Add tests for token generation

internal/authentication/token.go

@@ -2,15 +2,14 @@ package authentication
 
 import (
 	"crypto/rand"
-	"log"
 	"math/big"
 )
 
 var (
-	tokenCharacters     = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
-	standardTokenLength = 64 // This length includes the prefix (one character).
-	compatTokenLength   = 15 // This length includes the prefix (one character).
-	applicationPrefix   = "A"
+	tokenCharacters        = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
+	regularTokenLength     = 64 // This length includes the prefix (one character).
+	compatTokenLength      = 15 // This length includes the prefix (one character).
+	applicationTokenPrefix = "A"
 )
 
 func randIntn(n int) int {
@@ -46,23 +45,13 @@ func generateRandomString(length int) string {
 	return string(res)
 }
 
-func generateRandomToken(prefix string, compat bool) string {
-	tokenLength := standardTokenLength
+// GenerateApplicationToken generates a token for an application.
+func GenerateApplicationToken(compat bool) string {
+	tokenLength := regularTokenLength
 
 	if compat {
 		tokenLength = compatTokenLength
 	}
 
-	// Although constant at the time of writing, this check should prevent future changes from generating insecure tokens.
-	randomLength := tokenLength - len(prefix)
-	if randomLength < 14 {
-		log.Fatalf("Tokens should have more than %d random characters", randomLength)
-	}
-
-	return prefix + generateRandomString(randomLength)
-}
-
-// GenerateApplicationToken generates a token for an application.
-func GenerateApplicationToken(compat bool) string {
-	return generateRandomToken(applicationPrefix, compat)
+	return applicationTokenPrefix + generateRandomString(tokenLength)
 }

internal/authentication/token_test.go

@@ -0,0 +1,48 @@
+package authentication
+
+import (
+	"log"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func isGoodToken(assert *assert.Assertions, require *require.Assertions, token string, compat bool) {
+	prefix := token[0:len(applicationTokenPrefix)]
+	token = token[len(applicationTokenPrefix):]
+
+	// Although constant at the time of writing, this check should prevent future changes from generating insecure tokens.
+	if len(token) < 14 {
+		log.Fatalf("Tokens should have more random characters")
+	}
+
+	if compat {
+		assert.Equal(len(token), compatTokenLength, "Unexpected compatibility token length")
+	} else {
+		assert.Equal(len(token), regularTokenLength, "Unexpected regular token length")
+	}
+
+	assert.Equal(prefix, applicationTokenPrefix, "Invalid token prefix")
+
+	for _, c := range []byte(token) {
+		assert.Contains(tokenCharacters, c, "Unexpected character in token")
+	}
+}
+
+func TestAuthentication_GenerateApplicationToken(t *testing.T) {
+	assert := assert.New(t)
+	require := require.New(t)
+
+	for i := 0; i < 64; i++ {
+		token := GenerateApplicationToken(false)
+
+		isGoodToken(assert, require, token, false)
+	}
+
+	for i := 0; i < 64; i++ {
+		token := GenerateApplicationToken(true)
+
+		isGoodToken(assert, require, token, true)
+	}
+}