diff --git a/tests/blocks/test_blocks.js b/tests/blocks/test_blocks.js
index 501c55b62..d599c316c 100644
--- a/tests/blocks/test_blocks.js
+++ b/tests/blocks/test_blocks.js
@@ -205,6 +205,369 @@ Blockly.defineBlocksWithJsonArray([  // BEGIN JSON EXTRACT
     "inputsInline": false,
     "style": "math_blocks"
   },
+  {
+    "type": "test_connections_row_input",
+    "message0": "%1",
+    "args0": [
+      {
+        "type": "input_value",
+        "name": "NAME",
+      }
+    ],
+    "colour": '#aaaaaa',
+    "tooltip": "No Checks\n" +
+        "Can connect to any output connection."
+  },
+  {
+    "type": "test_connections_row_blue",
+    "message0": "%1",
+    "args0": [
+      {
+        "type": "input_value",
+        "name": "NAME",
+        "check": "greenRel"
+      }
+    ],
+    "output": "noneOut",
+    "colour": 230,
+    "tooltip": "Output: noneOut\n" +
+        "Input: greenRel\n" +
+        "Input connection can accept yellow blocks but not red blocks."
+  },
+  {
+    "type": "test_connections_row_yellow",
+    "message0": "%1",
+    "args0": [
+      {
+        "type": "input_value",
+        "name": "NAME",
+        "check": [
+          "orangeRel",
+          "yellowRel"
+        ]
+      }
+    ],
+    "output": [
+      "yellowRel",
+      "greenRel"
+    ],
+    "colour": 60,
+    "tooltip": "Output: yellowRel, greenRel\n" +
+        "Input: yellowRel, orangeRel\n" +
+        "Output can connect to yellow blocks and blue blocks, but not red blocks.\n" +
+        "Input can connect to yellow blocks and red blocks, but not blue blocks."
+  },
+  {
+    "type": "test_connections_row_red",
+    "message0": "%1",
+    "args0": [
+      {
+        "type": "input_value",
+        "name": "NAME",
+        "check": "noneIn"
+      }
+    ],
+    "output": "orangeRel",
+    "colour": 0,
+    "tooltip": "Output: orangeRel\n" +
+        "Input: noneIn\n" +
+        "Output can connect to yellow blocks, but not blue blocks."
+  },
+  {
+    "type": "test_connections_row_output",
+    "message0": "",
+    "output": null,
+    "colour": '#aaaaaa',
+    "tooltip": "No Checks\n" +
+        "Can connect to any input connection."
+  },
+  {
+    "type": "test_connections_multivalue_1valid",
+    "message0": "none %1 both %2",
+    "args0": [
+      {
+        "type": "input_value",
+        "name": "NAME1",
+        "align": "RIGHT",
+        "check": "noneIn"
+      },
+      {
+        "type": "input_value",
+        "name": "NAME2",
+        "align": "RIGHT",
+        "check": [
+          "yellowRel",
+          "orangeRel"
+        ]
+      }
+    ],
+    "output": [
+      "yellowRel",
+      "greenRel"
+    ],
+    "colour": 60,
+    "tooltip": "Output: yellowRel, greenRel\n" +
+        "Input Top: noneIn\n" +
+        "Input Bottom: yellowRel, orangeRel\n" +
+        "Output can connect to yellow blocks and blue blocks, but not red blocks.\n" +
+        "Top Input can connect to nothing, except grey blocks.\n" +
+        "Bottom Input can connect to yellow blocks and red blocks, but not blue" +
+        " blocks."
+  },
+  {
+    "type": "test_connections_multivalue_2valid",
+    "message0": "both %1 both %2",
+    "args0": [
+      {
+        "type": "input_value",
+        "name": "NAME1",
+        "align": "RIGHT",
+        "check": [
+          "yellowRel",
+          "orangeRel"
+        ]
+      },
+      {
+        "type": "input_value",
+        "name": "NAME2",
+        "align": "RIGHT",
+        "check": [
+          "yellowRel",
+          "orangeRel"
+        ]
+      }
+    ],
+    "output": [
+      "yellowRel",
+      "greenRel"
+    ],
+    "colour": 60,
+    "tooltip": "Output: yellowRel, greenRel\n" +
+        "Input Top:  yellowRel, orangeRel\n" +
+        "Input Bottom: yellowRel, orangeRel\n" +
+        "Output can connect to yellow blocks and blue blocks, but not red blocks.\n" +
+        "Top Input can connect to yellow blocks and red blocks, but not blue" +
+        " blocks.\n" +
+        "Bottom Input can connect to yellow blocks and red blocks, but not blue" +
+        " blocks."
+  },
+  {
+    "type": "test_connections_stack_next",
+    "message0": "",
+    "nextStatement": null,
+    "colour": '#aaaaaa',
+    "tooltip": "No Checks\n" +
+        "Can connect to any previous connection."
+  },
+  {
+    "type": "test_connections_stack_blue",
+    "message0": "",
+    "previousStatement": "nonePrev",
+    "nextStatement": "greenRel",
+    "colour": 230,
+    "tooltip": "Prev: nonePrev\n" +
+        "Next: greenRel\n" +
+        "Next connection can accept yellow blocks but not red blocks."
+  },
+  {
+    "type": "test_connections_stack_yellow",
+    "message0": "",
+    "previousStatement": [
+      "greenRel",
+      "yellowRel"
+    ],
+    "nextStatement": [
+      "yellowRel",
+      "orangeRel"
+    ],
+    "colour": 60,
+    "tooltip": "Prev: yellowRel, greenRel\n" +
+        "Next: yellowRel, orangeRel\n" +
+        "Prev can connect to yellow blocks and blue blocks, but not red blocks.\n" +
+        "Next can connect to yellow blocks and red blocks, but not blue blocks."
+  },
+  {
+    "type": "test_connections_stack_red",
+    "message0": "",
+    "previousStatement": "orangeRel",
+    "nextStatement": "noneNext",
+    "colour": 0,
+    "tooltip": "Prev: orangeRel\n" +
+        "Next: noneNext\n" +
+        "Prev can connect to yellow blocks, but not blue blocks."
+  },
+  {
+    "type": "test_connections_stack_prev",
+    "message0": "",
+    "previousStatement": null,
+    "colour": '#aaaaaa',
+    "tooltip": "No Checks\n" +
+        "Can connect to any input connection."
+  },
+  {
+    "type": "test_connections_statement_blue",
+    "message0": "%1",
+    "args0": [
+      {
+        "type": "input_statement",
+        "name": "NAME",
+        "check": "greenRel"
+      }
+    ],
+    "previousStatement": "nonePrev",
+    "nextStatement": "greenRel",
+    "colour": 230,
+    "tooltip": "Prev: nonePrev\n" +
+        "Next: greenRel\n" +
+        "Statement: greenRel\n" +
+        "Next connection can accept yellow blocks but not red blocks.\n" +
+        "Statement connection can accept yellow blocks but not red blocks."
+  },
+  {
+    "type": "test_connections_statement_yellow",
+    "message0": "%1",
+    "args0": [
+      {
+        "type": "input_statement",
+        "name": "NAME",
+        "check":  [
+          "yellowRel",
+          "orangeRel"
+        ]
+      }
+    ],
+    "previousStatement": [
+      "greenRel",
+      "yellowRel"
+    ],
+    "nextStatement": [
+      "yellowRel",
+      "orangeRel"
+    ],
+    "colour": 60,
+    "tooltip": "Prev: yellowRel, greenRel\n" +
+        "Next: yellowRel, orangeRel\n" +
+        "Statement: orangeRel\n" +
+        "Prev can connect to yellow blocks and blue blocks, but not red" +
+        " blocks.\n" +
+        "Next can connect to yellow blocks and red blocks, but not blue" +
+        " blocks.\n" +
+        "Statement connection can accept yellow blocks and red blocks but not" +
+        " blue blocks.\n"
+  },
+  {
+    "type": "test_connections_statement_red",
+    "message0": "%1",
+    "args0": [
+      {
+        "type": "input_statement",
+        "name": "NAME",
+        "check": "noneNext"
+      }
+    ],
+    "previousStatement": "orangeRel",
+    "nextStatement": "noneNext",
+    "colour": 0,
+    "tooltip": "Prev: orangeRel\n" +
+        "Next: noneNext\n" +
+        "Statement: noneNext\n" +
+        "Prev connection can accept yellow blocks but not blue blocks.\n" +
+        "Statement connection accepts none."
+  },
+  {
+    "type": "test_connections_statement_nonext",
+    "message0": "%1",
+    "args0": [
+      {
+        "type": "input_statement",
+        "name": "NAME",
+        "check":  [
+          "yellowRel",
+          "orangeRel"
+        ]
+      }
+    ],
+    "previousStatement": [
+      "greenRel",
+      "yellowRel"
+    ],
+    "colour": 60,
+    "tooltip": "Prev: yellowRel, greenRel\n" +
+        "Next: yellowRel, orangeRel\n" +
+        "Statement: orangeRel\n" +
+        "Prev can connect to yellow blocks and blue blocks, but not red" +
+        " blocks.\n" +
+        "Statement connection can accept yellow blocks and red blocks but not" +
+        " blue blocks.\n"
+  },
+  {
+    "type": "test_connections_multistatement_1valid",
+    "message0": "none %1 both %2",
+    "args0": [
+      {
+        "type": "input_statement",
+        "name": "NAME",
+        "check": "noneNext"
+      },
+      {
+        "type": "input_statement",
+        "name": "NAME",
+        "check":  [
+          "yellowRel",
+          "orangeRel"
+        ]
+      }
+    ],
+    "previousStatement": [
+      "greenRel",
+      "yellowRel"
+    ],
+    "colour": 60,
+    "tooltip": "Prev: yellowRel, greenRel\n" +
+        "Next: yellowRel, orangeRel\n" +
+        "Statement: orangeRel\n" +
+        "Prev can connect to yellow blocks and blue blocks, but not red" +
+        " blocks.\n" +
+        "Top Statement cannot connect to anything, except grey blocks.\n" +
+        "Bottom Statement connection can accept yellow blocks and red blocks" +
+        " but not blue blocks.\n"
+  },
+  {
+    "type": "test_connections_multistatement_2valid",
+    "message0": "both %1 both %2",
+    "args0": [
+      {
+        "type": "input_statement",
+        "name": "NAME",
+        "check": [
+          "yellowRel",
+          "orangeRel"
+        ]
+      },
+      {
+        "type": "input_statement",
+        "name": "NAME",
+        "check": [
+          "yellowRel",
+          "orangeRel"
+        ]
+      }
+    ],
+    "previousStatement": [
+      "greenRel",
+      "yellowRel"
+    ],
+    "colour": 60,
+    "tooltip": "Prev: yellowRel, greenRel\n" +
+        "Next: yellowRel, orangeRel\n" +
+        "Statement: orangeRel\n" +
+        "Prev can connect to yellow blocks and blue blocks, but not red" +
+        " blocks.\n" +
+        "Top Statement connection can accept yellow blocks and red blocks but" +
+        " not blue blocks.\n" +
+        "Bottom Statement connection can accept yellow blocks and red blocks" +
+        " but not blue blocks.\n"
+  },
   {
     "type": "test_dropdowns_long",
     "message0": "long: %1",
diff --git a/tests/playground.html b/tests/playground.html
index d866fd0d6..f3a306dc8 100644
--- a/tests/playground.html
+++ b/tests/playground.html
@@ -249,6 +249,82 @@ function addToolboxButtonCallbacks() {
     workspace.createVariable('2b', '', '2B');
     workspace.createVariable('2c', '', '2C');
   };
+  var insertConnectionRows = function(button) {
+    var workspace = button.getTargetWorkspace();
+    Blockly.Xml.domToWorkspace(Blockly.Xml.textToDom(
+            '<xml xmlns="https://developers.google.com/blockly/xml">\n' +
+            '  <block type="test_connections_row_input">\n' +
+            '    <value name="NAME">\n' +
+            '      <block type="test_connections_row_blue">\n' +
+            '        <value name="NAME">\n' +
+            '          <block type="test_connections_row_yellow">\n' +
+            '            <value name="NAME">\n' +
+            '              <block type="test_connections_row_yellow">\n' +
+            '                <value name="NAME">\n' +
+            '                  <block type="test_connections_row_red">\n' +
+            '                    <value name="NAME">\n' +
+            '                      <block type="test_connections_row_output"/>\n' +
+            '                    </value>\n' +
+            '                  </block>\n' +
+            '                </value>\n' +
+            '              </block>\n' +
+            '            </value>\n' +
+            '          </block>\n' +
+            '        </value>\n' +
+            '      </block>\n' +
+            '    </value>\n' +
+            '  </block>\n' +
+            '</xml>'
+    ), workspace)
+  };
+  var insertConnectionStacks = function(button) {
+    var workspace = button.getTargetWorkspace();
+    Blockly.Xml.domToWorkspace(Blockly.Xml.textToDom(
+            '<xml xmlns="https://developers.google.com/blockly/xml">\n' +
+            '  <block type="test_connections_stack_next">\n' +
+            '    <next>\n' +
+            '      <block type="test_connections_stack_blue">\n' +
+            '        <next>\n' +
+            '          <block type="test_connections_stack_yellow">\n' +
+            '            <next>\n' +
+            '              <block type="test_connections_stack_yellow">\n' +
+            '                <next>\n' +
+            '                  <block type="test_connections_stack_red">\n' +
+            '                    <next>\n' +
+            '                      <block type="test_connections_stack_prev"/>\n' +
+            '                    </next>\n' +
+            '                  </block>\n' +
+            '                </next>\n' +
+            '              </block>\n' +
+            '            </next>\n' +
+            '          </block>\n' +
+            '        </next>\n' +
+            '      </block>\n' +
+            '    </next>\n' +
+            '  </block>\n' +
+            '</xml>'
+    ), workspace);
+  };
+  var insertConnectionStatements = function(button) {
+    var workspace = button.getTargetWorkspace();
+    Blockly.Xml.domToWorkspace(Blockly.Xml.textToDom(
+            '<xml xmlns="https://developers.google.com/blockly/xml">\n' +
+            '  <block type="test_connections_statement_blue">\n' +
+            '    <statement name="NAME">\n' +
+            '      <block type="test_connections_statement_yellow">\n' +
+            '        <statement name="NAME">\n' +
+            '          <block type="test_connections_statement_yellow">\n' +
+            '            <statement name="NAME">\n' +
+            '              <block type="test_connections_statement_red"/>\n' +
+            '            </statement>\n' +
+            '          </block>\n' +
+            '        </statement>\n' +
+            '      </block>\n' +
+            '    </statement>\n' +
+            '  </block>\n' +
+            '</xml>'
+    ), workspace);
+  };
 
   workspace.registerButtonCallback(
     'addVariables', addVariables);
@@ -272,6 +348,12 @@ function addToolboxButtonCallbacks() {
       'addDynamicOption', Blockly.TestBlocks.addDynamicDropdownOption_);
   workspace.registerButtonCallback(
       'removeDynamicOption', Blockly.TestBlocks.removeDynamicDropdownOption_);
+  workspace.registerButtonCallback(
+          'insertConnectionRows', insertConnectionRows);
+  workspace.registerButtonCallback(
+          'insertConnectionStacks', insertConnectionStacks);
+  workspace.registerButtonCallback(
+          'insertConnectionStatements', insertConnectionStatements);
 }
 
 function setRenderDebugOptionCheckboxState(overrideOptions) {
@@ -1361,6 +1443,11 @@ var spaghettiXml = [
   the standard predefined blocks, and so test alternative block rendering
   code paths. -->
   <xml xmlns="https://developers.google.com/blockly/xml" id="toolbox-test-blocks" style="display: none">
+    <category name="Align">
+      <block type="test_align_dummy_right"></block>
+      <block type="test_align_all"></block>
+      <block type="test_align_with_external_input"></block>
+    </category>
     <category name="Basic">
       <block type="test_basic_empty"></block>
       <block type="test_basic_empty_with_mutator"></block>
@@ -1374,10 +1461,73 @@ var spaghettiXml = [
       <block type="test_basic_tooltips"></block>
       <block type="test_basic_javascript"></block>
     </category>
-    <category name="Align">
-      <block type="test_align_dummy_right"></block>
-      <block type="test_align_all"></block>
-      <block type="test_align_with_external_input"></block>
+    <category name="Connections" expanded="true">
+      <category name="Row">
+        <label text="blocks have"></label>
+        <sep gap="-1"></sep>
+        <label text="tooltips"></label>
+
+        <button text="insert" callbackkey="insertConnectionRows"></button>
+        <sep gap="7"></sep>
+        <block type="test_connections_row_input"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_row_blue"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_row_yellow"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_row_red"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_row_output"></block>
+        <block type="test_connections_row_yellow">
+          <value name="NAME">
+            <block type="test_connections_row_yellow" movable="false"></block>
+          </value>
+        </block>
+        <sep gap="7"></sep>
+        <block type="test_connections_multivalue_1valid"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_multivalue_2valid"></block>
+      </category>
+      <category name="Stack">
+        <label text="blocks have"></label>
+        <sep gap="-1"></sep>
+        <label text="tooltips"></label>
+
+        <button text="insert" callbackkey="insertConnectionStacks"></button>
+        <sep gap="7"></sep>
+        <block type="test_connections_stack_next"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_stack_blue"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_stack_yellow"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_stack_red"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_stack_prev"></block>
+        <block type="test_connections_stack_yellow">
+          <next>
+            <block type="test_connections_stack_yellow" movable="false"></block>
+          </next>
+        </block>
+      </category>
+      <category name="Statement">
+        <label text="blocks have"></label>
+        <sep gap="-1"></sep>
+        <label text="tooltips"></label>
+
+        <button text="insert" callbackkey="insertConnectionStatements"></button>
+        <sep gap="7"></sep>
+        <block type="test_connections_statement_blue"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_statement_yellow"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_statement_red"></block>
+        <block type="test_connections_statement_nonext"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_multistatement_1valid"></block>
+        <sep gap="7"></sep>
+        <block type="test_connections_multistatement_2valid"></block>
+      </category>
     </category>
     <category name="Drag">
       <label text="Drag each to the workspace"></label>