optional insert operation

lib/json0.js

@@ -70,6 +70,7 @@ json.invertComponent = function(c) {
   if (c.li !== void 0) c_.ld = c.li;
   if (c.ld !== void 0) c_.li = c.ld;
   if (c.na !== void 0) c_.na = -c.na;
+  if (c.oin !== void 0) c_.od = c.oin;
 
   if (c.lm !== void 0) {
     c_.lm = c.p[c.p.length-1];
@@ -215,6 +216,15 @@ json.apply = function(snapshot, op) {
       delete elem[key];
     }
 
+    // Init value
+    else if (c.oin !== void 0) {
+      json.checkObj(elem);
+      // set value if not exists in the object
+      if(elem[key] === void 0) {
+        elem[key] = c.oin;
+      }
+    }
+
     else {
       throw new Error('invalid / missing instruction in op');
     }
@@ -301,19 +311,23 @@ json.append = function(dest,c) {
       } else {
         dest.pop();
       }
-    } else if (last.od !== undefined && last.oi === undefined && c.oi !== undefined && c.od === undefined) {
-      last.oi = c.oi;
-    } else if (last.oi !== undefined && c.od !== undefined) {
+    } else if (last.od !== undefined && last.oi === undefined && last.oin === undefined && (c.oi !== undefined || c.oin !== undefined) && c.od === undefined) {
+      last.oi = c.oi === undefined ? c.oin : c.oi;
+    } else if ((last.oi !== undefined || last.oin !== undefined) && c.od !== undefined) {
       // The last path component inserted something that the new component deletes (or replaces).
       // Just merge them.
       if (c.oi !== undefined) {
+        delete last.oin; // just in case we had it, overwrite with object insert
         last.oi = c.oi;
       } else if (last.od !== undefined) {
         delete last.oi;
+        delete last.oin;
       } else {
         // An insert directly followed by a delete turns into a no-op and can be removed.
         dest.pop();
       }
+    } else if ((last.oi !== undefined || last.oin !== undefined) && c.oin !== undefined) {
+      // last component has optional insert over previous insert - ignore it
     } else if (c.lm !== undefined && c.p[c.p.length - 1] === c.lm) {
       // don't do anything
     } else {
@@ -602,7 +616,7 @@ json.transformComponent = function(dest, c, otherC, type) {
     }
     else if (otherC.oi !== void 0 && otherC.od !== void 0) {
       if (c.p[common] === otherC.p[common]) {
-        if (c.oi !== void 0 && commonOperand) {
+        if ((c.oi !== void 0 || c.oin !== void 0) && commonOperand) {
           // we inserted where someone else replaced
           if (type === 'right') {
             // left wins
@@ -617,12 +631,23 @@ json.transformComponent = function(dest, c, otherC, type) {
         }
       }
     } else if (otherC.oi !== void 0) {
-      if (c.oi !== void 0 && c.p[common] === otherC.p[common]) {
+      if ((c.oi !== void 0 || c.oin !== void 0) && c.p[common] === otherC.p[common]) {
         // left wins if we try to insert at the same place
         if (type === 'left') {
-          json.append(dest,{p: c.p, od:otherC.oi});
+          if (c.oi !== void 0) {
+            json.append(dest,{p: c.p, od:otherC.oi});
+          } else {
+            return dest;
+          }
         } else {
-          return dest;
+          if(c.oin !== void 0) {
+            // we need to rebuild operation into object insert
+            json.append(dest,{p: c.p, od:c.oin});
+            c.oi = otherC.oi;
+            delete c.oin;
+          } else {
+            return dest;
+          }
         }
       }
     } else if (otherC.od !== void 0) {
@@ -635,6 +660,21 @@ json.transformComponent = function(dest, c, otherC, type) {
           return dest;
         }
       }
+    } else if (otherC.oin !== void 0) {
+      if ((c.oi !== void 0 || c.oin !== void 0) && c.p[common] === otherC.p[common]) {
+        // left wins if we try to insert at the same place
+        if (type === 'left') {
+          if (c.oi !== void 0) {
+            json.append(dest,{p: c.p, od:otherC.oin});
+          } else {
+            return dest;
+          }
+        } else {
+          if(c.oi !== void 0 || c.oin !== void 0) {
+            return dest;
+          }
+        }
+      }
     }
   }
 

randomizer/json0.coffee

@@ -159,7 +159,18 @@ json0.generateRandomOp = (data) ->
       # Object
       k = randomKey(operand)
 
-      if randomReal() > 0.5 or not k?
+      if json0._testOin and not k? and operand[k] is undefined
+        # "oin" is only valid when client knows there is no value for the key and 
+        # someone can initiate the same key. If we try to insert over existing value
+        # (and operation will be ignored since key exists), invertion will fail
+        k = randomNewKey(operand)
+        # All clients should start with the same initial value
+        obj = {alwaysSameInitialValue: k}
+
+        path.push(k);
+        operand[k] = obj
+        {p:path, oin:clone(obj)}
+      else if (randomReal() > 0.7 or not k?) and not json0._testOin
         # Insert
         k = randomNewKey(operand)
         obj = randomThing()

test/json0.coffee

@@ -24,7 +24,18 @@ genTests = (type) ->
         assert.deepEqual [{p:['foo'], od:1},{p:['bar'], oi:2}], type.compose [{p:['foo'],od:1}],[{p:['bar'],oi:2}]
       it 'merges od+oi, od+oi -> od+oi', ->
         assert.deepEqual [{p:['foo'], od:1, oi:2}], type.compose [{p:['foo'],od:1,oi:3}],[{p:['foo'],od:3,oi:2}]
-
+      it 'oi,oin -> oi', ->
+        assert.deepEqual [{p:['foo'], oi:1}], type.compose [{p:['foo'],oi:1}],[{p:['foo'],oin:2}]
+      it 'oin,oin` -> oin', ->
+        assert.deepEqual [{p:['foo'], oin:1}], type.compose [{p:['foo'],oin:1}],[{p:['foo'],oin:2}]
+      it 'od,oin -> od+oi', ->
+        assert.deepEqual [{p:['foo'], od:1, oi:2}], type.compose [{p:['foo'],od:1}],[{p:['foo'],oin:2}]
+      it 'od+oi,oin -> od+oi', ->
+        assert.deepEqual [{p:['foo'], od:1, oi:3}], type.compose [{p:['foo'],od:1,oi:3}],[{p:['foo'],oin:2}]
+
+    describe '#invert()', ->
+      it 'optional insert inverts to delete', ->
+        assert.deepEqual [{p:['foo'], od:1}], type.invert [{p:['foo'], oin:1}]
 
     describe '#transform()', -> it 'returns sane values', ->
       t = (op1, op2) ->
@@ -316,6 +327,7 @@ genTests = (type) ->
       assert.deepEqual {x:'a', y:'b'}, type.apply {x:'a'}, [{p:['y'], oi:'b'}]
       assert.deepEqual {}, type.apply {x:'a'}, [{p:['x'], od:'a'}]
       assert.deepEqual {x:'b'}, type.apply {x:'a'}, [{p:['x'], od:'a', oi:'b'}]
+      assert.deepEqual {x:'a'}, type.apply {x:'a'}, [{p:['x'], oin: 'b'}]
 
     it 'Ops on deleted elements become noops', ->
       assert.deepEqual [], type.transform [{p:[1, 0], si:'hi'}], [{p:[1], od:'x'}], 'left'
@@ -374,6 +386,16 @@ genTests = (type) ->
       assert.deepEqual [], type.transform [{p:['k'], od:'x'}], [{p:['k'], od:'x'}], 'left'
       assert.deepEqual [], type.transform [{p:['k'], od:'x'}], [{p:['k'], od:'x'}], 'right'
 
+    it 'Optional insert vs insert', ->
+      assert.deepEqual [], type.transform [{p:[1], oin:'a'}], [{p:[1], oi:'b'}], 'left'
+      assert.deepEqual [{p:[1], od:'a', oi:'b'}], type.transform [{p:[1], oin:'a'}], [{p:[1], oi:'b'}], 'right'
+
+    it 'Optional vs optional, no one wins', ->
+      assert.deepEqual [], type.transform [{p:[1], oin:'a'}], [{p:[1], oin:'b'}], 'left'
+      assert.deepEqual [], type.transform [{p:[1], oin:'a'}], [{p:[1], oin:'b'}], 'right'
+
+
+
   describe 'randomizer', ->
     it 'passes', ->
       @slow 6000
@@ -384,6 +406,11 @@ genTests = (type) ->
       randomizer type, 1000
       delete type._testStringSubtype
 
+    it 'passes with `oin` operation', ->
+      type._testOin = true # hack
+      randomizer type, 1000
+      delete type._testOin
+
 describe 'json', ->
   describe 'native type', -> genTests nativetype
   #exports.webclient = genTests require('../helpers/webclient').types.json