Merge pull request #32 from siriustnt/mybranch

Eq now returns an empty Selector when an invalid index is given

array.go

@@ -5,13 +5,15 @@ import (
 )
 
 // First() reduces the set of matched elements to the first in the set.
-// It returns a new Selection object.
+// It returns a new Selection object, and an empty Selection object if the
+// the selection is empty.
 func (this *Selection) First() *Selection {
 	return this.Eq(0)
 }
 
 // Last() reduces the set of matched elements to the last in the set.
-// It returns a new Selection object.
+// It returns a new Selection object, and an empty Selection object if
+// the selection is empty.
 func (this *Selection) Last() *Selection {
 	return this.Eq(-1)
 }
@@ -24,6 +26,11 @@ func (this *Selection) Eq(index int) *Selection {
 	if index < 0 {
 		index += len(this.Nodes)
 	}
+
+	if index >= len(this.Nodes) || index < 0 {
+		return newEmptySelection(this.document)
+	}
+
 	return this.Slice(index, index+1)
 }
 

array_test.go

@@ -10,8 +10,8 @@ func TestFirst(t *testing.T) {
 }
 
 func TestFirstEmpty(t *testing.T) {
-	defer AssertPanic(t)
-	Doc().Find(".pvk-zzcontentzz").First()
+	sel := Doc().Find(".pvk-zzcontentzz").First()
+	AssertLength(t, sel.Nodes, 0)
 }
 
 func TestFirstRollback(t *testing.T) {
@@ -31,6 +31,11 @@ func TestLast(t *testing.T) {
 	}
 }
 
+func TestLastEmpty(t *testing.T) {
+	sel := Doc().Find(".pvk-zzcontentzz").Last()
+	AssertLength(t, sel.Nodes, 0)
+}
+
 func TestLastRollback(t *testing.T) {
 	sel := Doc().Find(".pvk-content")
 	sel2 := sel.Last().End()
@@ -53,6 +58,21 @@ func TestEqNegative(t *testing.T) {
 	}
 }
 
+func TestEqEmpty(t *testing.T) {
+	sel := Doc().Find("something_random_that_does_not_exists").Eq(0)
+	AssertLength(t, sel.Nodes, 0)
+}
+
+func TestEqInvalidPositive(t *testing.T) {
+	sel := Doc().Find(".pvk-content").Eq(3)
+	AssertLength(t, sel.Nodes, 0)
+}
+
+func TestEqInvalidNegative(t *testing.T) {
+	sel := Doc().Find(".pvk-content").Eq(-4)
+	AssertLength(t, sel.Nodes, 0)
+}
+
 func TestEqRollback(t *testing.T) {
 	sel := Doc().Find(".pvk-content")
 	sel2 := sel.Eq(1).End()