fix(package): fix a bug in $input.json

- Don't parse twice.
- Don't parse as JSON if payload starts with { or [ or "

Author: ToQoz

index.js

@@ -35,13 +35,13 @@ module.exports = function(parameters) {
         return jsonpath(obj, path);
       },
       json: function(path) {
-        var obj = JSON.parse(payload);
-        if (typeof obj === 'string') {
-          // re-parse when parsed payload is string.
-          // because of
-          //   - https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-a669d28c
-          //   - https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-1b8d22cd
-          obj = JSON.parse(obj);
+        var obj;
+        // if payload starts with `{` or `[` or `"`, treat as JSON
+        if (/^\s*(?:{|\[|")/.test(this._payload)) {
+          obj = JSON.parse(this._payload);
+        } else {
+          // treat as string
+          obj = this._payload;
         }
 
         return JSON.stringify(jsonpath(obj, path));

misc/examples.js

@@ -10,12 +10,12 @@ module.exports = [
     headers: {},
   },
   {
-    template: '"$input.json(\'$\')"',
+    template: '$input.json(\'$\')',
     payload: "a=b",
     headers: {},
   },
   {
-    template: '"$input.json(\'$\')"',
+    template: '$input.json(\'$\')',
     payload: '"a=b"',
     headers: {},
   },
@@ -30,7 +30,7 @@ module.exports = [
     headers: {},
   },
   {
-    template: '"$input.json(\'$\')"',
+    template: '$input.json(\'$\')',
     payload: "{}",
     headers: {},
   },

test/_.js

@@ -20,16 +20,20 @@ describe('$input.path|$input.json', function() {
       assert.deepEqual(expected, actual);
     });
   });
-  // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-a669d28c
-  describe('H=`{}` P=`a=b` ===> T=`"$input.json(\'$\')"`', function() {
-    it('throw error', function() {
-      assert.throws(function() { mappingTemplate({template: "\"$input.json('$')\"", payload: "a=b"}); });
+  // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-0dce6fa3
+  describe('H=`{}` P=`a=b` ===> T=`$input.json(\'$\')`', function() {
+    it('return a=b', function() {
+      var expected = "a=b";
+      var actual = JSON.parse(mappingTemplate({template: "$input.json('$')", payload: "a=b"}));
+      assert.deepEqual(expected, actual);
     });
   });
-  // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-0ce08526
-  describe('H=`{}` P=`"a=b"` ===> T=`"$input.json(\'$\')"`', function() {
-    it('throw error', function() {
-      assert.throws(function() { mappingTemplate({template: "\"$input.json('$')\"", payload: "\"a=b\""}); });
+  // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-dbd6cf1c
+  describe('H=`{}` P=`"a=b"` ===> T=`$input.json(\'$\')`', function() {
+    it('return "a=b"', function() {
+      var expected = "a=b";
+      var actual = JSON.parse(mappingTemplate({template: "$input.json('$')", payload: "\"a=b\""}));
+      assert.deepEqual(expected, actual);
     });
   });
   // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-03be1e25
@@ -48,11 +52,11 @@ describe('$input.path|$input.json', function() {
       assert.deepEqual(expected, actual);
     });
   });
-  // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-c1b4a9a5
-  describe('H=`{}` P=`{}` ===> T=`"$input.json(\'$\')"`', function() {
+  // https://github.com/ToQoz/api-gateway-mapping-template/blob/master/test/_.md#example-b9f18c27
+  describe('H=`{}` P=`{}` ===> T=`$input.json(\'$\')`', function() {
     it('return {}', function() {
-      var expected = "{}";
-      var actual = JSON.parse(mappingTemplate({template: "\"$input.json('$')\"", payload: "{}"}));
+      var expected = {};
+      var actual = JSON.parse(mappingTemplate({template: "$input.json('$')", payload: "{}"}));
       assert.deepEqual(expected, actual);
     });
   });

test/_.md

@@ -8,15 +8,15 @@ Template|Header|Payload|Status code|Result
 --------|------|-------|-----------|------
 `"$input.path('$')"`|`None`|`"a=b"`|`200`|`"a=b"`
 
-## example-a669d28c
+## example-0dce6fa3
 Template|Header|Payload|Status code|Result
 --------|------|-------|-----------|------
-`"$input.json('$')"`|`None`|`a=b`|`200`|`{errorMessage=Unable to parse input as json: Unexpected token a, errorType=SyntaxError}`
+`$input.json('$')`|`None`|`a=b`|`200`|`"a=b"`
 
-## example-0ce08526
+## example-dbd6cf1c
 Template|Header|Payload|Status code|Result
 --------|------|-------|-----------|------
-`"$input.json('$')"`|`None`|`"a=b"`|`200`|`{errorMessage=Unable to parse input as json: Unexpected token a, errorType=SyntaxError}`
+`$input.json('$')`|`None`|`"a=b"`|`200`|`"a=b"`
 
 ## example-03be1e25
 Template|Header|Payload|Status code|Result
@@ -28,10 +28,10 @@ Template|Header|Payload|Status code|Result
 --------|------|-------|-----------|------
 `"$input.path('$')"`|`None`|`"{}"`|`200`|`"{}"`
 
-## example-c1b4a9a5
+## example-b9f18c27
 Template|Header|Payload|Status code|Result
 --------|------|-------|-----------|------
-`"$input.json('$')"`|`None`|`{}`|`200`|`"{}"`
+`$input.json('$')`|`None`|`{}`|`200`|`{}`
 
 ## example-25c6993c
 Template|Header|Payload|Status code|Result