feat(functional-parameters): add option to ignore getters and setters

this is true by default

Author: RebeccaStevens

docs/rules/functional-parameters.md

@@ -63,6 +63,7 @@ type Options = {
         count: "atLeastOne" | "exactlyOne";
         ignoreLambdaExpression: boolean;
         ignoreIIFE: boolean;
+        ignoreGettersAndSetters: boolean;
       };
   ignorePattern?: string[] | string;
   ignorePrefixSelector?: string[] | string;
@@ -79,6 +80,7 @@ const defaults = {
     count: "atLeastOne",
     ignoreLambdaExpression: false,
     ignoreIIFE: true,
+    ignoreGettersAndSetters: true,
   },
 };
 ```
@@ -92,6 +94,7 @@ const recommendedOptions = {
   enforceParameterCount: {
     ignoreLambdaExpression: true,
     ignoreIIFE: true,
+    ignoreGettersAndSetters: true,
   },
 };
 ```
@@ -163,6 +166,10 @@ Here, a lambda function expression refers to any function being defined in place
 
 If true, this option allows for the use of [IIFEs](https://developer.mozilla.org/en-US/docs/Glossary/IIFE) that do not have any parameters.
 
+#### `enforceParameterCount.ignoreGettersAndSetters`
+
+Getters should always take zero parameters, and setter one. If for some reason you want to treat these function like any other function, then you can set this option to `false`.
+
 ### `ignorePrefixSelector`
 
 This allows for ignore functions where one of the given selectors matches the parent node in the AST of the function node.\

src/configs/recommended.ts

@@ -22,6 +22,7 @@ const overrides: Linter.Config = {
         enforceParameterCount: {
           ignoreLambdaExpression: true,
           ignoreIIFE: true,
+          ignoreGettersAndSetters: true,
         },
       },
     ],

src/rules/functional-parameters.ts

@@ -23,6 +23,8 @@ import {
 import { createRuleUsingFunction } from "#eslint-plugin-functional/utils/rule";
 import {
   isArgument,
+  isGetter,
+  isSetter,
   isIIFE,
   isPropertyAccess,
   isPropertyName,
@@ -54,6 +56,7 @@ type Options = [
             count: ParameterCountOptions;
             ignoreLambdaExpression: boolean;
             ignoreIIFE: boolean;
+            ignoreGettersAndSetters: boolean;
           };
     },
 ];
@@ -91,6 +94,9 @@ const schema: JSONSchema4[] = [
                   type: "string",
                   enum: ["atLeastOne", "exactlyOne"],
                 },
+                ignoreGettersAndSetters: {
+                  type: "boolean",
+                },
                 ignoreLambdaExpression: {
                   type: "boolean",
                 },
@@ -119,6 +125,7 @@ const defaultOptions: Options = [
       count: "atLeastOne",
       ignoreLambdaExpression: false,
       ignoreIIFE: true,
+      ignoreGettersAndSetters: true,
     },
   },
 ];
@@ -179,7 +186,9 @@ function getParamCountViolations(
     (node.params.length === 0 &&
       typeof enforceParameterCount === "object" &&
       ((enforceParameterCount.ignoreIIFE && isIIFE(node)) ||
-        (enforceParameterCount.ignoreLambdaExpression && isArgument(node))))
+        (enforceParameterCount.ignoreLambdaExpression && isArgument(node)) ||
+        (enforceParameterCount.ignoreGettersAndSetters &&
+          (isGetter(node) || isSetter(node)))))
   ) {
     return [];
   }

src/utils/tree.ts

@@ -207,6 +207,28 @@ export function isArgument(node: TSESTree.Node): boolean {
   );
 }
 
+/**
+ * Is the given node a getter function?
+ */
+export function isGetter(node: TSESTree.Node): boolean {
+  return (
+    node.parent !== undefined &&
+    isProperty(node.parent) &&
+    node.parent.kind === "get"
+  );
+}
+
+/**
+ * Is the given node a setter function?
+ */
+export function isSetter(node: TSESTree.Node): boolean {
+  return (
+    node.parent !== undefined &&
+    isProperty(node.parent) &&
+    node.parent.kind === "set"
+  );
+}
+
 /**
  * Get the key the given node is assigned to in its parent ObjectExpression.
  */

tests/rules/functional-parameters/es2015/valid.ts

@@ -102,6 +102,16 @@ const tests: Array<ValidTestCaseSet<OptionsOf<typeof rule>>> = [
     `,
     optionsSet: [[{ enforceParameterCount: { ignoreLambdaExpression: true } }]],
   },
+  {
+    code: dedent`
+      const foo = {
+        get bar() {
+          return "baz";
+        }
+      }
+    `,
+    optionsSet: [[{ enforceParameterCount: {} }]],
+  },
 ];
 
 export default tests;