feat(no-sync): Add ignores option (#386)

Co-authored-by: scagood <[email protected]>

Author: aladdin-add

docs/rules/no-sync.md

@@ -10,6 +10,8 @@ This rule is aimed at preventing synchronous methods from being called in Node.j
 
 ### Options
 
+#### allowAtRootLevel
+
 This rule has an optional object option `{ allowAtRootLevel: <boolean> }`, which determines whether synchronous methods should be allowed at the top level of a file, outside of any functions. This option defaults to `false`.
 
 Examples of **incorrect** code for this rule with the default `{ allowAtRootLevel: false }` option:
@@ -56,6 +58,26 @@ Examples of **correct** code for this rule with the `{ allowAtRootLevel: true }`
 fs.readFileSync(somePath).toString();
 ```
 
+#### ignores
+
+You can `ignore` specific function names using this option.
+
+Examples of **incorrect** code for this rule with the `{ ignores: ['readFileSync'] }` option:
+
+```js
+/*eslint n/no-sync: ["error", { ignores: ['readFileSync'] }] */
+
+fs.readdirSync(somePath);
+```
+
+Examples of **correct** code for this rule with the `{ ignores: ['readFileSync'] }` option:
+
+```js
+/*eslint n/no-sync: ["error", { ignores: ['readFileSync'] }] */
+
+fs.readFileSync(somePath);
+```
+
 ## 🔎 Implementation
 
 - [Rule source](../../lib/rules/no-sync.js)

lib/rules/no-sync.js

@@ -4,23 +4,13 @@
  */
 "use strict"
 
-const allowedAtRootLevelSelector = [
+const selectors = [
     // fs.readFileSync()
-    ":function MemberExpression > Identifier[name=/Sync$/]",
     // readFileSync.call(null, 'path')
-    ":function MemberExpression > Identifier[name=/Sync$/]",
+    "CallExpression > MemberExpression.callee Identifier[name=/Sync$/]",
     // readFileSync()
-    ":function :not(MemberExpression) > Identifier[name=/Sync$/]",
-].join(",")
-
-const disallowedAtRootLevelSelector = [
-    // fs.readFileSync()
-    "MemberExpression > Identifier[name=/Sync$/]",
-    // readFileSync.call(null, 'path')
-    "MemberExpression > Identifier[name=/Sync$/]",
-    // readFileSync()
-    ":not(MemberExpression) > Identifier[name=/Sync$/]",
-].join(",")
+    "CallExpression > Identifier[name=/Sync$/]",
+]
 
 /** @type {import('eslint').Rule.RuleModule} */
 module.exports = {
@@ -40,6 +30,11 @@ module.exports = {
                         type: "boolean",
                         default: false,
                     },
+                    ignores: {
+                        type: "array",
+                        items: { type: "string" },
+                        default: [],
+                    },
                 },
                 additionalProperties: false,
             },
@@ -50,17 +45,22 @@ module.exports = {
     },
 
     create(context) {
-        const selector = context.options[0]?.allowAtRootLevel
-            ? allowedAtRootLevelSelector
-            : disallowedAtRootLevelSelector
+        const options = context.options[0] ?? {}
+        const ignores = options.ignores ?? []
 
+        const selector = options.allowAtRootLevel
+            ? selectors.map(selector => `:function ${selector}`)
+            : selectors
         return {
             /**
-             * [node description]
              * @param {import('estree').Identifier & {parent: import('estree').Node}} node
              * @returns {void}
              */
-            [selector](node) {
+            [selector.join(",")](node) {
+                if (ignores.includes(node.name)) {
+                    return
+                }
+
                 context.report({
                     node: node.parent,
                     messageId: "noSync",

tests/lib/rules/no-sync.js

@@ -10,6 +10,10 @@ const rule = require("../../../lib/rules/no-sync")
 new RuleTester().run("no-sync", rule, {
     valid: [
         "var foo = fs.foo.foo();",
+        // Allow non-function called to be ignored
+        "fs.fooSync;",
+        "fooSync;",
+        "() => fooSync;",
         {
             code: "var foo = fs.fooSync;",
             options: [{ allowAtRootLevel: true }],
@@ -26,6 +30,11 @@ new RuleTester().run("no-sync", rule, {
             code: "if (true) {fooSync();}",
             options: [{ allowAtRootLevel: true }],
         },
+        // ignores
+        {
+            code: "fooSync();",
+            options: [{ ignores: ["fooSync"] }],
+        },
     ],
     invalid: [
         {
@@ -90,7 +99,7 @@ new RuleTester().run("no-sync", rule, {
             ],
         },
         {
-            code: "var foo = fs.fooSync;",
+            code: "function someFunction() {fs.fooSync();}",
             errors: [
                 {
                     messageId: "noSync",
@@ -101,6 +110,7 @@ new RuleTester().run("no-sync", rule, {
         },
         {
             code: "function someFunction() {fs.fooSync();}",
+            options: [{ allowAtRootLevel: true }],
             errors: [
                 {
                     messageId: "noSync",
@@ -110,7 +120,7 @@ new RuleTester().run("no-sync", rule, {
             ],
         },
         {
-            code: "function someFunction() {fs.fooSync();}",
+            code: "var a = function someFunction() {fs.fooSync();}",
             options: [{ allowAtRootLevel: true }],
             errors: [
                 {
@@ -120,9 +130,15 @@ new RuleTester().run("no-sync", rule, {
                 },
             ],
         },
+        // ignores
         {
-            code: "var a = function someFunction() {fs.fooSync();}",
-            options: [{ allowAtRootLevel: true }],
+            code: "() => {fs.fooSync();}",
+            options: [
+                {
+                    allowAtRootLevel: true,
+                    ignores: ["barSync"],
+                },
+            ],
             errors: [
                 {
                     messageId: "noSync",