Fix validation for Gumroad licenses

Fixes an issue where JWT license validation caused Gumroad
tokens to fail validation.

Fixes: #137

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

config.go

@@ -50,9 +50,13 @@ func (c InletsProConfig) GetLicenseKey() (string, error) {
 		return "", fmt.Errorf("--license or --license-key is required for inlets PRO")
 	}
 
-	if total := strings.Count(val, "."); total >= 2 {
+	if dots := strings.Count(val, "."); dots >= 2 {
 		return strings.TrimSpace(val), nil
 	}
 
-	return "", fmt.Errorf("inlets PRO license may be invalid")
+	if dashes := strings.Count(val, "-"); dashes == 3 {
+		return strings.TrimSpace(val), nil
+	}
+
+	return "", fmt.Errorf("inlets license may be invalid")
 }

config_test.go

@@ -53,7 +53,7 @@ func Test_GetLicenseKey_FromFile(t *testing.T) {
 	}
 }
 
-func Test_GetLicenseKey_FromFileTrimsWhitespace(t *testing.T) {
+func Test_GetLicenseKey_FromFileTrimsWhitespace_JWT(t *testing.T) {
 	want := `static.key.text`
 
 	tmp := os.TempDir()
@@ -84,3 +84,20 @@ func Test_GetLicenseKey_FromFileTrimsWhitespace(t *testing.T) {
 		t.Fatalf("want %q but got %q", want, key)
 	}
 }
+
+func Test_GetLicenseKey_FromLiteral_WithDashes(t *testing.T) {
+	want := `static-dashes-key-text`
+
+	c := InletsProConfig{
+		License: want,
+	}
+
+	key, err := c.GetLicenseKey()
+	if err != nil {
+		t.Fatalf("no error wanted for a valid key")
+	}
+
+	if want != key {
+		t.Fatalf("want %q but got %q", want, key)
+	}
+}