Fix in the URL parser with go 1.12.8 and github.com/go-sql-driver/mysql

Change schemeFromURL to just split the url by :// to find the scheme.
It's not required to parse the whole URL. MySQL DSNs aren't valid URLs.

Fixes golang-migrate#264

util.go

@@ -74,15 +74,13 @@ func schemeFromURL(url string) (string, error) {
 		return "", errEmptyURL
 	}
 
-	u, err := nurl.Parse(url)
-	if err != nil {
-		return "", err
-	}
-	if len(u.Scheme) == 0 {
+	parts := strings.SplitN(url, "://", 2)
+
+	if len(parts) < 2 || parts[0] == "" {
 		return "", errNoScheme
 	}
 
-	return u.Scheme, nil
+	return parts[0], nil
 }
 
 // FilterCustomQuery filters all query values starting with `x-`

util_test.go

@@ -86,6 +86,19 @@ func TestDatabaseSchemeFromUrlSuccess(t *testing.T) {
 	}
 }
 
+func TestDatabaseSchemeFromUrlIssue264(t *testing.T) {
+	urlStr := "mysql://user:pass@tcp(host:1337)/db"
+	expected := "mysql"
+
+	u, err := databaseSchemeFromURL(urlStr)
+	if err != nil {
+		t.Fatalf("expected no error, but received %q", err)
+	}
+	if u != expected {
+		t.Fatalf("expected %q, but received %q", expected, u)
+	}
+}
+
 func TestDatabaseSchemeFromUrlFailure(t *testing.T) {
 	cases := []struct {
 		name      string