Added first tests

README.md

@@ -37,8 +37,7 @@ Thus, with a connection and a way of communication, the sender will send some pa
 - No way to verify if the transferred file is not corrupted; FIXED via checksum- [x]
 - No encryption; FIXED via AES encryption of packets` body - [x] 
 - Messy and hard to follow code && file structure; FIXED? - [x] 
-- No way to stop the download/upload and resume it later or even during the next connection; FIXED - [ ] 
+- No tests; FIXED - [x]; Not every packet has its tests, but they are present
-- No tests; FIXED - [ ]
 
 ## Good points
 - It works.
@@ -80,6 +79,14 @@ Thus, with a connection and a way of communication, the sender will send some pa
 - `./FTU -downloadto="/home/some_path_here/Downloads/" -addr="192.168.1.104"` - creates a client (receiver) that will try to connect to `192.168.1.104` (local device) on port `8080` and if successful - downloads a file to given path
 - `./FTU -downloadto="/home/some_path_here/Downloads/" -addr=145.125.53.212 -port=8888` - same as before, but will try to connect to `145.125.53.212` on port `8888`
 
+---
+
+## Testing
+
+In FTU directory:
+
+- `go test ./...` - to test recursively
+- `go test -v ./...` - to test recursively, with additional information 
 
 ---
 

checksum/checksum.go

@@ -32,7 +32,7 @@ func GetPartialCheckSum(file *os.File) (CheckSum, error) {
 	fileSize := fileStats.Size()
 
 	if fileSize < int64(CHUNKS*CHUNKSIZE+STEP*(CHUNKS-1)) {
-		// file is too small, doing full checksum
+		// file is too small to chop it in chunks, so just doing full checksum
 
 		checksum, err := getFullCheckSum(file)
 		if err != nil {
@@ -85,6 +85,8 @@ func AreEqual(checksum1, checksum2 CheckSum) bool {
 func BytesToChecksum(bytes []byte) (CheckSum, error) {
 	if uint(len(bytes)) > CHECKSUMLEN {
 		return CheckSum{}, fmt.Errorf("provided bytes` length is bigger than the checksum`s")
+	} else if uint(len(bytes)) < CHECKSUMLEN {
+		return CheckSum{}, fmt.Errorf("provided bytes` length is smaller than needed")
 	}
 
 	var checksum [CHECKSUMLEN]byte

checksum/checksum_test.go

@@ -0,0 +1,42 @@
+package checksum
+
+import (
+	"testing"
+)
+
+func TestBytesToChecksum(t *testing.T) {
+	invalidChecksumBytes := []byte("LESSTHAN32")
+	_, err := BytesToChecksum(invalidChecksumBytes)
+	if err == nil {
+		t.Error("BytesToChecksum failed: expected an error")
+	}
+
+	invalidChecksumBytes = []byte("BIGGERTHAN32_IFJOWIJFOIHJGLVKNS'O[DFJQWG[OJHNE[OJGNJOREG")
+	_, err = BytesToChecksum(invalidChecksumBytes)
+	if err == nil {
+		t.Error("BytesToChecksum failed: expected an error")
+	}
+
+	validChecksumBytes := []byte{5, 194, 47, 217, 251, 195, 69, 230, 216, 121, 253, 38,
+		116, 68, 152, 68, 103, 226, 16, 58, 235, 47, 6, 55, 27, 20, 83, 152, 89, 38, 59, 29}
+	_, err = BytesToChecksum(validChecksumBytes)
+	if err != nil {
+		t.Errorf("BytesToChecksum failed: not expected an error, got : %s; length of given bytes: %d", err, len(validChecksumBytes))
+	}
+}
+
+func TestChecksumToBytes(t *testing.T) {
+	validChecksumBytes := []byte{5, 194, 47, 217, 251, 195, 69, 230, 216, 121, 253, 38,
+		116, 68, 152, 68, 103, 226, 16, 58, 235, 47, 6, 55, 27, 20, 83, 152, 89, 38, 59, 29}
+
+	var validChecksum CheckSum = CheckSum{5, 194, 47, 217, 251, 195, 69, 230, 216, 121, 253, 38,
+		116, 68, 152, 68, 103, 226, 16, 58, 235, 47, 6, 55, 27, 20, 83, 152, 89, 38, 59, 29}
+
+	result := ChecksumToBytes(validChecksum)
+
+	for index, b := range result {
+		if b != validChecksumBytes[index] {
+			t.Errorf("ChecksumToBytes failed, invalid result")
+		}
+	}
+}

encryption/encrypt.go

@@ -20,5 +20,6 @@ func Encrypt(key, dataToEncrypt []byte) ([]byte, error) {
 	nonce := make([]byte, aesGCM.NonceSize())
 	encryptedData := aesGCM.Seal(nonce, nonce, dataToEncrypt, nil)
 
+	fmt.Printf("EEEEEEEEEEEEEEEEEE %v\n", encryptedData)
 	return encryptedData, nil
 }

encryption/encryption_test.go

@@ -0,0 +1,11 @@
+package encryption
+
+import "testing"
+
+func TestGenerate32AESkey(t *testing.T) {
+	generatedKey := Generate32AESkey()
+
+	if len(generatedKey) != int(KEYLEN) {
+		t.Errorf("Generate32AESkey failed: generated key`s length does not equal KEYLEN const (32)")
+	}
+}