feat(functional-parameters): add support for ignoring selector prefixes

re #207 re #244

docs/rules/functional-parameters.md

@@ -56,6 +56,7 @@ type Options = {
     ignoreIIFE: boolean;
   };
   ignorePattern?: string[] | string;
+  ignorePrefixSelector?: string[] | string;
 }
 ```
 
@@ -68,7 +69,8 @@ const defaults = {
   enforceParameterCount: {
     count: "atLeastOne",
     ignoreIIFE: true
-  }
+  },
+  ignorePrefixSelector: undefined,
 }
 ```
 
@@ -78,7 +80,8 @@ Note: the `lite` ruleset overrides the default options to:
 const liteDefaults = {
   allowRestParameter: false,
   allowArgumentsKeyword: false,
-  enforceParameterCount: false
+  enforceParameterCount: false,
+  ignorePrefixSelector: undefined,
 }
 ```
 
@@ -136,6 +139,31 @@ See [enforceParameterCount](#enforceparametercount).
 
 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.
 
+### `ignorePrefixSelector`
+
+This allows for ignore functions where one of the given selectors matches the parent node in the AST of the function node.\
+For more information see [ESLint Selectors](https://eslint.org/docs/developer-guide/selectors).
+
+Example:
+
+With the following config:
+
+```json
+{
+  "enforceParameterCount": "exactlyOne",
+  "ignorePrefixSelector": "CallExpression[callee.property.name='reduce']"
+},
+```
+
+The following inline callback won't be flaged:
+
+```js
+const sum = [1, 2, 3].reduce(
+  (carry, current) => current,
+  0
+);
+```
+
 ### `ignorePattern`
 
 Patterns will be matched against function names.

src/common/ignore-options.ts

@@ -109,6 +109,23 @@ export const ignoreInterfaceOptionSchema: JSONSchema4 = {
   additionalProperties: false,
 };
 
+export type IgnorePrefixSelectorOption = {
+  readonly ignorePrefixSelector?: ReadonlyArray<string> | string;
+};
+
+export const ignorePrefixSelectorOptionSchema: JSONSchema4 = {
+  type: "object",
+  properties: {
+    ignorePrefixSelector: {
+      type: ["string", "array"],
+      items: {
+        type: "string",
+      },
+    },
+  },
+  additionalProperties: false,
+};
+
 /**
  * Get the identifier text of the given node.
  */

src/rules/functional-parameters.ts

@@ -2,13 +2,17 @@ import type { TSESTree } from "@typescript-eslint/experimental-utils";
 import { deepmerge } from "deepmerge-ts";
 import type { JSONSchema4 } from "json-schema";
 
-import type { IgnorePatternOption } from "~/common/ignore-options";
+import type {
+  IgnorePatternOption,
+  IgnorePrefixSelectorOption,
+} from "~/common/ignore-options";
 import {
   shouldIgnorePattern,
   ignorePatternOptionSchema,
+  ignorePrefixSelectorOptionSchema,
 } from "~/common/ignore-options";
 import type { RuleContext, RuleMetaData, RuleResult } from "~/util/rule";
-import { createRule } from "~/util/rule";
+import { createRuleUsingFunction } from "~/util/rule";
 import { isIIFE, isPropertyAccess, isPropertyName } from "~/util/tree";
 import { isRestElement } from "~/util/typeguard";
 
@@ -18,21 +22,22 @@ export const name = "functional-parameters" as const;
 type ParameterCountOptions = "atLeastOne" | "exactlyOne";
 
 // The options this rule can take.
-type Options = IgnorePatternOption & {
-  readonly allowRestParameter: boolean;
-  readonly allowArgumentsKeyword: boolean;
-  readonly enforceParameterCount:
-    | ParameterCountOptions
-    | false
-    | {
-        readonly count: ParameterCountOptions;
-        readonly ignoreIIFE: boolean;
-      };
-};
+type Options = IgnorePatternOption &
+  IgnorePrefixSelectorOption & {
+    readonly allowRestParameter: boolean;
+    readonly allowArgumentsKeyword: boolean;
+    readonly enforceParameterCount:
+      | ParameterCountOptions
+      | false
+      | {
+          readonly count: ParameterCountOptions;
+          readonly ignoreIIFE: boolean;
+        };
+  };
 
 // The schema for the rule options.
 const schema: JSONSchema4 = [
-  deepmerge(ignorePatternOptionSchema, {
+  deepmerge(ignorePatternOptionSchema, ignorePrefixSelectorOptionSchema, {
     type: "object",
     properties: {
       allowRestParameter: {
@@ -232,14 +237,33 @@ function checkIdentifier(
 }
 
 // Create the rule.
-export const rule = createRule<keyof typeof errorMessages, Options>(
-  name,
-  meta,
-  defaultOptions,
-  {
-    FunctionDeclaration: checkFunction,
-    FunctionExpression: checkFunction,
-    ArrowFunctionExpression: checkFunction,
+export const rule = createRuleUsingFunction<
+  keyof typeof errorMessages,
+  Options
+>(name, meta, defaultOptions, (context, options) => {
+  const baseFunctionSelectors = [
+    "FunctionDeclaration",
+    "FunctionExpression",
+    "ArrowFunctionExpression",
+  ];
+
+  const ignoreSelectors: ReadonlyArray<string> | undefined =
+    options.ignorePrefixSelector === undefined
+      ? undefined
+      : Array.isArray(options.ignorePrefixSelector)
+      ? options.ignorePrefixSelector
+      : [options.ignorePrefixSelector];
+
+  const fullFunctionSelectors = baseFunctionSelectors.flatMap((baseSelector) =>
+    ignoreSelectors === undefined
+      ? [baseSelector]
+      : `:not(:matches(${ignoreSelectors.join(",")})) > ${baseSelector}`
+  );
+
+  return {
+    ...Object.fromEntries(
+      fullFunctionSelectors.map((selector) => [selector, checkFunction])
+    ),
     Identifier: checkIdentifier,
-  }
-);
+  };
+});

src/util/rule.ts

@@ -89,6 +89,29 @@ export function createRule<
   meta: RuleMetaData<MessageIds>,
   defaultOptions: Options,
   ruleFunctionsMap: RuleFunctionsMap<MessageIds, Options>
+): Rule.RuleModule {
+  return createRuleUsingFunction(
+    name,
+    meta,
+    defaultOptions,
+    () => ruleFunctionsMap
+  );
+}
+
+/**
+ * Create a rule.
+ */
+export function createRuleUsingFunction<
+  MessageIds extends string,
+  Options extends BaseOptions
+>(
+  name: string,
+  meta: RuleMetaData<MessageIds>,
+  defaultOptions: Options,
+  createFunction: (
+    context: TSESLint.RuleContext<MessageIds, readonly [Options]>,
+    options: Options
+  ) => RuleFunctionsMap<MessageIds, Options>
 ): Rule.RuleModule {
   return ESLintUtils.RuleCreator(
     (name) =>
@@ -100,13 +123,15 @@ export function createRule<
     create: (
       context: TSESLint.RuleContext<MessageIds, readonly [Options]>,
       [options]: readonly [Options]
-    ) =>
-      Object.fromEntries(
+    ) => {
+      const ruleFunctionsMap = createFunction(context, options);
+      return Object.fromEntries(
         Object.entries(ruleFunctionsMap).map(([nodeSelector, ruleFunction]) => [
           nodeSelector,
           checkNode(ruleFunction, context, options),
         ])
-      ),
+      );
+    },
     /* eslint-disable-next-line @typescript-eslint/no-explicit-any */
   } as any) as any;
 }

tests/rules/functional-parameters/es3/invalid.ts

@@ -99,6 +99,37 @@ const tests: ReadonlyArray<InvalidTestCase> = [
       },
     ],
   },
+  {
+    code: dedent`
+      [1, 2, 3]
+        .map(
+          function(element, index) {
+            return element + index;
+          }
+        )
+        .reduce(
+          function(carry, current) {
+            return carry + current;
+          },
+          0
+        );
+    `,
+    optionsSet: [[{ enforceParameterCount: "exactlyOne" }]],
+    errors: [
+      {
+        messageId: "paramCountExactlyOne",
+        type: "FunctionExpression",
+        line: 3,
+        column: 5,
+      },
+      {
+        messageId: "paramCountExactlyOne",
+        type: "FunctionExpression",
+        line: 8,
+        column: 5,
+      },
+    ],
+  },
 ];
 
 export default tests;

tests/rules/functional-parameters/es3/valid.ts

@@ -42,6 +42,69 @@ const tests: ReadonlyArray<ValidTestCase> = [
       [{ ignorePattern: "^foo", enforceParameterCount: "exactlyOne" }],
     ],
   },
+  {
+    code: dedent`
+      [1, 2, 3].reduce(
+        function(carry, current) {
+          return carry + current;
+        },
+        0
+      );
+    `,
+    optionsSet: [
+      [
+        {
+          ignorePrefixSelector: "CallExpression[callee.property.name='reduce']",
+          enforceParameterCount: "exactlyOne",
+        },
+      ],
+    ],
+  },
+  {
+    code: dedent`
+      [1, 2, 3].map(
+        function(element, index) {
+          return element + index;
+        },
+        0
+      );
+    `,
+    optionsSet: [
+      [
+        {
+          enforceParameterCount: "exactlyOne",
+          ignorePrefixSelector: "CallExpression[callee.property.name='map']",
+        },
+      ],
+    ],
+  },
+  {
+    code: dedent`
+      [1, 2, 3]
+        .map(
+          function(element, index) {
+            return element + index;
+          }
+        )
+        .reduce(
+          function(carry, current) {
+            return carry + current;
+          },
+          0
+        );
+    `,
+    optionsSet: [
+      [
+        {
+          enforceParameterCount: "exactlyOne",
+          ignorePrefixSelector: [
+            "CallExpression[callee.property.name='reduce']",
+            "CallExpression[callee.property.name='map']",
+          ],
+        },
+      ],
+    ],
+  },
 ];
 
 export default tests;