Addtitional agreement test

election/agreement_test.go

 package election
 
 import (
+	"math/big"
+	"strconv"
 	"testing"
 
 	"github.com/google/uuid"
@@ -79,3 +81,81 @@ func TestMaxSubset(t *testing.T) {
 		t.Error()
 	}
 }
+
+func TestBallotIntersect(t *testing.T) {
+	lists := []BallotList{
+		map[string]uuid.UUID{},
+		map[string]uuid.UUID{},
+		map[string]uuid.UUID{},
+	}
+
+	xs := createXS(3)
+	ballots := createAllBallots([]*big.Int{
+		big.NewInt(0), big.NewInt(1), big.NewInt(0), big.NewInt(0),
+		big.NewInt(1), big.NewInt(0), big.NewInt(1), big.NewInt(0),
+		big.NewInt(0), big.NewInt(1),
+	}, 3, 2, xs)
+
+	for _, bmap := range ballots {
+		for id, b := range bmap {
+			i, _ := strconv.Atoi(string(id))
+			lists[i-1][b.Hash()] = b.ID
+		}
+	}
+
+	inter := Intersection(lists)
+	if len(inter) != 10 {
+		t.Error()
+	}
+
+	for i := 0; i < len(lists); i++ {
+		count := 0
+		for h := range lists[i] {
+			if _, ok := inter[h]; ok {
+				count++
+			}
+		}
+		if count != 10 {
+			t.Error(i)
+		}
+	}
+}
+
+func TestBallotMaxSubset(t *testing.T) {
+	lists := []BallotList{
+		map[string]uuid.UUID{},
+		map[string]uuid.UUID{},
+		map[string]uuid.UUID{},
+	}
+
+	xs := createXS(3)
+	ballots := createAllBallots([]*big.Int{
+		big.NewInt(0), big.NewInt(1), big.NewInt(0), big.NewInt(0),
+		big.NewInt(1), big.NewInt(0), big.NewInt(1), big.NewInt(0),
+		big.NewInt(0), big.NewInt(1),
+	}, 3, 2, xs)
+
+	for _, bmap := range ballots {
+		for id, b := range bmap {
+			i, _ := strconv.Atoi(string(id))
+			lists[i-1][b.Hash()] = b.ID
+		}
+	}
+
+	inter := MaxSubset(2, lists)
+	if len(inter) != 10 {
+		t.Error()
+	}
+
+	for i := 0; i < len(lists); i++ {
+		count := 0
+		for h := range lists[i] {
+			if _, ok := inter[h]; ok {
+				count++
+			}
+		}
+		if count != 10 {
+			t.Error(i)
+		}
+	}
+}