1 | /**
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2 | * @fileoverview Rule to enforce spacing before and after keywords.
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3 | * @author Toru Nagashima
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4 | */
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5 |
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6 | ;
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7 |
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8 | //------------------------------------------------------------------------------
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9 | // Requirements
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10 | //------------------------------------------------------------------------------
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11 |
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12 | const astUtils = require("../ast-utils"),
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13 | keywords = require("../util/keywords");
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14 |
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15 | //------------------------------------------------------------------------------
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16 | // Constants
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17 | //------------------------------------------------------------------------------
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18 |
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19 | const PREV_TOKEN = /^[)\]}>]$/;
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20 | const NEXT_TOKEN = /^(?:[([{<~!]|\+\+?|--?)$/;
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21 | const PREV_TOKEN_M = /^[)\]}>*]$/;
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22 | const NEXT_TOKEN_M = /^[{*]$/;
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23 | const TEMPLATE_OPEN_PAREN = /\$\{$/;
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24 | const TEMPLATE_CLOSE_PAREN = /^\}/;
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25 | const CHECK_TYPE = /^(?:JSXElement|RegularExpression|String|Template)$/;
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26 | const KEYS = keywords.concat(["as", "async", "await", "from", "get", "let", "of", "set", "yield"]);
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27 |
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28 | // check duplications.
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29 | (function() {
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30 | KEYS.sort();
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31 | for (let i = 1; i < KEYS.length; ++i) {
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32 | if (KEYS[i] === KEYS[i - 1]) {
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33 | throw new Error(`Duplication was found in the keyword list: ${KEYS[i]}`);
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34 | }
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35 | }
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36 | }());
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37 |
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38 | //------------------------------------------------------------------------------
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39 | // Helpers
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40 | //------------------------------------------------------------------------------
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41 |
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42 | /**
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43 | * Checks whether or not a given token is a "Template" token ends with "${".
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44 | *
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45 | * @param {Token} token - A token to check.
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46 | * @returns {boolean} `true` if the token is a "Template" token ends with "${".
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47 | */
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48 | function isOpenParenOfTemplate(token) {
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49 | return token.type === "Template" && TEMPLATE_OPEN_PAREN.test(token.value);
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50 | }
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51 |
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52 | /**
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53 | * Checks whether or not a given token is a "Template" token starts with "}".
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54 | *
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55 | * @param {Token} token - A token to check.
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56 | * @returns {boolean} `true` if the token is a "Template" token starts with "}".
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57 | */
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58 | function isCloseParenOfTemplate(token) {
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59 | return token.type === "Template" && TEMPLATE_CLOSE_PAREN.test(token.value);
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60 | }
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61 |
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62 | //------------------------------------------------------------------------------
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63 | // Rule Definition
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64 | //------------------------------------------------------------------------------
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65 |
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66 | module.exports = {
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67 | meta: {
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68 | docs: {
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69 | description: "enforce consistent spacing before and after keywords",
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70 | category: "Stylistic Issues",
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71 | recommended: false,
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72 | url: "https://eslint.org/docs/rules/keyword-spacing"
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73 | },
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74 |
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75 | fixable: "whitespace",
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76 |
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77 | schema: [
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78 | {
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79 | type: "object",
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80 | properties: {
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81 | before: { type: "boolean" },
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82 | after: { type: "boolean" },
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83 | overrides: {
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84 | type: "object",
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85 | properties: KEYS.reduce((retv, key) => {
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86 | retv[key] = {
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87 | type: "object",
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88 | properties: {
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89 | before: { type: "boolean" },
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90 | after: { type: "boolean" }
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91 | },
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92 | additionalProperties: false
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93 | };
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94 | return retv;
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95 | }, {}),
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96 | additionalProperties: false
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97 | }
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98 | },
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99 | additionalProperties: false
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100 | }
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101 | ]
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102 | },
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103 |
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104 | create(context) {
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105 | const sourceCode = context.getSourceCode();
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106 |
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107 | /**
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108 | * Reports a given token if there are not space(s) before the token.
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109 | *
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110 | * @param {Token} token - A token to report.
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111 | * @param {RegExp|undefined} pattern - Optional. A pattern of the previous
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112 | * token to check.
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113 | * @returns {void}
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114 | */
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115 | function expectSpaceBefore(token, pattern) {
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116 | pattern = pattern || PREV_TOKEN;
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117 |
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118 | const prevToken = sourceCode.getTokenBefore(token);
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119 |
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120 | if (prevToken &&
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121 | (CHECK_TYPE.test(prevToken.type) || pattern.test(prevToken.value)) &&
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122 | !isOpenParenOfTemplate(prevToken) &&
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123 | astUtils.isTokenOnSameLine(prevToken, token) &&
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124 | !sourceCode.isSpaceBetweenTokens(prevToken, token)
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125 | ) {
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126 | context.report({
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127 | loc: token.loc.start,
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128 | message: "Expected space(s) before \"{{value}}\".",
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129 | data: token,
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130 | fix(fixer) {
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131 | return fixer.insertTextBefore(token, " ");
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132 | }
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133 | });
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134 | }
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135 | }
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136 |
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137 | /**
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138 | * Reports a given token if there are space(s) before the token.
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139 | *
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140 | * @param {Token} token - A token to report.
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141 | * @param {RegExp|undefined} pattern - Optional. A pattern of the previous
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142 | * token to check.
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143 | * @returns {void}
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144 | */
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145 | function unexpectSpaceBefore(token, pattern) {
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146 | pattern = pattern || PREV_TOKEN;
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147 |
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148 | const prevToken = sourceCode.getTokenBefore(token);
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149 |
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150 | if (prevToken &&
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151 | (CHECK_TYPE.test(prevToken.type) || pattern.test(prevToken.value)) &&
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152 | !isOpenParenOfTemplate(prevToken) &&
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153 | astUtils.isTokenOnSameLine(prevToken, token) &&
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154 | sourceCode.isSpaceBetweenTokens(prevToken, token)
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155 | ) {
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156 | context.report({
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157 | loc: token.loc.start,
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158 | message: "Unexpected space(s) before \"{{value}}\".",
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159 | data: token,
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160 | fix(fixer) {
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161 | return fixer.removeRange([prevToken.range[1], token.range[0]]);
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162 | }
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163 | });
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164 | }
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165 | }
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166 |
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167 | /**
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168 | * Reports a given token if there are not space(s) after the token.
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169 | *
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170 | * @param {Token} token - A token to report.
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171 | * @param {RegExp|undefined} pattern - Optional. A pattern of the next
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172 | * token to check.
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173 | * @returns {void}
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174 | */
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175 | function expectSpaceAfter(token, pattern) {
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176 | pattern = pattern || NEXT_TOKEN;
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177 |
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178 | const nextToken = sourceCode.getTokenAfter(token);
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179 |
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180 | if (nextToken &&
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181 | (CHECK_TYPE.test(nextToken.type) || pattern.test(nextToken.value)) &&
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182 | !isCloseParenOfTemplate(nextToken) &&
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183 | astUtils.isTokenOnSameLine(token, nextToken) &&
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184 | !sourceCode.isSpaceBetweenTokens(token, nextToken)
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185 | ) {
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186 | context.report({
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187 | loc: token.loc.start,
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188 | message: "Expected space(s) after \"{{value}}\".",
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189 | data: token,
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190 | fix(fixer) {
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191 | return fixer.insertTextAfter(token, " ");
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192 | }
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193 | });
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194 | }
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195 | }
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196 |
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197 | /**
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198 | * Reports a given token if there are space(s) after the token.
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199 | *
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200 | * @param {Token} token - A token to report.
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201 | * @param {RegExp|undefined} pattern - Optional. A pattern of the next
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202 | * token to check.
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203 | * @returns {void}
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204 | */
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205 | function unexpectSpaceAfter(token, pattern) {
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206 | pattern = pattern || NEXT_TOKEN;
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207 |
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208 | const nextToken = sourceCode.getTokenAfter(token);
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209 |
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210 | if (nextToken &&
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211 | (CHECK_TYPE.test(nextToken.type) || pattern.test(nextToken.value)) &&
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212 | !isCloseParenOfTemplate(nextToken) &&
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213 | astUtils.isTokenOnSameLine(token, nextToken) &&
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214 | sourceCode.isSpaceBetweenTokens(token, nextToken)
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215 | ) {
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216 | context.report({
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217 | loc: token.loc.start,
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218 | message: "Unexpected space(s) after \"{{value}}\".",
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219 | data: token,
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220 | fix(fixer) {
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221 | return fixer.removeRange([token.range[1], nextToken.range[0]]);
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222 | }
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223 | });
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224 | }
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225 | }
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226 |
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227 | /**
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228 | * Parses the option object and determines check methods for each keyword.
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229 | *
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230 | * @param {Object|undefined} options - The option object to parse.
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231 | * @returns {Object} - Normalized option object.
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232 | * Keys are keywords (there are for every keyword).
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233 | * Values are instances of `{"before": function, "after": function}`.
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234 | */
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235 | function parseOptions(options) {
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236 | const before = !options || options.before !== false;
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237 | const after = !options || options.after !== false;
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238 | const defaultValue = {
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239 | before: before ? expectSpaceBefore : unexpectSpaceBefore,
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240 | after: after ? expectSpaceAfter : unexpectSpaceAfter
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241 | };
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242 | const overrides = (options && options.overrides) || {};
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243 | const retv = Object.create(null);
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244 |
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245 | for (let i = 0; i < KEYS.length; ++i) {
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246 | const key = KEYS[i];
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247 | const override = overrides[key];
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248 |
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249 | if (override) {
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250 | const thisBefore = ("before" in override) ? override.before : before;
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251 | const thisAfter = ("after" in override) ? override.after : after;
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252 |
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253 | retv[key] = {
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254 | before: thisBefore ? expectSpaceBefore : unexpectSpaceBefore,
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255 | after: thisAfter ? expectSpaceAfter : unexpectSpaceAfter
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256 | };
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257 | } else {
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258 | retv[key] = defaultValue;
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259 | }
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260 | }
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261 |
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262 | return retv;
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263 | }
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264 |
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265 | const checkMethodMap = parseOptions(context.options[0]);
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266 |
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267 | /**
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268 | * Reports a given token if usage of spacing followed by the token is
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269 | * invalid.
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270 | *
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271 | * @param {Token} token - A token to report.
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272 | * @param {RegExp|undefined} pattern - Optional. A pattern of the previous
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273 | * token to check.
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274 | * @returns {void}
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275 | */
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276 | function checkSpacingBefore(token, pattern) {
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277 | checkMethodMap[token.value].before(token, pattern);
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278 | }
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279 |
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280 | /**
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281 | * Reports a given token if usage of spacing preceded by the token is
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282 | * invalid.
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283 | *
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284 | * @param {Token} token - A token to report.
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285 | * @param {RegExp|undefined} pattern - Optional. A pattern of the next
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286 | * token to check.
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287 | * @returns {void}
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288 | */
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289 | function checkSpacingAfter(token, pattern) {
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290 | checkMethodMap[token.value].after(token, pattern);
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291 | }
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292 |
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293 | /**
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294 | * Reports a given token if usage of spacing around the token is invalid.
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295 | *
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296 | * @param {Token} token - A token to report.
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297 | * @returns {void}
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298 | */
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299 | function checkSpacingAround(token) {
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300 | checkSpacingBefore(token);
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301 | checkSpacingAfter(token);
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302 | }
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303 |
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304 | /**
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305 | * Reports the first token of a given node if the first token is a keyword
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306 | * and usage of spacing around the token is invalid.
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307 | *
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308 | * @param {ASTNode|null} node - A node to report.
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309 | * @returns {void}
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310 | */
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311 | function checkSpacingAroundFirstToken(node) {
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312 | const firstToken = node && sourceCode.getFirstToken(node);
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313 |
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314 | if (firstToken && firstToken.type === "Keyword") {
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315 | checkSpacingAround(firstToken);
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316 | }
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317 | }
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318 |
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319 | /**
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320 | * Reports the first token of a given node if the first token is a keyword
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321 | * and usage of spacing followed by the token is invalid.
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322 | *
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323 | * This is used for unary operators (e.g. `typeof`), `function`, and `super`.
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324 | * Other rules are handling usage of spacing preceded by those keywords.
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325 | *
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326 | * @param {ASTNode|null} node - A node to report.
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327 | * @returns {void}
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328 | */
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329 | function checkSpacingBeforeFirstToken(node) {
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330 | const firstToken = node && sourceCode.getFirstToken(node);
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331 |
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332 | if (firstToken && firstToken.type === "Keyword") {
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333 | checkSpacingBefore(firstToken);
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334 | }
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335 | }
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336 |
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337 | /**
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338 | * Reports the previous token of a given node if the token is a keyword and
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339 | * usage of spacing around the token is invalid.
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340 | *
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341 | * @param {ASTNode|null} node - A node to report.
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342 | * @returns {void}
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343 | */
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344 | function checkSpacingAroundTokenBefore(node) {
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345 | if (node) {
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346 | const token = sourceCode.getTokenBefore(node, astUtils.isKeywordToken);
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347 |
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348 | checkSpacingAround(token);
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349 | }
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350 | }
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351 |
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352 | /**
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353 | * Reports `async` or `function` keywords of a given node if usage of
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354 | * spacing around those keywords is invalid.
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355 | *
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356 | * @param {ASTNode} node - A node to report.
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357 | * @returns {void}
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358 | */
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359 | function checkSpacingForFunction(node) {
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360 | const firstToken = node && sourceCode.getFirstToken(node);
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361 |
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362 | if (firstToken &&
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363 | ((firstToken.type === "Keyword" && firstToken.value === "function") ||
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364 | firstToken.value === "async")
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365 | ) {
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366 | checkSpacingBefore(firstToken);
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367 | }
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368 | }
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369 |
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370 | /**
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371 | * Reports `class` and `extends` keywords of a given node if usage of
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372 | * spacing around those keywords is invalid.
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373 | *
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374 | * @param {ASTNode} node - A node to report.
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375 | * @returns {void}
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376 | */
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377 | function checkSpacingForClass(node) {
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378 | checkSpacingAroundFirstToken(node);
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379 | checkSpacingAroundTokenBefore(node.superClass);
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380 | }
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381 |
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382 | /**
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383 | * Reports `if` and `else` keywords of a given node if usage of spacing
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384 | * around those keywords is invalid.
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385 | *
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386 | * @param {ASTNode} node - A node to report.
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387 | * @returns {void}
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388 | */
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389 | function checkSpacingForIfStatement(node) {
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390 | checkSpacingAroundFirstToken(node);
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391 | checkSpacingAroundTokenBefore(node.alternate);
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392 | }
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393 |
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394 | /**
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395 | * Reports `try`, `catch`, and `finally` keywords of a given node if usage
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396 | * of spacing around those keywords is invalid.
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397 | *
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398 | * @param {ASTNode} node - A node to report.
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399 | * @returns {void}
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400 | */
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401 | function checkSpacingForTryStatement(node) {
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402 | checkSpacingAroundFirstToken(node);
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403 | checkSpacingAroundFirstToken(node.handler);
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404 | checkSpacingAroundTokenBefore(node.finalizer);
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405 | }
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406 |
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407 | /**
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408 | * Reports `do` and `while` keywords of a given node if usage of spacing
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409 | * around those keywords is invalid.
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410 | *
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411 | * @param {ASTNode} node - A node to report.
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412 | * @returns {void}
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413 | */
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414 | function checkSpacingForDoWhileStatement(node) {
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415 | checkSpacingAroundFirstToken(node);
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416 | checkSpacingAroundTokenBefore(node.test);
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417 | }
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418 |
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419 | /**
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420 | * Reports `for` and `in` keywords of a given node if usage of spacing
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421 | * around those keywords is invalid.
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422 | *
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423 | * @param {ASTNode} node - A node to report.
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424 | * @returns {void}
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425 | */
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426 | function checkSpacingForForInStatement(node) {
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427 | checkSpacingAroundFirstToken(node);
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428 | checkSpacingAroundTokenBefore(node.right);
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429 | }
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430 |
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431 | /**
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432 | * Reports `for` and `of` keywords of a given node if usage of spacing
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433 | * around those keywords is invalid.
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434 | *
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435 | * @param {ASTNode} node - A node to report.
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436 | * @returns {void}
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437 | */
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438 | function checkSpacingForForOfStatement(node) {
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439 | if (node.await) {
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440 | checkSpacingBefore(sourceCode.getFirstToken(node, 0));
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441 | checkSpacingAfter(sourceCode.getFirstToken(node, 1));
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442 | } else {
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443 | checkSpacingAroundFirstToken(node);
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444 | }
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445 | checkSpacingAround(sourceCode.getTokenBefore(node.right, astUtils.isNotOpeningParenToken));
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446 | }
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447 |
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448 | /**
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449 | * Reports `import`, `export`, `as`, and `from` keywords of a given node if
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450 | * usage of spacing around those keywords is invalid.
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451 | *
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452 | * This rule handles the `*` token in module declarations.
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453 | *
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454 | * import*as A from "./a"; /*error Expected space(s) after "import".
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455 | * error Expected space(s) before "as".
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456 | *
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457 | * @param {ASTNode} node - A node to report.
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458 | * @returns {void}
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459 | */
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460 | function checkSpacingForModuleDeclaration(node) {
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461 | const firstToken = sourceCode.getFirstToken(node);
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462 |
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463 | checkSpacingBefore(firstToken, PREV_TOKEN_M);
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464 | checkSpacingAfter(firstToken, NEXT_TOKEN_M);
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465 |
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466 | if (node.source) {
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467 | const fromToken = sourceCode.getTokenBefore(node.source);
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468 |
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469 | checkSpacingBefore(fromToken, PREV_TOKEN_M);
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470 | checkSpacingAfter(fromToken, NEXT_TOKEN_M);
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471 | }
|
472 | }
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473 |
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474 | /**
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475 | * Reports `as` keyword of a given node if usage of spacing around this
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476 | * keyword is invalid.
|
477 | *
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478 | * @param {ASTNode} node - A node to report.
|
479 | * @returns {void}
|
480 | */
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481 | function checkSpacingForImportNamespaceSpecifier(node) {
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482 | const asToken = sourceCode.getFirstToken(node, 1);
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483 |
|
484 | checkSpacingBefore(asToken, PREV_TOKEN_M);
|
485 | }
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486 |
|
487 | /**
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488 | * Reports `static`, `get`, and `set` keywords of a given node if usage of
|
489 | * spacing around those keywords is invalid.
|
490 | *
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491 | * @param {ASTNode} node - A node to report.
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492 | * @returns {void}
|
493 | */
|
494 | function checkSpacingForProperty(node) {
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495 | if (node.static) {
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496 | checkSpacingAroundFirstToken(node);
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497 | }
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498 | if (node.kind === "get" ||
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499 | node.kind === "set" ||
|
500 | (
|
501 | (node.method || node.type === "MethodDefinition") &&
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502 | node.value.async
|
503 | )
|
504 | ) {
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505 | const token = sourceCode.getTokenBefore(
|
506 | node.key,
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507 | tok => {
|
508 | switch (tok.value) {
|
509 | case "get":
|
510 | case "set":
|
511 | case "async":
|
512 | return true;
|
513 | default:
|
514 | return false;
|
515 | }
|
516 | }
|
517 | );
|
518 |
|
519 | if (!token) {
|
520 | throw new Error("Failed to find token get, set, or async beside method name");
|
521 | }
|
522 |
|
523 |
|
524 | checkSpacingAround(token);
|
525 | }
|
526 | }
|
527 |
|
528 | /**
|
529 | * Reports `await` keyword of a given node if usage of spacing before
|
530 | * this keyword is invalid.
|
531 | *
|
532 | * @param {ASTNode} node - A node to report.
|
533 | * @returns {void}
|
534 | */
|
535 | function checkSpacingForAwaitExpression(node) {
|
536 | checkSpacingBefore(sourceCode.getFirstToken(node));
|
537 | }
|
538 |
|
539 | return {
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540 |
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541 | // Statements
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542 | DebuggerStatement: checkSpacingAroundFirstToken,
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543 | WithStatement: checkSpacingAroundFirstToken,
|
544 |
|
545 | // Statements - Control flow
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546 | BreakStatement: checkSpacingAroundFirstToken,
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547 | ContinueStatement: checkSpacingAroundFirstToken,
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548 | ReturnStatement: checkSpacingAroundFirstToken,
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549 | ThrowStatement: checkSpacingAroundFirstToken,
|
550 | TryStatement: checkSpacingForTryStatement,
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551 |
|
552 | // Statements - Choice
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553 | IfStatement: checkSpacingForIfStatement,
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554 | SwitchStatement: checkSpacingAroundFirstToken,
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555 | SwitchCase: checkSpacingAroundFirstToken,
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556 |
|
557 | // Statements - Loops
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558 | DoWhileStatement: checkSpacingForDoWhileStatement,
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559 | ForInStatement: checkSpacingForForInStatement,
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560 | ForOfStatement: checkSpacingForForOfStatement,
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561 | ForStatement: checkSpacingAroundFirstToken,
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562 | WhileStatement: checkSpacingAroundFirstToken,
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563 |
|
564 | // Statements - Declarations
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565 | ClassDeclaration: checkSpacingForClass,
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566 | ExportNamedDeclaration: checkSpacingForModuleDeclaration,
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567 | ExportDefaultDeclaration: checkSpacingAroundFirstToken,
|
568 | ExportAllDeclaration: checkSpacingForModuleDeclaration,
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569 | FunctionDeclaration: checkSpacingForFunction,
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570 | ImportDeclaration: checkSpacingForModuleDeclaration,
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571 | VariableDeclaration: checkSpacingAroundFirstToken,
|
572 |
|
573 | // Expressions
|
574 | ArrowFunctionExpression: checkSpacingForFunction,
|
575 | AwaitExpression: checkSpacingForAwaitExpression,
|
576 | ClassExpression: checkSpacingForClass,
|
577 | FunctionExpression: checkSpacingForFunction,
|
578 | NewExpression: checkSpacingBeforeFirstToken,
|
579 | Super: checkSpacingBeforeFirstToken,
|
580 | ThisExpression: checkSpacingBeforeFirstToken,
|
581 | UnaryExpression: checkSpacingBeforeFirstToken,
|
582 | YieldExpression: checkSpacingBeforeFirstToken,
|
583 |
|
584 | // Others
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585 | ImportNamespaceSpecifier: checkSpacingForImportNamespaceSpecifier,
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586 | MethodDefinition: checkSpacingForProperty,
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587 | Property: checkSpacingForProperty
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588 | };
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589 | }
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590 | };
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