Adds `querySelectorLocal` which returns matching nodes in `shadyRoot`…

…; fixes leaking clients list.

src/features/base/content.html

@@ -57,8 +57,8 @@
           this._distributePool(this.contentRoot, this._collectPool());
         }
         // now fully distribute/compose "clients"
-        var l = this._clients.length;
-        for (var i=0, c; (i<l) && (c=this._clients[i]); i++) {
+        var c$ = this._getDistributionClients();
+        for (var i=0, l= c$.length, c; (i<l) && (c=c$[i]); i++) {
           c.distributeContent();
         }
         // compose self
@@ -106,6 +106,36 @@
         return matchesSelector.call(node, selector);
       },
 
+      querySelectorLocal: function(selector) {
+        var self = this;
+        return this.queryLocal(function(n) {
+          return self.elementMatches(selector, n);
+        });
+      },
+
+      queryLocal: function(matcher) {
+        var c$ = this.children;
+        var list = [];
+        for (var i=0, l=c$.length, c; (i<l) && (c=c$[i]); i++) {
+          if (!c._destinationInsertionPoints) {
+            this._queryLocal(c, matcher, list);
+          }
+        }
+        return list;
+      },
+
+      _queryLocal: function(node, matcher, list) {
+        if (matcher(node)) {
+          list.push(node);
+        }
+        var c$ = getLightChildren(node);
+        for (var i=0, l=c$.length, c; (i<l) && (c=c$[i]); i++) {
+          if (c.nodeType === Node.ELEMENT_NODE) {
+            this._queryLocal(c, matcher, list);
+          }
+        }
+      },
+
       // Many of the following methods are all conceptually static, but they are
       // included here as "protected" methods to allow overriding.
 
@@ -174,6 +204,14 @@
         }
       },
 
+      _getDistributionClients: function() {
+        return this._clients ? this._clients :
+          this.queryLocal(function(n) {
+            // TODO(sorvell): need a better test here
+            return Boolean(n.distributeContent);
+          });
+      },
+
       _composeTree: function(node) {
         var children = this._composeNode(node);
         for (var i = 0; i < children.length; i++) {

src/features/base/ready.html

@@ -84,9 +84,7 @@
           for (var i=0, l=n$.length, n; (i<l) && (n=n$[i]); i++) {
             n._ready();
           }
-          // TODO(sorvell): this leaks if we don't clean it up here, but
-          // it's currently needed for dynamic shadyDOM distribution... =(
-          //this._clients = [];
+          this._clients = null;
         }
       },
 

test/unit/content.html

@@ -103,7 +103,6 @@
   syncLightDOM(host);
   setInnerHTML(host.contentRoot, '<x-content-test id="p"></x-content-test>');
   var p = host.contentRoot.firstChild;
-  host._clients.push(p);
   p.innerHTML = '<b></b><content></content>';
   var b = p.firstChild;
   var content = p.lastChild;
@@ -122,6 +121,8 @@
   function testRender() {
     // Simulate the correct ordering as "ready" would fire.
     host.distributeContent();
+    // NOTE: needed only for this imperative test that needs
+    // to simulate distribution from `contentRoot`
     p.distributeContent();
 
     assert.strictEqual(host.innerHTML,
@@ -375,6 +376,31 @@
     assert.strictEqual(host.innerHTML, '<b></b>');
   });
 
+  test('querySelectorLocal', function() {
+    var host = document.createElement('x-content-test');
+    host.innerHTML = '<div id="main"></div>';
+    syncLightDOM(host);
+    setInnerHTML(host.contentRoot, '<content></content><span id="main"></span>' +
+      '<x-content-test></x-content-test>');
+    var hostLocalMain = host.contentRoot.firstChild.nextSibling;
+    var child = host.contentRoot.lastChild;
+    // force upgrade on polyfilled browsers
+    CustomElements.upgrade(child);
+    child.innerHTML = '<div id="sub"></div>';
+    var childLightSub = child.firstChild;
+    syncLightDOM(child);
+    setInnerHTML(child.contentRoot, '<content></content><span id="sub"></span>');
+    var childLocalSub = child.contentRoot.lastChild;
+    host.distributeContent();
+    // NOTE: needed only for this imperative test that needs
+    // to simulate distribution from `contentRoot`
+    child.distributeContent();
+
+    assert.deepEqual(host.querySelectorLocal('#main'), [hostLocalMain]);
+    assert.deepEqual(host.querySelectorLocal('#sub'), [childLightSub]);
+    assert.deepEqual(child.querySelectorLocal('#sub'), [childLocalSub]);
+  });
+
 });
 
 function setInnerHTML(node, value) {