1 | /**
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2 | * @fileoverview Rule to enforce spacing around colons of switch statements.
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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 |
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14 | //------------------------------------------------------------------------------
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15 | // Rule Definition
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16 | //------------------------------------------------------------------------------
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17 |
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18 | module.exports = {
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19 | meta: {
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20 | type: "layout",
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21 |
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22 | docs: {
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23 | description: "enforce spacing around colons of switch statements",
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24 | category: "Stylistic Issues",
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25 | recommended: false,
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26 | url: "https://eslint.org/docs/rules/switch-colon-spacing"
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27 | },
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28 |
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29 | schema: [
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30 | {
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31 | type: "object",
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32 | properties: {
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33 | before: { type: "boolean", default: false },
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34 | after: { type: "boolean", default: true }
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35 | },
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36 | additionalProperties: false
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37 | }
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38 | ],
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39 | fixable: "whitespace",
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40 | messages: {
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41 | expectedBefore: "Expected space(s) before this colon.",
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42 | expectedAfter: "Expected space(s) after this colon.",
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43 | unexpectedBefore: "Unexpected space(s) before this colon.",
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44 | unexpectedAfter: "Unexpected space(s) after this colon."
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45 | }
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46 | },
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47 |
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48 | create(context) {
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49 | const sourceCode = context.getSourceCode();
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50 | const options = context.options[0] || {};
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51 | const beforeSpacing = options.before === true; // false by default
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52 | const afterSpacing = options.after !== false; // true by default
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53 |
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54 | /**
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55 | * Get the colon token of the given SwitchCase node.
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56 | * @param {ASTNode} node The SwitchCase node to get.
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57 | * @returns {Token} The colon token of the node.
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58 | */
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59 | function getColonToken(node) {
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60 | if (node.test) {
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61 | return sourceCode.getTokenAfter(node.test, astUtils.isColonToken);
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62 | }
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63 | return sourceCode.getFirstToken(node, 1);
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64 | }
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65 |
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66 | /**
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67 | * Check whether the spacing between the given 2 tokens is valid or not.
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68 | * @param {Token} left The left token to check.
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69 | * @param {Token} right The right token to check.
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70 | * @param {boolean} expected The expected spacing to check. `true` if there should be a space.
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71 | * @returns {boolean} `true` if the spacing between the tokens is valid.
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72 | */
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73 | function isValidSpacing(left, right, expected) {
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74 | return (
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75 | astUtils.isClosingBraceToken(right) ||
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76 | !astUtils.isTokenOnSameLine(left, right) ||
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77 | sourceCode.isSpaceBetweenTokens(left, right) === expected
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78 | );
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79 | }
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80 |
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81 | /**
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82 | * Check whether comments exist between the given 2 tokens.
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83 | * @param {Token} left The left token to check.
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84 | * @param {Token} right The right token to check.
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85 | * @returns {boolean} `true` if comments exist between the given 2 tokens.
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86 | */
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87 | function commentsExistBetween(left, right) {
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88 | return sourceCode.getFirstTokenBetween(
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89 | left,
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90 | right,
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91 | {
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92 | includeComments: true,
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93 | filter: astUtils.isCommentToken
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94 | }
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95 | ) !== null;
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96 | }
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97 |
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98 | /**
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99 | * Fix the spacing between the given 2 tokens.
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100 | * @param {RuleFixer} fixer The fixer to fix.
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101 | * @param {Token} left The left token of fix range.
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102 | * @param {Token} right The right token of fix range.
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103 | * @param {boolean} spacing The spacing style. `true` if there should be a space.
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104 | * @returns {Fix|null} The fix object.
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105 | */
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106 | function fix(fixer, left, right, spacing) {
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107 | if (commentsExistBetween(left, right)) {
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108 | return null;
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109 | }
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110 | if (spacing) {
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111 | return fixer.insertTextAfter(left, " ");
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112 | }
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113 | return fixer.removeRange([left.range[1], right.range[0]]);
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114 | }
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115 |
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116 | return {
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117 | SwitchCase(node) {
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118 | const colonToken = getColonToken(node);
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119 | const beforeToken = sourceCode.getTokenBefore(colonToken);
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120 | const afterToken = sourceCode.getTokenAfter(colonToken);
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121 |
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122 | if (!isValidSpacing(beforeToken, colonToken, beforeSpacing)) {
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123 | context.report({
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124 | node,
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125 | loc: colonToken.loc,
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126 | messageId: beforeSpacing ? "expectedBefore" : "unexpectedBefore",
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127 | fix: fixer => fix(fixer, beforeToken, colonToken, beforeSpacing)
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128 | });
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129 | }
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130 | if (!isValidSpacing(colonToken, afterToken, afterSpacing)) {
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131 | context.report({
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132 | node,
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133 | loc: colonToken.loc,
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134 | messageId: afterSpacing ? "expectedAfter" : "unexpectedAfter",
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135 | fix: fixer => fix(fixer, colonToken, afterToken, afterSpacing)
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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 | }
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141 | };
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