test(span): More tests and docs for span lib

Author: angch

angch/span/span.go

@@ -18,6 +18,8 @@ func (s Spans[T]) Add(from, to int, content T) Spans[T] {
 	return newspan
 }
 
+// AddCompress add a new span, sort and compress existing one and returns a *new*
+// Spans[T]. Make sure you assign or reassign the new Spans. Can't help it, generics
 func (s Spans[T]) AddCompress(from, to int, content T) Spans[T] {
 	// FIXME, this func hasn't been fixed to make sure content is the same before merging
 	from, to = min(from, to), max(from, to)

angch/span/span_test.go

@@ -1,6 +1,7 @@
 package span
 
 import (
+	"log"
 	"reflect"
 	"testing"
 )
@@ -48,3 +49,36 @@ func TestAddInt(t *testing.T) {
 		})
 	}
 }
+
+func TestSpans_Contains(t *testing.T) {
+
+	// Test spans based on AoC 2025-05
+	spans := NewSpans[bool]()
+	spans = spans.AddCompress(3, 5, true)
+	spans = spans.AddCompress(10, 14, true)
+	spans = spans.AddCompress(16, 20, true)
+	spans = spans.AddCompress(12, 18, true)
+
+	tests := []struct {
+		name string // description of this test case
+		// Named input parameters for target function.
+		i    int
+		want bool
+	}{
+		{"1", 1, false},
+		{"5", 5, true},
+		{"8", 8, false},
+		{"11", 11, true},
+		{"17", 17, true},
+		{"32", 32, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			log.Println(spans)
+			got := spans.Contains(tt.i)
+			if got != tt.want {
+				t.Errorf("Contains() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}