Merge pull request #16 from jogold/prefer-both-either

Add prefer-both-either

README.md

@@ -45,6 +45,7 @@ Configure it in `package.json`.
       "ramda/no-redundant-not": "error",
       "ramda/no-redundant-or": "error",
       "ramda/pipe-simplification": "error",
+      "ramda/prefer-both-either": "error",
       "ramda/prefer-complement": "error",
       "ramda/prefer-ramda-boolean": "error",
       "ramda/prop-satisfies-simplification": "error",
@@ -77,6 +78,7 @@ Configure it in `package.json`.
 - `no-redundant-not` - Forbids `not` with 1 parameter in favor of `!`
 - `no-redundant-or` - Forbids `or` with 2 parameters in favor of `||`
 - `pipe-simplification` - Detects when a function that has the same behavior already exists
+- `prefer-both-either` - Enforces using `both`/`either` instead of `allPass`/`anyPass` with a list of only two predicates
 - `prefer-complement` - Enforces using `complement` instead of compositions using `not`
 - `prefer-ramda-boolean` - Enforces using `R.T` and `R.F` instead of explicit functions
 - `prop-satisfies-simplification` - Detects when can replace `propSatisfies` by more simple functions

rules/prefer-both-either.js

@@ -0,0 +1,51 @@
+'use strict';
+const R = require('ramda');
+const ast = require('../ast-helper');
+
+const isCalling = ast.isCalling;
+const getName = ast.getName;
+
+const prefer = {
+    allPass: 'both',
+    anyPass: 'either'
+}
+
+const match = name => isCalling({
+    name,
+    arguments: R.where({
+        0: R.both(
+            R.propEq('type', 'ArrayExpression'),
+            R.pathEq(['elements', 'length'], 2)
+        ),
+    })
+})
+
+const elementsToString = R.pipe(
+    R.prop('elements'),
+    R.map(getName),
+    R.join(', ')
+);
+
+const report = instead => `Instead of \`${instead}\`, prefer \`${prefer[instead]}\` when there are only two predicates`
+
+const create = context => ({
+    CallExpression(node) {
+        if (match('allPass')(node) || match('anyPass')(node)) {
+            const callee = getName(node.callee);
+            context.report({
+                node,
+                message: report(callee)
+            });
+        }
+    }
+});
+
+module.exports = {
+    create,
+    meta: {
+        docs: {
+            description: 'Enforces using `both`/`either` instead of `allPass`/`anyPass` with a list of only two predicates',
+            recommended: 'off'
+        }
+    }
+};

test/prefer-both-either.js

@@ -0,0 +1,65 @@
+import test from 'ava';
+import avaRuleTester from 'eslint-ava-rule-tester';
+import rule from '../rules/prefer-both-either';
+
+const ruleTester = avaRuleTester(test, {
+    env: {
+        es6: true
+    },
+    parserOptions: {
+        sourceType: 'module'
+    }
+});
+
+const prefer = {
+    allPass: 'both',
+    anyPass: 'either'
+}
+
+const error = instead => ({
+    ruleId: 'prefer-both-either',
+    message: `Instead of \`${instead}\`, prefer \`${prefer[instead]}\` when there are only two predicates`
+});
+
+ruleTester.run('prefer-both-either', rule, {
+    valid: [
+        'both(foo, bar)',
+        'either(foo, bar)',
+        'allPass([foo, bar, baz])',
+        'anyPass([foo, bar, baz])',
+        'allPass(predicates)',
+        'allPass(predicates, foo)',
+        'anyPass(predicates)',
+        'anyPass(predicates, foo)'
+    ],
+    invalid: [
+        {
+            code: 'allPass([foo, bar])',
+            errors: [error('allPass')]
+        },
+        {
+            code: 'allPass([foo, bar], baz)',
+            errors: [error('allPass')]
+        },
+        {
+            code: 'allPass([(foo) => !foo, function () { return false; }])',
+            errors: [error('allPass')]
+        },
+        {
+            code: 'allPass([complement(foo), complement(bar)])',
+            errors: [error('allPass')]
+        },
+        {
+            code: 'anyPass([foo, bar])',
+            errors: [error('anyPass')]
+        },
+        {
+            code: 'anyPass([foo, bar], baz)',
+            errors: [error('anyPass')]
+        },
+        {
+            code: 'anyPass([R.T, R.F])',
+            errors: [error('anyPass')]
+        }
+    ]
+});