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