feat: Add JSONparseSafe helper (#235)

* feat: Add JSONparseSafe helper

* feat: Update tests

helpers.js

@@ -30,6 +30,7 @@ const helpersList = [
     'join',
     'jsContext',
     'json',
+    'jsonParseSafe',
     'lang',
     'langJson',
     'limit',

helpers/jsonParseSafe.js

@@ -0,0 +1,18 @@
+'use strict';
+
+function factory(globals) {
+  return function (value) {
+    const options = arguments[arguments.length - 1];
+
+    try {
+      return options.fn(JSON.parse(value));
+    } catch (err) {
+      return options.inverse(this);
+    }
+  };
+}
+
+module.exports = [{
+  name: 'JSONparseSafe',
+  factory: factory,
+}];

spec/helpers.js

@@ -146,6 +146,7 @@ describe('helper registration', () => {
             'hasOwn',
             'isObject',
             'merge',
+            'JSONparseSafe',
             'JSONparse',
             'JSONstringify',
             'camelcase',

spec/helpers/jsonParseSafe.js

@@ -0,0 +1,38 @@
+const { describe, it } = exports.lab = require('lab').script();
+
+const { testRunner } = require('../spec-helpers');
+
+describe('JSONParseSafe helper', () => {
+    const context = {
+        jsonString: '{"name": "John"}',
+        string: 'John Doe',
+    };
+    const runTestCases = testRunner({context});
+
+    it('should execute the main instruction', done => {
+        runTestCases([
+            {
+                input: '{{#JSONparseSafe jsonString}}{{name}}{{/JSONparseSafe}}',
+                output: 'John',
+            },
+        ], done);
+    });
+
+    it('should skip the main instruction if variable is non-json', done => {
+        runTestCases([
+            {
+                input: '{{#JSONparseSafe string}}{{name}}{{/JSONparseSafe}}',
+                output: '',
+            },
+        ], done);
+    });
+
+    it('should execute the else instruction if variable is non-json', done => {
+        runTestCases([
+            {
+                input: '{{#JSONparseSafe string}}{{name}}{{else}}{{string}}{{/JSONparseSafe}}',
+                output: 'John Doe',
+            },
+        ], done);
+    });
+});