Deprecate rule no-await-in-loop

README.md

@@ -30,8 +30,6 @@ original ones as well!).
   "rules": {
     "babel/new-cap": 1,
     "babel/object-curly-spacing": 1,
-    "babel/no-await-in-loop": 1,
-    "babel/flow-object-type": 1,
     "babel/no-invalid-this": 1,
     "babel/semi": 1
   }
@@ -41,17 +39,12 @@ original ones as well!).
 
 Each rule corresponds to a core `eslint` rule, and has the same options.
 
-🛠 : means it's autofixable with `--fix`.
+🛠: means it's autofixable with `--fix`.
 
 - `babel/new-cap`: Ignores capitalized decorators (`@Decorator`)
-- `babel/object-curly-spacing`: doesn't complain about `export x from "mod";` or `export * as x from "mod";` (🛠 )
+- `babel/object-curly-spacing`: doesn't complain about `export x from "mod";` or `export * as x from "mod";` (🛠)
 - `babel/no-invalid-this`: doesn't fail when inside class properties (`class A { a = this.b; }`)
-- `babel/semi`: Includes class properties (🛠 )
-
-The following rules are not in `eslint`, but are relevant only to syntax that is not specified by
-the current JavaScript standard or supported by `eslint`.
-
-- `babel/no-await-in-loop`: guard against awaiting async functions inside of a loop
+- `babel/semi`: Includes class properties (🛠)
 
 #### Deprecated
 
@@ -61,3 +54,4 @@ the current JavaScript standard or supported by `eslint`.
 - `babel/func-params-comma-dangle`: Use [`comma-dangle`](http://eslint.org/docs/rules/comma-dangle).
 - `babel/array-bracket-spacing`: Use [`array-bracket-spacing`](http://eslint.org/docs/rules/array-bracket-spacing).
 - `babel/flow-object-type`: Use [`flowtype/object-type-delimiter`](https://github.com/gajus/eslint-plugin-flowtype#eslint-plugin-flowtype-rules-object-type-delimiter).
+- `babel/no-await-in-loop`: Use [`no-await-in-loop`](http://eslint.org/docs/rules/no-await-in-loop).

rules/no-await-in-loop.js

@@ -1,68 +1,24 @@
-/**
- * @fileoverview Rule to disallow uses of await inside of loops.
- * @author Nat Mote
- */
 "use strict";
 
-// Node types which are considered loops.
-var loopTypes = {
-  'ForStatement': true,
-  'ForOfStatement': true,
-  'ForInStatement': true,
-  'WhileStatement': true,
-  'DoWhileStatement': true,
-};
+var isWarnedForDeprecation = false;
+module.exports = {
+    meta: {
+        deprecated: true,
+        schema: []
+    },
+    create: function() {
+        return {
+            Program: function() {
+                if (isWarnedForDeprecation || /\=-(f|-format)=/.test(process.argv.join('='))) {
+                    return;
+                }
 
-// Node types at which we should stop looking for loops. For example, it is fine to declare an async
-// function within a loop, and use await inside of that.
-var boundaryTypes = {
-  'FunctionDeclaration': true,
-  'FunctionExpression': true,
-  'ArrowFunctionExpression': true,
+                /* eslint-disable no-console */
+                console.log('The babel/no-await-in-loop rule is deprecated. Please ' +
+                            'use the built in no-await-in-loop rule instead.');
+                /* eslint-enable no-console */
+                isWarnedForDeprecation = true;
+            }
+        };
+    }
 };
-
-module.exports = function(context) {
-  return {
-    AwaitExpression(node) {
-      var ancestors = context.getAncestors();
-      // Reverse so that we can traverse from the deepest node upwards.
-      ancestors.reverse();
-      // Create a set of all the ancestors plus this node so that we can check
-      // if this use of await appears in the body of the loop as opposed to
-      // the right-hand side of a for...of, for example.
-      //
-      // Implement the set with an Array since there are likely to be very few
-      // elements. An Object would not be appropriate since the elements are
-      // not strings.
-      var ancestorSet = [].concat(ancestors, [node]);
-      var ancestorSetHas = function(element) {
-        return ancestorSet.indexOf(element) !== -1;
-      }
-      for (var i = 0; i < ancestors.length; i++) {
-        var ancestor = ancestors[i];
-        if (boundaryTypes.hasOwnProperty(ancestor.type)) {
-          // Short-circuit out if we encounter a boundary type. Loops above
-          // this do not matter.
-          return;
-        }
-        if (loopTypes.hasOwnProperty(ancestor.type)) {
-          // Only report if we are actually in the body or another part that gets executed on
-          // every iteration.
-          if (
-            ancestorSetHas(ancestor.body) ||
-            ancestorSetHas(ancestor.test) ||
-            ancestorSetHas(ancestor.update)
-          ) {
-            context.report(
-              node,
-              'Avoid using await inside a loop. Consider refactoring to use Promise.all. If ' +
-              'you are sure you want to do this, add `// eslint-disable-line ' +
-              context.id + '` at the end of this line.'
-            );
-            return;
-          }
-        }
-      }
-    },
-  };
-}