[chore] add some more slice related utility functions + remove duplicated functions (#3149)

internal/util/slices_test.go

@@ -0,0 +1,94 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package util_test
+
+import (
+	"net/url"
+	"slices"
+	"testing"
+
+	"github.com/superseriousbusiness/gotosocial/internal/util"
+)
+
+var (
+	testURLSlice = []*url.URL{}
+)
+
+func TestGather(t *testing.T) {
+	out := util.Gather(nil, []*url.URL{
+		{Scheme: "https", Host: "google.com", Path: "/some-search"},
+		{Scheme: "http", Host: "example.com", Path: "/robots.txt"},
+	}, (*url.URL).String)
+	if !slices.Equal(out, []string{
+		"https://google.com/some-search",
+		"http://example.com/robots.txt",
+	}) {
+		t.Fatal("unexpected gather output")
+	}
+
+	out = util.Gather([]string{
+		"starting input string",
+		"another starting input",
+	}, []*url.URL{
+		{Scheme: "https", Host: "google.com", Path: "/some-search"},
+		{Scheme: "http", Host: "example.com", Path: "/robots.txt"},
+	}, (*url.URL).String)
+	if !slices.Equal(out, []string{
+		"starting input string",
+		"another starting input",
+		"https://google.com/some-search",
+		"http://example.com/robots.txt",
+	}) {
+		t.Fatal("unexpected gather output")
+	}
+}
+
+func TestGatherIf(t *testing.T) {
+	out := util.GatherIf(nil, []string{
+		"hello world",
+		"not hello world",
+		"hello world",
+	}, func(s string) (string, bool) {
+		return s, s == "hello world"
+	})
+	if !slices.Equal(out, []string{
+		"hello world",
+		"hello world",
+	}) {
+		t.Fatal("unexpected gatherif output")
+	}
+
+	out = util.GatherIf([]string{
+		"starting input string",
+		"another starting input",
+	}, []string{
+		"hello world",
+		"not hello world",
+		"hello world",
+	}, func(s string) (string, bool) {
+		return s, s == "hello world"
+	})
+	if !slices.Equal(out, []string{
+		"starting input string",
+		"another starting input",
+		"hello world",
+		"hello world",
+	}) {
+		t.Fatal("unexpected gatherif output")
+	}
+}