diff --git a/lib/internal/url.js b/lib/internal/url.js
index ba54aa8c233354..9d7448be8f6a20 100644
--- a/lib/internal/url.js
+++ b/lib/internal/url.js
@@ -85,34 +85,39 @@ class TupleOrigin {
   }
 }
 
+// Reused by URL constructor and URL#href setter.
+function parse(url, input, base) {
+  input = String(input);
+  const base_context = base ? base[context] : undefined;
+  url[context] = new StorageObject();
+  binding.parse(input.trim(), -1, base_context, undefined,
+    (flags, protocol, username, password,
+      host, port, path, query, fragment) => {
+      if (flags & binding.URL_FLAGS_FAILED)
+        throw new TypeError('Invalid URL');
+      url[context].flags = flags;
+      url[context].scheme = protocol;
+      url[context].username = username;
+      url[context].password = password;
+      url[context].port = port;
+      url[context].path = path;
+      url[context].query = query;
+      url[context].fragment = fragment;
+      url[context].host = host;
+      if (url[searchParams]) {  // invoked from href setter
+        initSearchParams(url[searchParams], query);
+      } else {
+        url[searchParams] = new URLSearchParams(query);
+      }
+      url[searchParams][context] = url;
+    });
+}
+
 class URL {
   constructor(input, base) {
     if (base !== undefined && !(base instanceof URL))
       base = new URL(String(base));
-    input = String(input);
-    const base_context = base ? base[context] : undefined;
-    this[context] = new StorageObject();
-    binding.parse(input.trim(), -1, base_context, undefined,
-      (flags, protocol, username, password,
-       host, port, path, query, fragment) => {
-        if (flags & binding.URL_FLAGS_FAILED)
-          throw new TypeError('Invalid URL');
-        this[context].flags = flags;
-        this[context].scheme = protocol;
-        this[context].username = username;
-        this[context].password = password;
-        this[context].port = port;
-        this[context].path = path;
-        this[context].query = query;
-        this[context].fragment = fragment;
-        this[context].host = host;
-        this[searchParams] = new URLSearchParams(query);
-        this[searchParams][context] = this;
-      });
-  }
-
-  get origin() {
-    return URL.originFor(this).toString(true);
+    parse(this, input, base);
   }
 
   get [special]() {
@@ -123,309 +128,6 @@ class URL {
     return (this[context].flags & binding.URL_FLAGS_CANNOT_BE_BASE) != 0;
   }
 
-  get protocol() {
-    return this[context].scheme;
-  }
-
-  get searchParams() {
-    return this[searchParams];
-  }
-
-  set protocol(scheme) {
-    scheme = String(scheme);
-    if (scheme.length === 0)
-      return;
-    binding.parse(scheme,
-                  binding.kSchemeStart,
-                  null,
-                  this[context],
-      (flags, protocol, username, password,
-       host, port, path, query, fragment) => {
-        if (flags & binding.URL_FLAGS_FAILED)
-          return;
-        const newIsSpecial = (flags & binding.URL_FLAGS_SPECIAL) != 0;
-        if ((this[special] && !newIsSpecial) ||
-            (!this[special] && newIsSpecial) ||
-            (newIsSpecial && !this[special] &&
-             this[context].host === undefined)) {
-          return;
-        }
-        if (newIsSpecial) {
-          this[context].flags |= binding.URL_FLAGS_SPECIAL;
-        } else {
-          this[context].flags &= ~binding.URL_FLAGS_SPECIAL;
-        }
-        if (protocol) {
-          this[context].scheme = protocol;
-          this[context].flags |= binding.URL_FLAGS_HAS_SCHEME;
-        } else {
-          this[context].flags &= ~binding.URL_FLAGS_HAS_SCHEME;
-        }
-      });
-  }
-
-  get username() {
-    return this[context].username || '';
-  }
-
-  set username(username) {
-    username = String(username);
-    if (!this.hostname)
-      return;
-    if (!username) {
-      this[context].username = null;
-      this[context].flags &= ~binding.URL_FLAGS_HAS_USERNAME;
-      return;
-    }
-    this[context].username = binding.encodeAuth(username);
-    this[context].flags |= binding.URL_FLAGS_HAS_USERNAME;
-  }
-
-  get password() {
-    return this[context].password || '';
-  }
-
-  set password(password) {
-    password = String(password);
-    if (!this.hostname)
-      return;
-    if (!password) {
-      this[context].password = null;
-      this[context].flags &= ~binding.URL_FLAGS_HAS_PASSWORD;
-      return;
-    }
-    this[context].password = binding.encodeAuth(password);
-    this[context].flags |= binding.URL_FLAGS_HAS_PASSWORD;
-  }
-
-  get host() {
-    var ret = this[context].host || '';
-    if (this[context].port !== undefined)
-      ret += `:${this[context].port}`;
-    return ret;
-  }
-
-  set host(host) {
-    host = String(host);
-    if (this[cannotBeBase] ||
-        (this[special] && host.length === 0)) {
-      // Cannot set the host if cannot-be-base is set or
-      // scheme is special and host length is zero
-      return;
-    }
-    if (!host) {
-      this[context].host = null;
-      this[context].flags &= ~binding.URL_FLAGS_HAS_HOST;
-      return;
-    }
-    binding.parse(host, binding.kHost, null, this[context],
-      (flags, protocol, username, password,
-       host, port, path, query, fragment) => {
-        if (flags & binding.URL_FLAGS_FAILED)
-          return;
-        if (host) {
-          this[context].host = host;
-          this[context].flags |= binding.URL_FLAGS_HAS_HOST;
-        } else {
-          this[context].flags &= ~binding.URL_FLAGS_HAS_HOST;
-        }
-        if (port !== undefined)
-          this[context].port = port;
-      });
-  }
-
-  get hostname() {
-    return this[context].host || '';
-  }
-
-  set hostname(host) {
-    host = String(host);
-    if (this[cannotBeBase] ||
-        (this[special] && host.length === 0)) {
-      // Cannot set the host if cannot-be-base is set or
-      // scheme is special and host length is zero
-      return;
-    }
-    if (!host) {
-      this[context].host = null;
-      this[context].flags &= ~binding.URL_FLAGS_HAS_HOST;
-      return;
-    }
-    binding.parse(host,
-                  binding.kHostname,
-                  null,
-                  this[context],
-      (flags, protocol, username, password,
-       host, port, path, query, fragment) => {
-        if (flags & binding.URL_FLAGS_FAILED)
-          return;
-        if (host) {
-          this[context].host = host;
-          this[context].flags |= binding.URL_FLAGS_HAS_HOST;
-        } else {
-          this[context].flags &= ~binding.URL_FLAGS_HAS_HOST;
-        }
-      });
-  }
-
-  get port() {
-    const port = this[context].port;
-    return port === undefined ? '' : String(port);
-  }
-
-  set port(port) {
-    if (!this[context].host || this[cannotBeBase] || this.protocol === 'file:')
-      return;
-    port = String(port);
-    if (port === '') {
-      // Currently, if port number is empty, left unchanged.
-      // TODO(jasnell): This might be changing in the spec
-      return;
-    }
-    binding.parse(port, binding.kPort, null, this[context],
-      (flags, protocol, username, password,
-       host, port, path, query, fragment) => {
-        if (flags & binding.URL_FLAGS_FAILED)
-          return;
-        this[context].port = port;
-      });
-  }
-
-  get pathname() {
-    if (this[cannotBeBase])
-      return this[context].path[0];
-    return this[context].path !== undefined ?
-      `/${this[context].path.join('/')}` : '';
-  }
-
-  set pathname(path) {
-    if (this[cannotBeBase])
-      return;
-    path = String(path);
-    binding.parse(path,
-                  binding.kPathStart,
-                  null,
-                  this[context],
-      (flags, protocol, username, password,
-       host, port, path, query, fragment) => {
-        if (flags & binding.URL_FLAGS_FAILED)
-          return;
-        if (path) {
-          this[context].path = path;
-          this[context].flags |= binding.URL_FLAGS_HAS_PATH;
-        } else {
-          this[context].flags &= ~binding.URL_FLAGS_HAS_PATH;
-        }
-      });
-  }
-
-  get search() {
-    return !this[context].query ? '' : `?${this[context].query}`;
-  }
-
-  set search(search) {
-    search = String(search);
-    if (search[0] === '?') search = search.slice(1);
-    if (!search) {
-      this[context].query = null;
-      this[context].flags &= ~binding.URL_FLAGS_HAS_QUERY;
-      this[searchParams][searchParams] = {};
-      return;
-    }
-    this[context].query = '';
-    binding.parse(search,
-                  binding.kQuery,
-                  null,
-                  this[context],
-      (flags, protocol, username, password,
-       host, port, path, query, fragment) => {
-        if (flags & binding.URL_FLAGS_FAILED)
-          return;
-        if (query) {
-          this[context].query = query;
-          this[context].flags |= binding.URL_FLAGS_HAS_QUERY;
-        } else {
-          this[context].flags &= ~binding.URL_FLAGS_HAS_QUERY;
-        }
-      });
-    this[searchParams][searchParams] = querystring.parse(search);
-  }
-
-  get hash() {
-    return !this[context].fragment ? '' : `#${this[context].fragment}`;
-  }
-
-  set hash(hash) {
-    hash = String(hash);
-    if (this.protocol === 'javascript:')
-      return;
-    if (!hash) {
-      this[context].fragment = null;
-      this[context].flags &= ~binding.URL_FLAGS_HAS_FRAGMENT;
-      return;
-    }
-    if (hash[0] === '#') hash = hash.slice(1);
-    this[context].fragment = '';
-    binding.parse(hash,
-                  binding.kFragment,
-                  null,
-                  this[context],
-      (flags, protocol, username, password,
-       host, port, path, query, fragment) => {
-        if (flags & binding.URL_FLAGS_FAILED)
-          return;
-        if (fragment) {
-          this[context].fragment = fragment;
-          this[context].flags |= binding.URL_FLAGS_HAS_FRAGMENT;
-        } else {
-          this[context].flags &= ~binding.URL_FLAGS_HAS_FRAGMENT;
-        }
-      });
-  }
-
-  get href() {
-    return this.toString();
-  }
-
-  toString(options) {
-    options = options || {};
-    const fragment =
-      options.fragment !== undefined ?
-        !!options.fragment : true;
-    const unicode = !!options.unicode;
-    var ret;
-    if (this.protocol)
-      ret = this.protocol;
-    if (this[context].host !== undefined) {
-      ret += '//';
-      const has_username = typeof this[context].username === 'string';
-      const has_password = typeof this[context].password === 'string';
-      if (has_username || has_password) {
-        if (has_username)
-          ret += this[context].username;
-        if (has_password)
-          ret += `:${this[context].password}`;
-        ret += '@';
-      }
-      if (unicode) {
-        ret += punycode.toUnicode(this.hostname);
-        if (this.port !== undefined)
-          ret += `:${this.port}`;
-      } else {
-        ret += this.host;
-      }
-    } else if (this[context].scheme === 'file:') {
-      ret += '//';
-    }
-    if (this.pathname)
-      ret += this.pathname;
-    if (typeof this[context].query === 'string')
-      ret += `?${this[context].query}`;
-    if (fragment & typeof this[context].fragment === 'string')
-      ret += `#${this[context].fragment}`;
-    return ret;
-  }
-
   inspect(depth, opts) {
     var ret = 'URL {\n';
     ret += `  href: ${this.href}\n`;
@@ -456,6 +158,353 @@ class URL {
   }
 }
 
+Object.defineProperties(URL.prototype, {
+  toString: {
+    // https://heycam.github.io/webidl/#es-stringifier
+    writable: true,
+    enumerable: true,
+    configurable: true,
+    // eslint-disable-next-line func-name-matching
+    value: function toString(options) {
+      options = options || {};
+      const fragment =
+        options.fragment !== undefined ?
+          !!options.fragment : true;
+      const unicode = !!options.unicode;
+      var ret;
+      if (this.protocol)
+        ret = this.protocol;
+      if (this[context].host !== undefined) {
+        ret += '//';
+        const has_username = typeof this[context].username === 'string';
+        const has_password = typeof this[context].password === 'string';
+        if (has_username || has_password) {
+          if (has_username)
+            ret += this[context].username;
+          if (has_password)
+            ret += `:${this[context].password}`;
+          ret += '@';
+        }
+        if (unicode) {
+          ret += punycode.toUnicode(this.hostname);
+          if (this.port !== undefined)
+            ret += `:${this.port}`;
+        } else {
+          ret += this.host;
+        }
+      } else if (this[context].scheme === 'file:') {
+        ret += '//';
+      }
+      if (this.pathname)
+        ret += this.pathname;
+      if (typeof this[context].query === 'string')
+        ret += `?${this[context].query}`;
+      if (fragment & typeof this[context].fragment === 'string')
+        ret += `#${this[context].fragment}`;
+      return ret;
+    }
+  },
+  href: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      return this.toString();
+    },
+    set(input) {
+      parse(this, input);
+    }
+  },
+  origin: {  // readonly
+    enumerable: true,
+    configurable: true,
+    get() {
+      return originFor(this).toString(true);
+    }
+  },
+  protocol: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      return this[context].scheme;
+    },
+    set(scheme) {
+      scheme = String(scheme);
+      if (scheme.length === 0)
+        return;
+      binding.parse(scheme,
+                    binding.kSchemeStart,
+                    null,
+                    this[context],
+        (flags, protocol, username, password,
+        host, port, path, query, fragment) => {
+          if (flags & binding.URL_FLAGS_FAILED)
+            return;
+          const newIsSpecial = (flags & binding.URL_FLAGS_SPECIAL) != 0;
+          if ((this[special] && !newIsSpecial) ||
+              (!this[special] && newIsSpecial) ||
+              (newIsSpecial && !this[special] &&
+              this[context].host === undefined)) {
+            return;
+          }
+          if (newIsSpecial) {
+            this[context].flags |= binding.URL_FLAGS_SPECIAL;
+          } else {
+            this[context].flags &= ~binding.URL_FLAGS_SPECIAL;
+          }
+          if (protocol) {
+            this[context].scheme = protocol;
+            this[context].flags |= binding.URL_FLAGS_HAS_SCHEME;
+          } else {
+            this[context].flags &= ~binding.URL_FLAGS_HAS_SCHEME;
+          }
+        });
+    }
+  },
+  username: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      return this[context].username || '';
+    },
+    set(username) {
+      username = String(username);
+      if (!this.hostname)
+        return;
+      if (!username) {
+        this[context].username = null;
+        this[context].flags &= ~binding.URL_FLAGS_HAS_USERNAME;
+        return;
+      }
+      this[context].username = binding.encodeAuth(username);
+      this[context].flags |= binding.URL_FLAGS_HAS_USERNAME;
+    }
+  },
+  password: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      return this[context].password || '';
+    },
+    set(password) {
+      password = String(password);
+      if (!this.hostname)
+        return;
+      if (!password) {
+        this[context].password = null;
+        this[context].flags &= ~binding.URL_FLAGS_HAS_PASSWORD;
+        return;
+      }
+      this[context].password = binding.encodeAuth(password);
+      this[context].flags |= binding.URL_FLAGS_HAS_PASSWORD;
+    }
+  },
+  host: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      var ret = this[context].host || '';
+      if (this[context].port !== undefined)
+        ret += `:${this[context].port}`;
+      return ret;
+    },
+    set(host) {
+      host = String(host);
+      if (this[cannotBeBase] ||
+          (this[special] && host.length === 0)) {
+        // Cannot set the host if cannot-be-base is set or
+        // scheme is special and host length is zero
+        return;
+      }
+      if (!host) {
+        this[context].host = null;
+        this[context].flags &= ~binding.URL_FLAGS_HAS_HOST;
+        return;
+      }
+      binding.parse(host, binding.kHost, null, this[context],
+        (flags, protocol, username, password,
+        host, port, path, query, fragment) => {
+          if (flags & binding.URL_FLAGS_FAILED)
+            return;
+          if (host) {
+            this[context].host = host;
+            this[context].flags |= binding.URL_FLAGS_HAS_HOST;
+          } else {
+            this[context].flags &= ~binding.URL_FLAGS_HAS_HOST;
+          }
+          if (port !== undefined)
+            this[context].port = port;
+        });
+    }
+  },
+  hostname: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      return this[context].host || '';
+    },
+    set(host) {
+      host = String(host);
+      if (this[cannotBeBase] ||
+          (this[special] && host.length === 0)) {
+        // Cannot set the host if cannot-be-base is set or
+        // scheme is special and host length is zero
+        return;
+      }
+      if (!host) {
+        this[context].host = null;
+        this[context].flags &= ~binding.URL_FLAGS_HAS_HOST;
+        return;
+      }
+      binding.parse(host,
+                    binding.kHostname,
+                    null,
+                    this[context],
+        (flags, protocol, username, password,
+        host, port, path, query, fragment) => {
+          if (flags & binding.URL_FLAGS_FAILED)
+            return;
+          if (host) {
+            this[context].host = host;
+            this[context].flags |= binding.URL_FLAGS_HAS_HOST;
+          } else {
+            this[context].flags &= ~binding.URL_FLAGS_HAS_HOST;
+          }
+        });
+    }
+  },
+  port: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      const port = this[context].port;
+      return port === undefined ? '' : String(port);
+    },
+    set(port) {
+      if (!this[context].host || this[cannotBeBase] ||
+          this.protocol === 'file:')
+        return;
+      port = String(port);
+      if (port === '') {
+        // Currently, if port number is empty, left unchanged.
+        // TODO(jasnell): This might be changing in the spec
+        return;
+      }
+      binding.parse(port, binding.kPort, null, this[context],
+        (flags, protocol, username, password,
+        host, port, path, query, fragment) => {
+          if (flags & binding.URL_FLAGS_FAILED)
+            return;
+          this[context].port = port;
+        });
+    }
+  },
+  pathname: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      if (this[cannotBeBase])
+        return this[context].path[0];
+      return this[context].path !== undefined ?
+        `/${this[context].path.join('/')}` : '';
+    },
+    set(path) {
+      if (this[cannotBeBase])
+        return;
+      path = String(path);
+      binding.parse(path,
+                    binding.kPathStart,
+                    null,
+                    this[context],
+        (flags, protocol, username, password,
+        host, port, path, query, fragment) => {
+          if (flags & binding.URL_FLAGS_FAILED)
+            return;
+          if (path) {
+            this[context].path = path;
+            this[context].flags |= binding.URL_FLAGS_HAS_PATH;
+          } else {
+            this[context].flags &= ~binding.URL_FLAGS_HAS_PATH;
+          }
+        });
+    }
+  },
+  search: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      return !this[context].query ? '' : `?${this[context].query}`;
+    },
+    set(search) {
+      search = String(search);
+      if (search[0] === '?') search = search.slice(1);
+      if (!search) {
+        this[context].query = null;
+        this[context].flags &= ~binding.URL_FLAGS_HAS_QUERY;
+        this[searchParams][searchParams] = {};
+        return;
+      }
+      this[context].query = '';
+      binding.parse(search,
+                    binding.kQuery,
+                    null,
+                    this[context],
+        (flags, protocol, username, password,
+        host, port, path, query, fragment) => {
+          if (flags & binding.URL_FLAGS_FAILED)
+            return;
+          if (query) {
+            this[context].query = query;
+            this[context].flags |= binding.URL_FLAGS_HAS_QUERY;
+          } else {
+            this[context].flags &= ~binding.URL_FLAGS_HAS_QUERY;
+          }
+        });
+      this[searchParams][searchParams] = querystring.parse(search);
+    }
+  },
+  searchParams: {  // readonly
+    enumerable: true,
+    configurable: true,
+    get() {
+      return this[searchParams];
+    }
+  },
+  hash: {
+    enumerable: true,
+    configurable: true,
+    get() {
+      return !this[context].fragment ? '' : `#${this[context].fragment}`;
+    },
+    set(hash) {
+      hash = String(hash);
+      if (this.protocol === 'javascript:')
+        return;
+      if (!hash) {
+        this[context].fragment = null;
+        this[context].flags &= ~binding.URL_FLAGS_HAS_FRAGMENT;
+        return;
+      }
+      if (hash[0] === '#') hash = hash.slice(1);
+      this[context].fragment = '';
+      binding.parse(hash,
+                    binding.kFragment,
+                    null,
+                    this[context],
+        (flags, protocol, username, password,
+        host, port, path, query, fragment) => {
+          if (flags & binding.URL_FLAGS_FAILED)
+            return;
+          if (fragment) {
+            this[context].fragment = fragment;
+            this[context].flags |= binding.URL_FLAGS_HAS_FRAGMENT;
+          } else {
+            this[context].flags &= ~binding.URL_FLAGS_HAS_FRAGMENT;
+          }
+        });
+    }
+  }
+});
+
 var hexTable = new Array(256);
 for (var i = 0; i < 256; ++i)
   hexTable[i] = '%' + ((i < 16 ? '0' : '') + i.toString(16)).toUpperCase();
@@ -546,6 +595,12 @@ function getSearchParamPairs(target) {
   return values;
 }
 
+// Reused by the URL parse function invoked by
+// the href setter, and the URLSearchParams constructor
+function initSearchParams(url, init) {
+  url[searchParams] = querystring.parse(init);
+}
+
 class URLSearchParams {
   constructor(init = '') {
     if (init instanceof URLSearchParams) {
@@ -554,7 +609,7 @@ class URLSearchParams {
     } else {
       init = String(init);
       if (init[0] === '?') init = init.slice(1);
-      this[searchParams] = querystring.parse(init);
+      initSearchParams(this, init);
     }
 
     // "associated url object"
@@ -790,7 +845,7 @@ Object.defineProperty(URLSearchParamsIteratorPrototype, Symbol.toStringTag, {
   configurable: true
 });
 
-URL.originFor = function(url, base) {
+function originFor(url, base) {
   if (!(url instanceof URL))
     url = new URL(url, base);
   var origin;
@@ -822,8 +877,9 @@ URL.originFor = function(url, base) {
       origin = new OpaqueOrigin();
   }
   return origin;
-};
+}
 
+URL.originFor = originFor;
 URL.domainToASCII = function(domain) {
   return binding.domainToASCII(String(domain));
 };
diff --git a/test/parallel/test-whatwg-url-properties.js b/test/parallel/test-whatwg-url-properties.js
new file mode 100644
index 00000000000000..60cf581ad8da4d
--- /dev/null
+++ b/test/parallel/test-whatwg-url-properties.js
@@ -0,0 +1,127 @@
+'use strict';
+
+require('../common');
+
+const URL = require('url').URL;
+const assert = require('assert');
+
+const url = new URL('http://user:pass@foo.bar.com:21/aaa/zzz?l=24#test');
+const oldParams = url.searchParams;  // for test of [SameObject]
+
+// To retrieve enumerable but not necessarily own properties,
+// we need to use the for-in loop.
+const props = [];
+for (const prop in url) {
+  props.push(prop);
+}
+
+// See: https://url.spec.whatwg.org/#api
+// https://heycam.github.io/webidl/#es-attributes
+// https://heycam.github.io/webidl/#es-stringifier
+const expected = ['toString',
+  'href', 'origin', 'protocol',
+  'username', 'password', 'host', 'hostname', 'port',
+  'pathname', 'search', 'searchParams', 'hash'];
+
+assert.deepStrictEqual(props, expected);
+
+// href is writable (not readonly) and is stringifier
+assert.strictEqual(url.toString(), url.href);
+url.href = 'http://user:pass@foo.bar.com:21/aaa/zzz?l=25#test';
+assert.strictEqual(url.href,
+                   'http://user:pass@foo.bar.com:21/aaa/zzz?l=25#test');
+assert.strictEqual(url.toString(), url.href);
+// Return true because it's configurable, but because the properties
+// are defined on the prototype per the spec, the deletion has no effect
+assert.strictEqual((delete url.href), true);
+assert.strictEqual(url.href,
+                   'http://user:pass@foo.bar.com:21/aaa/zzz?l=25#test');
+assert.strictEqual(url.searchParams, oldParams);  // [SameObject]
+
+// searchParams is readonly. Under strict mode setting a
+// non-writable property should throw.
+// Note: this error message is subject to change in V8 updates
+assert.throws(() => url.origin = 'http://foo.bar.com:22',
+              new RegExp('TypeError: Cannot set property origin of' +
+                         ' \\[object Object\\] which has only a getter'));
+assert.strictEqual(url.origin, 'http://foo.bar.com:21');
+assert.strictEqual(url.toString(),
+                   'http://user:pass@foo.bar.com:21/aaa/zzz?l=25#test');
+assert.strictEqual((delete url.origin), true);
+assert.strictEqual(url.origin, 'http://foo.bar.com:21');
+
+// The following properties should be writable (not readonly)
+url.protocol = 'https:';
+assert.strictEqual(url.protocol, 'https:');
+assert.strictEqual(url.toString(),
+                   'https://user:pass@foo.bar.com:21/aaa/zzz?l=25#test');
+assert.strictEqual((delete url.protocol), true);
+assert.strictEqual(url.protocol, 'https:');
+
+url.username = 'user2';
+assert.strictEqual(url.username, 'user2');
+assert.strictEqual(url.toString(),
+                   'https://user2:pass@foo.bar.com:21/aaa/zzz?l=25#test');
+assert.strictEqual((delete url.username), true);
+assert.strictEqual(url.username, 'user2');
+
+url.password = 'pass2';
+assert.strictEqual(url.password, 'pass2');
+assert.strictEqual(url.toString(),
+                   'https://user2:pass2@foo.bar.com:21/aaa/zzz?l=25#test');
+assert.strictEqual((delete url.password), true);
+assert.strictEqual(url.password, 'pass2');
+
+url.host = 'foo.bar.net:22';
+assert.strictEqual(url.host, 'foo.bar.net:22');
+assert.strictEqual(url.toString(),
+                   'https://user2:pass2@foo.bar.net:22/aaa/zzz?l=25#test');
+assert.strictEqual((delete url.host), true);
+assert.strictEqual(url.host, 'foo.bar.net:22');
+
+url.hostname = 'foo.bar.org';
+assert.strictEqual(url.hostname, 'foo.bar.org');
+assert.strictEqual(url.toString(),
+                   'https://user2:pass2@foo.bar.org:22/aaa/zzz?l=25#test');
+assert.strictEqual((delete url.hostname), true);
+assert.strictEqual(url.hostname, 'foo.bar.org');
+
+url.port = '23';
+assert.strictEqual(url.port, '23');
+assert.strictEqual(url.toString(),
+                   'https://user2:pass2@foo.bar.org:23/aaa/zzz?l=25#test');
+assert.strictEqual((delete url.port), true);
+assert.strictEqual(url.port, '23');
+
+url.pathname = '/aaa/bbb';
+assert.strictEqual(url.pathname, '/aaa/bbb');
+assert.strictEqual(url.toString(),
+                   'https://user2:pass2@foo.bar.org:23/aaa/bbb?l=25#test');
+assert.strictEqual((delete url.pathname), true);
+assert.strictEqual(url.pathname, '/aaa/bbb');
+
+url.search = '?k=99';
+assert.strictEqual(url.search, '?k=99');
+assert.strictEqual(url.toString(),
+                   'https://user2:pass2@foo.bar.org:23/aaa/bbb?k=99#test');
+assert.strictEqual((delete url.search), true);
+assert.strictEqual(url.search, '?k=99');
+
+url.hash = '#abcd';
+assert.strictEqual(url.hash, '#abcd');
+assert.strictEqual(url.toString(),
+                   'https://user2:pass2@foo.bar.org:23/aaa/bbb?k=99#abcd');
+assert.strictEqual((delete url.hash), true);
+assert.strictEqual(url.hash, '#abcd');
+
+// searchParams is readonly. Under strict mode setting a
+// non-writable property should throw.
+// Note: this error message is subject to change in V8 updates
+assert.throws(() => url.searchParams = '?k=88',
+              new RegExp('TypeError: Cannot set property searchParams of' +
+                         ' \\[object Object\\] which has only a getter'));
+assert.strictEqual(url.searchParams, oldParams);
+assert.strictEqual(url.toString(),
+                   'https://user2:pass2@foo.bar.org:23/aaa/bbb?k=99#abcd');
+assert.strictEqual((delete url.searchParams), true);
+assert.strictEqual(url.searchParams, oldParams);