Add more test cases and add UniqueValues check

cmd/web/handlers.go

@@ -69,6 +69,11 @@ func isRequestValid(r *createElectionRequestWithValidator) bool {
 	r.CheckField(validator.GreaterThan(r.Tokens, 0), "tokens", "must be greater than 0")
 	r.CheckField(validator.After(r.ExpiresAt, time.Now()), "expiresAt", "must expire in a future date")
 	r.CheckField(validator.GreaterThan(len(r.Choices), 1), "choices", "there must be more than 1 choice")
+	r.CheckField(validator.UniqueValues(r.Choices), "choices", "must not contain duplicate values")
+
+	for _, choice := range r.Choices {
+		r.CheckField(validator.NotBlank(choice), "choice", "must not be blank")
+	}
 
 	if r.AreVotersKnown {
 		r.CheckField(

cmd/web/handlers_test.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"bytes"
-	api "code.dlmw.ch/dlmw/qv/internal"
+	"code.dlmw.ch/dlmw/qv/internal"
 	"encoding/json"
 	"github.com/stretchr/testify/assert"
 	"net/http"
@@ -47,6 +47,19 @@ func TestCreateElection(t *testing.T) {
 			},
 			expectedCode: http.StatusOK,
 		},
+		{
+			name:    "Valid request (with 3 choices)",
+			urlPath: "/election",
+			body: api.CreateElectionRequest{
+				Choices:        []string{"Gandhi", "Buddha", "You"},
+				ExpiresAt:      time.Now().Add(24 * time.Hour),
+				AreVotersKnown: false,
+				MaxVoters:      0,
+				Name:           "Guy of the year",
+				Tokens:         100,
+			},
+			expectedCode: http.StatusOK,
+		},
 		{
 			name:    "Valid request (voters unknown with max voters)",
 			urlPath: "/election",
@@ -125,6 +138,32 @@ func TestCreateElection(t *testing.T) {
 			},
 			expectedCode: http.StatusUnprocessableEntity,
 		},
+		{
+			name:    "Invalid request (choices are not unique)",
+			urlPath: "/election",
+			body: api.CreateElectionRequest{
+				Choices:        []string{"Gandhi", "Gandhi"},
+				ExpiresAt:      time.Now().Add(24 * time.Hour),
+				AreVotersKnown: false,
+				MaxVoters:      0,
+				Name:           "Guy of the year",
+				Tokens:         100,
+			},
+			expectedCode: http.StatusUnprocessableEntity,
+		},
+		{
+			name:    "Invalid request (choices contain blank entries)",
+			urlPath: "/election",
+			body: api.CreateElectionRequest{
+				Choices:        []string{"Gandhi", "Buddha", ""},
+				ExpiresAt:      time.Now().Add(24 * time.Hour),
+				AreVotersKnown: false,
+				MaxVoters:      0,
+				Name:           "Guy of the year",
+				Tokens:         100,
+			},
+			expectedCode: http.StatusUnprocessableEntity,
+		},
 	}
 
 	for _, tt := range tests {

internal/validator/validator.go

@@ -67,3 +67,16 @@ func GreaterThanOrEquals(value int, n int) bool {
 func After(value time.Time, n time.Time) bool {
 	return value.After(n)
 }
+
+func UniqueValues[T comparable](values []T) bool {
+	seen := make(map[T]bool)
+
+	for _, value := range values {
+		if seen[value] {
+			return false
+		}
+		seen[value] = true
+	}
+
+	return true
+}