Add basic unit tests (#5)

* Add basic unit tests

cmd/root.go

@@ -43,10 +43,14 @@ func generateSecretSantaMatches(data []Data) []MatchPair {
 		shuffledData[i], shuffledData[j] = shuffledData[j], shuffledData[i]
 	})
 
+	return circlularMatchingAlgorithm(shuffledData)
+}
+
+func circlularMatchingAlgorithm(data []Data) []MatchPair {
 	var matches []MatchPair
-	for i := 0; i < len(shuffledData); i++ {
-		from := shuffledData[i]
-		to := shuffledData[(i+1)%len(shuffledData)]
+	for i := 0; i < len(data); i++ {
+		from := data[i]
+		to := data[(i+1)%len(data)]
 		matches = append(matches, MatchPair{From: from, To: to})
 	}
 	return matches

cmd/root_test.go

@@ -0,0 +1,64 @@
+package cmd
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestCheckFileExistsReturnsTrueWhenFileExists(t *testing.T) {
+	if !checkFileExists("../test_data.json") {
+		t.Error("Expected checkFileExists to return true when file exists")
+	}
+
+}
+
+func TestCheckFileExistsReturnsFalseWhenFileDoesNotExist(t *testing.T) {
+	if checkFileExists("file_does_not_exist.json") {
+		t.Error("Expected checkFileExists to return false when file does not exist")
+	}
+}
+
+func TestCheckIsJsonReturnsTrueWhenFileIsJson(t *testing.T) {
+	if !checkIsJson("../test_data.json") {
+		t.Error("Expected checkIsJson to return true when file is json")
+	}
+}
+
+func TestCheckIsJsonReturnsFalseWhenFileIsNotJson(t *testing.T) {
+	if checkIsJson("../test_data.txt") {
+		t.Error("Expected checkIsJson to return false when file is not json")
+	}
+}
+
+func TestGenerateSecretSantaMachesReturnsAppropriateLenghtOfMatchPairs(t *testing.T) {
+	var payload []Data
+	payload = append(payload, Data{Name: "A", Email: "testa@test.org"})
+	payload = append(payload, Data{Name: "B", Email: "testb@test.org"})
+	payload = append(payload, Data{Name: "C", Email: "testb@test.org"})
+
+	matches := generateSecretSantaMatches(payload)
+
+	if len(matches) != len(payload) {
+		t.Error("Expected generateSecretSantaMatches to return the same number of matches as participants")
+	}
+}
+
+func TestCircularMatchingAlgorithmReturnsExpectedMatchPairs(t *testing.T) {
+	var payload []Data
+	payload = append(payload, Data{Name: "A", Email: "testa@test.org"})
+	payload = append(payload, Data{Name: "B", Email: "testb@test.org"})
+	payload = append(payload, Data{Name: "C", Email: "testb@test.org"})
+
+	var expected []MatchPair
+
+	expected = append(expected, MatchPair{From: payload[0], To: payload[1]})
+	expected = append(expected, MatchPair{From: payload[1], To: payload[2]})
+	expected = append(expected, MatchPair{From: payload[2], To: payload[0]})
+
+	result := circlularMatchingAlgorithm(payload)
+
+	if !reflect.DeepEqual(result, expected) {
+		t.Error("Expected circlularMatchingAlgorithm to return expected list of match pairs")
+	}
+
+}