1 files changed, 83 insertions, 0 deletions
diff --git a/common/predicate/predicate_test.go b/common/predicate/predicate_test.go
new file mode 100644
index 000000000..1e1ec004b
--- /dev/null
+++ b/common/predicate/predicate_test.go
@@ -0,0 +1,83 @@
+// Copyright 2024 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package predicate_test
+
+import (
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+	"github.com/gohugoio/hugo/common/predicate"
+)
+
+func TestAdd(t *testing.T) {
+	c := qt.New(t)
+
+	var p predicate.P[int] = intP1
+
+	c.Assert(p(1), qt.IsTrue)
+	c.Assert(p(2), qt.IsFalse)
+
+	neg := p.Negate()
+	c.Assert(neg(1), qt.IsFalse)
+	c.Assert(neg(2), qt.IsTrue)
+
+	and := p.And(intP2)
+	c.Assert(and(1), qt.IsFalse)
+	c.Assert(and(2), qt.IsFalse)
+	c.Assert(and(10), qt.IsTrue)
+
+	or := p.Or(intP2)
+	c.Assert(or(1), qt.IsTrue)
+	c.Assert(or(2), qt.IsTrue)
+	c.Assert(or(10), qt.IsTrue)
+	c.Assert(or(11), qt.IsFalse)
+}
+
+func TestFilter(t *testing.T) {
+	c := qt.New(t)
+
+	var p predicate.P[int] = intP1
+	p = p.Or(intP2)
+
+	ints := []int{1, 2, 3, 4, 1, 6, 7, 8, 2}
+
+	c.Assert(p.Filter(ints), qt.DeepEquals, []int{1, 2, 1, 2})
+	c.Assert(ints, qt.DeepEquals, []int{1, 2, 1, 2, 1, 6, 7, 8, 2})
+}
+
+func TestFilterCopy(t *testing.T) {
+	c := qt.New(t)
+
+	var p predicate.P[int] = intP1
+	p = p.Or(intP2)
+
+	ints := []int{1, 2, 3, 4, 1, 6, 7, 8, 2}
+
+	c.Assert(p.FilterCopy(ints), qt.DeepEquals, []int{1, 2, 1, 2})
+	c.Assert(ints, qt.DeepEquals, []int{1, 2, 3, 4, 1, 6, 7, 8, 2})
+}
+
+var intP1 = func(i int) bool {
+	if i == 10 {
+		return true
+	}
+	return i == 1
+}
+
+var intP2 = func(i int) bool {
+	if i == 10 {
+		return true
+	}
+	return i == 2
+}