From ffb79c747c313051ce96f24ec0372569c9ce4822 Mon Sep 17 00:00:00 2001
From: Joachim Bauch <bauch@struktur.de>
Date: Fri, 6 Aug 2021 15:41:18 +0200
Subject: [PATCH] Add method "IsValidContinent".

---
 geoip.go      | 28 ++++++++++++++++++++++++++++
 geoip_test.go | 10 ++++++++++
 2 files changed, 38 insertions(+)

diff --git a/geoip.go b/geoip.go
index 824d62d..1f1457a 100644
--- a/geoip.go
+++ b/geoip.go
@@ -239,3 +239,31 @@ func LookupContinents(country string) []string {
 		return continents
 	}
 }
+
+func IsValidContinent(continent string) bool {
+	switch continent {
+	case "AF":
+		// Africa
+		fallthrough
+	case "AN":
+		// Antartica
+		fallthrough
+	case "AS":
+		// Asia
+		fallthrough
+	case "EU":
+		// Europe
+		fallthrough
+	case "NA":
+		// North America
+		fallthrough
+	case "SA":
+		// South America
+		fallthrough
+	case "OC":
+		// Oceania
+		return true
+	default:
+		return false
+	}
+}
diff --git a/geoip_test.go b/geoip_test.go
index 8413f29..a0ef7b6 100644
--- a/geoip_test.go
+++ b/geoip_test.go
@@ -200,3 +200,13 @@ func TestGeoLookupFromFile(t *testing.T) {
 
 	testGeoLookupReader(t, reader)
 }
+
+func TestIsValidContinent(t *testing.T) {
+	for country, continents := range ContinentMap {
+		for _, continent := range continents {
+			if !IsValidContinent(continent) {
+				t.Errorf("Continent %s of country %s is not valid", continent, country)
+			}
+		}
+	}
+}