feat: strigify Maps, Sets and Typed arrays with option es6: true (#3)

Author: epoberezkin

.eslintrc.yml

@@ -1,3 +1,5 @@
+parserOptions:
+  ecmaVersion: 6
 extends: eslint:recommended
 env:
   node: true
@@ -7,7 +9,7 @@ rules:
   no-shadow: 1
   block-scoped-var: 2
   callback-return: 2
-  complexity: [2, 13]
+  complexity: [2, 15]
   curly: [2, multi-or-nest, consistent]
   dot-location: [2, property]
   dot-notation: 2
@@ -27,3 +29,5 @@ rules:
   valid-jsdoc: [2, requireReturn: false]
 globals:
   BigInt: false
+  Map: true
+  Set: true

README.md

@@ -1,7 +1,7 @@
 # json-source-map
 Parse/stringify JSON and provide source-map for JSON-pointers to all nodes.
 
-NEW: BigInt support.
+NEW: supports BigInt, Maps, Sets and Typed arrays.
 
 [![Build Status](https://travis-ci.org/epoberezkin/json-source-map.svg?branch=master)](https://travis-ci.org/epoberezkin/json-source-map)
 [![npm version](https://badge.fury.io/js/json-source-map.svg)](https://www.npmjs.com/package/json-source-map)
@@ -131,6 +131,7 @@ Comparison with the standard `JSON.stringify`:
 
 Options:
 - _space_: same as `space` parameter.
+- _es6_: stringify ES6 Maps, Sets and Typed arrays (as JSON arrays).
 
 
 ## License

index.js

@@ -279,6 +279,7 @@ exports.stringify = function (data, _, options) {
   var line = 0;
   var column = 0;
   var pos = 0;
+  var es6 = options && options.es6 && typeof Map == 'function';
   _stringify(data, 0, '');
   return {
     json: json,
@@ -295,14 +296,24 @@ exports.stringify = function (data, _, options) {
       case 'string':
         out(quoted(_data)); break;
       case 'object':
-        if (_data === null)
+        if (_data === null) {
           out('null');
-        else if (typeof _data.toJSON == 'function')
+        } else if (typeof _data.toJSON == 'function') {
           out(quoted(_data.toJSON()));
-        else if (Array.isArray(_data))
+        } else if (Array.isArray(_data)) {
           stringifyArray();
-        else
+        } else if (es6) {
+          if (_data.constructor.BYTES_PER_ELEMENT)
+            stringifyArray();
+          else if (_data instanceof Map)
+            stringifyMapSet();
+          else if (_data instanceof Set)
+            stringifyMapSet(true);
+          else
+            stringifyObject();
+        } else {
           stringifyObject();
+        }
     }
     map(ptr, 'valueEnd');
 
@@ -350,6 +361,34 @@ exports.stringify = function (data, _, options) {
         out('{}');
       }
     }
+
+    function stringifyMapSet(isSet) {
+      if (_data.size) {
+        out('{');
+        var propLvl = lvl + 1;
+        var first = true;
+        for (var item of _data.entries()) {
+          var key = item[0];
+          var value = isSet ? true : item[1];
+          if (validType(value)) {
+            if (!first) out(',');
+            first = false;
+            var propPtr = ptr + '/' + escapeJsonPointer(key);
+            indent(propLvl);
+            map(propPtr, 'key');
+            out(quoted(key));
+            map(propPtr, 'keyEnd');
+            out(':');
+            if (whitespace) out(' ');
+            _stringify(value, propLvl, propPtr);
+          }
+        }
+        indent(lvl);
+        out('}');
+      } else {
+        out('{}');
+      }
+    }
   }
 
   function out(str) {

spec/.eslintrc.yml

@@ -1,9 +1,8 @@
-parserOptions:
-  ecmaVersion: 6
 rules:
   no-console: 0
   quotes: 0
 globals:
   describe: false
   it: false
   Symbol: false
+  Int8Array: false

spec/index.js

@@ -618,14 +618,51 @@ describe('stringify', function() {
     assert.equal(result.json, '{\n  "foo": "bar"\n}');
   });
 
+  describe('option es6', function() {
+    it('should strigify Maps', function() {
+      var data = new Map;
+      testStringify(data, {}, false, {es6: true});
+
+      data.set('foo', 1);
+      data.set('bar', 2);
+      testStringify(data, {foo: 1, bar: 2}, false, {es6: true});
+      testStringify(data, {foo: 1, bar: 2}, false, {es6: true, space: 2});
+    });
+
+    it('should strigify Sets', function() {
+      var data = new Set;
+      testStringify(data, {}, false, {es6: true});
+
+      data.add('foo');
+      data.add('bar');
+      testStringify(data, {foo: true, bar: true}, false, {es6: true});
+      testStringify(data, {foo: true, bar: true}, false, {es6: true, space: 2});
+    });
+
+    it('should strigify Typed arrays', function() {
+      var data = new Int8Array(2);
+      testStringify(data, [0, 0], false, {es6: true});
+
+      data[0] = 1;
+      data[1] = 2;
+      testStringify(data, [1, 2], false, {es6: true});
+      testStringify(data, [1, 2], false, {es6: true, space: 2});
+    });
+
+    it('should still strigify Objects', function() {
+      testStringify({}, {}, false, {es6: true});
+      testStringify({foo: 1, bar: 2}, {foo: 1, bar: 2}, false, {es6: true});
+    });
+  });
+
   function equal(objects) {
     for (var i=1; i<objects.length; i++)
       assert.deepStrictEqual(objects[0], objects[i]);
   }
 
-  function testStringify(data, reverseData, skipReverseCheck, whitespace) {
+  function testStringify(data, reverseData, skipReverseCheck, options) {
     if (reverseData === undefined) reverseData = data;
-    var result = jsonMap.stringify(data, null, whitespace);
+    var result = jsonMap.stringify(data, null, options);
     var json = result.json;
     var pointers = result.pointers;