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| 1 | +/** |
| 2 | + * @fileoverview Ensure symmetric naming of useState hook value and setter variables |
| 3 | + * @author Duncan Beevers |
| 4 | + */ |
| 5 | + |
| 6 | +'use strict'; |
| 7 | + |
| 8 | +const Components = require('../util/Components'); |
| 9 | +const docsUrl = require('../util/docsUrl'); |
| 10 | +const report = require('../util/report'); |
| 11 | + |
| 12 | +// ------------------------------------------------------------------------------ |
| 13 | +// Rule Definition |
| 14 | +// ------------------------------------------------------------------------------ |
| 15 | + |
| 16 | +const messages = { |
| 17 | + useStateErrorMessage: 'useState call is not destructured into value + setter pair', |
| 18 | +}; |
| 19 | + |
| 20 | +module.exports = { |
| 21 | + meta: { |
| 22 | + docs: { |
| 23 | + description: 'Ensure symmetric naming of useState hook value and setter variables', |
| 24 | + category: 'Best Practices', |
| 25 | + recommended: false, |
| 26 | + url: docsUrl('hook-use-state'), |
| 27 | + }, |
| 28 | + messages, |
| 29 | + schema: [], |
| 30 | + type: 'suggestion', |
| 31 | + hasSuggestions: true, |
| 32 | + }, |
| 33 | + |
| 34 | + create: Components.detect((context, components, util) => ({ |
| 35 | + CallExpression(node) { |
| 36 | + const isImmediateReturn = node.parent |
| 37 | + && node.parent.type === 'ReturnStatement'; |
| 38 | + |
| 39 | + if (isImmediateReturn || !util.isReactHookCall(node, ['useState'])) { |
| 40 | + return; |
| 41 | + } |
| 42 | + |
| 43 | + const isDestructuringDeclarator = node.parent |
| 44 | + && node.parent.type === 'VariableDeclarator' |
| 45 | + && node.parent.id.type === 'ArrayPattern'; |
| 46 | + |
| 47 | + if (!isDestructuringDeclarator) { |
| 48 | + report( |
| 49 | + context, |
| 50 | + messages.useStateErrorMessage, |
| 51 | + 'useStateErrorMessage', |
| 52 | + { node } |
| 53 | + ); |
| 54 | + return; |
| 55 | + } |
| 56 | + |
| 57 | + const variableNodes = node.parent.id.elements; |
| 58 | + const valueVariable = variableNodes[0]; |
| 59 | + const setterVariable = variableNodes[1]; |
| 60 | + |
| 61 | + const valueVariableName = valueVariable |
| 62 | + ? valueVariable.name |
| 63 | + : undefined; |
| 64 | + |
| 65 | + const setterVariableName = setterVariable |
| 66 | + ? setterVariable.name |
| 67 | + : undefined; |
| 68 | + |
| 69 | + const expectedSetterVariableName = valueVariableName ? ( |
| 70 | + `set${valueVariableName.charAt(0).toUpperCase()}${valueVariableName.slice(1)}` |
| 71 | + ) : undefined; |
| 72 | + |
| 73 | + const isSymmetricGetterSetterPair = valueVariable |
| 74 | + && setterVariable |
| 75 | + && setterVariableName === expectedSetterVariableName |
| 76 | + && variableNodes.length === 2; |
| 77 | + |
| 78 | + if (!isSymmetricGetterSetterPair) { |
| 79 | + const suggestions = [ |
| 80 | + { |
| 81 | + desc: 'Destructure useState call into value + setter pair', |
| 82 | + fix: (fixer) => { |
| 83 | + const fix = fixer.replaceTextRange( |
| 84 | + node.parent.id.range, |
| 85 | + `[${valueVariableName}, ${expectedSetterVariableName}]` |
| 86 | + ); |
| 87 | + |
| 88 | + return fix; |
| 89 | + }, |
| 90 | + }, |
| 91 | + ]; |
| 92 | + |
| 93 | + const defaultReactImports = components.getDefaultReactImports(); |
| 94 | + const defaultReactImportSpecifier = defaultReactImports |
| 95 | + ? defaultReactImports[0] |
| 96 | + : undefined; |
| 97 | + |
| 98 | + const defaultReactImportName = defaultReactImportSpecifier |
| 99 | + ? defaultReactImportSpecifier.local.name |
| 100 | + : undefined; |
| 101 | + |
| 102 | + const namedReactImports = components.getNamedReactImports(); |
| 103 | + const useStateReactImportSpecifier = namedReactImports |
| 104 | + ? namedReactImports.find((specifier) => specifier.imported.name === 'useState') |
| 105 | + : undefined; |
| 106 | + |
| 107 | + const isSingleGetter = valueVariable && variableNodes.length === 1; |
| 108 | + const isUseStateCalledWithSingleArgument = node.arguments.length === 1; |
| 109 | + if (isSingleGetter && isUseStateCalledWithSingleArgument) { |
| 110 | + const useMemoReactImportSpecifier = namedReactImports |
| 111 | + && namedReactImports.find((specifier) => specifier.imported.name === 'useMemo'); |
| 112 | + |
| 113 | + let useMemoCode; |
| 114 | + if (useMemoReactImportSpecifier) { |
| 115 | + useMemoCode = useMemoReactImportSpecifier.local.name; |
| 116 | + } else if (defaultReactImportName) { |
| 117 | + useMemoCode = `${defaultReactImportName}.useMemo`; |
| 118 | + } else { |
| 119 | + useMemoCode = 'useMemo'; |
| 120 | + } |
| 121 | + |
| 122 | + suggestions.unshift({ |
| 123 | + desc: 'Replace useState call with useMemo', |
| 124 | + fix: (fixer) => [ |
| 125 | + // Add useMemo import, if necessary |
| 126 | + useStateReactImportSpecifier |
| 127 | + && (!useMemoReactImportSpecifier || defaultReactImportName) |
| 128 | + && fixer.insertTextAfter(useStateReactImportSpecifier, ', useMemo'), |
| 129 | + // Convert single-value destructure to simple assignment |
| 130 | + fixer.replaceTextRange(node.parent.id.range, valueVariableName), |
| 131 | + // Convert useState call to useMemo + arrow function + dependency array |
| 132 | + fixer.replaceTextRange( |
| 133 | + node.range, |
| 134 | + `${useMemoCode}(() => ${context.getSourceCode().getText(node.arguments[0])}, [])` |
| 135 | + ), |
| 136 | + ].filter(Boolean), |
| 137 | + }); |
| 138 | + } |
| 139 | + |
| 140 | + report( |
| 141 | + context, |
| 142 | + messages.useStateErrorMessage, |
| 143 | + 'useStateErrorMessage', |
| 144 | + { |
| 145 | + node: node.parent.id, |
| 146 | + suggest: suggestions, |
| 147 | + } |
| 148 | + ); |
| 149 | + } |
| 150 | + }, |
| 151 | + })), |
| 152 | +}; |
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