Add unit test for pkg/version/channelversion.go (linkerd#4784)

* Add unit test for pkg/version/channelversion.go

Signed-off-by: zouyu <[email protected]>
Signed-off-by: Eric Solomon <[email protected]>

Author: zouy414

pkg/version/channelversion_test.go

@@ -0,0 +1,54 @@
+package version
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestIsReleaseChannel(t *testing.T) {
+	cases := []struct {
+		version       string
+		expected      bool
+		expectedError bool
+	}{
+		{
+			version:  "edge-1.0",
+			expected: true,
+		},
+		{
+			version:  "stable-1.0",
+			expected: true,
+		},
+		{
+			version:  "edge-",
+			expected: true,
+		},
+		{
+			version:  "stable-",
+			expected: true,
+		},
+		{
+			version:       "edge",
+			expected:      false,
+			expectedError: true,
+		},
+		{
+			version:       "stable",
+			expected:      false,
+			expectedError: true,
+		},
+	}
+
+	for _, c := range cases {
+		c := c
+		t.Run(c.version, func(t *testing.T) {
+			got, err := IsReleaseChannel(c.version)
+			if (err != nil) != c.expectedError {
+				t.Errorf("got unexpected error: %v", err)
+			}
+			if !reflect.DeepEqual(c.expected, got) {
+				t.Errorf("expected: %v, got: %v", c.expected, got)
+			}
+		})
+	}
+}