[eslint config] [base] [breaking] Prevent line breaks before and after =

Author: sharmilajesupaul

README.md

@@ -1699,6 +1699,28 @@ Other Style Guides
     const truthyCount = array.filter(Boolean).length;
     ```
 
+  - [13.7](#variables--linebreak) Avoid linebreaks before or after `=` in an assignment. If your assignment violates [`max-len`](https://eslint.org/docs/rules/max-len.html), surround the value in parens. eslint [`operator-linebreak`](https://eslint.org/docs/rules/operator-linebreak.html).
+
+    > Why? Linebreaks surrounding `=` can obfuscate the value of an assignment.
+
+    ```javascript
+    // bad
+    const foo =
+      superLongLongLongLongLongLongLongLongFunctionName();
+
+    // bad
+    const foo
+      = 'superLongLongLongLongLongLongLongLongString';
+
+    // good
+    const foo = (
+      superLongLongLongLongLongLongLongLongFunctionName()
+    );
+
+    // good
+    const foo = 'superLongLongLongLongLongLongLongLongString';
+    ```
+
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 ## Hoisting

packages/eslint-config-airbnb-base/rules/style.js

@@ -405,7 +405,7 @@ module.exports = {
 
     // Requires operator at the beginning of the line in multiline statements
     // https://eslint.org/docs/rules/operator-linebreak
-    'operator-linebreak': ['error', 'before'],
+    'operator-linebreak': ['error', 'before', { overrides: { '=': 'none' } }],
 
     // disallow padding within blocks
     'padded-blocks': ['error', { blocks: 'never', classes: 'never', switches: 'never' }],