Added code to make slots optional

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 * Your contribution here.
 
+### 
+
+* Added ability to make slots optional by adding "+" before and after slot name (example: {+SLOTNAME+|}) - [@dominicankev] (https://github.com/dominicankev).
+
 ### 0.2.1
 
 * Updated tap module to `6.1.1` - [@mreinstein](https://github.com/mreinstein).

README.md

@@ -134,6 +134,19 @@ You may want to work with [Custom Slot Types](https://developer.amazon.com/appsa
 "your least favorite snack is {Fruit}"
 ```
 
+You can use a special syntax to leave a curly-braced slot name unparsed and make it optional. For example, if you have defined in your skill a `ROOM_NAME` with the values `Bedroom`, `Office` and `Living Room` for the slot `Room_Name`, you can keep `Room_Name` a curly-braced literal and optional as follows
+
+```javascript
+"change channel {to|} {-|ChannelNumber} {in +ROOM_NAME+|+ROOM_NAME+|}"
+=>
+"change channel to {ChannelNumber} in {ROOM_NAME}"
+"change channel {ChannelNumber} in {ROOM_NAME}"
+"change channel to {ChannelNumber} {ROOM_NAME}"
+"change channel {ChannelNumber} {ROOM_NAME}"
+"change channel to {ChannelNumber}"
+"change channel {ChannelNumber}"
+```
+
 ### Contributing
 
 See [CONTRIBUTING](CONTRIBUTING.md)

index.js

@@ -154,13 +154,22 @@ function generateUtterances(str, slots, dictionary, exhaustiveUtterances) {
     utterances = [str];
   }
 
-  // Convert all {-|Name} to {Name} to accomodate slot literals
+  // Convert all {-|Name} to {Name} and +Name+ to {Name} to accomodate slot literals and optional slot literals
   for (var idx in utterances) {
     utterances[idx] = utterances[idx].replace(/\{\-\|/g, "{");
+    var strArray = utterances[idx].split(" ");
+    var strTemp = "";
+    var strTemp2 = "";
+    utterances[idx] = strArray.forEach(function(item){
+      strTemp = item.replace(/\+(.*?)/, "{");
+      strTemp = strTemp.replace(/\+$/, "}");
+      strTemp2 += " " + strTemp;
+    });
+    utterances[idx] = strTemp2;
+    utterances[idx] = utterances[idx].trim();
   }
-
+  
   return utterances;
 }
 
-
 module.exports = generateUtterances;

test/index.js

@@ -19,7 +19,7 @@ test('optional terms', function (t) {
   var template = 'do {it |}';
 
   var result = utterances(template, slots, dictionary);
-  t.deepEqual(result, [ 'do it ', 'do ' ]);
+  t.deepEqual(result, [ 'do it', 'do' ]);
   t.end();
 });
 
@@ -123,3 +123,30 @@ test('raw curly braces for custom slot types', function (t) {
   ]);
   t.end();
 });
+
+test('optional custom slot types', function (t) {
+  var dictionary = {};
+  var slots = {"FRUIT": "CUSTOM_TYPE","COLOR": "CUSTOM_TYPE","ROOM_NAME": "AMAZON.Room"};
+  var template = "{my|your} {favorite|least favorite} thing is {+FRUIT+|+COLOR+} {in +ROOM_NAME+|}";
+
+  var result = utterances(template, slots, dictionary);
+  t.deepEqual(result, [
+    "my favorite thing is {FRUIT} in {ROOM_NAME}",
+    "your favorite thing is {FRUIT} in {ROOM_NAME}",
+    "my least favorite thing is {FRUIT} in {ROOM_NAME}",
+    "your least favorite thing is {FRUIT} in {ROOM_NAME}",
+    "my favorite thing is {COLOR} in {ROOM_NAME}",
+    "your favorite thing is {COLOR} in {ROOM_NAME}",
+    "my least favorite thing is {COLOR} in {ROOM_NAME}",
+    "your least favorite thing is {COLOR} in {ROOM_NAME}",
+    "my favorite thing is {FRUIT}",
+    "your favorite thing is {FRUIT}",
+    "my least favorite thing is {FRUIT}",
+    "your least favorite thing is {FRUIT}",
+    "my favorite thing is {COLOR}",
+    "your favorite thing is {COLOR}",
+    "my least favorite thing is {COLOR}",
+    "your least favorite thing is {COLOR}"
+  ]);
+  t.end();
+});