fix(package): In $input.json, if payload is empty, treat it as empty …

…object

index.js

@@ -36,8 +36,12 @@ module.exports = function(parameters) {
       },
       json: function(path) {
         var obj;
-        // if payload starts with `{` or `[` or `"`, treat as JSON
-        if (/^\s*(?:{|\[|")/.test(this._payload)) {
+        if (this._payload === '') {
+          // if payload is empty, treat it as empty object
+          //   https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-098fd028
+          obj = {};
+        } else if (/^\s*(?:{|\[|")/.test(this._payload)) {
+          // if payload starts with `{` or `[` or `"`, treat as JSON
           obj = JSON.parse(this._payload);
         } else {
           // treat as string

misc/examples.js

@@ -34,6 +34,11 @@ module.exports = [
     payload: "{}",
     headers: {},
   },
+  {
+    template: '$input.json(\'$\')',
+    payload: "",
+    headers: {},
+  },
   {
     template: '{"name": "$input.path(\'$\')"}',
     payload: "name=toqoz",

test/_.js

@@ -60,6 +60,14 @@ describe('$input.path|$input.json', function() {
       assert.deepEqual(expected, actual);
     });
   });
+  // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-098fd028
+  describe('H=`{}` P=`` ===> T=`$input.json(\'$\')`', function() {
+    it('return ', function() {
+      var expected = {};
+      var actual = JSON.parse(mappingTemplate({template: "$input.json('$')", payload: ""}));
+      assert.deepEqual(expected, actual);
+    });
+  });
   // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-25c6993c
   describe('H=`{}` P=`name=toqoz` ===> T=`{"name": "$input.path(\'$\')"}`', function() {
     it('return name=toqoz', function() {

test/_.md

@@ -33,6 +33,11 @@ Template|Header|Payload|Status code|Result
 --------|------|-------|-----------|------
 `$input.json('$')`|`None`|`{}`|`200`|`{}`
 
+## example-098fd028
+Template|Header|Payload|Status code|Result
+--------|------|-------|-----------|------
+`$input.json('$')`|`None`|``|`200`|`{}`
+
 ## example-25c6993c
 Template|Header|Payload|Status code|Result
 --------|------|-------|-----------|------