refactor: use selectors instead of code

Author: freaktechnik

lib/helpers/call-expression.js

@@ -13,6 +13,4 @@ const {
 
 exports.isMethod = (node, name) => "callee" in node && node.callee.type === MEMBER_EXPRESSION && node.callee.property.name === name;
 
-exports.getParent = (node) => node.callee.object;
-
 exports.isOnObject = (node, name) => "object" in node.callee && node.callee.object.type === IDENTIFIER && node.callee.object.name === name;

lib/type.js

@@ -7,4 +7,3 @@
 exports.MEMBER_EXPRESSION = "MemberExpression";
 exports.ARROW_FUNCTION_EXPRESSION = "ArrowFunctionExpression";
 exports.IDENTIFIER = "Identifier";
-exports.SPREAD_ELEMENT = "SpreadElement";

rules/avoid-reverse.js

@@ -4,10 +4,7 @@
  */
 "use strict";
 
-const {
-        isMethod,
-        getParent
-    } = require("../lib/helpers/call-expression"),
+const { isMethod } = require("../lib/helpers/call-expression"),
 
     REPLACEMENTS = {
         indexOf: "lastIndexOf",
@@ -27,16 +24,12 @@ module.exports = {
     },
     create(context) {
         return {
-            "CallExpression:exit"(node) {
+            'CallExpression[callee.type="MemberExpression"] > MemberExpression > CallExpression[callee.property.name="reverse"]'(node) {
+                const parent = node;
+                node = parent.parent.parent;
                 if(Object.keys(REPLACEMENTS).every((m) => !isMethod(node, m))) {
                     return;
                 }
-
-                const parent = getParent(node);
-                if(!isMethod(parent, 'reverse')) {
-                    return;
-                }
-
                 const reversed = REPLACEMENTS[node.callee.property.name];
 
                 context.report({

rules/from-map.js

@@ -4,12 +4,7 @@
  */
 "use strict";
 
-const {
-        isMethod,
-        getParent,
-        isOnObject
-    } = require("../lib/helpers/call-expression"),
-    { ARROW_FUNCTION_EXPRESSION } = require("../lib/type");
+const { ARROW_FUNCTION_EXPRESSION } = require("../lib/type");
 
 module.exports = {
     meta: {
@@ -22,16 +17,10 @@ module.exports = {
     },
     create(context) {
         return {
-            "CallExpression:exit"(node) {
-                if(!isMethod(node, "map")) {
-                    return;
-                }
-                const { callee } = node,
-                    parent = getParent(node);
-
-                if(!isMethod(parent, "from") || !isOnObject(parent, "Array")) {
-                    return;
-                }
+            'CallExpression[callee.type="MemberExpression"] > MemberExpression[property.name="map"] > CallExpression[callee.type="MemberExpression"][callee.property.name="from"][callee.object.type="Identifier"][callee.object.name="Array"]'(node) {
+                const parent = node,
+                    callee = node.parent;
+                node = callee.parent;
 
                 context.report({
                     node: callee.property,

rules/prefer-array-from.js

@@ -4,13 +4,10 @@
  */
 "use strict";
 
-const { SPREAD_ELEMENT } = require("../lib/type"),
-
-    SINGLE_ELEMENT = 1,
-    firstElement = (arr) => {
-        const [ el ] = arr;
-        return el;
-    };
+const firstElement = (arr) => {
+    const [ el ] = arr;
+    return el;
+};
 
 module.exports = {
     meta: {
@@ -23,13 +20,10 @@ module.exports = {
     },
     create(context) {
         return {
-            "ArrayExpression:exit"(node) {
-                if(node.elements.length !== SINGLE_ELEMENT || firstElement(node.elements).type !== SPREAD_ELEMENT) {
-                    return;
-                }
+            "ArrayExpression > SpreadElement:first-child:last-child"(node) {
+                node = node.parent;
                 context.report({
                     node,
-                    loc: node.loc,
                     message: "Use Array.from to convert from iterable to array",
                     fix(fixer) {
                         const sourceCode = context.getSourceCode();

test/helpers-call-expression.js

@@ -1,6 +1,6 @@
 import test from 'ava';
 import {
-    isMethod, getParent, isOnObject
+    isMethod, isOnObject
 } from '../lib/helpers/call-expression';
 import {
     MEMBER_EXPRESSION, IDENTIFIER
@@ -39,15 +39,6 @@ test('not is method', (t) => {
     }));
 });
 
-test('get parent', (t) => {
-    const parent = 'foo';
-    t.is(getParent({
-        callee: {
-            object: parent
-        }
-    }), parent);
-});
-
 test('is on object', (t) => {
     const name = 'test';
     t.true(isOnObject({

test/type.js

@@ -1,15 +1,10 @@
 import test from 'ava';
 import {
-    SPREAD_ELEMENT,
     ARROW_FUNCTION_EXPRESSION,
     MEMBER_EXPRESSION,
     IDENTIFIER
 } from '../lib/type';
 
-test('Spread element', (t) => {
-    t.is(SPREAD_ELEMENT, "SpreadElement");
-});
-
 test('Arrow function expression', (t) => {
     t.is(ARROW_FUNCTION_EXPRESSION, "ArrowFunctionExpression");
 });