From 9c5642f1417da63d1a1d6b21b99ee393dcdeb443 Mon Sep 17 00:00:00 2001
From: John Guo <john@johng.cn>
Date: Tue, 10 Aug 2021 19:29:54 +0800
Subject: [PATCH] fix issue in border value checks for
 gstr.CompareVersion/CompareVersionGo

---
 text/gstr/gstr_version.go             | 8 ++++----
 text/gstr/gstr_z_unit_version_test.go | 6 ++++++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/text/gstr/gstr_version.go b/text/gstr/gstr_version.go
index eaf12f66b..ac74f6423 100644
--- a/text/gstr/gstr_version.go
+++ b/text/gstr/gstr_version.go
@@ -24,10 +24,10 @@ import (
 // 10.2.0
 // etc.
 func CompareVersion(a, b string) int {
-	if a[0] == 'v' {
+	if a != "" && a[0] == 'v' {
 		a = a[1:]
 	}
-	if b[0] == 'v' {
+	if b != "" && b[0] == 'v' {
 		b = b[1:]
 	}
 	var (
@@ -71,10 +71,10 @@ func CompareVersion(a, b string) int {
 // v4.20.0+incompatible
 // etc.
 func CompareVersionGo(a, b string) int {
-	if a[0] == 'v' {
+	if a != "" && a[0] == 'v' {
 		a = a[1:]
 	}
-	if b[0] == 'v' {
+	if b != "" && b[0] == 'v' {
 		b = b[1:]
 	}
 	if Count(a, "-") > 1 {
diff --git a/text/gstr/gstr_z_unit_version_test.go b/text/gstr/gstr_z_unit_version_test.go
index 948c3e2fe..2d4a81210 100644
--- a/text/gstr/gstr_z_unit_version_test.go
+++ b/text/gstr/gstr_z_unit_version_test.go
@@ -17,6 +17,9 @@ import (
 
 func Test_CompareVersion(t *testing.T) {
 	gtest.C(t, func(t *gtest.T) {
+		t.AssertEQ(gstr.CompareVersion("1", ""), 1)
+		t.AssertEQ(gstr.CompareVersion("", ""), 0)
+		t.AssertEQ(gstr.CompareVersion("", "v0.1"), -1)
 		t.AssertEQ(gstr.CompareVersion("1", "v0.99"), 1)
 		t.AssertEQ(gstr.CompareVersion("v1.0", "v0.99"), 1)
 		t.AssertEQ(gstr.CompareVersion("v1.0.1", "v1.1.0"), -1)
@@ -28,6 +31,9 @@ func Test_CompareVersion(t *testing.T) {
 
 func Test_CompareVersionGo(t *testing.T) {
 	gtest.C(t, func(t *gtest.T) {
+		t.AssertEQ(gstr.CompareVersionGo("1", ""), 1)
+		t.AssertEQ(gstr.CompareVersionGo("", ""), 0)
+		t.AssertEQ(gstr.CompareVersionGo("", "v0.1"), -1)
 		t.AssertEQ(gstr.CompareVersionGo("v1.0.1", "v1.1.0"), -1)
 		t.AssertEQ(gstr.CompareVersionGo("1.0.1", "v1.1.0"), -1)
 		t.AssertEQ(gstr.CompareVersionGo("1.0.0", "v0.1.0"), 1)