✨ isParenthesized supports to check redundant parens

Author: mysticatea

.eslintrc.yml

@@ -6,6 +6,7 @@ extends:
   - plugin:@mysticatea/+node
 
 rules:
+  init-declarations: "off"
   "@mysticatea/node/no-unsupported-features/es-syntax":
     - error
     - ignores:

docs/api/ast-utils.md

@@ -414,7 +414,8 @@ module.exports = {
 ## isParenthesized
 
 ```js
-const ret = utils.isParenthesized(node, sourceCode)
+const ret1 = utils.isParenthesized(times, node, sourceCode)
+const ret2 = utils.isParenthesized(node, sourceCode)
 ```
 
 Check whether a given node is parenthesized or not.
@@ -445,13 +446,16 @@ with ((b)) {}
 
  Name | Type | Description
 :-----|:-----|:------------
+times | number | Optional. The number of redundant parenthesized. Default is `1`.
 node | Node | The node to check.
 sourceCode | SourceCode | The source code object to get tokens.
 
 ### Return value
 
 `true` if the node is parenthesized.
 
+If `times` was given, it returns `true` only if the node is parenthesized the `times` times. For example, `isParenthesized(2, node, sourceCode)` returns `true` for `((foo))`, but not for `(foo)`.
+
 ### Example
 
 ```js{9}

src/is-parenthesized.js

@@ -54,26 +54,55 @@ function getParentSyntaxParen(node, sourceCode) {
     }
 }
 
+/**
+ * Check whether a given node is parenthesized or not.
+ * @param {number} times The number of parantheses.
+ * @param {Node} node The AST node to check.
+ * @param {SourceCode} sourceCode The source code object to get tokens.
+ * @returns {boolean} `true` if the node is parenthesized the given times.
+ */
 /**
  * Check whether a given node is parenthesized or not.
  * @param {Node} node The AST node to check.
  * @param {SourceCode} sourceCode The source code object to get tokens.
  * @returns {boolean} `true` if the node is parenthesized.
  */
-export function isParenthesized(node, sourceCode) {
+export function isParenthesized(
+    timesOrNode,
+    nodeOrSourceCode,
+    optionalSourceCode
+) {
+    let times, node, sourceCode, maybeLeftParen, maybeRightParen
+    if (typeof timesOrNode === "number") {
+        times = timesOrNode | 0
+        node = nodeOrSourceCode
+        sourceCode = optionalSourceCode
+        if (!(times >= 1)) {
+            throw new TypeError("'times' should be a positive integer.")
+        }
+    } else {
+        times = 1
+        node = timesOrNode
+        sourceCode = nodeOrSourceCode
+    }
+
     if (node == null) {
         return false
     }
 
-    const maybeLeftParen = sourceCode.getTokenBefore(node)
-    const maybeRightParen = sourceCode.getTokenAfter(node)
-
-    return (
+    maybeLeftParen = maybeRightParen = node
+    do {
+        maybeLeftParen = sourceCode.getTokenBefore(maybeLeftParen)
+        maybeRightParen = sourceCode.getTokenAfter(maybeRightParen)
+    } while (
         maybeLeftParen != null &&
         maybeRightParen != null &&
         isOpeningParenToken(maybeLeftParen) &&
         isClosingParenToken(maybeRightParen) &&
         // Avoid false positive such as `if (a) {}`
-        maybeLeftParen !== getParentSyntaxParen(node, sourceCode)
+        maybeLeftParen !== getParentSyntaxParen(node, sourceCode) &&
+        --times > 0
     )
+
+    return times === 0
 }

test/is-parenthesized.js

@@ -234,4 +234,80 @@ describe("The 'isParenthesized' function", () => {
             }
         })
     }
+
+    for (const { code, expected } of [
+        {
+            code: "777",
+            expected: {
+                "body.0": false,
+                "body.0.expression": false,
+            },
+        },
+        {
+            code: "(777)",
+            expected: {
+                "body.0": false,
+                "body.0.expression": false,
+            },
+        },
+        {
+            code: "((777))",
+            expected: {
+                "body.0": false,
+                "body.0.expression": true,
+            },
+        },
+        {
+            code: "if (a) ;",
+            expected: {
+                "body.0": false,
+                "body.0.test": false,
+            },
+        },
+        {
+            code: "if ((a)) ;",
+            expected: {
+                "body.0": false,
+                "body.0.test": false,
+            },
+        },
+        {
+            code: "if (((a))) ;",
+            expected: {
+                "body.0": false,
+                "body.0.test": true,
+            },
+        },
+    ]) {
+        describe(`on the code \`${code}\` and 2 times`, () => {
+            for (const key of Object.keys(expected)) {
+                it(`should return ${expected[key]} at "${key}"`, () => {
+                    const linter = new eslint.Linter()
+
+                    let actual = null
+                    linter.defineRule("test", context => ({
+                        Program(node) {
+                            actual = isParenthesized(
+                                2,
+                                dotProp.get(node, key),
+                                context.getSourceCode()
+                            )
+                        },
+                    }))
+                    const messages = linter.verify(code, {
+                        env: { es6: true },
+                        parserOptions: { ecmaVersion: 2018 },
+                        rules: { test: "error" },
+                    })
+
+                    assert.strictEqual(
+                        messages.length,
+                        0,
+                        messages[0] && messages[0].message
+                    )
+                    assert.strictEqual(actual, expected[key])
+                })
+            }
+        })
+    }
 })