all: use semver to compare versions (#6147)

2 files changed, 69 insertions, 0 deletions

diff --git a/internal/semverutil/semverutil.go b/internal/semverutil/semverutil.go
new file mode 100644
index 00000000..d66dbfb8
--- /dev/null
+++ b/internal/semverutil/semverutil.go
@@ -0,0 +1,37 @@
+// Copyright 2020 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package semverutil
+
+import (
+	"strings"
+
+	"github.com/Masterminds/semver/v3"
+)
+
+// Compare returns true if the comparison is true for given versions. It returns false if
+// comparison is false, or failed to parse one or both versions as Semantic Versions.
+//
+// See https://github.com/Masterminds/semver#basic-comparisons for supported comparisons.
+func Compare(version1, comparison, version2 string) bool {
+	clean := func(v string) string {
+		if strings.Count(v, ".") > 2 {
+			fields := strings.SplitN(v, ".", 4)
+			v = strings.Join(fields[:3], ".")
+		}
+		return v
+	}
+
+	v, err := semver.NewVersion(clean(version1))
+	if err != nil {
+		return false
+	}
+
+	c, err := semver.NewConstraint(comparison + " " + clean(version2))
+	if err != nil {
+		return false
+	}
+
+	return c.Check(v)
+}
diff --git a/internal/semverutil/semverutil_test.go b/internal/semverutil/semverutil_test.go
new file mode 100644
index 00000000..d11421b8
--- /dev/null
+++ b/internal/semverutil/semverutil_test.go
@@ -0,0 +1,32 @@
+// Copyright 2020 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package semverutil
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCheck(t *testing.T) {
+	tests := []struct {
+		version1   string
+		comparison string
+		version2   string
+		expVal     bool
+	}{
+		{version1: "1.0.c", comparison: ">", version2: "0.9", expVal: false},
+		{version1: "1.0.1", comparison: ">", version2: "0.9.a", expVal: false},
+
+		{version1: "7.2", comparison: ">=", version2: "5.1", expVal: true},
+		{version1: "1.8.3.1", comparison: ">=", version2: "1.8.3", expVal: true},
+		{version1: "0.12.0+dev", comparison: ">=", version2: "0.11.68.1023", expVal: true},
+	}
+	for _, test := range tests {
+		t.Run(test.version1+" "+test.comparison+" "+test.version2, func(t *testing.T) {
+			assert.Equal(t, test.expVal, Compare(test.version1, test.comparison, test.version2))
+		})
+	}
+}