) {
 	m.Set("key", "value2")
 	assert.Equal(t, "value2", m["key"])
 }
+
+func TestMetadataMerge(t *testing.T) {
+	for _, test := range []struct {
+		in    Metadata
+		merge Metadata
+		want  Metadata
+	}{
+		{
+			in:    Metadata{},
+			merge: Metadata{},
+			want:  Metadata{},
+		}, {
+			in:    nil,
+			merge: nil,
+			want:  nil,
+		}, {
+			in:    nil,
+			merge: Metadata{},
+			want:  nil,
+		}, {
+			in:    nil,
+			merge: Metadata{"a": "1", "b": "2"},
+			want:  Metadata{"a": "1", "b": "2"},
+		}, {
+			in:    Metadata{"a": "1", "b": "2"},
+			merge: nil,
+			want:  Metadata{"a": "1", "b": "2"},
+		}, {
+			in:    Metadata{"a": "1", "b": "2"},
+			merge: Metadata{"b": "B", "c": "3"},
+			want:  Metadata{"a": "1", "b": "B", "c": "3"},
+		},
+	} {
+		what := fmt.Sprintf("in=%v, merge=%v", test.in, test.merge)
+		test.in.Merge(test.merge)
+		assert.Equal(t, test.want, test.in, what)
+	}
+}
+
+func TestMetadataMergeOptions(t *testing.T) {
+	for _, test := range []struct {
+		in   Metadata
+		opts []OpenOption
+		want Metadata
+	}{
+		{
+			opts: []OpenOption{},
+			want: nil,
+		}, {
+			opts: []OpenOption{&HTTPOption{}},
+			want: nil,
+		}, {
+			opts: []OpenOption{MetadataOption{"a": "1", "b": "2"}},
+			want: Metadata{"a": "1", "b": "2"},
+		}, {
+			opts: []OpenOption{
+				&HTTPOption{},
+				MetadataOption{"a": "1", "b": "2"},
+				MetadataOption{"b": "B", "c": "3"},
+				&HTTPOption{},
+			},
+			want: Metadata{"a": "1", "b": "B", "c": "3"},
+		}, {
+			in: Metadata{"a": "first", "z": "OK"},
+			opts: []OpenOption{
+				&HTTPOption{},
+				MetadataOption{"a": "1", "b": "2"},
+				MetadataOption{"b": "B", "c": "3"},
+				&HTTPOption{},
+			},
+			want: Metadata{"a": "1", "b": "B", "c": "3", "z": "OK"},
+		},
+	} {
+		what := fmt.Sprintf("in=%v, opts=%v", test.in, test.opts)
+		test.in.MergeOptions(test.opts)
+		assert.Equal(t, test.want, test.in, what)
+	}
+}