reimplement noncommutative sort

the workaround for handlebars-lang/handlebars.js/issues/748 employed a sorting
routine that was not commutative; its output relied on the order of its
arguments, and with the V8 engine upgrade in node11, that order has
changed[1]

the order of the arguments to Array#sory is considered an implementation
detail that we can't rely on

this patch reimplements that sorting routine to always return the same
result regardless of the order of its operands, and so it should work on
node <= 10 and >= 11

test plan: there is already a case for this, so I just added node12 to
           the travis language matrix

[1]: nodejs/node#24294

.travis.yml

@@ -1,6 +1,5 @@
 before_script: 'npm install -g grunt-cli'
 language: node_js
 node_js:
-  - "6"
-  - "5"
-  - "4"
+  - "10"
+  - "12"

dist/lib/pre_processor.js

@@ -97,22 +97,6 @@ function concatNode(string, tempMap) {
   return new SexprNode(parts);
 }
 
-function sortBy(array, fn) {
-  return array.map(function (item, i) {
-    return [fn(item), i, item];
-  }).sort(function (left, right) {
-    var leftSort = left[0],
-        rightSort = right[0];
-    if (leftSort !== rightSort) {
-      if (leftSort > rightSort) return 1;
-      if (leftSort < rightSort) return 0;
-    }
-    return left[1] - right[1];
-  }).map(function (obj) {
-    return obj[2];
-  });
-}
-
 var PreProcessor = {
   process: function process(ast) {
     var statements = ast.statements,
@@ -180,9 +164,14 @@ var PreProcessor = {
    * https://github.com/wycats/handlebars.js/issues/767
    */
   applySubExpressionHack: function applySubExpressionHack(node) {
-    node.hash.pairs = sortBy(node.hash.pairs, function (pair) {
-      var type = pair[1].type;
-      return type === "sexpr" ? 0 : 1;
+    node.hash.pairs = node.hash.pairs.sort(function (a, b) {
+      if (a[1].type === b[1].type) {
+        return 0;
+      } else if (a[1].type === 'sexpr') {
+        return -1;
+      } else if (b[1].type === 'sexpr') {
+        return 1;
+      }
     });
     var pairs = node.hash.pairs;
     if (pairs.length > 1 && pairs[1][1].type === "sexpr") throw new _errors2.default.MultipleSubExpressionsError(node.firstLine, "Handlebars 1.3 doesn't support multiple sub-expressions in the options hash");

lib/pre_processor.js

@@ -88,22 +88,6 @@ function concatNode(string, tempMap) {
   return new SexprNode(parts);
 }
 
-function sortBy(array, fn) {
-  return array.map(function(item, i) {
-    return [fn(item), i, item];
-  }).sort(function(left, right) {
-    var leftSort = left[0]
-      , rightSort = right[0];
-    if (leftSort !== rightSort) {
-      if (leftSort > rightSort) return 1;
-      if (leftSort < rightSort) return 0;
-    }
-    return left[1] - right[1];
-  }).map(function(obj) {
-    return obj[2];
-  });
-}
-
 var PreProcessor = {
   process: function(ast) {
     var statements = ast.statements
@@ -176,9 +160,16 @@ var PreProcessor = {
    * https://github.com/wycats/handlebars.js/issues/767
    */
   applySubExpressionHack: function(node) {
-    node.hash.pairs = sortBy(node.hash.pairs, function(pair) {
-      var type = pair[1].type;
-      return type === "sexpr" ? 0 : 1;
+    node.hash.pairs = node.hash.pairs.sort(function(a,b) {
+      if (a[1].type === b[1].type) {
+        return 0
+      }
+      else if (a[1].type === 'sexpr') {
+        return -1;
+      }
+      else if (b[1].type === 'sexpr') {
+        return 1;
+      }
     });
     var pairs = node.hash.pairs;
     if (pairs.length > 1 && pairs[1][1].type === "sexpr")

package.json

@@ -25,7 +25,7 @@
     "grunt-contrib-clean": "~1.0.0",
     "grunt-contrib-copy": "~1.0.0",
     "gruntify-eslint": "~3.1.0",
-    "handlebars": ">=1.3 <3",
+    "handlebars": "~1.3.0",
     "i18nliner": "~0.2.0",
     "jsdom": "~8.5.0",
     "matchdep": "~1.0.1",