From 6222559f20004338b11ea2ea951a089290fc1673 Mon Sep 17 00:00:00 2001
From: Renato Oliveira <renato.oliveira@dogeforce.com>
Date: Mon, 16 May 2022 09:50:18 -0300
Subject: [PATCH] Replaces index test with generic exception handling that
 returns null. Adds more tests, for invalid and longer indexes.

---
 force-app/main/default/classes/JSONPath.cls   | 27 +++++---------
 .../main/default/classes/JSONPathTest.cls     | 37 +++++++++++++------
 2 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/force-app/main/default/classes/JSONPath.cls b/force-app/main/default/classes/JSONPath.cls
index 1c1fabd..c515d4f 100644
--- a/force-app/main/default/classes/JSONPath.cls
+++ b/force-app/main/default/classes/JSONPath.cls
@@ -8,7 +8,12 @@ public class JSONPath {
     }
 
     public Object get(String path) {
-        return this.get(path.removeStart('$'), this.data);
+        try {
+            Object o = this.get(path.removeStart('$'), this.data);
+            return o;
+        } catch (Exception e) {
+            return null;
+        }
     }
 
     private Object get(String path, Object data) {
@@ -39,7 +44,7 @@ public class JSONPath {
         if (currentLevel.endsWith(']')) {
             return this.get(
                 ('[' +
-                currentLevel.reverse().substringBetween(']', '[') +
+                currentLevel.reverse().substringBetween(']', '[').reverse() +
                 '].' +
                 String.join(levels, '.')),
                 d.get(currentLevel.split('\\[').remove(0))
@@ -65,32 +70,20 @@ public class JSONPath {
                         this.get(String.join(levels, '.'), objectInstance)
                     );
                 }
-                System.debug(result);
                 return result;
             }
             return dataList;
         }
 
-        Integer index = getIndex(currentLevel);
+        Integer index = Integer.valueOf(
+            currentLevel.substringBetween('[', ']')
+        );
 
         return levels.size() == 0
             ? dataList.get(index)
             : this.get(String.join(levels, '.'), dataList.get(index));
     }
 
-    private Integer getIndex(String currentLevel) {
-        String indexStr = currentLevel.substringBetween('[', ']');
-
-        if (indexStr == null) {
-            String m = 'Invalid path.';
-            JSONPathException e = new JSONPathException(m);
-            e.setMessage(m);
-            throw e;
-        }
-
-        return Integer.valueOf(indexStr);
-    }
-
     public class JSONPathException extends Exception {
     }
 }
diff --git a/force-app/main/default/classes/JSONPathTest.cls b/force-app/main/default/classes/JSONPathTest.cls
index 2561733..e293ee5 100644
--- a/force-app/main/default/classes/JSONPathTest.cls
+++ b/force-app/main/default/classes/JSONPathTest.cls
@@ -5,11 +5,7 @@ private class JSONPathTest {
         JSONPath jpObject = new JSONPath(
             '{"name":"John","company":{"name":"Company"}}'
         );
-        System.assertEquals(
-            'John',
-            jpObject.get('$.name'),
-            'Incorrect data.'
-        );
+        System.assertEquals('John', jpObject.get('$.name'), 'Incorrect data.');
         System.assertEquals(
             'Company',
             jpObject.get('$.company.name'),
@@ -18,11 +14,7 @@ private class JSONPathTest {
         JSONPath jpList = new JSONPath(
             '[{"name":"John","company":{"name":"Company"}}]'
         );
-        System.assertEquals(
-            'John',
-            jpList.get('$[0].name'),
-            'Incorrect data.'
-        );
+        System.assertEquals('John', jpList.get('$[0].name'), 'Incorrect data.');
         System.assert(
             jpList.get('$[]') instanceof List<Object>,
             'Should be a list.'
@@ -46,7 +38,9 @@ private class JSONPathTest {
         JSONPath jpAttributeListFromObjectList = new JSONPath(
             '[{"name":"John"},{"name":"Mary"}]'
         );
-        List<Object> names = (List<Object>) jpAttributeListFromObjectList.get('$[].name');
+        List<Object> names = (List<Object>) jpAttributeListFromObjectList.get(
+            '$[].name'
+        );
         System.assert(
             names[0] == 'John' &&
             names[1] == 'Mary',
@@ -55,11 +49,30 @@ private class JSONPathTest {
         JSONPath jpAttributeListFromInnerObjectList = new JSONPath(
             '{"people":[{"name":"John"},{"name":"Mary"}]}}'
         );
-        names = (List<Object>) jpAttributeListFromInnerObjectList.get('$.people[].name');
+        names = (List<Object>) jpAttributeListFromInnerObjectList.get(
+            '$.people[].name'
+        );
         System.assert(
             names[0] == 'John' &&
             names[1] == 'Mary',
             'Should have returned a list of names.'
         );
+        JSONPath invalidPath = new JSONPath(
+            '{"messages":["Hello, world!", "Goodbye, world!"]}'
+        );
+        System.assertEquals(
+            null,
+            invalidPath.get('$.messages[-1]'),
+            'Should have returned null for invalid path.'
+        );
+
+        JSONPath twoDigitsList = new JSONPath(
+            '{"integers":[0,1,2,3,4,5,6,7,8,9,10]}'
+        );
+        System.assertEquals(
+            10,
+            twoDigitsList.get('$.integers[10]'),
+            'Should have returned 10.'
+        );
     }
 }