Can use with

avansteijn · Jan 26, 2016 · 1e65f36 · 1e65f36
1 parent 9289c79
commit 1e65f36
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Showing 2 changed files with 35 additions and 19 deletions.
diff --git a/lib/model.js b/lib/model.js
@@ -264,38 +264,42 @@ lastStepModifierFunctions.$unset = function (obj, field, value) {
 
 /**
  * Push an element to the end of an array field
+ * Optional modifier $each instead of value to push several values
+ * Optional modifier $slice to slice the resulting array, see https://docs.mongodb.org/manual/reference/operator/update/slice/
+ * Différeence with MongoDB: if $slice is specified and not $each, we act as if value is an empty array
  */
 lastStepModifierFunctions.$push = function (obj, field, value) {
   // Create the array if it doesn't exist
   if (!obj.hasOwnProperty(field)) { obj[field] = []; }
 
   if (!util.isArray(obj[field])) { throw new Error("Can't $push an element on non-array values"); }
 
+  if (value !== null && typeof value === 'object' && value.$slice && value.$each === undefined) {
+    value.$each = [];
+  }
+
   if (value !== null && typeof value === 'object' && value.$each) {
-    var keys = Object.keys(value);
-    if (keys.length > 1 && keys.sort()[1] !== '$slice') {
-      throw new Error("Can't use another field in conjunction with $each"); }
+    if (Object.keys(value).length >= 3 || (Object.keys(value).length === 2 && value.$slice === undefined)) { throw new Error("Can only use $slice in cunjunction with $each when $push to array"); }
     if (!util.isArray(value.$each)) { throw new Error("$each requires an array value"); }
 
     value.$each.forEach(function (v) {
       obj[field].push(v);
     });
 
-    var slice = parseInt(value.$slice, 10);
-    if (!isNaN(slice)) {
-      if (slice === 0) {
-        obj[field] = [];
-      } else {
-        var start, end, n = obj[field].length;
-        if (slice < 0) {
-          start = Math.max(0, n + slice);
-          end = n;
-        } else if (slice > 0) {
-          start = 0;
-          end = Math.min(n, slice);
-        }
-        obj[field] = obj[field].slice(start, end);
+    if (value.$slice === undefined || typeof value.$slice !== 'number') { return; }
+
+    if (value.$slice === 0) {
+      obj[field] = [];
+    } else {
+      var start, end, n = obj[field].length;
+      if (value.$slice < 0) {
+        start = Math.max(0, n + value.$slice);
+        end = n;
+      } else if (value.$slice > 0) {
+        start = 0;
+        end = Math.min(n, value.$slice);
       }
+      obj[field] = obj[field].slice(start, end);
     }
   } else {
     obj[field].push(value);

diff --git a/test/model.test.js b/test/model.test.js
@@ -208,7 +208,7 @@ describe('Model', function () {
 
       model.checkObject(obj);
     });
-    
+
     it('Can check if an object is a primitive or not', function () {
       model.isPrimitiveType(5).should.equal(true);
       model.isPrimitiveType('sdsfdfs').should.equal(true);
@@ -520,7 +520,7 @@ describe('Model', function () {
         }).should.throw();
       });
 
-      it('Can use the $slice modifier to limits the number of array elements', function () {
+      it('Can use the $slice modifier to limit the number of array elements', function () {
         var obj = { arr: ['hello'] }
           , modified;
 
@@ -547,6 +547,18 @@ describe('Model', function () {
 
         modified = model.modify(obj, { $push: { arr: { $each: [], $slice: 1 } } });
         assert.deepEqual(modified, { arr: ['hello'] });
+
+        // $each not specified, but $slice is
+        modified = model.modify(obj, { $push: { arr: { $slice: 1 } } });
+        assert.deepEqual(modified, { arr: ['hello'] });
+
+        (function () {
+          modified = model.modify(obj, { $push: { arr: { $slice: 1, unauthorized: true } } });
+        }).should.throw();
+
+        (function () {
+          modified = model.modify(obj, { $push: { arr: { $each: [], unauthorized: true } } });
+        }).should.throw();
       });
 
     });   // End of '$push modifier'