backend v4 half

SerpentRace_Backend/node_modules/libphonenumber-js/source/helpers/getIddPrefix.js

@@ -0,0 +1,25 @@
+import Metadata from '../metadata.js'
+
+/**
+ * Pattern that makes it easy to distinguish whether a region has a single
+ * international dialing prefix or not. If a region has a single international
+ * prefix (e.g. 011 in USA), it will be represented as a string that contains
+ * a sequence of ASCII digits, and possibly a tilde, which signals waiting for
+ * the tone. If there are multiple available international prefixes in a
+ * region, they will be represented as a regex string that always contains one
+ * or more characters that are not ASCII digits or a tilde.
+ */
+const SINGLE_IDD_PREFIX_REG_EXP = /^[\d]+(?:[~\u2053\u223C\uFF5E][\d]+)?$/
+
+// For regions that have multiple IDD prefixes
+// a preferred IDD prefix is returned.
+export default function getIddPrefix(country, callingCode, metadata) {
+	const countryMetadata = new Metadata(metadata)
+	countryMetadata.selectNumberingPlan(country, callingCode)
+	if (countryMetadata.defaultIDDPrefix()) {
+		return countryMetadata.defaultIDDPrefix()
+	}
+	if (SINGLE_IDD_PREFIX_REG_EXP.test(countryMetadata.IDDPrefix())) {
+		return countryMetadata.IDDPrefix()
+	}
+}