From 5c27fed594a3cff7c10ecebf52b064f9d8d2801b Mon Sep 17 00:00:00 2001
From: rubeniskov <me@rubeniskov.com>
Date: Mon, 23 Nov 2020 23:24:51 +0100
Subject: [PATCH] feat: add traverse recursively through the same key

---
 index.js | 42 ++++++++++++++++++++++++++++++++++--------
 test.js  | 20 ++++++++++++++++++++
 utils.js |  5 ++++-
 3 files changed, 58 insertions(+), 9 deletions(-)

diff --git a/index.js b/index.js
index 1d032d7..a986536 100644
--- a/index.js
+++ b/index.js
@@ -3,6 +3,8 @@ const {
   createMatcher,
   wrapIterator,
   entries,
+  formatJsonPath,
+  JSONPATH_SEP,
 } = require('./utils');
 
 /**
@@ -133,34 +135,57 @@ const {
  * [ '/nested/nested/nested/depth', 3 ]
  * [ '/nested/nested/nested/nested/depth', 4 ]
  * ```
+ * __{ [test](#traversejsonoptions--object): "@nested" }__
+ * ```
+ * [ '/nested',
+ *   { depth: 1, nested: { depth: 2, nested: [Object] } } ]
+ * [ '/nested/nested',
+ *   { depth: 2, nested: { depth: 3, nested: [Object] } } ]
+ * [ '/nested/nested/nested', { depth: 3, nested: { depth: 4 } } ]
+ * [ '/nested/nested/nested/nested', { depth: 4 } ]
+ * ```
  */
 const traverseJson = (obj, opts) => {
-  const {
+  let {
     recursive = true,
     nested = false,
     test = null,
     step = 1,
   } = { ...opts };
 
-  let filter = createMatcher(test);
+  let rkey;
+  let filter;
   let overall = [];
   let cursor = 0;
 
+  if (typeof test === 'string' && test[0] === '@') {
+    rkey = test.substring(1);
+    nested = true;
+    filter = false;
+  } else {
+    filter = createMatcher(test);
+  }
+
   const dive = (value, prefix) => {
-    const remain = overall.slice(cursor + 1);
+    if (rkey) {
+      overall = value[rkey] !== undefined
+        ? [[formatJsonPath(prefix, rkey), value[rkey]]]
+        : [];
+    } else {
+      const remain = overall.slice(cursor + 1);
 
-    overall = entries(value, prefix);
+      overall = entries(value, prefix);
 
-    for(let i = 0; i < remain.length; i++) {
-      overall.push(remain[i]);
+      for(let i = 0; i < remain.length; i++) {
+        overall.push(remain[i]);
+      }
+      cursor = 0;
     }
-    return overall[cursor = 0];
   };
 
   dive(obj);
 
   const next = () => {
-
     if (cursor < overall.length) {
       let entry = overall[cursor];
       if (recursive) {
@@ -239,3 +264,4 @@ const createIterator = (obj, opts) => {
 
 module.exports = traverseJson;
 module.exports.createIterator = createIterator;
+module.exports.JSONPATH_SEP = JSONPATH_SEP;
diff --git a/test.js b/test.js
index 35f61e7..7e1290c 100644
--- a/test.js
+++ b/test.js
@@ -229,6 +229,26 @@ test('should iterate filtering with minimatch through the entries of the given n
   iterateEqual(t, ientries, expected, true);
 });
 
+test('should iterate recursively through the same key', (t) => {
+
+  const expected = [
+    ['/nested', recursiveObject.nested],
+    ['/nested/nested', recursiveObject.nested.nested],
+    ['/nested/nested/nested', recursiveObject.nested.nested.nested],
+    ['/nested/nested/nested/nested', recursiveObject.nested.nested.nested.nested],
+  ];
+
+  const merged = {
+    ...recursiveObject, ...nestedObject,
+  };
+
+  const ientries = traverseObject(merged, {
+    test: '@nested',
+  });
+
+  iterateEqual(t, ientries, expected, true);
+});
+
 test('should works as iterable', (t) => {
 
   const { createIterator } = traverseObject;
diff --git a/utils.js b/utils.js
index 76f0c1c..00836c6 100644
--- a/utils.js
+++ b/utils.js
@@ -1,6 +1,8 @@
 const { isPlainObject } = require('is-plain-object');
 const minimatch = require('minimatch');
 
+const JSONPATH_SEP = '/';
+
 const isTraversable = (value) => Array.isArray(value) || isPlainObject(value);
 
 const createMatcher = (test) => {
@@ -15,7 +17,7 @@ const createMatcher = (test) => {
   return test && test.test ? ([path]) => test.test(path) : test;
 };
 
-const formatJsonPath = (prefix, key) => [prefix, key].join('/');
+const formatJsonPath = (prefix, key) => [prefix, key].join(JSONPATH_SEP);
 
 /**
  * Wraps a function iteratior to become an iterable
@@ -45,5 +47,6 @@ module.exports = {
   isTraversable,
   createMatcher,
   wrapIterator,
+  formatJsonPath,
   entries,
 };