1 files changed, 162 insertions, 0 deletions
diff --git a/internal/util/xslices/slices_test.go b/internal/util/xslices/slices_test.go
new file mode 100644
index 000000000..7c62ac77f
--- /dev/null
+++ b/internal/util/xslices/slices_test.go
@@ -0,0 +1,162 @@
+// 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 xslices_test
+
+import (
+	"math/rand"
+	"net/url"
+	"slices"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/superseriousbusiness/gotosocial/internal/util/xslices"
+)
+
+func TestGrowJust(t *testing.T) {
+	for _, l := range []int{0, 2, 4, 8, 16, 32, 64} {
+		for _, x := range []int{0, 2, 4, 8, 16, 32, 64} {
+			s := make([]int, l, l+x)
+			for _, g := range []int{0, 2, 4, 8, 16, 32, 64} {
+				s2 := xslices.GrowJust(s, g)
+
+				// Slice length should not be different.
+				assert.Equal(t, len(s), len(s2))
+
+				switch {
+				// If slice already has capacity for
+				// 'g' then it should not be changed.
+				case cap(s) >= len(s)+g:
+					assert.Equal(t, cap(s), cap(s2))
+
+				// Else, returned slice should only
+				// have capacity for original length
+				// plus extra elements, NOTHING MORE.
+				default:
+					assert.Equal(t, cap(s2), len(s)+g)
+				}
+			}
+		}
+	}
+}
+
+func TestAppendJust(t *testing.T) {
+	for _, l := range []int{0, 2, 4, 8, 16, 32, 64} {
+		for _, x := range []int{0, 2, 4, 8, 16, 32, 64} {
+			s := make([]int, l, l+x)
+
+			// Randomize slice.
+			for i := range s {
+				s[i] = rand.Int()
+			}
+
+			for _, a := range []int{0, 2, 4, 8, 16, 32, 64} {
+				toAppend := make([]int, a)
+
+				// Randomize appended vals.
+				for i := range toAppend {
+					toAppend[i] = rand.Int()
+				}
+
+				s2 := xslices.AppendJust(s, toAppend...)
+
+				// Slice length should be as expected.
+				assert.Equal(t, len(s)+a, len(s2))
+
+				// Slice contents should be as expected.
+				assert.Equal(t, append(s, toAppend...), s2)
+
+				switch {
+				// If slice already has capacity for
+				// 'toAppend' then it should not change.
+				case cap(s) >= len(s)+a:
+					assert.Equal(t, cap(s), cap(s2))
+
+				// Else, returned slice should only
+				// have capacity for original length
+				// plus extra elements, NOTHING MORE.
+				default:
+					assert.Equal(t, len(s)+a, cap(s2))
+				}
+			}
+		}
+	}
+}
+
+func TestGather(t *testing.T) {
+	out := xslices.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 = xslices.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 := xslices.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 = xslices.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")
+	}
+}