Adds InventorySet Equals() function

cmd/kubectl/kubectlcobra/inventory.go

@@ -164,6 +164,16 @@ func (is *InventorySet) Subtract(other *InventorySet) (*InventorySet, error) {
 	return result, nil
 }
 
+// Equals returns true if the "other" inventory set is the same
+// as this current inventory set. Relies on the fact that the
+// inventory items are sorted for the String() function.
+func (is *InventorySet) Equals(other *InventorySet) bool {
+	if other == nil {
+		return false
+	}
+	return is.String() == other.String()
+}
+
 // String returns a string describing set of Inventory structs.
 func (is *InventorySet) String() string {
 	strs := []string{}

cmd/kubectl/kubectlcobra/inventory_test.go

@@ -487,3 +487,60 @@ func TestInventorySetSubtract(t *testing.T) {
 		}
 	}
 }
+
+func TestInventorySetEquals(t *testing.T) {
+	tests := []struct {
+		set1    []*Inventory
+		set2    []*Inventory
+		isEqual bool
+	}{
+		{
+			set1:    []*Inventory{},
+			set2:    []*Inventory{&inventory1},
+			isEqual: false,
+		},
+		{
+			set1:    []*Inventory{&inventory1},
+			set2:    []*Inventory{},
+			isEqual: false,
+		},
+		{
+			set1:    []*Inventory{&inventory1, &inventory2},
+			set2:    []*Inventory{&inventory1},
+			isEqual: false,
+		},
+		{
+			set1:    []*Inventory{&inventory1, &inventory2},
+			set2:    []*Inventory{&inventory3, &inventory4},
+			isEqual: false,
+		},
+		// Empty sets are equal.
+		{
+			set1:    []*Inventory{},
+			set2:    []*Inventory{},
+			isEqual: true,
+		},
+		{
+			set1:    []*Inventory{&inventory1},
+			set2:    []*Inventory{&inventory1},
+			isEqual: true,
+		},
+		// Ordering of the inventory items does not matter for equality.
+		{
+			set1:    []*Inventory{&inventory1, &inventory2},
+			set2:    []*Inventory{&inventory2, &inventory1},
+			isEqual: true,
+		},
+	}
+
+	for _, test := range tests {
+		invSet1 := NewInventorySet(test.set1)
+		invSet2 := NewInventorySet(test.set2)
+		if !invSet1.Equals(invSet2) && test.isEqual {
+			t.Errorf("Expected equal inventory sets; got unequal (%s)/(%s)\n", invSet1, invSet2)
+		}
+		if invSet1.Equals(invSet2) && !test.isEqual {
+			t.Errorf("Expected inequal inventory sets; got equal (%s)/(%s)\n", invSet1, invSet2)
+		}
+	}
+}