fixes #27: array (patch): clean up source comments

Author: kaelzhang

src/array.js

@@ -7,7 +7,7 @@ const {
   UNDEFINED,
 
   symbol,
-  copy_all_comments,
+  copy_comments,
   swap_comments
 } = require('./common')
 
@@ -23,7 +23,7 @@ const reverse_comments = array => {
 }
 
 const move_comment = (target, source, i, offset, remove) => {
-  copy_all_comments(target, source, i + offset, i, remove)
+  copy_comments(target, source, i + offset, i, remove)
 }
 
 const move_comments = (
@@ -50,13 +50,12 @@ const move_comments = (
 
     // From [count - 1, 0]
     while (i -- > 0) {
-      move_comment(target, source, start + i, offset, remove && i < offset)
+      move_comment(target, source, start + i, offset, remove)
     }
     return
   }
 
   let i = 0
-  const min_remove = count + offset
   // | remove  |  count    |
   //           -------------
   // -------------
@@ -65,10 +64,17 @@ const move_comments = (
   // From [0, count - 1]
   while (i < count) {
     const ii = i ++
-    move_comment(target, source, start + ii, offset, remove && i >= min_remove)
+    move_comment(target, source, start + ii, offset, remove)
   }
 }
 
+const remove_comments = (array, key) => {
+  SYMBOL_PREFIXES.forEach(prefix => {
+    const prop = symbol(prefix, key)
+    delete array[prop]
+  })
+}
+
 const get_mapped = (map, key) => {
   let mapped = key
 
@@ -178,6 +184,7 @@ class CommentArray extends Array {
     const ret = super.shift()
     const {length} = this
 
+    remove_comments(this, 0)
     move_comments(this, this, 1, length, - 1, true)
 
     return ret
@@ -195,11 +202,7 @@ class CommentArray extends Array {
     const ret = super.pop()
 
     // Removes comments
-    const {length} = this
-    SYMBOL_PREFIXES.forEach(prefix => {
-      const prop = symbol(prefix, length)
-      delete this[prop]
-    })
+    remove_comments(this, this.length)
 
     return ret
   }

src/common.js

@@ -45,7 +45,7 @@ const define = (target, key, value) => Object.defineProperty(target, key, {
   configurable: true
 })
 
-const copy_comments = (
+const copy_comments_by_kind = (
   target, source, target_key, source_key, prefix, remove_source
 ) => {
   const source_prop = symbol(prefix, source_key)
@@ -64,11 +64,13 @@ const copy_comments = (
   }
 }
 
-const copy_all_comments = (
+const copy_comments = (
   target, source, target_key, source_key, remove_source
 ) => {
   SYMBOL_PREFIXES.forEach(prefix => {
-    copy_comments(target, source, target_key, source_key, prefix, remove_source)
+    copy_comments_by_kind(
+      target, source, target_key, source_key, prefix, remove_source
+    )
   })
 }
 
@@ -80,14 +82,14 @@ const swap_comments = (array, from, to) => {
   SYMBOL_PREFIXES.forEach(prefix => {
     const target_prop = symbol(prefix, to)
     if (!hasOwnProperty(array, target_prop)) {
-      copy_comments(array, array, to, from, prefix, true)
+      copy_comments_by_kind(array, array, to, from, prefix, true)
       return
     }
 
     const comments = array[target_prop]
     delete array[target_prop]
 
-    copy_comments(array, array, to, from, prefix, true)
+    copy_comments_by_kind(array, array, to, from, prefix, true)
     define(array, symbol(prefix, from), comments)
   })
 }
@@ -110,7 +112,7 @@ const assign = (target, source, keys) => {
     }
 
     target[key] = source[key]
-    copy_all_comments(target, source, key, key)
+    copy_comments(target, source, key, key)
   })
 
   return target
@@ -144,7 +146,6 @@ module.exports = {
   symbol,
   define,
   copy_comments,
-  copy_all_comments,
   swap_comments,
   assign_non_prop_comments,
 

test/array.test.js

@@ -152,6 +152,19 @@ const CASES = [
     array => array.slice(0, 1),
     slice([0], a3)
   ],
+  [
+    'slice(0, 1), no mess',
+    `[
+  // 0
+  0,
+  1 // 1
+]`,
+    array => array.slice(0, 1),
+    slice([0], `[
+  // 0
+  0
+]`)
+  ],
   [
     'unshift()',
     a1,
@@ -181,6 +194,20 @@ const CASES = [
   1,
   // 2
   2
+]`)
+  ],
+  [
+    'shift, no mess',
+    `[
+  // 0
+  0,
+  1 /* 1 */,
+  2 // 2
+]`,
+    array => array.shift(),
+    unshift(0, `[
+  1 /* 1 */,
+  2 // 2
 ]`)
   ],
   [