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6 | 'use strict';
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7 |
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8 | const has = require('has');
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9 | const variableUtil = require('../util/variable');
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10 | const jsxUtil = require('../util/jsx');
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11 | const docsUrl = require('../util/docsUrl');
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12 |
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13 |
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14 |
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15 |
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16 | module.exports = {
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17 | meta: {
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18 | docs: {
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19 | description: 'Validate JSX maximum depth',
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20 | category: 'Stylistic Issues',
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21 | recommended: false,
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22 | url: docsUrl('jsx-max-depth')
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23 | },
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24 | schema: [
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25 | {
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26 | type: 'object',
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27 | properties: {
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28 | max: {
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29 | type: 'integer',
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30 | minimum: 0
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31 | }
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32 | },
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33 | additionalProperties: false
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34 | }
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35 | ]
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36 | },
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37 | create(context) {
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38 | const MESSAGE = 'Expected the depth of nested jsx elements to be <= {{needed}}, but found {{found}}.';
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39 | const DEFAULT_DEPTH = 2;
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40 |
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41 | const option = context.options[0] || {};
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42 | const maxDepth = has(option, 'max') ? option.max : DEFAULT_DEPTH;
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43 |
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44 | function isExpression(node) {
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45 | return node.type === 'JSXExpressionContainer';
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46 | }
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47 |
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48 | function hasJSX(node) {
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49 | return jsxUtil.isJSX(node) || isExpression(node) && jsxUtil.isJSX(node.expression);
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50 | }
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51 |
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52 | function isLeaf(node) {
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53 | const children = node.children;
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54 |
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55 | return !children.length || !children.some(hasJSX);
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56 | }
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57 |
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58 | function getDepth(node) {
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59 | let count = 0;
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60 |
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61 | while (jsxUtil.isJSX(node.parent) || isExpression(node.parent)) {
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62 | node = node.parent;
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63 | if (jsxUtil.isJSX(node)) {
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64 | count++;
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65 | }
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66 | }
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67 |
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68 | return count;
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69 | }
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70 |
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71 | function report(node, depth) {
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72 | context.report({
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73 | node,
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74 | message: MESSAGE,
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75 | data: {
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76 | found: depth,
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77 | needed: maxDepth
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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 | function findJSXElementOrFragment(variables, name) {
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83 | function find(refs) {
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84 | let i = refs.length;
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85 |
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86 | while (--i >= 0) {
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87 | if (has(refs[i], 'writeExpr')) {
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88 | const writeExpr = refs[i].writeExpr;
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89 |
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90 | return jsxUtil.isJSX(writeExpr)
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91 | && writeExpr
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92 | || (writeExpr && writeExpr.type === 'Identifier')
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93 | && findJSXElementOrFragment(variables, writeExpr.name);
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94 | }
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95 | }
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96 |
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97 | return null;
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98 | }
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99 |
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100 | const variable = variableUtil.getVariable(variables, name);
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101 | return variable && variable.references && find(variable.references);
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102 | }
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103 |
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104 | function checkDescendant(baseDepth, children) {
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105 | baseDepth++;
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106 | (children || []).forEach((node) => {
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107 | if (!hasJSX(node)) {
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108 | return;
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109 | }
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110 |
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111 | if (baseDepth > maxDepth) {
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112 | report(node, baseDepth);
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113 | } else if (!isLeaf(node)) {
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114 | checkDescendant(baseDepth, node.children);
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115 | }
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116 | });
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117 | }
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118 |
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119 | function handleJSX(node) {
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120 | if (!isLeaf(node)) {
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121 | return;
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122 | }
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123 |
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124 | const depth = getDepth(node);
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125 | if (depth > maxDepth) {
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126 | report(node, depth);
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127 | }
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128 | }
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129 |
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130 | return {
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131 | JSXElement: handleJSX,
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132 | JSXFragment: handleJSX,
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133 |
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134 | JSXExpressionContainer(node) {
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135 | if (node.expression.type !== 'Identifier') {
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136 | return;
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137 | }
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138 |
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139 | const variables = variableUtil.variablesInScope(context);
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140 | const element = findJSXElementOrFragment(variables, node.expression.name);
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141 |
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142 | if (element) {
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143 | const baseDepth = getDepth(node);
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144 | checkDescendant(baseDepth, element.children);
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145 | }
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146 | }
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147 | };
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148 | }
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149 | };
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