chore: update lua block generators to const and let (#5662)

2025-12-16 06:10:12 +01:00 · 2021-11-05 09:57:59 -07:00
parent 3e706acc22
commit 3746688ebd
9 changed files with 267 additions and 256 deletions
--- a/generators/lua/colour.js
+++ b/generators/lua/colour.js
@@ -16,19 +16,19 @@ goog.require('Blockly.Lua');

 Blockly.Lua['colour_picker'] = function(block) {
  // Colour picker.
-  var code = Blockly.Lua.quote_(block.getFieldValue('COLOUR'));
+  const code = Blockly.Lua.quote_(block.getFieldValue('COLOUR'));
  return [code, Blockly.Lua.ORDER_ATOMIC];
 };

 Blockly.Lua['colour_random'] = function(block) {
  // Generate a random colour.
-  var code = 'string.format("#%06x", math.random(0, 2^24 - 1))';
+  const code = 'string.format("#%06x", math.random(0, 2^24 - 1))';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['colour_rgb'] = function(block) {
  // Compose a colour from RGB components expressed as percentages.
-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'colour_rgb',
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(r, g, b)',
       '  r = math.floor(math.min(100, math.max(0, r)) * 2.55 + .5)',
@@ -36,19 +36,19 @@ Blockly.Lua['colour_rgb'] = function(block) {
       '  b = math.floor(math.min(100, math.max(0, b)) * 2.55 + .5)',
       '  return string.format("#%02x%02x%02x", r, g, b)',
       'end']);
-  var r = Blockly.Lua.valueToCode(block, 'RED',
+  const r = Blockly.Lua.valueToCode(block, 'RED',
      Blockly.Lua.ORDER_NONE) || 0;
-  var g = Blockly.Lua.valueToCode(block, 'GREEN',
+  const g = Blockly.Lua.valueToCode(block, 'GREEN',
      Blockly.Lua.ORDER_NONE) || 0;
-  var b = Blockly.Lua.valueToCode(block, 'BLUE',
+  const b = Blockly.Lua.valueToCode(block, 'BLUE',
      Blockly.Lua.ORDER_NONE) || 0;
-  var code = functionName + '(' + r + ', ' + g + ', ' + b + ')';
+  const code = functionName + '(' + r + ', ' + g + ', ' + b + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['colour_blend'] = function(block) {
  // Blend two colours together.
-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'colour_blend',
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ +
           '(colour1, colour2, ratio)',
@@ -64,12 +64,12 @@ Blockly.Lua['colour_blend'] = function(block) {
       '  local b = math.floor(b1 * (1 - ratio) + b2 * ratio + .5)',
       '  return string.format("#%02x%02x%02x", r, g, b)',
       'end']);
-  var colour1 = Blockly.Lua.valueToCode(block, 'COLOUR1',
+  const colour1 = Blockly.Lua.valueToCode(block, 'COLOUR1',
      Blockly.Lua.ORDER_NONE) || '\'#000000\'';
-  var colour2 = Blockly.Lua.valueToCode(block, 'COLOUR2',
+  const colour2 = Blockly.Lua.valueToCode(block, 'COLOUR2',
      Blockly.Lua.ORDER_NONE) || '\'#000000\'';
-  var ratio = Blockly.Lua.valueToCode(block, 'RATIO',
+  const ratio = Blockly.Lua.valueToCode(block, 'RATIO',
      Blockly.Lua.ORDER_NONE) || 0;
-  var code = functionName + '(' + colour1 + ', ' + colour2 + ', ' + ratio + ')';
+  const code = functionName + '(' + colour1 + ', ' + colour2 + ', ' + ratio + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };
--- a/generators/lua/lists.js
+++ b/generators/lua/lists.js
@@ -21,18 +21,18 @@ Blockly.Lua['lists_create_empty'] = function(block) {

 Blockly.Lua['lists_create_with'] = function(block) {
  // Create a list with any number of elements of any type.
-  var elements = new Array(block.itemCount_);
-  for (var i = 0; i < block.itemCount_; i++) {
+  const elements = new Array(block.itemCount_);
+  for (let i = 0; i < block.itemCount_; i++) {
    elements[i] = Blockly.Lua.valueToCode(block, 'ADD' + i,
        Blockly.Lua.ORDER_NONE) || 'None';
  }
-  var code = '{' + elements.join(', ') + '}';
+  const code = '{' + elements.join(', ') + '}';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['lists_repeat'] = function(block) {
  // Create a list with one element repeated.
-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'create_list_repeated',
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(item, count)',
       '  local t = {}',
@@ -41,37 +41,38 @@ Blockly.Lua['lists_repeat'] = function(block) {
       '  end',
       '  return t',
       'end']);
-  var element = Blockly.Lua.valueToCode(block, 'ITEM',
+  const element = Blockly.Lua.valueToCode(block, 'ITEM',
      Blockly.Lua.ORDER_NONE) || 'None';
-  var repeatCount = Blockly.Lua.valueToCode(block, 'NUM',
+  const repeatCount = Blockly.Lua.valueToCode(block, 'NUM',
      Blockly.Lua.ORDER_NONE) || '0';
-  var code = functionName + '(' + element + ', ' + repeatCount + ')';
+  const code = functionName + '(' + element + ', ' + repeatCount + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['lists_length'] = function(block) {
  // String or array length.
-  var list = Blockly.Lua.valueToCode(block, 'VALUE',
+  const list = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_UNARY) || '{}';
  return ['#' + list, Blockly.Lua.ORDER_UNARY];
 };

 Blockly.Lua['lists_isEmpty'] = function(block) {
  // Is the string null or array empty?
-  var list = Blockly.Lua.valueToCode(block, 'VALUE',
+  const list = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_UNARY) || '{}';
-  var code = '#' + list + ' == 0';
+  const code = '#' + list + ' == 0';
  return [code, Blockly.Lua.ORDER_RELATIONAL];
 };

 Blockly.Lua['lists_indexOf'] = function(block) {
  // Find an item in the list.
-  var item = Blockly.Lua.valueToCode(block, 'FIND',
+  const item = Blockly.Lua.valueToCode(block, 'FIND',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var list = Blockly.Lua.valueToCode(block, 'VALUE',
+  const list = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_NONE) || '{}';
+  let functionName;
  if (block.getFieldValue('END') === 'FIRST') {
-    var functionName = Blockly.Lua.provideFunction_(
+    functionName = Blockly.Lua.provideFunction_(
        'first_index',
        ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(t, elem)',
         '  for k, v in ipairs(t) do',
@@ -82,7 +83,7 @@ Blockly.Lua['lists_indexOf'] = function(block) {
         '  return 0',
         'end']);
  } else {
-    var functionName = Blockly.Lua.provideFunction_(
+    functionName = Blockly.Lua.provideFunction_(
        'last_index',
        ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(t, elem)',
         '  for i = #t, 1, -1 do',
@@ -93,7 +94,7 @@ Blockly.Lua['lists_indexOf'] = function(block) {
         '  return 0',
         'end']);
  }
-  var code = functionName + '(' + list + ', ' + item + ')';
+  const code = functionName + '(' + list + ', ' + item + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

@@ -122,11 +123,11 @@ Blockly.Lua.lists.getIndex_ = function(listName, where, opt_at) {
 Blockly.Lua['lists_getIndex'] = function(block) {
  // Get element at index.
  // Note: Until January 2013 this block did not have MODE or WHERE inputs.
-  var mode = block.getFieldValue('MODE') || 'GET';
-  var where = block.getFieldValue('WHERE') || 'FROM_START';
-  var list = Blockly.Lua.valueToCode(block, 'VALUE', Blockly.Lua.ORDER_HIGH) ||
+  const mode = block.getFieldValue('MODE') || 'GET';
+  const where = block.getFieldValue('WHERE') || 'FROM_START';
+  const list = Blockly.Lua.valueToCode(block, 'VALUE', Blockly.Lua.ORDER_HIGH) ||
      '({})';
-  var getIndex_ = Blockly.Lua.lists.getIndex_;
+  const getIndex_ = Blockly.Lua.lists.getIndex_;

  // If `list` would be evaluated more than once (which is the case for LAST,
  // FROM_END, and RANDOM) and is non-trivial, make sure to access it only once.
@@ -135,21 +136,22 @@ Blockly.Lua['lists_getIndex'] = function(block) {
    // `list` is an expression, so we may not evaluate it more than once.
    if (mode === 'REMOVE') {
      // We can use multiple statements.
-      var atOrder = (where === 'FROM_END') ? Blockly.Lua.ORDER_ADDITIVE :
+      const atOrder = (where === 'FROM_END') ? Blockly.Lua.ORDER_ADDITIVE :
          Blockly.Lua.ORDER_NONE;
-      var at = Blockly.Lua.valueToCode(block, 'AT', atOrder) || '1';
-      var listVar = Blockly.Lua.nameDB_.getDistinctName(
+      let at = Blockly.Lua.valueToCode(block, 'AT', atOrder) || '1';
+      const listVar = Blockly.Lua.nameDB_.getDistinctName(
          'tmp_list', Blockly.VARIABLE_CATEGORY_NAME);
      at = getIndex_(listVar, where, at);
-      var code = listVar + ' = ' + list + '\n' +
+      const code = listVar + ' = ' + list + '\n' +
          'table.remove(' + listVar + ', ' + at + ')\n';
      return code;
    } else {
      // We need to create a procedure to avoid reevaluating values.
-      var at = Blockly.Lua.valueToCode(block, 'AT', Blockly.Lua.ORDER_NONE) ||
+      const at = Blockly.Lua.valueToCode(block, 'AT', Blockly.Lua.ORDER_NONE) ||
          '1';
+      let functionName;
      if (mode === 'GET') {
-        var functionName = Blockly.Lua.provideFunction_(
+        functionName = Blockly.Lua.provideFunction_(
            'list_get_' + where.toLowerCase(),
            ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(t' +
                // The value for 'FROM_END' and'FROM_START' depends on `at` so
@@ -159,7 +161,7 @@ Blockly.Lua['lists_getIndex'] = function(block) {
             '  return t[' + getIndex_('t', where, 'at') + ']',
             'end']);
      } else {  // `mode` === 'GET_REMOVE'
-        var functionName = Blockly.Lua.provideFunction_(
+        functionName = Blockly.Lua.provideFunction_(
            'list_remove_' + where.toLowerCase(),
            ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(t' +
                // The value for 'FROM_END' and'FROM_START' depends on `at` so
@@ -169,7 +171,7 @@ Blockly.Lua['lists_getIndex'] = function(block) {
             '  return table.remove(t, ' + getIndex_('t', where, 'at') + ')',
             'end']);
      }
-      var code = functionName + '(' + list +
+      const code = functionName + '(' + list +
          // The value for 'FROM_END' and 'FROM_START' depends on `at` so we
          // pass it.
          ((where === 'FROM_END' || where === 'FROM_START') ? ', ' + at : '') +
@@ -179,15 +181,15 @@ Blockly.Lua['lists_getIndex'] = function(block) {
  } else {
    // Either `list` is a simple variable, or we only need to refer to `list`
    // once.
-    var atOrder = (mode === 'GET' && where === 'FROM_END') ?
+    const atOrder = (mode === 'GET' && where === 'FROM_END') ?
        Blockly.Lua.ORDER_ADDITIVE : Blockly.Lua.ORDER_NONE;
-    var at = Blockly.Lua.valueToCode(block, 'AT', atOrder) || '1';
+    let at = Blockly.Lua.valueToCode(block, 'AT', atOrder) || '1';
    at = getIndex_(list, where, at);
    if (mode === 'GET') {
-      var code = list + '[' + at + ']';
+      const code = list + '[' + at + ']';
      return [code, Blockly.Lua.ORDER_HIGH];
    } else {
-      var code = 'table.remove(' + list + ', ' + at + ')';
+      const code = 'table.remove(' + list + ', ' + at + ')';
      if (mode === 'GET_REMOVE') {
        return [code, Blockly.Lua.ORDER_HIGH];
      } else {  // `mode` === 'REMOVE'
@@ -200,24 +202,24 @@ Blockly.Lua['lists_getIndex'] = function(block) {
 Blockly.Lua['lists_setIndex'] = function(block) {
  // Set element at index.
  // Note: Until February 2013 this block did not have MODE or WHERE inputs.
-  var list = Blockly.Lua.valueToCode(block, 'LIST',
+  let list = Blockly.Lua.valueToCode(block, 'LIST',
      Blockly.Lua.ORDER_HIGH) || '{}';
-  var mode = block.getFieldValue('MODE') || 'SET';
-  var where = block.getFieldValue('WHERE') || 'FROM_START';
-  var at = Blockly.Lua.valueToCode(block, 'AT',
+  const mode = block.getFieldValue('MODE') || 'SET';
+  const where = block.getFieldValue('WHERE') || 'FROM_START';
+  const at = Blockly.Lua.valueToCode(block, 'AT',
      Blockly.Lua.ORDER_ADDITIVE) || '1';
-  var value = Blockly.Lua.valueToCode(block, 'TO',
+  const value = Blockly.Lua.valueToCode(block, 'TO',
      Blockly.Lua.ORDER_NONE) || 'None';
-  var getIndex_ = Blockly.Lua.lists.getIndex_;
+  const getIndex_ = Blockly.Lua.lists.getIndex_;

-  var code = '';
+  let code = '';
  // If `list` would be evaluated more than once (which is the case for LAST,
  // FROM_END, and RANDOM) and is non-trivial, make sure to access it only once.
  if ((where === 'LAST' || where === 'FROM_END' || where === 'RANDOM') &&
      !list.match(/^\w+$/)) {
    // `list` is an expression, so we may not evaluate it more than once.
    // We can use multiple statements.
-    var listVar = Blockly.Lua.nameDB_.getDistinctName(
+    const listVar = Blockly.Lua.nameDB_.getDistinctName(
        'tmp_list', Blockly.VARIABLE_CATEGORY_NAME);
    code = listVar + ' = ' + list + '\n';
    list = listVar;
@@ -236,17 +238,17 @@ Blockly.Lua['lists_setIndex'] = function(block) {

 Blockly.Lua['lists_getSublist'] = function(block) {
  // Get sublist.
-  var list = Blockly.Lua.valueToCode(block, 'LIST',
+  const list = Blockly.Lua.valueToCode(block, 'LIST',
      Blockly.Lua.ORDER_NONE) || '{}';
-  var where1 = block.getFieldValue('WHERE1');
-  var where2 = block.getFieldValue('WHERE2');
-  var at1 = Blockly.Lua.valueToCode(block, 'AT1',
+  const where1 = block.getFieldValue('WHERE1');
+  const where2 = block.getFieldValue('WHERE2');
+  const at1 = Blockly.Lua.valueToCode(block, 'AT1',
      Blockly.Lua.ORDER_NONE) || '1';
-  var at2 = Blockly.Lua.valueToCode(block, 'AT2',
+  const at2 = Blockly.Lua.valueToCode(block, 'AT2',
      Blockly.Lua.ORDER_NONE) || '1';
-  var getIndex_ = Blockly.Lua.lists.getIndex_;
+  const getIndex_ = Blockly.Lua.lists.getIndex_;

-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'list_sublist_' + where1.toLowerCase() + '_' + where2.toLowerCase(),
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(source' +
          // The value for 'FROM_END' and'FROM_START' depends on `at` so
@@ -262,7 +264,7 @@ Blockly.Lua['lists_getSublist'] = function(block) {
       '  end',
       '  return t',
       'end']);
-  var code = functionName + '(' + list +
+  const code = functionName + '(' + list +
      // The value for 'FROM_END' and 'FROM_START' depends on `at` so we
      // pass it.
      ((where1 === 'FROM_END' || where1 === 'FROM_START') ? ', ' + at1 : '') +
@@ -273,12 +275,12 @@ Blockly.Lua['lists_getSublist'] = function(block) {

 Blockly.Lua['lists_sort'] = function(block) {
  // Block for sorting a list.
-  var list = Blockly.Lua.valueToCode(
+  const list = Blockly.Lua.valueToCode(
      block, 'LIST', Blockly.Lua.ORDER_NONE) || '{}';
-  var direction = block.getFieldValue('DIRECTION') === '1' ? 1 : -1;
-  var type = block.getFieldValue('TYPE');
+  const direction = block.getFieldValue('DIRECTION') === '1' ? 1 : -1;
+  const type = block.getFieldValue('TYPE');

-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'list_sort',
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ +
          '(list, typev, direction)',
@@ -302,19 +304,19 @@ Blockly.Lua['lists_sort'] = function(block) {
       '  return t',
       'end']);

-  var code = functionName +
+  const code = functionName +
      '(' + list + ',"' + type + '", ' + direction + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['lists_split'] = function(block) {
  // Block for splitting text into a list, or joining a list into text.
-  var input = Blockly.Lua.valueToCode(block, 'INPUT',
+  let input = Blockly.Lua.valueToCode(block, 'INPUT',
      Blockly.Lua.ORDER_NONE);
-  var delimiter = Blockly.Lua.valueToCode(block, 'DELIM',
+  const delimiter = Blockly.Lua.valueToCode(block, 'DELIM',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var mode = block.getFieldValue('MODE');
-  var functionName;
+  const mode = block.getFieldValue('MODE');
+  let functionName;
  if (mode === 'SPLIT') {
    if (!input) {
      input = '\'\'';
@@ -345,15 +347,15 @@ Blockly.Lua['lists_split'] = function(block) {
  } else {
    throw Error('Unknown mode: ' + mode);
  }
-  var code = functionName + '(' + input + ', ' + delimiter + ')';
+  const code = functionName + '(' + input + ', ' + delimiter + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['lists_reverse'] = function(block) {
  // Block for reversing a list.
-  var list = Blockly.Lua.valueToCode(block, 'LIST',
+  const list = Blockly.Lua.valueToCode(block, 'LIST',
      Blockly.Lua.ORDER_NONE) || '{}';
-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'list_reverse',
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(input)',
       '  local reversed = {}',
@@ -362,6 +364,6 @@ Blockly.Lua['lists_reverse'] = function(block) {
       '  end',
       '  return reversed',
       'end']);
-  var code = functionName + '(' + list + ')';
+  const code = functionName + '(' + list + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };
--- a/generators/lua/logic.js
+++ b/generators/lua/logic.js
@@ -16,16 +16,16 @@ goog.require('Blockly.Lua');

 Blockly.Lua['controls_if'] = function(block) {
  // If/elseif/else condition.
-  var n = 0;
-  var code = '', branchCode, conditionCode;
+  let n = 0;
+  let code = '';
  if (Blockly.Lua.STATEMENT_PREFIX) {
    // Automatic prefix insertion is switched off for this block.  Add manually.
    code += Blockly.Lua.injectId(Blockly.Lua.STATEMENT_PREFIX, block);
  }
  do {
-    conditionCode = Blockly.Lua.valueToCode(block, 'IF' + n,
+    const conditionCode = Blockly.Lua.valueToCode(block, 'IF' + n,
        Blockly.Lua.ORDER_NONE) || 'false';
-    branchCode = Blockly.Lua.statementToCode(block, 'DO' + n);
+    let branchCode = Blockly.Lua.statementToCode(block, 'DO' + n);
    if (Blockly.Lua.STATEMENT_SUFFIX) {
      branchCode = Blockly.Lua.prefixLines(
          Blockly.Lua.injectId(Blockly.Lua.STATEMENT_SUFFIX, block),
@@ -37,7 +37,7 @@ Blockly.Lua['controls_if'] = function(block) {
  } while (block.getInput('IF' + n));

  if (block.getInput('ELSE') || Blockly.Lua.STATEMENT_SUFFIX) {
-    branchCode = Blockly.Lua.statementToCode(block, 'ELSE');
+    let branchCode = Blockly.Lua.statementToCode(block, 'ELSE');
    if (Blockly.Lua.STATEMENT_SUFFIX) {
      branchCode = Blockly.Lua.prefixLines(
          Blockly.Lua.injectId(Blockly.Lua.STATEMENT_SUFFIX, block),
@@ -52,7 +52,7 @@ Blockly.Lua['controls_ifelse'] = Blockly.Lua['controls_if'];

 Blockly.Lua['logic_compare'] = function(block) {
  // Comparison operator.
-  var OPERATORS = {
+  const OPERATORS = {
    'EQ': '==',
    'NEQ': '~=',
    'LT': '<',
@@ -60,29 +60,29 @@ Blockly.Lua['logic_compare'] = function(block) {
    'GT': '>',
    'GTE': '>='
  };
-  var operator = OPERATORS[block.getFieldValue('OP')];
-  var argument0 = Blockly.Lua.valueToCode(block, 'A',
+  const operator = OPERATORS[block.getFieldValue('OP')];
+  const argument0 = Blockly.Lua.valueToCode(block, 'A',
      Blockly.Lua.ORDER_RELATIONAL) || '0';
-  var argument1 = Blockly.Lua.valueToCode(block, 'B',
+  const argument1 = Blockly.Lua.valueToCode(block, 'B',
      Blockly.Lua.ORDER_RELATIONAL) || '0';
-  var code = argument0 + ' ' + operator + ' ' + argument1;
+  const code = argument0 + ' ' + operator + ' ' + argument1;
  return [code, Blockly.Lua.ORDER_RELATIONAL];
 };

 Blockly.Lua['logic_operation'] = function(block) {
  // Operations 'and', 'or'.
-  var operator = (block.getFieldValue('OP') === 'AND') ? 'and' : 'or';
-  var order = (operator === 'and') ? Blockly.Lua.ORDER_AND :
+  const operator = (block.getFieldValue('OP') === 'AND') ? 'and' : 'or';
+  const order = (operator === 'and') ? Blockly.Lua.ORDER_AND :
      Blockly.Lua.ORDER_OR;
-  var argument0 = Blockly.Lua.valueToCode(block, 'A', order);
-  var argument1 = Blockly.Lua.valueToCode(block, 'B', order);
+  let argument0 = Blockly.Lua.valueToCode(block, 'A', order);
+  let argument1 = Blockly.Lua.valueToCode(block, 'B', order);
  if (!argument0 && !argument1) {
    // If there are no arguments, then the return value is false.
    argument0 = 'false';
    argument1 = 'false';
  } else {
    // Single missing arguments have no effect on the return value.
-    var defaultArgument = (operator === 'and') ? 'true' : 'false';
+    const defaultArgument = (operator === 'and') ? 'true' : 'false';
    if (!argument0) {
      argument0 = defaultArgument;
    }
@@ -90,21 +90,21 @@ Blockly.Lua['logic_operation'] = function(block) {
      argument1 = defaultArgument;
    }
  }
-  var code = argument0 + ' ' + operator + ' ' + argument1;
+  const code = argument0 + ' ' + operator + ' ' + argument1;
  return [code, order];
 };

 Blockly.Lua['logic_negate'] = function(block) {
  // Negation.
-  var argument0 = Blockly.Lua.valueToCode(block, 'BOOL',
+  const argument0 = Blockly.Lua.valueToCode(block, 'BOOL',
      Blockly.Lua.ORDER_UNARY) || 'true';
-  var code = 'not ' + argument0;
+  const code = 'not ' + argument0;
  return [code, Blockly.Lua.ORDER_UNARY];
 };

 Blockly.Lua['logic_boolean'] = function(block) {
  // Boolean values true and false.
-  var code = (block.getFieldValue('BOOL') === 'TRUE') ? 'true' : 'false';
+  const code = (block.getFieldValue('BOOL') === 'TRUE') ? 'true' : 'false';
  return [code, Blockly.Lua.ORDER_ATOMIC];
 };

@@ -115,12 +115,12 @@ Blockly.Lua['logic_null'] = function(block) {

 Blockly.Lua['logic_ternary'] = function(block) {
  // Ternary operator.
-  var value_if = Blockly.Lua.valueToCode(block, 'IF',
+  const value_if = Blockly.Lua.valueToCode(block, 'IF',
      Blockly.Lua.ORDER_AND) || 'false';
-  var value_then = Blockly.Lua.valueToCode(block, 'THEN',
+  const value_then = Blockly.Lua.valueToCode(block, 'THEN',
      Blockly.Lua.ORDER_AND) || 'nil';
-  var value_else = Blockly.Lua.valueToCode(block, 'ELSE',
+  const value_else = Blockly.Lua.valueToCode(block, 'ELSE',
      Blockly.Lua.ORDER_OR) || 'nil';
-  var code = value_if + ' and ' + value_then + ' or ' + value_else;
+  const code = value_if + ' and ' + value_then + ' or ' + value_else;
  return [code, Blockly.Lua.ORDER_OR];
 };
--- a/generators/lua/loops.js
+++ b/generators/lua/loops.js
@@ -43,12 +43,13 @@ Blockly.Lua.addContinueLabel_ = function(branch) {

 Blockly.Lua['controls_repeat_ext'] = function(block) {
  // Repeat n times.
+  let repeats;
  if (block.getField('TIMES')) {
    // Internal number.
-    var repeats = String(Number(block.getFieldValue('TIMES')));
+    repeats = String(Number(block.getFieldValue('TIMES')));
  } else {
    // External number.
-    var repeats = Blockly.Lua.valueToCode(block, 'TIMES',
+    repeats = Blockly.Lua.valueToCode(block, 'TIMES',
        Blockly.Lua.ORDER_NONE) || '0';
  }
  if (Blockly.isNumber(repeats)) {
@@ -56,12 +57,12 @@ Blockly.Lua['controls_repeat_ext'] = function(block) {
  } else {
    repeats = 'math.floor(' + repeats + ')';
  }
-  var branch = Blockly.Lua.statementToCode(block, 'DO');
+  let branch = Blockly.Lua.statementToCode(block, 'DO');
  branch = Blockly.Lua.addLoopTrap(branch, block);
  branch = Blockly.Lua.addContinueLabel_(branch);
-  var loopVar = Blockly.Lua.nameDB_.getDistinctName(
+  const loopVar = Blockly.Lua.nameDB_.getDistinctName(
      'count', Blockly.VARIABLE_CATEGORY_NAME);
-  var code = 'for ' + loopVar + ' = 1, ' + repeats + ' do\n' +
+  const code = 'for ' + loopVar + ' = 1, ' + repeats + ' do\n' +
      branch + 'end\n';
  return code;
 };
@@ -70,11 +71,11 @@ Blockly.Lua['controls_repeat'] = Blockly.Lua['controls_repeat_ext'];

 Blockly.Lua['controls_whileUntil'] = function(block) {
  // Do while/until loop.
-  var until = block.getFieldValue('MODE') === 'UNTIL';
-  var argument0 = Blockly.Lua.valueToCode(block, 'BOOL',
+  const until = block.getFieldValue('MODE') === 'UNTIL';
+  let argument0 = Blockly.Lua.valueToCode(block, 'BOOL',
      until ? Blockly.Lua.ORDER_UNARY :
      Blockly.Lua.ORDER_NONE) || 'false';
-  var branch = Blockly.Lua.statementToCode(block, 'DO');
+  let branch = Blockly.Lua.statementToCode(block, 'DO');
  branch = Blockly.Lua.addLoopTrap(branch, block);
  branch = Blockly.Lua.addContinueLabel_(branch);
  if (until) {
@@ -85,24 +86,24 @@ Blockly.Lua['controls_whileUntil'] = function(block) {

 Blockly.Lua['controls_for'] = function(block) {
  // For loop.
-  var variable0 = Blockly.Lua.nameDB_.getName(
+  const variable0 = Blockly.Lua.nameDB_.getName(
      block.getFieldValue('VAR'), Blockly.VARIABLE_CATEGORY_NAME);
-  var startVar = Blockly.Lua.valueToCode(block, 'FROM',
+  const startVar = Blockly.Lua.valueToCode(block, 'FROM',
      Blockly.Lua.ORDER_NONE) || '0';
-  var endVar = Blockly.Lua.valueToCode(block, 'TO',
+  const endVar = Blockly.Lua.valueToCode(block, 'TO',
      Blockly.Lua.ORDER_NONE) || '0';
-  var increment = Blockly.Lua.valueToCode(block, 'BY',
+  const increment = Blockly.Lua.valueToCode(block, 'BY',
      Blockly.Lua.ORDER_NONE) || '1';
-  var branch = Blockly.Lua.statementToCode(block, 'DO');
+  let branch = Blockly.Lua.statementToCode(block, 'DO');
  branch = Blockly.Lua.addLoopTrap(branch, block);
  branch = Blockly.Lua.addContinueLabel_(branch);
-  var code = '';
-  var incValue;
+  let code = '';
+  let incValue;
  if (Blockly.isNumber(startVar) && Blockly.isNumber(endVar) &&
      Blockly.isNumber(increment)) {
    // All arguments are simple numbers.
-    var up = Number(startVar) <= Number(endVar);
-    var step = Math.abs(Number(increment));
+    const up = Number(startVar) <= Number(endVar);
+    const step = Math.abs(Number(increment));
    incValue = (up ? '' : '-') + step;
  } else {
    code = '';
@@ -128,21 +129,21 @@ Blockly.Lua['controls_for'] = function(block) {

 Blockly.Lua['controls_forEach'] = function(block) {
  // For each loop.
-  var variable0 = Blockly.Lua.nameDB_.getName(
+  const variable0 = Blockly.Lua.nameDB_.getName(
      block.getFieldValue('VAR'), Blockly.VARIABLE_CATEGORY_NAME);
-  var argument0 = Blockly.Lua.valueToCode(block, 'LIST',
+  const argument0 = Blockly.Lua.valueToCode(block, 'LIST',
      Blockly.Lua.ORDER_NONE) || '{}';
-  var branch = Blockly.Lua.statementToCode(block, 'DO');
+  let branch = Blockly.Lua.statementToCode(block, 'DO');
  branch = Blockly.Lua.addLoopTrap(branch, block);
  branch = Blockly.Lua.addContinueLabel_(branch);
-  var code = 'for _, ' + variable0 + ' in ipairs(' + argument0 + ') do \n' +
+  const code = 'for _, ' + variable0 + ' in ipairs(' + argument0 + ') do \n' +
      branch + 'end\n';
  return code;
 };

 Blockly.Lua['controls_flow_statements'] = function(block) {
  // Flow statements: continue, break.
-  var xfix = '';
+  let xfix = '';
  if (Blockly.Lua.STATEMENT_PREFIX) {
    // Automatic prefix insertion is switched off for this block.  Add manually.
    xfix += Blockly.Lua.injectId(Blockly.Lua.STATEMENT_PREFIX, block);
@@ -153,7 +154,7 @@ Blockly.Lua['controls_flow_statements'] = function(block) {
    xfix += Blockly.Lua.injectId(Blockly.Lua.STATEMENT_SUFFIX, block);
  }
  if (Blockly.Lua.STATEMENT_PREFIX) {
-    var loop = Blockly.Constants.Loops
+    const loop = Blockly.Constants.Loops
        .CONTROL_FLOW_IN_LOOP_CHECK_MIXIN.getSurroundLoop(block);
    if (loop && !loop.suppressPrefixSuffix) {
      // Inject loop's statement prefix here since the regular one at the end
--- a/generators/lua/math.js
+++ b/generators/lua/math.js
@@ -16,35 +16,34 @@ goog.require('Blockly.Lua');

 Blockly.Lua['math_number'] = function(block) {
  // Numeric value.
-  var code = Number(block.getFieldValue('NUM'));
-  var order = code < 0 ? Blockly.Lua.ORDER_UNARY :
+  const code = Number(block.getFieldValue('NUM'));
+  const order = code < 0 ? Blockly.Lua.ORDER_UNARY :
              Blockly.Lua.ORDER_ATOMIC;
  return [code, order];
 };

 Blockly.Lua['math_arithmetic'] = function(block) {
  // Basic arithmetic operators, and power.
-  var OPERATORS = {
+  const OPERATORS = {
    ADD: [' + ', Blockly.Lua.ORDER_ADDITIVE],
    MINUS: [' - ', Blockly.Lua.ORDER_ADDITIVE],
    MULTIPLY: [' * ', Blockly.Lua.ORDER_MULTIPLICATIVE],
    DIVIDE: [' / ', Blockly.Lua.ORDER_MULTIPLICATIVE],
    POWER: [' ^ ', Blockly.Lua.ORDER_EXPONENTIATION]
  };
-  var tuple = OPERATORS[block.getFieldValue('OP')];
-  var operator = tuple[0];
-  var order = tuple[1];
-  var argument0 = Blockly.Lua.valueToCode(block, 'A', order) || '0';
-  var argument1 = Blockly.Lua.valueToCode(block, 'B', order) || '0';
-  var code = argument0 + operator + argument1;
+  const tuple = OPERATORS[block.getFieldValue('OP')];
+  const operator = tuple[0];
+  const order = tuple[1];
+  const argument0 = Blockly.Lua.valueToCode(block, 'A', order) || '0';
+  const argument1 = Blockly.Lua.valueToCode(block, 'B', order) || '0';
+  const code = argument0 + operator + argument1;
  return [code, order];
 };

 Blockly.Lua['math_single'] = function(block) {
  // Math operators with single operand.
-  var operator = block.getFieldValue('OP');
-  var code;
-  var arg;
+  const operator = block.getFieldValue('OP');
+  let arg;
  if (operator === 'NEG') {
    // Negation is a special case given its different operator precedence.
    arg = Blockly.Lua.valueToCode(block, 'NUM',
@@ -63,6 +62,8 @@ Blockly.Lua['math_single'] = function(block) {
    arg = Blockly.Lua.valueToCode(block, 'NUM',
        Blockly.Lua.ORDER_NONE) || '0';
  }
+
+  let code;
  switch (operator) {
    case 'ABS':
      code = 'math.abs(' + arg + ')';
@@ -115,7 +116,7 @@ Blockly.Lua['math_single'] = function(block) {

 Blockly.Lua['math_constant'] = function(block) {
  // Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
-  var CONSTANTS = {
+  const CONSTANTS = {
    PI: ['math.pi', Blockly.Lua.ORDER_HIGH],
    E: ['math.exp(1)', Blockly.Lua.ORDER_HIGH],
    GOLDEN_RATIO: ['(1 + math.sqrt(5)) / 2', Blockly.Lua.ORDER_MULTIPLICATIVE],
@@ -129,13 +130,13 @@ Blockly.Lua['math_constant'] = function(block) {
 Blockly.Lua['math_number_property'] = function(block) {
  // Check if a number is even, odd, prime, whole, positive, or negative
  // or if it is divisible by certain number. Returns true or false.
-  var number_to_check = Blockly.Lua.valueToCode(block, 'NUMBER_TO_CHECK',
+  const number_to_check = Blockly.Lua.valueToCode(block, 'NUMBER_TO_CHECK',
      Blockly.Lua.ORDER_MULTIPLICATIVE) || '0';
-  var dropdown_property = block.getFieldValue('PROPERTY');
-  var code;
+  const dropdown_property = block.getFieldValue('PROPERTY');
+  let code;
  if (dropdown_property === 'PRIME') {
    // Prime is a special case as it is not a one-liner test.
-    var functionName = Blockly.Lua.provideFunction_(
+    const functionName = Blockly.Lua.provideFunction_(
        'math_isPrime',
        ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(n)',
         '  -- https://en.wikipedia.org/wiki/Primality_test#Naive_methods',
@@ -174,8 +175,8 @@ Blockly.Lua['math_number_property'] = function(block) {
    case 'NEGATIVE':
      code = number_to_check + ' < 0';
      break;
-    case 'DIVISIBLE_BY':
-      var divisor = Blockly.Lua.valueToCode(block, 'DIVISOR',
+    case 'DIVISIBLE_BY': {
+      const divisor = Blockly.Lua.valueToCode(block, 'DIVISOR',
          Blockly.Lua.ORDER_MULTIPLICATIVE);
      // If 'divisor' is some code that evals to 0, Lua will produce a nan.
      // Let's produce nil if we can determine this at compile-time.
@@ -187,15 +188,16 @@ Blockly.Lua['math_number_property'] = function(block) {
      // because nil is false, so allow a runtime failure. :-(
      code = number_to_check + ' % ' + divisor + ' == 0';
      break;
+    }
  }
  return [code, Blockly.Lua.ORDER_RELATIONAL];
 };

 Blockly.Lua['math_change'] = function(block) {
  // Add to a variable in place.
-  var argument0 = Blockly.Lua.valueToCode(block, 'DELTA',
+  const argument0 = Blockly.Lua.valueToCode(block, 'DELTA',
      Blockly.Lua.ORDER_ADDITIVE) || '0';
-  var varName = Blockly.Lua.nameDB_.getName(
+  const varName = Blockly.Lua.nameDB_.getName(
      block.getFieldValue('VAR'), Blockly.VARIABLE_CATEGORY_NAME);
  return varName + ' = ' + varName + ' + ' + argument0 + '\n';
 };
@@ -207,10 +209,10 @@ Blockly.Lua['math_trig'] = Blockly.Lua['math_single'];

 Blockly.Lua['math_on_list'] = function(block) {
  // Math functions for lists.
-  var func = block.getFieldValue('OP');
-  var list = Blockly.Lua.valueToCode(block, 'LIST',
+  const func = block.getFieldValue('OP');
+  const list = Blockly.Lua.valueToCode(block, 'LIST',
      Blockly.Lua.ORDER_NONE) || '{}';
-  var functionName;
+  let functionName;

  // Functions needed in more than one case.
  function provideSum() {
@@ -375,34 +377,34 @@ Blockly.Lua['math_on_list'] = function(block) {

 Blockly.Lua['math_modulo'] = function(block) {
  // Remainder computation.
-  var argument0 = Blockly.Lua.valueToCode(block, 'DIVIDEND',
+  const argument0 = Blockly.Lua.valueToCode(block, 'DIVIDEND',
      Blockly.Lua.ORDER_MULTIPLICATIVE) || '0';
-  var argument1 = Blockly.Lua.valueToCode(block, 'DIVISOR',
+  const argument1 = Blockly.Lua.valueToCode(block, 'DIVISOR',
      Blockly.Lua.ORDER_MULTIPLICATIVE) || '0';
-  var code = argument0 + ' % ' + argument1;
+  const code = argument0 + ' % ' + argument1;
  return [code, Blockly.Lua.ORDER_MULTIPLICATIVE];
 };

 Blockly.Lua['math_constrain'] = function(block) {
  // Constrain a number between two limits.
-  var argument0 = Blockly.Lua.valueToCode(block, 'VALUE',
+  const argument0 = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_NONE) || '0';
-  var argument1 = Blockly.Lua.valueToCode(block, 'LOW',
+  const argument1 = Blockly.Lua.valueToCode(block, 'LOW',
      Blockly.Lua.ORDER_NONE) || '-math.huge';
-  var argument2 = Blockly.Lua.valueToCode(block, 'HIGH',
+  const argument2 = Blockly.Lua.valueToCode(block, 'HIGH',
      Blockly.Lua.ORDER_NONE) || 'math.huge';
-  var code = 'math.min(math.max(' + argument0 + ', ' + argument1 + '), ' +
+  const code = 'math.min(math.max(' + argument0 + ', ' + argument1 + '), ' +
      argument2 + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['math_random_int'] = function(block) {
  // Random integer between [X] and [Y].
-  var argument0 = Blockly.Lua.valueToCode(block, 'FROM',
+  const argument0 = Blockly.Lua.valueToCode(block, 'FROM',
      Blockly.Lua.ORDER_NONE) || '0';
-  var argument1 = Blockly.Lua.valueToCode(block, 'TO',
+  const argument1 = Blockly.Lua.valueToCode(block, 'TO',
      Blockly.Lua.ORDER_NONE) || '0';
-  var code = 'math.random(' + argument0 + ', ' + argument1 + ')';
+  const code = 'math.random(' + argument0 + ', ' + argument1 + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

@@ -413,9 +415,9 @@ Blockly.Lua['math_random_float'] = function(block) {

 Blockly.Lua['math_atan2'] = function(block) {
  // Arctangent of point (X, Y) in degrees from -180 to 180.
-  var argument0 = Blockly.Lua.valueToCode(block, 'X',
+  const argument0 = Blockly.Lua.valueToCode(block, 'X',
      Blockly.Lua.ORDER_NONE) || '0';
-  var argument1 = Blockly.Lua.valueToCode(block, 'Y',
+  const argument1 = Blockly.Lua.valueToCode(block, 'Y',
      Blockly.Lua.ORDER_NONE) || '0';
  return ['math.deg(math.atan2(' + argument1 + ', ' + argument0 + '))',
      Blockly.Lua.ORDER_HIGH];
--- a/generators/lua/procedures.js
+++ b/generators/lua/procedures.js
@@ -16,9 +16,9 @@ goog.require('Blockly.Lua');

 Blockly.Lua['procedures_defreturn'] = function(block) {
  // Define a procedure with a return value.
-  var funcName = Blockly.Lua.nameDB_.getName(
+  const funcName = Blockly.Lua.nameDB_.getName(
      block.getFieldValue('NAME'), Blockly.PROCEDURE_CATEGORY_NAME);
-  var xfix1 = '';
+  let xfix1 = '';
  if (Blockly.Lua.STATEMENT_PREFIX) {
    xfix1 += Blockly.Lua.injectId(Blockly.Lua.STATEMENT_PREFIX, block);
  }
@@ -28,16 +28,16 @@ Blockly.Lua['procedures_defreturn'] = function(block) {
  if (xfix1) {
    xfix1 = Blockly.Lua.prefixLines(xfix1, Blockly.Lua.INDENT);
  }
-  var loopTrap = '';
+  let loopTrap = '';
  if (Blockly.Lua.INFINITE_LOOP_TRAP) {
    loopTrap = Blockly.Lua.prefixLines(
        Blockly.Lua.injectId(Blockly.Lua.INFINITE_LOOP_TRAP, block),
        Blockly.Lua.INDENT);
  }
-  var branch = Blockly.Lua.statementToCode(block, 'STACK');
-  var returnValue = Blockly.Lua.valueToCode(block, 'RETURN',
+  let branch = Blockly.Lua.statementToCode(block, 'STACK');
+  let returnValue = Blockly.Lua.valueToCode(block, 'RETURN',
      Blockly.Lua.ORDER_NONE) || '';
-  var xfix2 = '';
+  let xfix2 = '';
  if (branch && returnValue) {
    // After executing the function body, revisit this block for the return.
    xfix2 = xfix1;
@@ -47,13 +47,13 @@ Blockly.Lua['procedures_defreturn'] = function(block) {
  } else if (!branch) {
    branch = '';
  }
-  var args = [];
-  var variables = block.getVars();
-  for (var i = 0; i < variables.length; i++) {
+  const args = [];
+  const variables = block.getVars();
+  for (let i = 0; i < variables.length; i++) {
    args[i] = Blockly.Lua.nameDB_.getName(variables[i],
        Blockly.VARIABLE_CATEGORY_NAME);
  }
-  var code = 'function ' + funcName + '(' + args.join(', ') + ')\n' +
+  let code = 'function ' + funcName + '(' + args.join(', ') + ')\n' +
      xfix1 + loopTrap + branch + xfix2 + returnValue + 'end\n';
  code = Blockly.Lua.scrub_(block, code);
  // Add % so as not to collide with helper functions in definitions list.
@@ -68,15 +68,15 @@ Blockly.Lua['procedures_defnoreturn'] =

 Blockly.Lua['procedures_callreturn'] = function(block) {
  // Call a procedure with a return value.
-  var funcName = Blockly.Lua.nameDB_.getName(
+  const funcName = Blockly.Lua.nameDB_.getName(
      block.getFieldValue('NAME'), Blockly.PROCEDURE_CATEGORY_NAME);
-  var args = [];
-  var variables = block.getVars();
-  for (var i = 0; i < variables.length; i++) {
+  const args = [];
+  const variables = block.getVars();
+  for (let i = 0; i < variables.length; i++) {
    args[i] = Blockly.Lua.valueToCode(block, 'ARG' + i,
        Blockly.Lua.ORDER_NONE) || 'nil';
  }
-  var code = funcName + '(' + args.join(', ') + ')';
+  const code = funcName + '(' + args.join(', ') + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

@@ -84,15 +84,15 @@ Blockly.Lua['procedures_callnoreturn'] = function(block) {
  // Call a procedure with no return value.
  // Generated code is for a function call as a statement is the same as a
  // function call as a value, with the addition of line ending.
-  var tuple = Blockly.Lua['procedures_callreturn'](block);
+  const tuple = Blockly.Lua['procedures_callreturn'](block);
  return tuple[0] + '\n';
 };

 Blockly.Lua['procedures_ifreturn'] = function(block) {
  // Conditionally return value from a procedure.
-  var condition = Blockly.Lua.valueToCode(block, 'CONDITION',
+  const condition = Blockly.Lua.valueToCode(block, 'CONDITION',
      Blockly.Lua.ORDER_NONE) || 'false';
-  var code = 'if ' + condition + ' then\n';
+  let code = 'if ' + condition + ' then\n';
  if (Blockly.Lua.STATEMENT_SUFFIX) {
    // Inject any statement suffix here since the regular one at the end
    // will not get executed if the return is triggered.
@@ -101,7 +101,7 @@ Blockly.Lua['procedures_ifreturn'] = function(block) {
        Blockly.Lua.INDENT);
  }
  if (block.hasReturnValue_) {
-    var value = Blockly.Lua.valueToCode(block, 'VALUE',
+    const value = Blockly.Lua.valueToCode(block, 'VALUE',
        Blockly.Lua.ORDER_NONE) || 'nil';
    code += Blockly.Lua.INDENT + 'return ' + value + '\n';
  } else {
--- a/generators/lua/text.js
+++ b/generators/lua/text.js
@@ -16,14 +16,14 @@ goog.require('Blockly.Lua');

 Blockly.Lua['text'] = function(block) {
  // Text value.
-  var code = Blockly.Lua.quote_(block.getFieldValue('TEXT'));
+  const code = Blockly.Lua.quote_(block.getFieldValue('TEXT'));
  return [code, Blockly.Lua.ORDER_ATOMIC];
 };

 Blockly.Lua['text_multiline'] = function(block) {
  // Text value.
-  var code = Blockly.Lua.multiline_quote_(block.getFieldValue('TEXT'));
-  var order = code.indexOf('..') !== -1 ? Blockly.Lua.ORDER_CONCATENATION :
+  const code = Blockly.Lua.multiline_quote_(block.getFieldValue('TEXT'));
+  const order = code.indexOf('..') !== -1 ? Blockly.Lua.ORDER_CONCATENATION :
      Blockly.Lua.ORDER_ATOMIC;
  return [code, order];
 };
@@ -33,59 +33,60 @@ Blockly.Lua['text_join'] = function(block) {
  if (block.itemCount_ === 0) {
    return ['\'\'', Blockly.Lua.ORDER_ATOMIC];
  } else if (block.itemCount_ === 1) {
-    var element = Blockly.Lua.valueToCode(block, 'ADD0',
+    const element = Blockly.Lua.valueToCode(block, 'ADD0',
        Blockly.Lua.ORDER_NONE) || '\'\'';
-    var code = 'tostring(' + element + ')';
+    const code = 'tostring(' + element + ')';
    return [code, Blockly.Lua.ORDER_HIGH];
  } else if (block.itemCount_ === 2) {
-    var element0 = Blockly.Lua.valueToCode(block, 'ADD0',
+    const element0 = Blockly.Lua.valueToCode(block, 'ADD0',
        Blockly.Lua.ORDER_CONCATENATION) || '\'\'';
-    var element1 = Blockly.Lua.valueToCode(block, 'ADD1',
+    const element1 = Blockly.Lua.valueToCode(block, 'ADD1',
        Blockly.Lua.ORDER_CONCATENATION) || '\'\'';
-    var code = element0 + ' .. ' + element1;
+    const code = element0 + ' .. ' + element1;
    return [code, Blockly.Lua.ORDER_CONCATENATION];
  } else {
-    var elements = [];
-    for (var i = 0; i < block.itemCount_; i++) {
+    const elements = [];
+    for (let i = 0; i < block.itemCount_; i++) {
      elements[i] = Blockly.Lua.valueToCode(block, 'ADD' + i,
          Blockly.Lua.ORDER_NONE) || '\'\'';
    }
-    var code = 'table.concat({' + elements.join(', ') + '})';
+    const code = 'table.concat({' + elements.join(', ') + '})';
    return [code, Blockly.Lua.ORDER_HIGH];
  }
 };

 Blockly.Lua['text_append'] = function(block) {
  // Append to a variable in place.
-  var varName = Blockly.Lua.nameDB_.getName(
+  const varName = Blockly.Lua.nameDB_.getName(
      block.getFieldValue('VAR'), Blockly.VARIABLE_CATEGORY_NAME);
-  var value = Blockly.Lua.valueToCode(block, 'TEXT',
+  const value = Blockly.Lua.valueToCode(block, 'TEXT',
      Blockly.Lua.ORDER_CONCATENATION) || '\'\'';
  return varName + ' = ' + varName + ' .. ' + value + '\n';
 };

 Blockly.Lua['text_length'] = function(block) {
  // String or array length.
-  var text = Blockly.Lua.valueToCode(block, 'VALUE',
+  const text = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_UNARY) || '\'\'';
  return ['#' + text, Blockly.Lua.ORDER_UNARY];
 };

 Blockly.Lua['text_isEmpty'] = function(block) {
  // Is the string null or array empty?
-  var text = Blockly.Lua.valueToCode(block, 'VALUE',
+  const text = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_UNARY) || '\'\'';
  return ['#' + text + ' == 0', Blockly.Lua.ORDER_RELATIONAL];
 };

 Blockly.Lua['text_indexOf'] = function(block) {
  // Search the text for a substring.
-  var substring = Blockly.Lua.valueToCode(block, 'FIND',
+  const substring = Blockly.Lua.valueToCode(block, 'FIND',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var text = Blockly.Lua.valueToCode(block, 'VALUE',
+  const text = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_NONE) || '\'\'';
+  let functionName;
  if (block.getFieldValue('END') === 'FIRST') {
-    var functionName = Blockly.Lua.provideFunction_(
+    functionName = Blockly.Lua.provideFunction_(
        'firstIndexOf',
        ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ +
             '(str, substr) ',
@@ -97,7 +98,7 @@ Blockly.Lua['text_indexOf'] = function(block) {
         '  end',
         'end']);
  } else {
-    var functionName = Blockly.Lua.provideFunction_(
+    functionName = Blockly.Lua.provideFunction_(
        'lastIndexOf',
        ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ +
             '(str, substr)',
@@ -109,22 +110,22 @@ Blockly.Lua['text_indexOf'] = function(block) {
         '  return 0',
         'end']);
  }
-  var code = functionName + '(' + text + ', ' + substring + ')';
+  const code = functionName + '(' + text + ', ' + substring + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['text_charAt'] = function(block) {
  // Get letter at index.
  // Note: Until January 2013 this block did not have the WHERE input.
-  var where = block.getFieldValue('WHERE') || 'FROM_START';
-  var atOrder = (where === 'FROM_END') ? Blockly.Lua.ORDER_UNARY :
+  const where = block.getFieldValue('WHERE') || 'FROM_START';
+  const atOrder = (where === 'FROM_END') ? Blockly.Lua.ORDER_UNARY :
      Blockly.Lua.ORDER_NONE;
-  var at = Blockly.Lua.valueToCode(block, 'AT', atOrder) || '1';
-  var text = Blockly.Lua.valueToCode(block, 'VALUE',
+  const at = Blockly.Lua.valueToCode(block, 'AT', atOrder) || '1';
+  const text = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var code;
+  let code;
  if (where === 'RANDOM') {
-    var functionName = Blockly.Lua.provideFunction_(
+    const functionName = Blockly.Lua.provideFunction_(
        'text_random_letter',
        ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(str)',
         '  local index = math.random(string.len(str))',
@@ -132,15 +133,16 @@ Blockly.Lua['text_charAt'] = function(block) {
         'end']);
    code = functionName + '(' + text + ')';
  } else {
+    let start;
    if (where === 'FIRST') {
-      var start = '1';
+      start = '1';
    } else if (where === 'LAST') {
-      var start = '-1';
+      start = '-1';
    } else {
      if (where === 'FROM_START') {
-        var start = at;
+        start = at;
      } else if (where === 'FROM_END') {
-        var start = '-' + at;
+        start = '-' + at;
      } else {
        throw Error('Unhandled option (text_charAt).');
      }
@@ -149,7 +151,7 @@ Blockly.Lua['text_charAt'] = function(block) {
      code = 'string.sub(' + text + ', ' + start + ', ' + start + ')';
    } else {
      // use function to avoid reevaluation
-      var functionName = Blockly.Lua.provideFunction_(
+      const functionName = Blockly.Lua.provideFunction_(
          'text_char_at',
          ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ +
               '(str, index)',
@@ -163,53 +165,56 @@ Blockly.Lua['text_charAt'] = function(block) {

 Blockly.Lua['text_getSubstring'] = function(block) {
  // Get substring.
-  var text = Blockly.Lua.valueToCode(block, 'STRING',
+  const text = Blockly.Lua.valueToCode(block, 'STRING',
      Blockly.Lua.ORDER_NONE) || '\'\'';

  // Get start index.
-  var where1 = block.getFieldValue('WHERE1');
-  var at1Order = (where1 === 'FROM_END') ? Blockly.Lua.ORDER_UNARY :
+  const where1 = block.getFieldValue('WHERE1');
+  const at1Order = (where1 === 'FROM_END') ? Blockly.Lua.ORDER_UNARY :
      Blockly.Lua.ORDER_NONE;
-  var at1 = Blockly.Lua.valueToCode(block, 'AT1', at1Order) || '1';
+  const at1 = Blockly.Lua.valueToCode(block, 'AT1', at1Order) || '1';
+  let start;
  if (where1 === 'FIRST') {
-    var start = 1;
+    start = 1;
  } else if (where1 === 'FROM_START') {
-    var start = at1;
+    start = at1;
  } else if (where1 === 'FROM_END') {
-    var start = '-' + at1;
+    start = '-' + at1;
  } else {
    throw Error('Unhandled option (text_getSubstring)');
  }

  // Get end index.
-  var where2 = block.getFieldValue('WHERE2');
-  var at2Order = (where2 === 'FROM_END') ? Blockly.Lua.ORDER_UNARY :
+  const where2 = block.getFieldValue('WHERE2');
+  const at2Order = (where2 === 'FROM_END') ? Blockly.Lua.ORDER_UNARY :
      Blockly.Lua.ORDER_NONE;
-  var at2 = Blockly.Lua.valueToCode(block, 'AT2', at2Order) || '1';
+  const at2 = Blockly.Lua.valueToCode(block, 'AT2', at2Order) || '1';
+  let end;
  if (where2 === 'LAST') {
-    var end = -1;
+    end = -1;
  } else if (where2 === 'FROM_START') {
-    var end = at2;
+    end = at2;
  } else if (where2 === 'FROM_END') {
-    var end = '-' + at2;
+    end = '-' + at2;
  } else {
    throw Error('Unhandled option (text_getSubstring)');
  }
-  var code = 'string.sub(' + text + ', ' + start + ', ' + end + ')';
+  const code = 'string.sub(' + text + ', ' + start + ', ' + end + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['text_changeCase'] = function(block) {
  // Change capitalization.
-  var operator = block.getFieldValue('CASE');
-  var text = Blockly.Lua.valueToCode(block, 'TEXT',
+  const operator = block.getFieldValue('CASE');
+  const text = Blockly.Lua.valueToCode(block, 'TEXT',
      Blockly.Lua.ORDER_NONE) || '\'\'';
+  let functionName;
  if (operator === 'UPPERCASE') {
-    var functionName = 'string.upper';
+    functionName = 'string.upper';
  } else if (operator === 'LOWERCASE') {
-    var functionName = 'string.lower';
+    functionName = 'string.lower';
  } else if (operator === 'TITLECASE') {
-    var functionName = Blockly.Lua.provideFunction_(
+    functionName = Blockly.Lua.provideFunction_(
        'text_titlecase',
        // There are shorter versions at
        // http://lua-users.org/wiki/SciteTitleCase
@@ -232,52 +237,53 @@ Blockly.Lua['text_changeCase'] = function(block) {
         '  return table.concat(buf)',
         'end']);
  }
-  var code = functionName + '(' + text + ')';
+  const code = functionName + '(' + text + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['text_trim'] = function(block) {
  // Trim spaces.
-  var OPERATORS = {
+  const OPERATORS = {
    LEFT: '^%s*(,-)',
    RIGHT: '(.-)%s*$',
    BOTH: '^%s*(.-)%s*$'
  };
-  var operator = OPERATORS[block.getFieldValue('MODE')];
-  var text = Blockly.Lua.valueToCode(block, 'TEXT',
+  const operator = OPERATORS[block.getFieldValue('MODE')];
+  const text = Blockly.Lua.valueToCode(block, 'TEXT',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var code = 'string.gsub(' + text + ', "' + operator + '", "%1")';
+  const code = 'string.gsub(' + text + ', "' + operator + '", "%1")';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['text_print'] = function(block) {
  // Print statement.
-  var msg = Blockly.Lua.valueToCode(block, 'TEXT',
+  const msg = Blockly.Lua.valueToCode(block, 'TEXT',
      Blockly.Lua.ORDER_NONE) || '\'\'';
  return 'print(' + msg + ')\n';
 };

 Blockly.Lua['text_prompt_ext'] = function(block) {
  // Prompt function.
+  let msg;
  if (block.getField('TEXT')) {
    // Internal message.
-    var msg = Blockly.Lua.quote_(block.getFieldValue('TEXT'));
+    msg = Blockly.Lua.quote_(block.getFieldValue('TEXT'));
  } else {
    // External message.
-    var msg = Blockly.Lua.valueToCode(block, 'TEXT',
+    msg = Blockly.Lua.valueToCode(block, 'TEXT',
        Blockly.Lua.ORDER_NONE) || '\'\'';
  }

-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'text_prompt',
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(msg)',
       '  io.write(msg)',
       '  io.flush()',
       '  return io.read()',
       'end']);
-  var code = functionName + '(' + msg + ')';
+  let code = functionName + '(' + msg + ')';

-  var toNumber = block.getFieldValue('TYPE') === 'NUMBER';
+  const toNumber = block.getFieldValue('TYPE') === 'NUMBER';
  if (toNumber) {
    code = 'tonumber(' + code + ', 10)';
  }
@@ -287,11 +293,11 @@ Blockly.Lua['text_prompt_ext'] = function(block) {
 Blockly.Lua['text_prompt'] = Blockly.Lua['text_prompt_ext'];

 Blockly.Lua['text_count'] = function(block) {
-  var text = Blockly.Lua.valueToCode(block, 'TEXT',
+  const text = Blockly.Lua.valueToCode(block, 'TEXT',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var sub = Blockly.Lua.valueToCode(block, 'SUB',
+  const sub = Blockly.Lua.valueToCode(block, 'SUB',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'text_count',
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_
        + '(haystack, needle)',
@@ -311,18 +317,18 @@ Blockly.Lua['text_count'] = function(block) {
        '  return count',
        'end',
      ]);
-  var code = functionName + '(' + text + ', ' + sub + ')';
+  const code = functionName + '(' + text + ', ' + sub + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['text_replace'] = function(block) {
-  var text = Blockly.Lua.valueToCode(block, 'TEXT',
+  const text = Blockly.Lua.valueToCode(block, 'TEXT',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var from = Blockly.Lua.valueToCode(block, 'FROM',
+  const from = Blockly.Lua.valueToCode(block, 'FROM',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var to = Blockly.Lua.valueToCode(block, 'TO',
+  const to = Blockly.Lua.valueToCode(block, 'TO',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var functionName = Blockly.Lua.provideFunction_(
+  const functionName = Blockly.Lua.provideFunction_(
      'text_replace',
      ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_
        + '(haystack, needle, replacement)',
@@ -342,13 +348,13 @@ Blockly.Lua['text_replace'] = function(block) {
        '  return table.concat(buf)',
        'end',
      ]);
-  var code = functionName + '(' + text + ', ' + from + ', ' + to + ')';
+  const code = functionName + '(' + text + ', ' + from + ', ' + to + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };

 Blockly.Lua['text_reverse'] = function(block) {
-  var text = Blockly.Lua.valueToCode(block, 'TEXT',
+  const text = Blockly.Lua.valueToCode(block, 'TEXT',
      Blockly.Lua.ORDER_NONE) || '\'\'';
-  var code = 'string.reverse(' + text + ')';
+  const code = 'string.reverse(' + text + ')';
  return [code, Blockly.Lua.ORDER_HIGH];
 };
--- a/generators/lua/variables.js
+++ b/generators/lua/variables.js
@@ -16,16 +16,16 @@ goog.require('Blockly.Lua');

 Blockly.Lua['variables_get'] = function(block) {
  // Variable getter.
-  var code = Blockly.Lua.nameDB_.getName(block.getFieldValue('VAR'),
+  const code = Blockly.Lua.nameDB_.getName(block.getFieldValue('VAR'),
      Blockly.VARIABLE_CATEGORY_NAME);
  return [code, Blockly.Lua.ORDER_ATOMIC];
 };

 Blockly.Lua['variables_set'] = function(block) {
  // Variable setter.
-  var argument0 = Blockly.Lua.valueToCode(block, 'VALUE',
+  const argument0 = Blockly.Lua.valueToCode(block, 'VALUE',
      Blockly.Lua.ORDER_NONE) || '0';
-  var varName = Blockly.Lua.nameDB_.getName(
+  const varName = Blockly.Lua.nameDB_.getName(
      block.getFieldValue('VAR'), Blockly.VARIABLE_CATEGORY_NAME);
  return varName + ' = ' + argument0 + '\n';
 };
--- a/tests/deps.mocha.js
+++ b/tests/deps.mocha.js
@@ -282,14 +282,14 @@ goog.addDependency('../../generators/javascript/text.js', ['Blockly.JavaScript.t
 goog.addDependency('../../generators/javascript/variables.js', ['Blockly.JavaScript.variables'], ['Blockly.JavaScript'], {'lang': 'es6'});
 goog.addDependency('../../generators/javascript/variables_dynamic.js', ['Blockly.JavaScript.variablesDynamic'], ['Blockly.JavaScript', 'Blockly.JavaScript.variables']);
 goog.addDependency('../../generators/lua.js', ['Blockly.Lua'], ['Blockly.Generator', 'Blockly.inputTypes', 'Blockly.utils.object', 'Blockly.utils.string'], {'lang': 'es6'});
-goog.addDependency('../../generators/lua/colour.js', ['Blockly.Lua.colour'], ['Blockly.Lua']);
-goog.addDependency('../../generators/lua/lists.js', ['Blockly.Lua.lists'], ['Blockly.Lua']);
-goog.addDependency('../../generators/lua/logic.js', ['Blockly.Lua.logic'], ['Blockly.Lua']);
-goog.addDependency('../../generators/lua/loops.js', ['Blockly.Lua.loops'], ['Blockly.Lua']);
-goog.addDependency('../../generators/lua/math.js', ['Blockly.Lua.math'], ['Blockly.Lua']);
-goog.addDependency('../../generators/lua/procedures.js', ['Blockly.Lua.procedures'], ['Blockly.Lua']);
-goog.addDependency('../../generators/lua/text.js', ['Blockly.Lua.texts'], ['Blockly.Lua'], {'lang': 'es5'});
-goog.addDependency('../../generators/lua/variables.js', ['Blockly.Lua.variables'], ['Blockly.Lua']);
+goog.addDependency('../../generators/lua/colour.js', ['Blockly.Lua.colour'], ['Blockly.Lua'], {'lang': 'es6'});
+goog.addDependency('../../generators/lua/lists.js', ['Blockly.Lua.lists'], ['Blockly.Lua'], {'lang': 'es6'});
+goog.addDependency('../../generators/lua/logic.js', ['Blockly.Lua.logic'], ['Blockly.Lua'], {'lang': 'es6'});
+goog.addDependency('../../generators/lua/loops.js', ['Blockly.Lua.loops'], ['Blockly.Lua'], {'lang': 'es6'});
+goog.addDependency('../../generators/lua/math.js', ['Blockly.Lua.math'], ['Blockly.Lua'], {'lang': 'es6'});
+goog.addDependency('../../generators/lua/procedures.js', ['Blockly.Lua.procedures'], ['Blockly.Lua'], {'lang': 'es6'});
+goog.addDependency('../../generators/lua/text.js', ['Blockly.Lua.texts'], ['Blockly.Lua'], {'lang': 'es6'});
+goog.addDependency('../../generators/lua/variables.js', ['Blockly.Lua.variables'], ['Blockly.Lua'], {'lang': 'es6'});
 goog.addDependency('../../generators/lua/variables_dynamic.js', ['Blockly.Lua.variablesDynamic'], ['Blockly.Lua', 'Blockly.Lua.variables']);
 goog.addDependency('../../generators/php.js', ['Blockly.PHP'], ['Blockly.Generator', 'Blockly.inputTypes', 'Blockly.utils.object', 'Blockly.utils.string'], {'lang': 'es6'});
 goog.addDependency('../../generators/php/colour.js', ['Blockly.PHP.colour'], ['Blockly.PHP'], {'lang': 'es6'});