From cc1cee58b1aec2c9f3d03b659989beaf5d079c9d Mon Sep 17 00:00:00 2001
From: Emily Marigold Klassen <forivall@users.noreply.github.com>
Date: Wed, 25 Nov 2020 17:52:33 -0800
Subject: [PATCH] feat: keep comment-hack keys above preceding key

---
 index.js      | 37 ++++++++++++++++++++++++++++++++++++-
 tests/main.js |  6 ++++++
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 5dcb308e..fa991d47 100755
--- a/index.js
+++ b/index.js
@@ -16,6 +16,7 @@ const uniqAndSortArray = pipe([uniq, sortArray])
 const onObject = (fn) => (x) => (isPlainObject(x) ? fn(x) : x)
 const sortObjectBy = (comparator, deep) => {
   const over = onObject((object) => {
+    // TODO:  check for comments and update comparator accordingly
     object = sortObjectKeys(object, comparator)
     if (deep) {
       for (const [key, value] of Object.entries(object)) {
@@ -132,6 +133,7 @@ const defaultNpmScripts = new Set([
 ])
 
 const sortScripts = onObject((scripts) => {
+  // TODO: apply comments extraction and re-application here.
   const names = Object.keys(scripts)
   const prefixable = new Set()
 
@@ -309,6 +311,7 @@ function editStringJSON(json, over) {
 }
 
 const isPrivateKey = (key) => key[0] === '_'
+const isCommentKey = (key) => key.trim().startsWith('//')
 const partition = (array, predicate) =>
   array.reduce(
     (result, value) => {
@@ -317,21 +320,53 @@ const partition = (array, predicate) =>
     },
     [[], []],
   )
+const removeAndGatherComments = (keys, predicate) =>
+  keys.reduceRight(
+    (result, key) => {
+      const prev = result[0][0]
+      ;(predicate(key)
+        ? result[0].length > 0
+          ? result[1][prev] || (result[1][prev] = [])
+          : result[2]
+        : result[0]
+      ).unshift(key)
+      return result
+    },
+    // 0: non-comment keys and trailing comments
+    // 1: comments that precede a key
+    // 2: trailing comments
+    [[], {}, []],
+  )
 function sortPackageJson(jsonIsh, options = {}) {
   return editStringJSON(
     jsonIsh,
     onObject((json) => {
+      /** @type {string[]} */
       let sortOrder = options.sortOrder ? options.sortOrder : defaultSortOrder
 
       if (Array.isArray(sortOrder)) {
-        const keys = Object.keys(json)
+        const allKeys = Object.keys(json)
+        const [keys, comments, trailing] = removeAndGatherComments(
+          allKeys,
+          isCommentKey,
+        )
         const [privateKeys, publicKeys] = partition(keys, isPrivateKey)
         sortOrder = [
           ...sortOrder,
           ...defaultSortOrder,
           ...publicKeys.sort(),
+          ...trailing,
           ...privateKeys.sort(),
         ]
+        if (allKeys.length !== keys.length) {
+          // re-add comment keys
+          for (let i = sortOrder.length - 1; i >= 0; i--) {
+            const c = comments[sortOrder[i]]
+            if (c) {
+              sortOrder.splice(i, 0, ...c)
+            }
+          }
+        }
       }
 
       return overFields(sortObjectKeys(json, sortOrder))
diff --git a/tests/main.js b/tests/main.js
index 59e31c4b..40bcba68 100644
--- a/tests/main.js
+++ b/tests/main.js
@@ -39,3 +39,9 @@ test('private keys', macro.sortObject, {
   expect: keysToObject(['name', 'a', 'z', '_a', '_z']),
   message: 'Should put private keys at bottom',
 })
+
+test('comment keys', macro.sortObject, {
+  value: keysToObject(['//z', '//x', 'z', ' //name', 'name', 'a', '// end']),
+  expect: keysToObject([' //name', 'name', 'a', '//z', '//x', 'z', '// end']),
+  message: 'Should keep comment keys above preceding key',
+})