feat: add meta.defaultOptions

lib/linter/deep-merge.js

@@ -0,0 +1,61 @@
+/* eslint-disable eqeqeq, no-undefined -- `null` and `undefined` are different in options */
+/**
+ * @fileoverview Applies default rule options
+ * @author JoshuaKGoldberg
+ */
+
+"use strict";
+
+/**
+ * Check if the variable contains an object strictly rejecting arrays
+ * @param {unknown} obj an object
+ * @returns {boolean} Whether obj is an object
+ */
+function isObjectNotArray(obj) {
+ return typeof obj === "object" && obj != null && !Array.isArray(obj);
+}
+
+/**
+ * Deeply merges second on top of first, creating a new {} object if needed.
+ * @param {T} first Base, default value.
+ * @param {U} second User-specified value.
+ * @returns {T | U | (T & U)} Merged equivalent of second on top of first.
+ */
+function deepMerge(first, second) {
+ if (second === null || (second !== undefined && typeof second !== "object")) {
+ return second;
+ }
+
+ if (typeof first !== "object" && typeof second === "object" && second !== null) {
+ return second;
+ }
+
+ if (first === null || Array.isArray(first) || second === undefined) {
+ return first;
+ }
+
+ const keysUnion = new Set(Object.keys(first).concat(Object.keys(second)));
+
+ return Array.from(keysUnion).reduce((acc, key) => {
+ const firstValue = first[key];
+ const secondValue = second[key];
+
+ if (firstValue !== undefined && secondValue !== undefined) {
+ if (isObjectNotArray(firstValue) && isObjectNotArray(secondValue)) {
+ acc[key] = deepMerge(firstValue, secondValue);
+ } else {
+ acc[key] = secondValue;
+ }
+ } else if (firstValue !== undefined) {
+ acc[key] = firstValue;
+ } else {
+ acc[key] = secondValue;
+ }
+
+ return acc;
+ }, {});
+}
+
+module.exports = { deepMerge };
+
+/* eslint-enable eqeqeq, no-undefined -- `null` and `undefined` are different in options */

lib/linter/get-rule-options.js

@@ -0,0 +1,48 @@
+/**
+ * @fileoverview Applies default rule options
+ * @author JoshuaKGoldberg
+ */
+
+"use strict";
+
+const { deepMerge } = require("./deep-merge");
+
+/**
+ * Creates rule options by merging a user config on top of any default options.
+ * @param {Array|undefined} defaultOptions Default options from a rule's meta.
+ * @param {Array} ruleConfig User-specified rule configuration.
+ * @returns {Array} Rule options, factoring in user config and any defaults.
+ */
+function getMergedRuleOptions(defaultOptions, ruleConfig) {
+ if (!defaultOptions) {
+ return ruleConfig;
+ }
+
+ const options = [];
+ const sharedLength = Math.min(defaultOptions.length, ruleConfig.length);
+ let i;
+
+ for (i = 0; i < sharedLength; i += 1) {
+ options.push(deepMerge(defaultOptions[i], ruleConfig[i]));
+ }
+
+ options.push(...defaultOptions.slice(i));
+ options.push(...ruleConfig.slice(i));
+
+ return options;
+}
+
+/**
+ * Get the options for a rule (not including severity), if any, factoring in defaults
+ * @param {Array|undefined} defaultOptions default options from rule's meta.
+ * @param {Array|number} ruleConfig rule configuration
+ * @returns {Array} of rule options, empty Array if none
+ */
+function getRuleOptions(defaultOptions, ruleConfig) {
+ if (Array.isArray(ruleConfig)) {
+ return getMergedRuleOptions(defaultOptions, ruleConfig.slice(1));
+ }
+ return defaultOptions || [];
+}
+
+module.exports = { getRuleOptions };

lib/linter/linter.js

@@ -33,6 +33,7 @@ const
  CodePathAnalyzer = require("./code-path-analysis/code-path-analyzer"),
  applyDisableDirectives = require("./apply-disable-directives"),
  ConfigCommentParser = require("./config-comment-parser"),
+ { getRuleOptions } = require("./get-rule-options"),
  NodeEventGenerator = require("./node-event-generator"),
  createReportTranslator = require("./report-translator"),
  Rules = require("./rules"),
@@ -772,19 +773,6 @@ function stripUnicodeBOM(text) {
  return text;
 }
 
-/**
- * Get the options for a rule (not including severity), if any
- * @param {Array|number} ruleConfig rule configuration
- * @returns {Array} of rule options, empty Array if none
- */
-function getRuleOptions(ruleConfig) {
- if (Array.isArray(ruleConfig)) {
- return ruleConfig.slice(1);
- }
- return [];
-
-}
-
 /**
  * Analyze scope of the given AST.
  * @param {ASTNode} ast The `Program` node to analyze.
@@ -1037,7 +1025,7 @@ function runRules(sourceCode, configuredRules, ruleMapper, parserName, languageO
  Object.create(sharedTraversalContext),
  {
  id: ruleId,
- options: getRuleOptions(configuredRules[ruleId]),
+ options: getRuleOptions(rule.meta && rule.meta.defaultOptions, configuredRules[ruleId]),
  report(...args) {
 
  /*

lib/rules/accessor-pairs.js

@@ -139,6 +139,12 @@ module.exports = {
  meta: {
  type: "suggestion",
 
+ defaultOptions: [{
+ enforceForClassMembers: true,
+ getWithoutGet: false,
+ setWithoutGet: true
+ }],
+
  docs: {
  description: "Enforce getter and setter pairs in objects and classes",
  recommended: false,
@@ -149,16 +155,13 @@ module.exports = {
  type: "object",
  properties: {
  getWithoutSet: {
- type: "boolean",
- default: false
+ type: "boolean"
  },
  setWithoutGet: {
- type: "boolean",
- default: true
+ type: "boolean"
  },
  enforceForClassMembers: {
- type: "boolean",
- default: true
+ type: "boolean"
  }
  },
  additionalProperties: false
@@ -174,7 +177,7 @@ module.exports = {
  }
  },
  create(context) {
- const config = context.options[0] || {};
+ const [config] = context.options;
  const checkGetWithoutSet = config.getWithoutSet === true;
  const checkSetWithoutGet = config.setWithoutGet !== false;
  const enforceForClassMembers = config.enforceForClassMembers !== false;

lib/rules/array-bracket-spacing.js

@@ -15,6 +15,8 @@ module.exports = {
  meta: {
  type: "layout",
 
+ defaultOptions: ["never"],
+
  docs: {
  description: "Enforce consistent spacing inside array brackets",
  recommended: false,
@@ -55,6 +57,7 @@ module.exports = {
  const spaced = context.options[0] === "always",
  sourceCode = context.sourceCode;
 
+
  /**
  * Determines whether an option is set, relative to the spacing option.
  * If spaced is "always", then check whether option is set to false.

lib/rules/array-callback-return.js

@@ -215,6 +215,12 @@ module.exports = {
  meta: {
  type: "problem",
 
+ defaultOptions: [{
+ allowImplicit: false,
+ checkForEach: false,
+ allowVoid: false
+ }],
+
  docs: {
  description: "Enforce `return` statements in callbacks of array methods",
  recommended: false,
@@ -229,16 +235,13 @@ module.exports = {
  type: "object",
  properties: {
  allowImplicit: {
- type: "boolean",
- default: false
+ type: "boolean"
  },
  checkForEach: {
- type: "boolean",
- default: false
+ type: "boolean"
  },
  allowVoid: {
- type: "boolean",
- default: false
+ type: "boolean"
  }
  },
  additionalProperties: false
@@ -257,7 +260,7 @@ module.exports = {
 
  create(context) {
 
- const options = context.options[0] || { allowImplicit: false, checkForEach: false, allowVoid: false };
+ const [options] = context.options;
  const sourceCode = context.sourceCode;
 
  let funcInfo = {

lib/rules/array-element-newline.js

@@ -16,6 +16,8 @@ module.exports = {
  meta: {
  type: "layout",
 
+ defaultOptions: ["always"],
+
  docs: {
  description: "Enforce line breaks after each array element",
  recommended: false,

lib/rules/arrow-body-style.js

@@ -19,6 +19,8 @@ module.exports = {
  meta: {
  type: "suggestion",
 
+ defaultOptions: ["as-needed"],
+
  docs: {
  description: "Require braces around arrow function bodies",
  recommended: false,
@@ -71,7 +73,7 @@ module.exports = {
  create(context) {
  const options = context.options;
  const always = options[0] === "always";
- const asNeeded = !options[0] || options[0] === "as-needed";
+ const asNeeded = options[0] === "as-needed";
  const never = options[0] === "never";
  const requireReturnForObjectLiteral = options[1] && options[1].requireReturnForObjectLiteral;
  const sourceCode = context.sourceCode;

lib/rules/arrow-parens.js

@@ -32,6 +32,8 @@ module.exports = {
  meta: {
  type: "layout",
 
+ defaultOptions: ["always"],
+
  docs: {
  description: "Require parentheses around arrow function arguments",
  recommended: false,
@@ -48,8 +50,7 @@ module.exports = {
  type: "object",
  properties: {
  requireForBlockBody: {
- type: "boolean",
- default: false
+ type: "boolean"
  }
  },
  additionalProperties: false

lib/rules/arrow-spacing.js

@@ -19,6 +19,11 @@ module.exports = {
  meta: {
  type: "layout",
 
+ defaultOptions: [{
+ after: true,
+ before: true
+ }],
+
  docs: {
  description: "Enforce consistent spacing before and after the arrow in arrow functions",
  recommended: false,
@@ -32,12 +37,10 @@ module.exports = {
  type: "object",
  properties: {
  before: {
- type: "boolean",
- default: true
+ type: "boolean"
  },
  after: {
- type: "boolean",
- default: true
+ type: "boolean"
  }
  },
  additionalProperties: false
@@ -54,13 +57,7 @@ module.exports = {
  },
 
  create(context) {
-
- // merge rules with default
- const rule = Object.assign({}, context.options[0]);
-
- rule.before = rule.before !== false;
- rule.after = rule.after !== false;
-
+ const [options] = context.options;
  const sourceCode = context.sourceCode;
 
  /**
@@ -101,7 +98,7 @@ module.exports = {
  const tokens = getTokens(node);
  const countSpace = countSpaces(tokens);
 
- if (rule.before) {
+ if (options.before) {
 
  // should be space(s) before arrow
  if (countSpace.before === 0) {
@@ -127,7 +124,7 @@ module.exports = {
  }
  }
 
- if (rule.after) {
+ if (options.after) {
 
  // should be space(s) after arrow
  if (countSpace.after === 0) {

lib/rules/block-spacing.js

@@ -16,6 +16,8 @@ module.exports = {
  meta: {
  type: "layout",
 
+ defaultOptions: ["always"],
+
  docs: {
  description: "Disallow or enforce spaces inside of blocks after opening block and before closing block",
  recommended: false,

lib/rules/brace-style.js

@@ -16,6 +16,8 @@ module.exports = {
  meta: {
  type: "layout",
 
+ defaultOptions: ["1tbs", { allowSingleLine: false }],
+
  docs: {
  description: "Enforce consistent brace style for blocks",
  recommended: false,
@@ -30,8 +32,7 @@ module.exports = {
  type: "object",
  properties: {
  allowSingleLine: {
- type: "boolean",
- default: false
+ type: "boolean"
  }
  },
  additionalProperties: false
@@ -51,8 +52,8 @@ module.exports = {
  },
 
  create(context) {
- const style = context.options[0] || "1tbs",
- params = context.options[1] || {},
+ const style = context.options[0],
+ params = context.options[1],
  sourceCode = context.sourceCode;
 
  //--------------------------------------------------------------------------