|
| 1 | +const name = 'require-live-region-for-status-updates'; |
| 2 | + |
| 3 | +const STATUS_ROLES = new Set(['alert', 'status']); |
| 4 | + |
| 5 | +const meta = { |
| 6 | + type: 'problem', |
| 7 | + docs: { |
| 8 | + description: 'Require role/accessibilityRole and accessibilityLiveRegion to be used together for status updates.', |
| 9 | + recommended: 'error', |
| 10 | + }, |
| 11 | + schema: [], |
| 12 | + messages: { |
| 13 | + missingLiveRegion: 'Elements with role/accessibilityRole set to "alert" or "status" must include accessibilityLiveRegion so updates are announced.', |
| 14 | + missingStatusRole: 'Elements with accessibilityLiveRegion must include role/accessibilityRole set to "alert" or "status" so assistive technologies treat updates as status messages.', |
| 15 | + invalidLiveRegion: 'Use accessibilityLiveRegion="polite" or "assertive" for status updates; "none" suppresses announcements.', |
| 16 | + }, |
| 17 | +}; |
| 18 | + |
| 19 | +function getJSXAttribute(node, names) { |
| 20 | + return node.attributes.find((attribute) => attribute.type === 'JSXAttribute' && names.includes(attribute.name?.name)); |
| 21 | +} |
| 22 | + |
| 23 | +function getAttributeStringValue(attribute) { |
| 24 | + if (!attribute?.value) { |
| 25 | + return null; |
| 26 | + } |
| 27 | + |
| 28 | + if (attribute.value.type === 'Literal' && typeof attribute.value.value === 'string') { |
| 29 | + return attribute.value.value; |
| 30 | + } |
| 31 | + |
| 32 | + if (attribute.value.type !== 'JSXExpressionContainer') { |
| 33 | + return null; |
| 34 | + } |
| 35 | + |
| 36 | + if (attribute.value.expression.type === 'Literal' && typeof attribute.value.expression.value === 'string') { |
| 37 | + return attribute.value.expression.value; |
| 38 | + } |
| 39 | + |
| 40 | + return null; |
| 41 | +} |
| 42 | + |
| 43 | +function getConstRoleValue(attribute) { |
| 44 | + if (attribute?.value?.type !== 'JSXExpressionContainer') { |
| 45 | + return null; |
| 46 | + } |
| 47 | + |
| 48 | + return getConstRoleValueFromExpression(attribute.value.expression); |
| 49 | +} |
| 50 | + |
| 51 | +function getConstRoleValueFromExpression(expression) { |
| 52 | + if (expression.type !== 'MemberExpression' || expression.computed || expression.property.type !== 'Identifier') { |
| 53 | + return null; |
| 54 | + } |
| 55 | + |
| 56 | + if ( |
| 57 | + expression.object.type !== 'MemberExpression' || |
| 58 | + expression.object.computed || |
| 59 | + expression.object.object.type !== 'Identifier' || |
| 60 | + expression.object.object.name !== 'CONST' || |
| 61 | + expression.object.property.type !== 'Identifier' || |
| 62 | + expression.object.property.name !== 'ROLE' |
| 63 | + ) { |
| 64 | + return null; |
| 65 | + } |
| 66 | + |
| 67 | + return expression.property.name.toLowerCase(); |
| 68 | +} |
| 69 | + |
| 70 | +function getResolvedRolesFromExpression(expression) { |
| 71 | + if (expression.type === 'Literal' && typeof expression.value === 'string') { |
| 72 | + return new Set([expression.value.toLowerCase()]); |
| 73 | + } |
| 74 | + |
| 75 | + if (expression.type === 'Identifier' && expression.name === 'undefined') { |
| 76 | + return new Set(); |
| 77 | + } |
| 78 | + |
| 79 | + if (expression.type === 'MemberExpression') { |
| 80 | + const constRoleValue = getConstRoleValueFromExpression(expression); |
| 81 | + return constRoleValue ? new Set([constRoleValue]) : null; |
| 82 | + } |
| 83 | + |
| 84 | + if (expression.type === 'ConditionalExpression') { |
| 85 | + const consequentRoles = getResolvedRolesFromExpression(expression.consequent); |
| 86 | + const alternateRoles = getResolvedRolesFromExpression(expression.alternate); |
| 87 | + |
| 88 | + if (!consequentRoles || !alternateRoles) { |
| 89 | + return null; |
| 90 | + } |
| 91 | + |
| 92 | + return new Set([...consequentRoles, ...alternateRoles]); |
| 93 | + } |
| 94 | + |
| 95 | + if (expression.type === 'LogicalExpression' && expression.operator === '&&') { |
| 96 | + const rightRoles = getResolvedRolesFromExpression(expression.right); |
| 97 | + |
| 98 | + if (!rightRoles) { |
| 99 | + return null; |
| 100 | + } |
| 101 | + |
| 102 | + return rightRoles; |
| 103 | + } |
| 104 | + |
| 105 | + return null; |
| 106 | +} |
| 107 | + |
| 108 | +function getResolvedRoles(attribute) { |
| 109 | + if (!attribute?.value) { |
| 110 | + return new Set(); |
| 111 | + } |
| 112 | + |
| 113 | + if (attribute.value.type === 'Literal' && typeof attribute.value.value === 'string') { |
| 114 | + return new Set([attribute.value.value.toLowerCase()]); |
| 115 | + } |
| 116 | + |
| 117 | + if (attribute.value.type !== 'JSXExpressionContainer') { |
| 118 | + return null; |
| 119 | + } |
| 120 | + |
| 121 | + return getResolvedRolesFromExpression(attribute.value.expression); |
| 122 | +} |
| 123 | + |
| 124 | +function getResolvedRole(attribute) { |
| 125 | + return getAttributeStringValue(attribute)?.toLowerCase() ?? getConstRoleValue(attribute); |
| 126 | +} |
| 127 | + |
| 128 | +function create(context) { |
| 129 | + return { |
| 130 | + JSXOpeningElement(node) { |
| 131 | + const roleAttribute = getJSXAttribute(node, ['role', 'accessibilityRole']); |
| 132 | + const liveRegionAttribute = getJSXAttribute(node, ['accessibilityLiveRegion']); |
| 133 | + |
| 134 | + const resolvedRole = getResolvedRole(roleAttribute); |
| 135 | + const resolvedRoles = getResolvedRoles(roleAttribute); |
| 136 | + const hasKnownStatusRole = STATUS_ROLES.has(resolvedRole); |
| 137 | + const hasRoleAttribute = !!roleAttribute; |
| 138 | + const hasLiveRegion = !!liveRegionAttribute; |
| 139 | + const liveRegionValue = getAttributeStringValue(liveRegionAttribute)?.toLowerCase(); |
| 140 | + const hasAnyResolvedStatusRole = !!resolvedRoles && [...resolvedRoles].some((role) => STATUS_ROLES.has(role)); |
| 141 | + const hasOnlyResolvedNonStatusRoles = !!resolvedRoles && resolvedRoles.size > 0 && !hasAnyResolvedStatusRole; |
| 142 | + |
| 143 | + if ((hasKnownStatusRole || hasAnyResolvedStatusRole) && !hasLiveRegion) { |
| 144 | + context.report({ |
| 145 | + node, |
| 146 | + messageId: 'missingLiveRegion', |
| 147 | + }); |
| 148 | + return; |
| 149 | + } |
| 150 | + |
| 151 | + if (hasLiveRegion && (!hasRoleAttribute || hasOnlyResolvedNonStatusRoles)) { |
| 152 | + context.report({ |
| 153 | + node, |
| 154 | + messageId: 'missingStatusRole', |
| 155 | + }); |
| 156 | + return; |
| 157 | + } |
| 158 | + |
| 159 | + if ((hasKnownStatusRole || hasAnyResolvedStatusRole) && liveRegionValue === 'none') { |
| 160 | + context.report({ |
| 161 | + node, |
| 162 | + messageId: 'invalidLiveRegion', |
| 163 | + }); |
| 164 | + } |
| 165 | + }, |
| 166 | + }; |
| 167 | +} |
| 168 | + |
| 169 | +export {name, meta, create}; |
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