feat(no-sync): Add ignores option (eslint-community#354)

Author: scagood

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

@@ -30,6 +30,11 @@ module.exports = {
                         type: "boolean",
                         default: false,
                     },
+                    ignores: {
+                        type: "array",
+                        items: { type: "string" },
+                        default: [],
+                    },
                 },
                 additionalProperties: false,
             },
@@ -41,6 +46,7 @@ module.exports = {
 
     create(context) {
         const options = context.options[0] ?? {}
+        const ignores = options.ignores ?? []
 
         const selector = options.allowAtRootLevel
             ? selectors.map(selector => `:function ${selector}`)
@@ -51,6 +57,10 @@ module.exports = {
              * @returns {void}
              */
             [selector.join(",")](node) {
+                if (ignores.includes(node.name)) {
+                    return
+                }
+
                 context.report({
                     node: node.parent,
                     messageId: "noSync",

tests/lib/rules/no-sync.js

@@ -22,6 +22,11 @@ new RuleTester().run("no-sync", rule, {
             code: "if (true) {fooSync();}",
             options: [{ allowAtRootLevel: true }],
         },
+        // ignores
+        {
+            code: "fooSync();",
+            options: [{ ignores: ["fooSync"] }],
+        },
     ],
     invalid: [
         {
@@ -117,5 +122,22 @@ new RuleTester().run("no-sync", rule, {
                 },
             ],
         },
+        // ignores
+        {
+            code: "() => {fs.fooSync();}",
+            options: [
+                {
+                    allowAtRootLevel: true,
+                    ignores: ["barSync"],
+                },
+            ],
+            errors: [
+                {
+                    messageId: "noSync",
+                    data: { propertyName: "fooSync" },
+                    type: "MemberExpression",
+                },
+            ],
+        },
     ],
 })