refactor prefer-is-nil

wix-incubator · Feb 25, 2016 · 00e35b0 · 00e35b0
1 parent 8417432
commit 00e35b0
Showing 1 changed file with 24 additions and 25 deletions.
diff --git a/lib/rules/prefer-is-nil.js b/lib/rules/prefer-is-nil.js
@@ -11,37 +11,37 @@ module.exports = function (context) {
     var astUtil = require('../util/astUtil');
     var lodashUtil = require('../util/lodashUtil');
     var settings = require('../util/settingsUtil').getSettings(context);
+    var _ = require('lodash');
     var nilChecks = {
         null: {
-            isValue: function isNullLiteral(node) {
-                return node.type === 'Literal' && node.value === null;
-            },
-            expressionChecks: [getLodashTypeChecked.bind(null, 'isNull'), getValueComparedToNil.bind(null, 'null')]
+            isValue: _.matches({type: 'Literal', value: null}),
+            expressionChecks: [getLodashTypeCheckedBy('isNull'), getValueComparedTo('null')]
         },
         undefined: {
-            isValue: function isUndefinedIdentifier(node) {
-                return node.type === 'Identifier' && node.name === 'undefined';
-            },
-            expressionChecks: [getLodashTypeChecked.bind(null, 'isUndefined'), getValueComparedToNil.bind(null, 'undefined'), getValueWithTypeofUndefinedComparison]
+            isValue: _.matches({type: 'Identifier', name: 'undefined'}),
+            expressionChecks: [getLodashTypeCheckedBy('isUndefined'), getValueComparedTo('undefined'), getValueWithTypeofUndefinedComparison]
         }
     };
 
-    function getLodashTypeChecked(typecheck, node) {
-        return lodashUtil.isLodashCall(node, settings.pragma) && lodashUtil.isCallToMethod(node, settings.version, typecheck) && node.arguments[0];
+    function getLodashTypeCheckedBy(typecheck) {
+        return function (node) {
+            return lodashUtil.isLodashCallToMethod(node, settings, typecheck) && node.arguments[0];
+        };
     }
 
-    function getValueComparedToNil(nil, node, operator) {
-        return node.type === 'BinaryExpression' && node.operator === operator &&
-            ((nilChecks[nil].isValue(node.right) && node.left) || (nilChecks[nil].isValue(node.left) && node.right));
+    function getValueComparedTo(nil) {
+        return function (node, operator) {
+            return node.type === 'BinaryExpression' && node.operator === operator &&
+                ((nilChecks[nil].isValue(node.right) && node.left) || (nilChecks[nil].isValue(node.left) && node.right));
+        };
     }
 
-    function getTypeofArgument(node) {
-        return node.type === 'UnaryExpression' && node.operator === 'typeof' && node.argument;
-    }
 
-    function isUndefinedString(node) {
-        return node.type === 'Literal' && node.value === 'undefined';
-    }
+    var getTypeofArgument = _.cond([
+        [_.matches({type: 'UnaryExpression', operator: 'typeof'}), _.property('argument')]
+    ]);
+
+    var isUndefinedString = _.matches({type: 'Literal', value: 'undefined'});
 
     function getValueWithTypeofUndefinedComparison(node, operator) {
         return node.type === 'BinaryExpression' && node.operator === operator &&
@@ -50,12 +50,11 @@ module.exports = function (context) {
     }
 
     function checkExpression(nil, operator, node) {
-        var valueCompared;
-        nilChecks[nil].expressionChecks.some(function (check) {
-            valueCompared = check(node, operator);
-            return valueCompared;
-        });
-        return valueCompared;
+        return _(nilChecks[nil].expressionChecks)
+            .map(function (check) {
+                return check(node, operator);
+            })
+            .find();
     }
 
     function checkNegatedExpression(nil, node) {