fix: add bool to priorityComparator, add tests

Author: Redmega

src/utils.js

@@ -62,15 +62,21 @@ exports.priAndKeyComparator = function priAndKeyComparator(testPri, testKey, val
 };
 
 exports.priorityComparator = function priorityComparator(a, b) {
+  // https://firebase.google.com/docs/database/web/lists-of-data#data-order
   if (a !== b) {
     if (a === null || b === null) {
       return a === null ? -1 : 1;
     }
+    if(typeof a === 'boolean' && typeof b === 'boolean') {
+      return !a ? -1 : 1;
+    }
     if (typeof a !== typeof b) {
+      if(typeof a === 'boolean' || typeof b === 'boolean') {
+        return typeof a === 'boolean' ? -1 : 1;
+      }
       return typeof a === 'number' ? -1 : 1;
-    } else {
-      return a > b ? 1 : -1;
     }
+    return a > b ? 1 : -1;
   }
   return 0;
 };

test/unit/utils.js

@@ -7,6 +7,7 @@ var removeEmptyRtdbProperties = require('../../src/utils').removeEmptyRtdbProper
 var removeEmptyFirestoreProperties = require('../../src/utils').removeEmptyFirestoreProperties;
 var updateToRtdbObject = require('../../src/utils').updateToRtdbObject;
 var updateToFirestoreObject = require('../../src/utils').updateToFirestoreObject;
+var priorityComparator = require('../../src/utils').priorityComparator;
 
 describe('utils', function () {
   describe('removeEmptyRtdbProperties', function () {
@@ -164,4 +165,43 @@ describe('utils', function () {
       });
     });
   });
+
+  describe('priorityComparator', function() {
+    // https://firebase.google.com/docs/database/web/lists-of-data#data-order
+    it('should give no priority to equal items', function() {
+      expect(priorityComparator('a', 'a')).to.eql(0);
+    });
+    it('should order null items first', function() {
+      expect(priorityComparator(null, 0)).to.eql(-1);
+      expect(priorityComparator(0, null)).to.eql(1);
+    });
+    it('should order false before true', function() {
+      expect(priorityComparator(false, true)).to.eql(-1);
+      expect(priorityComparator(true, false)).to.eql(1);
+    });
+    it('should order booleans before numbers', function() {
+      expect(priorityComparator(false, 0)).to.eql(-1);
+      expect(priorityComparator(true, 1)).to.eql(-1);
+      expect(priorityComparator(0, false)).to.eql(1);
+      expect(priorityComparator(1, true)).to.eql(1);
+    });
+    it('should order numbers before strings', function() {
+      expect(priorityComparator(5, 'foo')).to.eql(-1);
+      expect(priorityComparator(3, '3')).to.eql(-1);
+      expect(priorityComparator('foo', 0)).to.eql(1);
+      expect(priorityComparator('10', 10)).to.eql(1);
+    });
+    it('should order numbers in ascending order', function() {
+      expect(priorityComparator(4,5)).to.eql(-1);
+      expect(priorityComparator(5,4)).to.eql(1);
+      expect(priorityComparator(1,10)).to.eql(-1);
+      expect(priorityComparator(10,1)).to.eql(1);
+    });
+    it('should order strings lexicographically', function() {
+      expect(priorityComparator('bar', 'foo')).to.eql(-1);
+      expect(priorityComparator('foo', 'bar')).to.eql(1);
+      expect(priorityComparator('ant', 'art')).to.eql(-1);
+      expect(priorityComparator('art', 'ant')).to.eql(1);
+    });
+  });
 });