From 04dcf163413e476372850895880dc45c4eef065a Mon Sep 17 00:00:00 2001
From: Sergey Sova <ssova@yandex-team.ru>
Date: Fri, 13 Oct 2017 19:45:44 +0300
Subject: [PATCH] Add rule no-magic-numbers

---
 .eslintrc.js     |  7 +++++++
 example/index.js | 16 +++++++++++-----
 readme.md        | 35 ++++++++++++++++++++++++++++++++++-
 3 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/.eslintrc.js b/.eslintrc.js
index 361a25e..7cd73a6 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -17,6 +17,13 @@ module.exports = {
     'semi': ['error', 'never'],
     'no-confusing-arrow': 'off',
 
+    'no-magic-numbers': ['warn', {
+      ignore: [1],
+      ignoreArrayIndexes: true,
+      enforceConst: true,
+      detectObjects: false,
+    }],
+
     'comma-dangle': ['error', {
       arrays: 'always-multiline',
       objects: 'always-multiline',
diff --git a/example/index.js b/example/index.js
index a5df01c..818be9e 100644
--- a/example/index.js
+++ b/example/index.js
@@ -9,18 +9,21 @@ const example = {
   first: 1,
   second: 2,
   'third-e': [
-    1,
-    2,
-    3,
+    '1',
+    '2',
+    '3',
     '4',
   ],
   five,
   four,
 }
 
+const PART_NUM = 12
+
 const inside = resolve(
   example,
   `report${example['third-e'].join(',')}`,
+  `foo${PART_NUM}`,
   reinstall.path
 )
 
@@ -49,11 +52,14 @@ catch (error) {
   example.second = 0
 }
 
+const OFFSET = 12
+const INCR = 0.3
+
 let target = global.meet
   ? 'overrided'
   : 'misleaded'
 
-target = example.first + 12
+target = example.first + OFFSET
 
-export const demo = target * 0.3
+export const demo = target * INCR
 export default example
diff --git a/readme.md b/readme.md
index d7d0198..ff25f9c 100644
--- a/readme.md
+++ b/readme.md
@@ -80,6 +80,39 @@ const x = a => 1 ? 2 : 3
 ```
 
 
+## no-magic-numbers: warn
+
+```js
+{
+  ignore: [1],
+  ignoreArrayIndexes: true,
+  enforceConst: true,
+  detectObjects: false,
+}
+```
+
+https://eslint.org/docs/rules/no-magic-numbers
+
+Magic numbers is not descriptive. Please name it.
+
+Exclude: 1, array indexes, object of numbers.
+
+```js
+// Good
+
+const TAX = 1.28
+const Coeff = {
+  A: 0.924,
+  B: 0.759,
+  C: 0.552,
+  V: 0.308,
+  Z: 0.116,
+}
+const val = myList[5]
+const prev = myList[val.next - 1]
+```
+
+
 ## comma-dangle: error
 
 ```js
@@ -348,7 +381,7 @@ import FooBar from './foo-bar' // Correct import. But not solved by rule
 ## unicorn/catch-error-name: error
 
 ```js
-{ name: 'error }
+{ name: 'error' }
 ```
 
 https://github.com/sindresorhus/eslint-plugin-unicorn/blob/master/docs/rules/catch-error-name.md