Consider the prefix when testing token length

Makefile

@@ -5,14 +5,12 @@ build:
 
 .PHONY: test
 test:
-	stdout=$$(gofmt -l . 2>&1); \
+	stdout=$$(gofmt -l . 2>&1); if [ "$$stdout" ]; then exit 1; fi
-	if [ "$$stdout" ]; then \
-		exit 1; \
-	fi
 	go vet ./...
 	gocyclo -over 10 $(shell find . -iname '*.go' -type f)
 	staticcheck ./...
 	go test -v -cover ./...
+	@printf '\n%s\n' "> Test successful"
 
 .PHONY: setup
 setup:

internal/authentication/token_test.go

@@ -8,20 +8,22 @@ import (
 )
 
 const (
-	minTokenLength = 14
+	minRandomChars = 14
 )
 
 func isGoodToken(assert *assert.Assertions, require *require.Assertions, token string, compat bool) {
+	tokenLength := len(token)
+
 	if compat {
-		assert.Equal(len(token), compatTokenLength, "Unexpected compatibility token length")
+		assert.Equal(tokenLength, compatTokenLength, "Unexpected compatibility token length")
 	} else {
-		assert.Equal(len(token), regularTokenLength, "Unexpected regular token length")
+		assert.Equal(tokenLength, regularTokenLength, "Unexpected regular token length")
 	}
 
-	assert.GreaterOrEqual(len(token), minTokenLength, "Token is too short to give sufficient entropy")
+	randomChars := tokenLength - len(applicationTokenPrefix)
+	assert.GreaterOrEqual(randomChars, minRandomChars, "Token is too short to give sufficient entropy")
 
 	prefix := token[0:len(applicationTokenPrefix)]
-
 	assert.Equal(prefix, applicationTokenPrefix, "Invalid token prefix")
 
 	for _, c := range []byte(token) {