ACT-362 Brackets Support (#993)

* add support for brackets inside js keys in get method

* add double quotes

* explanatory text + new link

* safari support

* remove invalid bracket test since it is now supported

* use class based regex to avoid parseError

* actually convert the regex correctly

* cleanup

* split tests by functionality

packages/core/src/__tests__/get.iso.test.ts

@@ -10,7 +10,11 @@ const obj = {
     },
     h: null
   },
-  u: undefined
+  u: undefined,
+  '[txt] non': true,
+  '[txt] nest': {
+    inner: true
+  }
 }
 
 const fixtures: Record<string, unknown> = {
@@ -27,6 +31,10 @@ const fixtures: Record<string, unknown> = {
   u: undefined
 }
 
+/** note that this test is basically a duplicate of the get.test.ts file,
+ * only with the tests that safari can't handle due to its lack of lookbehind (ES2018)
+ * grouping removed so it passes in webkit */
+
 describe('get', () => {
   for (const path of Object.keys(fixtures)) {
     test(`"${path}"`, () => {

packages/core/src/__tests__/get.test.ts

@@ -0,0 +1,44 @@
+import { get } from '../get'
+
+const obj = {
+  a: {
+    b: {
+      c: 42,
+      d: true,
+      e: 'hello',
+      f: [{ g: 'yay' }, { g: 'nay' }]
+    },
+    h: null
+  },
+  u: undefined,
+  '[txt] non': true,
+  '[txt] nest': {
+    inner: true
+  }
+}
+
+const fixtures: Record<string, unknown> = {
+  '': obj,
+  a: obj.a,
+  'a.b': obj.a.b,
+  "['a'].b": obj.a.b,
+  '["a"].b': obj.a.b,
+  'a.b.c': obj.a.b.c,
+  'a.b.d': obj.a.b.d,
+  'a.b.e': obj.a.b.e,
+  'a.b.f[0]': obj.a.b.f[0],
+  'a.b.f[0].g': obj.a.b.f[0].g,
+  'a.h': obj.a.h,
+  'a.b.x': undefined,
+  '[txt] non': true,
+  '[txt] nest.inner': true,
+  u: undefined
+}
+
+describe('get', () => {
+  for (const path of Object.keys(fixtures)) {
+    test(`"${path}"`, () => {
+      expect(get(obj, path)).toEqual(fixtures[path])
+    })
+  }
+})

packages/core/src/get.ts

@@ -2,6 +2,17 @@
  * Lightweight alternative to lodash.get with similar coverage
  * Supports basic path lookup via dot notation `'foo.bar[0].baz'` or an array ['foo', 'bar', '0', 'baz']
  */
+
+let arrayRe: RegExp
+
+try {
+  arrayRe = new RegExp(`\\[(?="|'|\\d)|\\.|(?<="|'|\\d)]+`, 'g')
+} catch (e) {
+  //safari does not support lookbehind operator so we will default
+  //to a simpler approach wherein [bar] will not be a valid key
+  arrayRe = /\[|\.|]+/g
+}
+
 export function get<T = unknown>(
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   obj: any,
@@ -13,9 +24,17 @@ export function get<T = unknown>(
   // Not defined
   if (path === null || path == undefined) return undefined
 
-  // Check if path is string or array. Regex : ensure that we do not have '.' and brackets.
-  // Regex explained: https://regexr.com/58j0k
-  const pathArray = Array.isArray(path) ? path : (path.match(/([^[.\]])+/g) as string[])
+  // Check if path is string or array. Regex : splits the path into valid array of path chunks
+  // we support an extra edge case that lodash does not around brackets
+  // a['b'] = ['a','b']
+  // a[b] = ['a[b]'] //brackets without numeric index or a string are considered part of the key
+  // Regex explained: https://regexr.com/74m2m
+  const pathArray = Array.isArray(path)
+    ? path
+    : path
+        .split(arrayRe)
+        .filter((f) => f)
+        .map((s) => s.replace(/'|"/g, ''))
 
   // Find value if exist return otherwise return undefined value
   return pathArray.reduce((prevObj, key) => prevObj && prevObj[key], obj)

packages/core/src/mapping-kit/__tests__/index.iso.test.ts

@@ -520,20 +520,6 @@ describe('@path', () => {
     expect(output).toStrictEqual({ neat: 'bar' })
   })
 
-  test('invalid bracket-spaced nested value', () => {
-    const output = transform(
-      { neat: { '@path': "$.integrations['Actions Amplitude'].session_id" } },
-      {
-        integrations: {
-          'Actions Amplitude': {
-            session_id: 'bar'
-          }
-        }
-      }
-    )
-    expect(output).toStrictEqual({})
-  })
-
   test('invalid nested value type', () => {
     const output = transform({ neat: { '@path': '$.foo.bar.baz' } }, { foo: 'bar' })
     expect(output).toStrictEqual({})