Fixing Issue #19 - relative scheme URLs

Author: rodneyrehm

docs.html

@@ -198,8 +198,16 @@ <h3 id="accessors-protocol">protocol(), scheme()</h3>
 // get protocol
 uri.protocol(); // returns string "http"
 // set protocol
-uri.protocol("ftp"); // returns the URI instance for chaining</pre>
-    <p>NOTE: Throws a <code>TypeError</code> on illegal input</p>
+uri.protocol("ftp"); // returns the URI instance for chaining
+
+// relative scheme
+uri.protocol("");
+uri.toString() === '//example.org/foo/hello.html';
+
+// remove scheme
+uri.protocol(null);
+uri.toString() === 'example.org/foo/hello.html';</pre>
+    <p>NOTE: Throws a <code>TypeError</code> on illegal input, that is anything but <code>[a-z0-9.+-]</code> and <code>[empty string]</code> and <code>null</code></p>
 
     <h3 id="accessors-username">username()</h3>
     <pre class="prettyprint lang-js">var uri = new URI("http://user:pass@example.org/foo/hello.html");

src/URI.js

@@ -198,17 +198,25 @@ URI.parse = function(string) {
     }
 
     // extract protocol
-    pos = string.indexOf(':');
-    if (pos > -1) {
-        parts.protocol = string.substring(0, pos);
-        if (string.substring(pos + 1, pos + 3) === '//') {
-            string = string.substring(pos + 3);
-
-            // extract "user:pass@host:port"
-            string = URI.parseAuthority(string, parts);
-        } else {
-            string = string.substring(pos + 1);
-            parts.urn = true;
+    if (string.substring(0, 2) === '//') {
+        // relative-scheme
+        parts.protocol = '';
+        string = string.substring(2);
+        // extract "user:pass@host:port"
+        string = URI.parseAuthority(string, parts);
+    } else {
+        pos = string.indexOf(':');
+        if (pos > -1) {
+            parts.protocol = string.substring(0, pos);
+            if (string.substring(pos + 1, pos + 3) === '//') {
+                string = string.substring(pos + 3);
+
+                // extract "user:pass@host:port"
+                string = URI.parseAuthority(string, parts);
+            } else {
+                string = string.substring(pos + 1);
+                parts.urn = true;
+            }
         }
     }
 
@@ -316,9 +324,10 @@ URI.build = function(parts) {
 
     if (typeof parts.protocol === "string" && parts.protocol.length) {
         t += parts.protocol + ":";
-        if (!parts.urn) {
-            t += '//';
-        }
+    }
+    
+    if ((t || parts.protocol === '') && !parts.urn) {
+        t += '//';
     }
 
     t += (URI.buildAuthority(parts) || '');
@@ -705,11 +714,11 @@ var _protocol = p.protocol,
 
 p.protocol = function(v, build) {
     if (v !== undefined) {
-        // accept trailing :
         if (v) {
-            if (v[v.length - 1] === ":") {
-                v = v.substring(0, v.length - 1);
-            } else if (v.match(/[^a-zA-z0-9\.+-]/)) {
+            // accept trailing ://
+            v = v.replace(/:(\/\/)?$/, '');
+
+            if (v.match(/[^a-zA-z0-9\.+-]/)) {
                 throw new TypeError("Protocol '" + v + "' contains characters other than [A-Z0-9.+-]");
             }
         }

test/test.js

@@ -82,12 +82,12 @@ test("protocol", function() {
     equal(u+"", "ftp://example.org/foo.html", "ftp url");
 
     u.protocol('');
-    equal(u.protocol(), "", "missing protocol");
-    equal(u+"", "example.org/foo.html", "no-scheme url");
+    equal(u.protocol(), "", "relative protocol");
+    equal(u+"", "//example.org/foo.html", "relative-scheme url");
 
     u.protocol(null);
     equal(u.protocol(), "", "missing protocol");
-    equal(u+"", "example.org/foo.html", "no-scheme url");
+    equal(u+"", "example.org/foo.html", "missing-scheme url");
 });
 test("username", function() {
     var u = new URI("http://example.org/foo.html");

test/urls.js

@@ -371,9 +371,9 @@ var urls = [{
     }, {
         name: 'ignoring scheme',
         url: '://user:pass@example.org:123/some/directory/file.html?query=string#fragment',
-        _url: 'user:pass@example.org:123/some/directory/file.html?query=string#fragment',
+        _url: '//user:pass@example.org:123/some/directory/file.html?query=string#fragment',
         parts: {
-            protocol: "", // not null
+            protocol: "",
             username: 'user',
             password: 'pass',
             hostname: 'example.org',
@@ -415,6 +415,52 @@ var urls = [{
             idn: false,
             punycode: false
         }
+    }, {
+        name: 'scheme-relative URL',
+        url: '//www.example.org/',
+        parts: {
+            protocol: '', // not null
+            username: null,
+            password: null,
+            hostname: 'www.example.org',
+            port: null,
+            path: '/',
+            query: null,
+            fragment: null
+        },
+        accessors: {
+            protocol: '',
+            username: '',
+            password: '',
+            port: '',
+            path: '/',
+            query: '',
+            fragment: '',
+            authority: 'www.example.org',
+            userinfo: '',
+            subdomain: 'www',
+            domain: 'example.org',
+            tld: 'org',
+            directory: '/',
+            filename: '',
+            suffix: '',
+            hash: '',
+            search: '',
+            host: 'www.example.org',
+            hostname: 'www.example.org'
+        },
+        is: {
+            urn: false,
+            url: true,
+            relative: false,
+            name: true,
+            sld: false,
+            ip: false,
+            ip4: false,
+            ip6: false,
+            idn: false,
+            punycode: false
+        }
     }, {
         name: 'IPv4',
         url: 'http://user:pass@123.123.123.123:123/some/directory/file.html?query=string#fragment',