support mailto: with RFC6068 hfields

lib/proto/mailto.js

@@ -5,6 +5,14 @@ const LinkCheckResult = require('../LinkCheckResult');
 
 module.exports = {
     check: function (link, opts, callback) {
-        callback(null, new LinkCheckResult(opts, link, Isemail.validate(link.substr(7)) ? 200 : 400, null));
+        const address = link
+                            .substr(7)      // strip "mailto:"
+                            .split('?')[0]; // trim ?subject=blah hfields
+
+        /* per RFC6068, the '?' is a reserved delimiter and email addresses containing '?' must be encoded,
+         * so it's safe to split on '?' and pick [0].
+         */
+
+        callback(null, new LinkCheckResult(opts, link, Isemail.validate(address) ? 200 : 400, null));
     }
 };

test/link-check.test.js

@@ -179,6 +179,24 @@ describe('link-check', function () {
         });
     });
 
+    it('should handle valid mailto with encoded characters in address', function (done) {
+        linkCheck('mailto:foo%[email protected]', function (err, result) {
+            expect(err).to.be(null);
+            expect(result.link).to.be('mailto:foo%[email protected]');
+            expect(result.status).to.be('alive');
+            done();
+        });
+    });
+
+    it('should handle valid mailto containing hfields', function (done) {
+        linkCheck('mailto:[email protected]?subject=caf%C3%A9', function (err, result) {
+            expect(err).to.be(null);
+            expect(result.link).to.be('mailto:[email protected]?subject=caf%C3%A9');
+            expect(result.status).to.be('alive');
+            done();
+        });
+    });
+
     it('should handle invalid mailto', function (done) {
         linkCheck('mailto:foo@@bar@@baz', function (err, result) {
             expect(err).to.be(null);