fix: do not throw on parsing client principal (#160)

Author: geoffrich

files/headers.js

@@ -54,9 +54,14 @@ export function getClientPrincipalFromHeaders(headers) {
 		return undefined;
 	}
 
-	const encoded = Buffer.from(header, 'base64');
-	const decoded = encoded.toString('ascii');
-	const clientPrincipal = JSON.parse(decoded);
+	try {
+		const encoded = Buffer.from(header, 'base64');
+		const decoded = encoded.toString('ascii');
+		const clientPrincipal = JSON.parse(decoded);
 
-	return clientPrincipal;
+		return clientPrincipal;
+	} catch (e) {
+		console.log('Unable to parse client principal:', e);
+		return undefined;
+	}
 }

test/headers.test.js

@@ -118,4 +118,12 @@ describe('client principal parsing', () => {
 	test('returns undefined when there is no client principal', () => {
 		expect(getClientPrincipalFromHeaders(new Headers())).toBeUndefined();
 	});
+
+	test('returns undefined if unable to parse', () => {
+		const headers = new Headers({
+			'x-ms-client-principal': 'boom'
+		});
+
+		expect(getClientPrincipalFromHeaders(headers)).toBeUndefined();
+	});
 });