fix: unexpected error with --select-tag and multiple files

[GGabriele]

When running sync with multiple files and --select-tag,
deck simply appends the existing _info.select_tags of the
various files. If the same tag(s) are present in the files,
these are appended together making deck fail because the
tags passed via the command flag and the ones coming from
the files are expected to match, but the way files are
merged may cause duplicates, hence the unexpected failure.

This removes duplicates from the _info.select_tags resulted
from the merged files.

Related to #561

[rainest]

Can you add a case to

deck/cmd/common_test.go

Lines 11 to 67 in d0573b4

	func TestDetermineSelectorTag(t *testing.T) {
	type args struct {
	dumpConfig dump.Config
	fileContent file.Content
	}
	tests := []struct {
	name string
	args args
	want []string
	wantErr bool
	}{
	{
	name: "both present and equal",
	args: args{
	dumpConfig: dump.Config{SelectorTags: []string{"foo"}},
	fileContent: file.Content{Info: &file.Info{SelectorTags: []string{"foo"}}},
	},
	want: []string{"foo"},
	wantErr: false,
	},
	{
	name: "both present and equal order invariant",
	args: args{
	dumpConfig: dump.Config{SelectorTags: []string{"foo", "bar"}},
	fileContent: file.Content{Info: &file.Info{SelectorTags: []string{"bar", "foo"}}},
	},
	want: []string{"bar", "foo"},
	wantErr: false,
	},
	{
	name: "both present and not equal",
	args: args{
	dumpConfig: dump.Config{SelectorTags: []string{"bar"}},
	fileContent: file.Content{Info: &file.Info{SelectorTags: []string{"foo"}}},
	},
	want: nil,
	wantErr: true,
	},
	{
	name: "only file has tags",
	args: args{
	dumpConfig: dump.Config{},
	fileContent: file.Content{Info: &file.Info{SelectorTags: []string{"foo"}}},
	},
	want: []string{"foo"},
	wantErr: false,
	},
	{
	name: "only config has tags",
	args: args{
	dumpConfig: dump.Config{SelectorTags: []string{"foo"}},
	fileContent: file.Content{Info: &file.Info{}},
	},
	want: []string{"foo"},
	wantErr: false,
	},
	}

that would trigger the issue without this fix?

[GGabriele]

Can you add a case to

deck/cmd/common_test.go

Lines 11 to 67 in d0573b4

	func TestDetermineSelectorTag(t *testing.T) {
	type args struct {
	dumpConfig dump.Config
	fileContent file.Content
	}
	tests := []struct {
	name string
	args args
	want []string
	wantErr bool
	}{
	{
	name: "both present and equal",
	args: args{
	dumpConfig: dump.Config{SelectorTags: []string{"foo"}},
	fileContent: file.Content{Info: &file.Info{SelectorTags: []string{"foo"}}},
	},
	want: []string{"foo"},
	wantErr: false,
	},
	{
	name: "both present and equal order invariant",
	args: args{
	dumpConfig: dump.Config{SelectorTags: []string{"foo", "bar"}},
	fileContent: file.Content{Info: &file.Info{SelectorTags: []string{"bar", "foo"}}},
	},
	want: []string{"bar", "foo"},
	wantErr: false,
	},
	{
	name: "both present and not equal",
	args: args{
	dumpConfig: dump.Config{SelectorTags: []string{"bar"}},
	fileContent: file.Content{Info: &file.Info{SelectorTags: []string{"foo"}}},
	},
	want: nil,
	wantErr: true,
	},
	{
	name: "only file has tags",
	args: args{
	dumpConfig: dump.Config{},
	fileContent: file.Content{Info: &file.Info{SelectorTags: []string{"foo"}}},
	},
	want: []string{"foo"},
	wantErr: false,
	},
	{
	name: "only config has tags",
	args: args{
	dumpConfig: dump.Config{SelectorTags: []string{"foo"}},
	fileContent: file.Content{Info: &file.Info{}},
	},
	want: []string{"foo"},
	wantErr: false,
	},
	}

that would trigger the issue without this fix?

Done: 32071ed