diff --git a/core/block.js b/core/block.js
index 71453bf6c..1d4b50163 100644
--- a/core/block.js
+++ b/core/block.js
@@ -639,7 +639,7 @@ Blockly.Block.prototype.getRootBlock = function() {
  * the top block of the sub stack. If we are nested in a statement input only
  * find the top-most nested block. Do not go all the way to the root block.
  * @return {!Blockly.Block} The top block in a stack.
- * @private
+ * @package
  */
 Blockly.Block.prototype.getTopStackBlock = function() {
   var block = this;
diff --git a/core/connection.js b/core/connection.js
index 3c0f1ace0..cbe6a217a 100644
--- a/core/connection.js
+++ b/core/connection.js
@@ -224,7 +224,7 @@ Blockly.Connection.prototype.dispose = function() {
 
 /**
  * Get the source block for this connection.
- * @return {Blockly.Block} The source block, or null if there is none.
+ * @return {!Blockly.Block} The source block.
  */
 Blockly.Connection.prototype.getSourceBlock = function() {
   return this.sourceBlock_;
@@ -253,9 +253,9 @@ Blockly.Connection.prototype.isConnected = function() {
  * @param {Blockly.Connection} target Connection to check compatibility with.
  * @return {number} Blockly.Connection.CAN_CONNECT if the connection is legal,
  *    an error code otherwise.
- * @private
+ * @package
  */
-Blockly.Connection.prototype.canConnectWithReason_ = function(target) {
+Blockly.Connection.prototype.canConnectWithReason = function(target) {
   if (!target) {
     return Blockly.Connection.REASON_TARGET_NULL;
   }
@@ -285,10 +285,10 @@ Blockly.Connection.prototype.canConnectWithReason_ = function(target) {
  * and throws an exception if they are not.
  * @param {Blockly.Connection} target The connection to check compatibility
  *    with.
- * @private
+ * @package
  */
-Blockly.Connection.prototype.checkConnection_ = function(target) {
-  switch (this.canConnectWithReason_(target)) {
+Blockly.Connection.prototype.checkConnection = function(target) {
+  switch (this.canConnectWithReason(target)) {
     case Blockly.Connection.CAN_CONNECT:
       break;
     case Blockly.Connection.REASON_SELF_CONNECTION:
@@ -358,7 +358,7 @@ Blockly.Connection.prototype.isConnectionAllowed = function(candidate) {
     return false;
   }
   // Type checking.
-  var canConnect = this.canConnectWithReason_(candidate);
+  var canConnect = this.canConnectWithReason(candidate);
   if (canConnect != Blockly.Connection.CAN_CONNECT) {
     return false;
   }
@@ -431,7 +431,7 @@ Blockly.Connection.prototype.connect = function(otherConnection) {
     // Already connected together.  NOP.
     return;
   }
-  this.checkConnection_(otherConnection);
+  this.checkConnection(otherConnection);
   var eventGroup = Blockly.Events.getGroup();
   if (!eventGroup) {
     Blockly.Events.setGroup(true);
diff --git a/core/keyboard_nav/ast_node.js b/core/keyboard_nav/ast_node.js
index f4328a0ae..b1ee7c70f 100644
--- a/core/keyboard_nav/ast_node.js
+++ b/core/keyboard_nav/ast_node.js
@@ -30,7 +30,7 @@ goog.provide('Blockly.ASTNode');
  * creating a node directly.
  * @param {string} type The type of the location.
  *     Must be in Bockly.ASTNode.types.
- * @param {Blockly.Block|Blockly.Connection|Blockly.Field|Blockly.Workspace}
+ * @param {!(Blockly.Block|Blockly.Connection|Blockly.Field|Blockly.Workspace)}
  *     location The position in the AST.
  * @param {!Object=} opt_params Optional dictionary of options.
  * @constructor
@@ -107,10 +107,13 @@ Blockly.ASTNode.isConnectionType_ = function(type) {
 
 /**
  * Create an AST node pointing to a field.
- * @param {!Blockly.Field} field The location of the AST node.
- * @return {!Blockly.ASTNode} An AST node pointing to a field.
+ * @param {Blockly.Field} field The location of the AST node.
+ * @return {Blockly.ASTNode} An AST node pointing to a field.
  */
 Blockly.ASTNode.createFieldNode = function(field) {
+  if (!field) {
+    return null;
+  }
   return new Blockly.ASTNode(Blockly.ASTNode.types.FIELD, field);
 };
 
@@ -144,10 +147,10 @@ Blockly.ASTNode.createConnectionNode = function(connection) {
  * Creates an AST node pointing to an input. Stores the input connection as the
  *     location.
  * @param {Blockly.Input} input The input used to create an AST node.
- * @return {!Blockly.ASTNode} An AST node pointing to a input.
+ * @return {Blockly.ASTNode} An AST node pointing to a input.
  */
 Blockly.ASTNode.createInputNode = function(input) {
-  if (!input) {
+  if (!input || !input.connection) {
     return null;
   }
   return new Blockly.ASTNode(Blockly.ASTNode.types.INPUT, input.connection);
@@ -155,22 +158,28 @@ Blockly.ASTNode.createInputNode = function(input) {
 
 /**
  * Creates an AST node pointing to a block.
- * @param {!Blockly.Block} block The block used to create an AST node.
- * @return {!Blockly.ASTNode} An AST node pointing to a block.
+ * @param {Blockly.Block} block The block used to create an AST node.
+ * @return {Blockly.ASTNode} An AST node pointing to a block.
  */
 Blockly.ASTNode.createBlockNode = function(block) {
+  if (!block) {
+    return null;
+  }
   return new Blockly.ASTNode(Blockly.ASTNode.types.BLOCK, block);
 };
 
 /**
  * Create an AST node of type stack. A stack, represented by its top block, is
  *     the set of all blocks connected to a top block, including the top block.
- * @param {!Blockly.Block} topBlock A top block has no parent and can be found
+ * @param {Blockly.Block} topBlock A top block has no parent and can be found
  *     in the list returned by workspace.getTopBlocks().
- * @return {!Blockly.ASTNode} An AST node of type stack that points to the top
+ * @return {Blockly.ASTNode} An AST node of type stack that points to the top
  *     block on the stack.
  */
 Blockly.ASTNode.createStackNode = function(topBlock) {
+  if (!topBlock) {
+    return null;
+  }
   return new Blockly.ASTNode(Blockly.ASTNode.types.STACK, topBlock);
 };
 
@@ -179,10 +188,13 @@ Blockly.ASTNode.createStackNode = function(topBlock) {
  * @param {!Blockly.Workspace} workspace The workspace that we are on.
  * @param {Blockly.utils.Coordinate} wsCoordinate The position on the workspace
  *     for this node.
- * @return {!Blockly.ASTNode} An AST node pointing to a workspace and a position
+ * @return {Blockly.ASTNode} An AST node pointing to a workspace and a position
  *     on the workspace.
  */
 Blockly.ASTNode.createWorkspaceNode = function(workspace, wsCoordinate) {
+  if (!wsCoordinate || !workspace) {
+    return null;
+  }
   var params = {
     wsCoordinate: wsCoordinate
   };
@@ -278,7 +290,7 @@ Blockly.ASTNode.prototype.findNextForInput_ = function() {
  * @private
  */
 Blockly.ASTNode.prototype.findNextForField_ = function() {
-  var location = this.location_;
+  var location = /** @type {!Blockly.Field} */ (this.location_);
   var input = location.getParentInput();
   var block = location.getSourceBlock();
   var curIdx = block.inputList.indexOf(input);
@@ -332,7 +344,7 @@ Blockly.ASTNode.prototype.findPrevForInput_ = function() {
  * @private
  */
 Blockly.ASTNode.prototype.findPrevForField_ = function() {
-  var location = this.location_;
+  var location = /** @type {!Blockly.Field} */ (this.location_);
   var parentInput = location.getParentInput();
   var block = location.getSourceBlock();
   var curIdx = block.inputList.indexOf(parentInput);
@@ -398,9 +410,11 @@ Blockly.ASTNode.prototype.navigateBetweenStacks_ = function(forward) {
 Blockly.ASTNode.prototype.findTopASTNodeForBlock_ = function(block) {
   var topConnection = block.previousConnection || block.outputConnection;
   if (topConnection) {
-    return Blockly.ASTNode.createConnectionNode(topConnection);
+    return /** @type {!Blockly.ASTNode} */ (Blockly.ASTNode.createConnectionNode(
+        topConnection));
   } else {
-    return Blockly.ASTNode.createBlockNode(block);
+    return /** @type {!Blockly.ASTNode} */ (Blockly.ASTNode.createBlockNode(
+        block));
   }
 };
 
@@ -477,20 +491,14 @@ Blockly.ASTNode.prototype.next = function() {
 
     case Blockly.ASTNode.types.BLOCK:
       var nextConnection = this.location_.nextConnection;
-      if (nextConnection) {
-        return Blockly.ASTNode.createConnectionNode(nextConnection);
-      }
-      break;
+      return Blockly.ASTNode.createConnectionNode(nextConnection);
 
     case Blockly.ASTNode.types.PREVIOUS:
       return Blockly.ASTNode.createBlockNode(this.location_.getSourceBlock());
 
     case Blockly.ASTNode.types.NEXT:
       var targetConnection = this.location_.targetConnection;
-      if (targetConnection) {
-        return Blockly.ASTNode.createConnectionNode(targetConnection);
-      }
-      break;
+      return Blockly.ASTNode.createConnectionNode(targetConnection);
   }
 
   return null;
@@ -517,14 +525,11 @@ Blockly.ASTNode.prototype.in = function() {
 
     case Blockly.ASTNode.types.BLOCK:
       var block = /** @type {!Blockly.Block} */ (this.location_);
-      return this.findFirstFieldOrInput_(this.location_);
+      return this.findFirstFieldOrInput_(block);
 
     case Blockly.ASTNode.types.INPUT:
       var targetConnection = this.location_.targetConnection;
-      if (targetConnection) {
-        return Blockly.ASTNode.createConnectionNode(targetConnection);
-      }
-      break;
+      return Blockly.ASTNode.createConnectionNode(targetConnection);
   }
 
   return null;
@@ -551,13 +556,9 @@ Blockly.ASTNode.prototype.prev = function() {
       return this.findPrevForInput_();
 
     case Blockly.ASTNode.types.BLOCK:
-      var prevConnection = this.location_.previousConnection;
-      var outputConnection = this.location_.outputConnection;
-      var topConnection = prevConnection || outputConnection;
-      if (topConnection) {
-        return Blockly.ASTNode.createConnectionNode(topConnection);
-      }
-      break;
+      var block = this.location_;
+      var topConnection = block.previousConnection || block.outputConnection;
+      return Blockly.ASTNode.createConnectionNode(topConnection);
 
     case Blockly.ASTNode.types.PREVIOUS:
       var targetConnection = this.location_.targetConnection;
diff --git a/core/keyboard_nav/cursor_svg.js b/core/keyboard_nav/cursor_svg.js
index 0151d4881..0c33aa8a7 100644
--- a/core/keyboard_nav/cursor_svg.js
+++ b/core/keyboard_nav/cursor_svg.js
@@ -274,7 +274,7 @@ Blockly.CursorSvg.prototype.showWithField_ = function(curNode) {
 Blockly.CursorSvg.prototype.showWithInput_ = function(curNode) {
   var connection = /** @type {Blockly.Connection} */
       (curNode.getLocation());
-  var sourceBlock = /** @type {Blockly.BlockSvg} */ (connection.getSourceBlock());
+  var sourceBlock = /** @type {!Blockly.BlockSvg} */ (connection.getSourceBlock());
 
   this.positionInput_(connection);
   this.setParent_(sourceBlock);
diff --git a/core/keyboard_nav/key_map.js b/core/keyboard_nav/key_map.js
index 2491cbc5b..e8bc32c54 100644
--- a/core/keyboard_nav/key_map.js
+++ b/core/keyboard_nav/key_map.js
@@ -30,7 +30,7 @@ goog.require('Blockly.utils.object');
 
 /**
  * Holds the serialized key to key action mapping.
- * @type {Object<string, Blockly.Action>}
+ * @type {!Object<string, Blockly.Action>}
  */
 Blockly.user.keyMap.map_ = {};
 
@@ -63,7 +63,7 @@ Blockly.user.keyMap.setActionForKey = function(keyCode, action) {
 
 /**
  * Creates a new key map.
- * @param {Object<string, Blockly.Action>} keyMap The object holding the key
+ * @param {!Object<string, Blockly.Action>} keyMap The object holding the key
  *     to action mapping.
  * @package
  */
diff --git a/core/keyboard_nav/navigation.js b/core/keyboard_nav/navigation.js
index 6aaecacff..90577c187 100644
--- a/core/keyboard_nav/navigation.js
+++ b/core/keyboard_nav/navigation.js
@@ -283,7 +283,7 @@ Blockly.navigation.modifyWarn_ = function() {
 /**
  * Disconnect the block from its parent and move to the position of the
  * workspace node.
- * @param {!Blockly.Block} block The block to be moved to the workspace.
+ * @param {Blockly.Block} block The block to be moved to the workspace.
  * @param {!Blockly.ASTNode} wsNode The workspace node holding the position the
  *     block will be moved to.
  * @return {boolean} True if the block can be moved to the workspace,
@@ -291,6 +291,9 @@ Blockly.navigation.modifyWarn_ = function() {
  * @private
  */
 Blockly.navigation.moveBlockToWorkspace_ = function(block, wsNode) {
+  if (!block) {
+    return false;
+  }
   if (block.isShadow()) {
     Blockly.navigation.warn_('Cannot move a shadow block to the workspace.');
     return false;
@@ -323,10 +326,14 @@ Blockly.navigation.modify_ = function() {
   var markerLoc = markerNode.getLocation();
 
   if (markerNode.isConnection() && cursorNode.isConnection()) {
+    cursorLoc = /** @type {!Blockly.Connection} */ (cursorLoc);
+    markerLoc = /** @type {!Blockly.Connection} */ (markerLoc);
     return Blockly.navigation.connect_(cursorLoc, markerLoc);
   } else if (markerNode.isConnection() &&
         (cursorType == Blockly.ASTNode.types.BLOCK ||
         cursorType == Blockly.ASTNode.types.STACK)) {
+    cursorLoc = /** @type {!Blockly.Block} */ (cursorLoc);
+    markerLoc = /** @type {!Blockly.Connection} */ (markerLoc);
     return Blockly.navigation.insertBlock(cursorLoc, markerLoc);
   } else if (markerType == Blockly.ASTNode.types.WORKSPACE) {
     var block = Blockly.navigation.getSourceBlock_(cursorNode);
@@ -372,7 +379,7 @@ Blockly.navigation.moveAndConnect_ = function(movingConnection, destConnection)
   }
   var movingBlock = movingConnection.getSourceBlock();
 
-  if (destConnection.canConnectWithReason_(movingConnection) ==
+  if (destConnection.canConnectWithReason(movingConnection) ==
       Blockly.Connection.CAN_CONNECT) {
 
     Blockly.navigation.disconnectChild_(movingConnection, destConnection);
@@ -458,7 +465,7 @@ Blockly.navigation.connect_ = function(movingConnection, destConnection) {
     return true;
   } else {
     try {
-      destConnection.checkConnection_(movingConnection);
+      destConnection.checkConnection(movingConnection);
     }
     catch (e) {
       // If nothing worked report the error from the original connections.
@@ -472,7 +479,7 @@ Blockly.navigation.connect_ = function(movingConnection, destConnection) {
  * Tries to connect the given block to the destination connection, making an
  * intelligent guess about which connection to use to on the moving block.
  * @param {!Blockly.Block} block The block to move.
- * @param {Blockly.Connection} destConnection The connection to connect to.
+ * @param {!Blockly.Connection} destConnection The connection to connect to.
  * @return {boolean} Whether the connection was successful.
  */
 Blockly.navigation.insertBlock = function(block, destConnection) {
@@ -525,7 +532,7 @@ Blockly.navigation.disconnectBlocks_ = function() {
     Blockly.navigation.log_('Cannot disconnect blocks when the cursor is not on a connection');
     return;
   }
-  var curConnection = curNode.getLocation();
+  var curConnection = /** @type {!Blockly.Connection} */ (curNode.getLocation());
   if (!curConnection.isConnected()) {
     Blockly.navigation.log_('Cannot disconnect unconnected connection');
     return;
@@ -652,7 +659,7 @@ Blockly.navigation.moveCursorOnBlockDelete = function(deletedBlock) {
       }
     // If the cursor is on a block whose parent is being deleted, move the
     // cursor to the workspace.
-    } else if (deletedBlock.getChildren(false).indexOf(block) > -1) {
+    } else if (block && deletedBlock.getChildren(false).indexOf(block) > -1) {
       cursor.setCurNode(Blockly.ASTNode.createWorkspaceNode(block.workspace,
           block.getRelativeToSurfaceXY()));
     }
diff --git a/core/workspace.js b/core/workspace.js
index cd1514bc5..cefd46038 100644
--- a/core/workspace.js
+++ b/core/workspace.js
@@ -168,7 +168,7 @@ Blockly.Workspace.prototype.connectionDBList = null;
 
 /**
  * Sets the cursor for keyboard navigation.
- * @param {Blockly.Cursor} cursor The cursor used to navigate around the Blockly
+ * @param {!Blockly.Cursor} cursor The cursor used to navigate around the Blockly
  *     AST for keyboard navigation.
  */
 Blockly.Workspace.prototype.setCursor = function(cursor) {
@@ -177,7 +177,7 @@ Blockly.Workspace.prototype.setCursor = function(cursor) {
 
 /**
  * Sets the marker for keyboard navigation.
- * @param {Blockly.MarkerCursor} marker The marker used to mark a location for
+ * @param {!Blockly.MarkerCursor} marker The marker used to mark a location for
  *     keyboard navigation.
  */
 Blockly.Workspace.prototype.setMarker = function(marker) {
diff --git a/core/workspace_svg.js b/core/workspace_svg.js
index f318c4364..6b01121cd 100644
--- a/core/workspace_svg.js
+++ b/core/workspace_svg.js
@@ -415,35 +415,31 @@ Blockly.WorkspaceSvg.prototype.getRenderer = function() {
 /**
  * Sets the cursor for use with keyboard navigation.
  *
- * @param {Blockly.Cursor} cursor The cursor used to move around this workspace.
+ * @param {!Blockly.Cursor} cursor The cursor used to move around this workspace.
  * @override
  */
 Blockly.WorkspaceSvg.prototype.setCursor = function(cursor) {
-  if (this.cursor_ && this.cursor_.getDrawer()) {
+  if (this.cursor_.getDrawer()) {
     this.cursor_.getDrawer().dispose();
   }
   this.cursor_ = cursor;
-  if (this.cursor_) {
-    this.cursor_.setDrawer(this.getRenderer().makeCursorDrawer(this, false));
-    this.setCursorSvg(this.cursor_.getDrawer().createDom());
-  }
+  this.cursor_.setDrawer(this.getRenderer().makeCursorDrawer(this, false));
+  this.setCursorSvg(this.cursor_.getDrawer().createDom());
 };
 
 /**
  * Sets the marker for use with keyboard navigation.
- * @param {Blockly.MarkerCursor} marker The immovable cursor used to mark a
+ * @param {!Blockly.MarkerCursor} marker The immovable cursor used to mark a
  *     location on the workspace.
  * @override
  */
 Blockly.WorkspaceSvg.prototype.setMarker = function(marker) {
-  if (this.marker_ && this.marker_.getDrawer()) {
+  if (this.marker_.getDrawer()) {
     this.marker_.getDrawer().dispose();
   }
   this.marker_ = marker;
-  if (this.marker_) {
-    this.marker_.setDrawer(this.getRenderer().makeCursorDrawer(this, true));
-    this.setMarkerSvg(this.marker_.getDrawer().createDom());
-  }
+  this.marker_.setDrawer(this.getRenderer().makeCursorDrawer(this, true));
+  this.setMarkerSvg(this.marker_.getDrawer().createDom());
 };
 
 /**
@@ -1187,8 +1183,11 @@ Blockly.WorkspaceSvg.prototype.pasteBlock_ = function(xmlBlock) {
 
     // Handle paste for keyboard navigation
     var markedNode = this.getMarker().getCurNode();
-    if (Blockly.keyboardAccessibilityMode && markedNode) {
-      Blockly.navigation.insertBlock(block, markedNode.getLocation());
+    if (Blockly.keyboardAccessibilityMode && markedNode &&
+        markedNode.isConnection()) {
+      var markedLocation =
+        /** @type {!Blockly.Connection} */ (markedNode.getLocation());
+      Blockly.navigation.insertBlock(block, markedLocation);
       return;
     }
 
diff --git a/tests/mocha/connection_test.js b/tests/mocha/connection_test.js
index 0e8776425..6a7faaf97 100644
--- a/tests/mocha/connection_test.js
+++ b/tests/mocha/connection_test.js
@@ -19,7 +19,7 @@ suite('Connections', function() {
   suite('Can Connect With Reason', function() {
     test('Target Null', function() {
       var connection = new Blockly.Connection({}, Blockly.INPUT_VALUE);
-      chai.assert.equal(connection.canConnectWithReason_(null),
+      chai.assert.equal(connection.canConnectWithReason(null),
           Blockly.Connection.REASON_TARGET_NULL);
     });
     test('Target Self', function() {
@@ -27,7 +27,7 @@ suite('Connections', function() {
       var connection1 = new Blockly.Connection(block, Blockly.INPUT_VALUE);
       var connection2 = new Blockly.Connection(block, Blockly.OUTPUT_VALUE);
 
-      chai.assert.equal(connection1.canConnectWithReason_(connection2),
+      chai.assert.equal(connection1.canConnectWithReason(connection2),
           Blockly.Connection.REASON_SELF_CONNECTION);
     });
     test('Different Workspaces', function() {
@@ -36,7 +36,7 @@ suite('Connections', function() {
       var connection2 = new Blockly.Connection(
           {workspace: 2}, Blockly.OUTPUT_VALUE);
 
-      chai.assert.equal(connection1.canConnectWithReason_(connection2),
+      chai.assert.equal(connection1.canConnectWithReason(connection2),
           Blockly.Connection.REASON_DIFFERENT_WORKSPACES);
     });
     suite('Types', function() {
@@ -57,51 +57,51 @@ suite('Connections', function() {
             inBlock, Blockly.INPUT_VALUE);
       });
       test('Previous, Next', function() {
-        chai.assert.equal(this.previous.canConnectWithReason_(this.next),
+        chai.assert.equal(this.previous.canConnectWithReason(this.next),
             Blockly.Connection.CAN_CONNECT);
       });
       test('Previous, Output', function() {
-        chai.assert.equal(this.previous.canConnectWithReason_(this.output),
+        chai.assert.equal(this.previous.canConnectWithReason(this.output),
             Blockly.Connection.REASON_WRONG_TYPE);
       });
       test('Previous, Input', function() {
-        chai.assert.equal(this.previous.canConnectWithReason_(this.input),
+        chai.assert.equal(this.previous.canConnectWithReason(this.input),
             Blockly.Connection.REASON_WRONG_TYPE);
       });
       test('Next, Previous', function() {
-        chai.assert.equal(this.next.canConnectWithReason_(this.previous),
+        chai.assert.equal(this.next.canConnectWithReason(this.previous),
             Blockly.Connection.CAN_CONNECT);
       });
       test('Next, Output', function() {
-        chai.assert.equal(this.next.canConnectWithReason_(this.output),
+        chai.assert.equal(this.next.canConnectWithReason(this.output),
             Blockly.Connection.REASON_WRONG_TYPE);
       });
       test('Next, Input', function() {
-        chai.assert.equal(this.next.canConnectWithReason_(this.input),
+        chai.assert.equal(this.next.canConnectWithReason(this.input),
             Blockly.Connection.REASON_WRONG_TYPE);
       });
       test('Output, Previous', function() {
-        chai.assert.equal(this.output.canConnectWithReason_(this.previous),
+        chai.assert.equal(this.output.canConnectWithReason(this.previous),
             Blockly.Connection.REASON_WRONG_TYPE);
       });
       test('Output, Next', function() {
-        chai.assert.equal(this.output.canConnectWithReason_(this.next),
+        chai.assert.equal(this.output.canConnectWithReason(this.next),
             Blockly.Connection.REASON_WRONG_TYPE);
       });
       test('Output, Input', function() {
-        chai.assert.equal(this.output.canConnectWithReason_(this.input),
+        chai.assert.equal(this.output.canConnectWithReason(this.input),
             Blockly.Connection.CAN_CONNECT);
       });
       test('Input, Previous', function() {
-        chai.assert.equal(this.input.canConnectWithReason_(this.previous),
+        chai.assert.equal(this.input.canConnectWithReason(this.previous),
             Blockly.Connection.REASON_WRONG_TYPE);
       });
       test('Input, Next', function() {
-        chai.assert.equal(this.input.canConnectWithReason_(this.next),
+        chai.assert.equal(this.input.canConnectWithReason(this.next),
             Blockly.Connection.REASON_WRONG_TYPE);
       });
       test('Input, Output', function() {
-        chai.assert.equal(this.input.canConnectWithReason_(this.output),
+        chai.assert.equal(this.input.canConnectWithReason(this.output),
             Blockly.Connection.CAN_CONNECT);
       });
     });
@@ -112,7 +112,7 @@ suite('Connections', function() {
         var prev = new Blockly.Connection(prevBlock, Blockly.PREVIOUS_STATEMENT);
         var next = new Blockly.Connection(nextBlock, Blockly.NEXT_STATEMENT);
 
-        chai.assert.equal(prev.canConnectWithReason_(next),
+        chai.assert.equal(prev.canConnectWithReason(next),
             Blockly.Connection.CAN_CONNECT);
       });
       test('Next Shadow', function() {
@@ -121,7 +121,7 @@ suite('Connections', function() {
         var prev = new Blockly.Connection(prevBlock, Blockly.PREVIOUS_STATEMENT);
         var next = new Blockly.Connection(nextBlock, Blockly.NEXT_STATEMENT);
 
-        chai.assert.equal(prev.canConnectWithReason_(next),
+        chai.assert.equal(prev.canConnectWithReason(next),
             Blockly.Connection.REASON_SHADOW_PARENT);
       });
       test('Prev and Next Shadow', function() {
@@ -130,7 +130,7 @@ suite('Connections', function() {
         var prev = new Blockly.Connection(prevBlock, Blockly.PREVIOUS_STATEMENT);
         var next = new Blockly.Connection(nextBlock, Blockly.NEXT_STATEMENT);
 
-        chai.assert.equal(prev.canConnectWithReason_(next),
+        chai.assert.equal(prev.canConnectWithReason(next),
             Blockly.Connection.CAN_CONNECT);
       });
       test('Output Shadow', function() {
@@ -139,7 +139,7 @@ suite('Connections', function() {
         var outCon = new Blockly.Connection(outBlock, Blockly.OUTPUT_VALUE);
         var inCon = new Blockly.Connection(inBlock, Blockly.INPUT_VALUE);
 
-        chai.assert.equal(outCon.canConnectWithReason_(inCon),
+        chai.assert.equal(outCon.canConnectWithReason(inCon),
             Blockly.Connection.CAN_CONNECT);
       });
       test('Input Shadow', function() {
@@ -148,7 +148,7 @@ suite('Connections', function() {
         var outCon = new Blockly.Connection(outBlock, Blockly.OUTPUT_VALUE);
         var inCon = new Blockly.Connection(inBlock, Blockly.INPUT_VALUE);
 
-        chai.assert.equal(outCon.canConnectWithReason_(inCon),
+        chai.assert.equal(outCon.canConnectWithReason(inCon),
             Blockly.Connection.REASON_SHADOW_PARENT);
       });
       test('Output and Input Shadow', function() {
@@ -157,7 +157,7 @@ suite('Connections', function() {
         var outCon = new Blockly.Connection(outBlock, Blockly.OUTPUT_VALUE);
         var inCon = new Blockly.Connection(inBlock, Blockly.INPUT_VALUE);
 
-        chai.assert.equal(outCon.canConnectWithReason_(inCon),
+        chai.assert.equal(outCon.canConnectWithReason(inCon),
             Blockly.Connection.CAN_CONNECT);
       });
     });