alt-text.js
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"use strict";
var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
Object.defineProperty(exports, "__esModule", {
value: true
});
exports["default"] = void 0;
var _jsxAstUtils = require("jsx-ast-utils");
var _schemas = require("../util/schemas");
var _getElementType = _interopRequireDefault(require("../util/getElementType"));
var _hasAccessibleChild = _interopRequireDefault(require("../util/hasAccessibleChild"));
var _isPresentationRole = _interopRequireDefault(require("../util/isPresentationRole"));
/**
* @fileoverview Enforce all elements that require alternative text have it.
* @author Ethan Cohen
*/
// ----------------------------------------------------------------------------
// Rule Definition
// ----------------------------------------------------------------------------
var DEFAULT_ELEMENTS = ['img', 'object', 'area', 'input[type="image"]'];
var schema = (0, _schemas.generateObjSchema)({
elements: _schemas.arraySchema,
img: _schemas.arraySchema,
object: _schemas.arraySchema,
area: _schemas.arraySchema,
'input[type="image"]': _schemas.arraySchema
});
var ariaLabelHasValue = function ariaLabelHasValue(prop) {
var value = (0, _jsxAstUtils.getPropValue)(prop);
if (value === undefined) {
return false;
}
if (typeof value === 'string' && value.length === 0) {
return false;
}
return true;
};
var ruleByElement = {
img(context, node, nodeType) {
var altProp = (0, _jsxAstUtils.getProp)(node.attributes, 'alt'); // Missing alt prop error.
if (altProp === undefined) {
if ((0, _isPresentationRole["default"])(nodeType, node.attributes)) {
context.report({
node,
message: 'Prefer alt="" over a presentational role. First rule of aria is to not use aria if it can be achieved via native HTML.'
});
return;
} // Check for `aria-label` to provide text alternative
// Don't create an error if the attribute is used correctly. But if it
// isn't, suggest that the developer use `alt` instead.
var ariaLabelProp = (0, _jsxAstUtils.getProp)(node.attributes, 'aria-label');
if (ariaLabelProp !== undefined) {
if (!ariaLabelHasValue(ariaLabelProp)) {
context.report({
node,
message: 'The aria-label attribute must have a value. The alt attribute is preferred over aria-label for images.'
});
}
return;
} // Check for `aria-labelledby` to provide text alternative
// Don't create an error if the attribute is used correctly. But if it
// isn't, suggest that the developer use `alt` instead.
var ariaLabelledbyProp = (0, _jsxAstUtils.getProp)(node.attributes, 'aria-labelledby');
if (ariaLabelledbyProp !== undefined) {
if (!ariaLabelHasValue(ariaLabelledbyProp)) {
context.report({
node,
message: 'The aria-labelledby attribute must have a value. The alt attribute is preferred over aria-labelledby for images.'
});
}
return;
}
context.report({
node,
message: "".concat(nodeType, " elements must have an alt prop, either with meaningful text, or an empty string for decorative images.")
});
return;
} // Check if alt prop is undefined.
var altValue = (0, _jsxAstUtils.getPropValue)(altProp);
var isNullValued = altProp.value === null; // <img alt />
if (altValue && !isNullValued || altValue === '') {
return;
} // Undefined alt prop error.
context.report({
node,
message: "Invalid alt value for ".concat(nodeType, ". Use alt=\"\" for presentational images.")
});
},
object(context, node, unusedNodeType, elementType) {
var ariaLabelProp = (0, _jsxAstUtils.getProp)(node.attributes, 'aria-label');
var arialLabelledByProp = (0, _jsxAstUtils.getProp)(node.attributes, 'aria-labelledby');
var hasLabel = ariaLabelHasValue(ariaLabelProp) || ariaLabelHasValue(arialLabelledByProp);
var titleProp = (0, _jsxAstUtils.getLiteralPropValue)((0, _jsxAstUtils.getProp)(node.attributes, 'title'));
var hasTitleAttr = !!titleProp;
if (hasLabel || hasTitleAttr || (0, _hasAccessibleChild["default"])(node.parent, elementType)) {
return;
}
context.report({
node,
message: 'Embedded <object> elements must have alternative text by providing inner text, aria-label or aria-labelledby props.'
});
},
area(context, node) {
var ariaLabelProp = (0, _jsxAstUtils.getProp)(node.attributes, 'aria-label');
var arialLabelledByProp = (0, _jsxAstUtils.getProp)(node.attributes, 'aria-labelledby');
var hasLabel = ariaLabelHasValue(ariaLabelProp) || ariaLabelHasValue(arialLabelledByProp);
if (hasLabel) {
return;
}
var altProp = (0, _jsxAstUtils.getProp)(node.attributes, 'alt');
if (altProp === undefined) {
context.report({
node,
message: 'Each area of an image map must have a text alternative through the `alt`, `aria-label`, or `aria-labelledby` prop.'
});
return;
}
var altValue = (0, _jsxAstUtils.getPropValue)(altProp);
var isNullValued = altProp.value === null; // <area alt />
if (altValue && !isNullValued || altValue === '') {
return;
}
context.report({
node,
message: 'Each area of an image map must have a text alternative through the `alt`, `aria-label`, or `aria-labelledby` prop.'
});
},
'input[type="image"]': function inputImage(context, node, nodeType) {
// Only test input[type="image"]
if (nodeType === 'input') {
var typePropValue = (0, _jsxAstUtils.getPropValue)((0, _jsxAstUtils.getProp)(node.attributes, 'type'));
if (typePropValue !== 'image') {
return;
}
}
var ariaLabelProp = (0, _jsxAstUtils.getProp)(node.attributes, 'aria-label');
var arialLabelledByProp = (0, _jsxAstUtils.getProp)(node.attributes, 'aria-labelledby');
var hasLabel = ariaLabelHasValue(ariaLabelProp) || ariaLabelHasValue(arialLabelledByProp);
if (hasLabel) {
return;
}
var altProp = (0, _jsxAstUtils.getProp)(node.attributes, 'alt');
if (altProp === undefined) {
context.report({
node,
message: '<input> elements with type="image" must have a text alternative through the `alt`, `aria-label`, or `aria-labelledby` prop.'
});
return;
}
var altValue = (0, _jsxAstUtils.getPropValue)(altProp);
var isNullValued = altProp.value === null; // <area alt />
if (altValue && !isNullValued || altValue === '') {
return;
}
context.report({
node,
message: '<input> elements with type="image" must have a text alternative through the `alt`, `aria-label`, or `aria-labelledby` prop.'
});
}
};
var _default = {
meta: {
docs: {
url: 'https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/tree/HEAD/docs/rules/alt-text.md',
description: 'Enforce all elements that require alternative text have meaningful information to relay back to end user.'
},
schema: [schema]
},
create: function create(context) {
var options = context.options[0] || {}; // Elements to validate for alt text.
var elementOptions = options.elements || DEFAULT_ELEMENTS; // Get custom components for just the elements that will be tested.
var customComponents = elementOptions.map(function (element) {
return options[element];
}).reduce(function (components, customComponentsForElement) {
return components.concat(customComponentsForElement || []);
}, []);
var typesToValidate = new Set([].concat(customComponents, elementOptions).map(function (type) {
return type === 'input[type="image"]' ? 'input' : type;
}));
var elementType = (0, _getElementType["default"])(context);
return {
JSXOpeningElement(node) {
var nodeType = elementType(node);
if (!typesToValidate.has(nodeType)) {
return;
}
var DOMElement = nodeType;
if (DOMElement === 'input') {
DOMElement = 'input[type="image"]';
} // Map nodeType to the DOM element if we are running this on a custom component.
if (elementOptions.indexOf(DOMElement) === -1) {
DOMElement = elementOptions.find(function (element) {
var customComponentsForElement = options[element] || [];
return customComponentsForElement.indexOf(nodeType) > -1;
});
}
ruleByElement[DOMElement](context, node, nodeType, elementType);
}
};
}
};
exports["default"] = _default;
module.exports = exports.default;