eslint-plugin-vue
Version:
Official ESLint plugin for Vue.js
291 lines (274 loc) • 9.27 kB
JavaScript
/**
* @author Toru Nagashima
* See LICENSE file in root directory for full license.
*/
'use strict'
const utils = require('../utils')
/**
* Get all `v-slot` directives on a given element.
* @param {VElement} node The VElement node to check.
* @returns {VDirective[]} The array of `v-slot` directives.
*/
function getSlotDirectivesOnElement(node) {
return utils.getDirectives(node, 'slot')
}
/**
* Get all `v-slot` directives on the children of a given element.
* @param {VElement} node The VElement node to check.
* @returns {VDirective[][]}
* The array of the group of `v-slot` directives.
* The group bundles `v-slot` directives of element sequence which is connected
* by `v-if`/`v-else-if`/`v-else`.
*/
function getSlotDirectivesOnChildren(node) {
return node.children
.reduce(
({ groups, vIf }, childNode) => {
if (childNode.type === 'VElement') {
let connected
if (utils.hasDirective(childNode, 'if')) {
connected = false
vIf = true
} else if (utils.hasDirective(childNode, 'else-if')) {
connected = vIf
vIf = true
} else if (utils.hasDirective(childNode, 'else')) {
connected = vIf
vIf = false
} else {
connected = false
vIf = false
}
if (connected) {
groups[groups.length - 1].push(childNode)
} else {
groups.push([childNode])
}
} else if (
childNode.type !== 'VText' ||
childNode.value.trim() !== ''
) {
vIf = false
}
return { groups, vIf }
},
{
/** @type {VElement[][]} */
groups: [],
vIf: false
}
)
.groups.map((group) =>
group
.map((childElement) =>
childElement.name === 'template'
? utils.getDirective(childElement, 'slot')
: null
)
.filter(utils.isDef)
)
.filter((group) => group.length >= 1)
}
/**
* Get the normalized name of a given `v-slot` directive node.
* @param {VDirective} node The `v-slot` directive node.
* @param {SourceCode} sourceCode The source code.
* @returns {string} The normalized name.
*/
function getNormalizedName(node, sourceCode) {
return node.key.argument == null
? 'default'
: sourceCode.getText(node.key.argument)
}
/**
* Get all `v-slot` directives which are distributed to the same slot as a given `v-slot` directive node.
* @param {VDirective[][]} vSlotGroups The result of `getAllNamedSlotElements()`.
* @param {VDirective} currentVSlot The current `v-slot` directive node.
* @param {SourceCode} sourceCode The source code.
* @returns {VDirective[][]} The array of the group of `v-slot` directives.
*/
function filterSameSlot(vSlotGroups, currentVSlot, sourceCode) {
const currentName = getNormalizedName(currentVSlot, sourceCode)
return vSlotGroups
.map((vSlots) =>
vSlots.filter(
(vSlot) => getNormalizedName(vSlot, sourceCode) === currentName
)
)
.filter((slots) => slots.length >= 1)
}
/**
* Check whether a given argument node is using an iteration variable that the element defined.
* @param {VExpressionContainer|VIdentifier|null} argument The argument node to check.
* @param {VElement} element The element node which has the argument.
* @returns {boolean} `true` if the argument node is using the iteration variable.
*/
function isUsingIterationVar(argument, element) {
if (argument && argument.type === 'VExpressionContainer') {
for (const { variable } of argument.references) {
if (
variable != null &&
variable.kind === 'v-for' &&
variable.id.range[0] > element.startTag.range[0] &&
variable.id.range[1] < element.startTag.range[1]
) {
return true
}
}
}
return false
}
/**
* Check whether a given argument node is using an scope variable that the directive defined.
* @param {VDirective} vSlot The `v-slot` directive to check.
* @returns {boolean} `true` if that argument node is using a scope variable the directive defined.
*/
function isUsingScopeVar(vSlot) {
const argument = vSlot.key.argument
const value = vSlot.value
if (argument && value && argument.type === 'VExpressionContainer') {
for (const { variable } of argument.references) {
if (
variable != null &&
variable.kind === 'scope' &&
variable.id.range[0] > value.range[0] &&
variable.id.range[1] < value.range[1]
) {
return true
}
}
}
return false
}
module.exports = {
meta: {
type: 'problem',
docs: {
description: 'enforce valid `v-slot` directives',
categories: ['vue3-essential', 'essential'],
url: 'https://eslint.vuejs.org/rules/valid-v-slot.html'
},
fixable: null,
schema: [],
messages: {
ownerMustBeCustomElement:
"'v-slot' directive must be owned by a custom element, but '{{name}}' is not.",
namedSlotMustBeOnTemplate:
"Named slots must use '<template>' on a custom element.",
defaultSlotMustBeOnTemplate:
"Default slot must use '<template>' on a custom element when there are other named slots.",
disallowDuplicateSlotsOnElement:
"An element cannot have multiple 'v-slot' directives.",
disallowDuplicateSlotsOnChildren:
"An element cannot have multiple '<template>' elements which are distributed to the same slot.",
disallowArgumentUseSlotParams:
"Dynamic argument of 'v-slot' directive cannot use that slot parameter.",
disallowAnyModifier: "'v-slot' directive doesn't support any modifier.",
requireAttributeValue:
"'v-slot' directive on a custom element requires that attribute value."
}
},
/** @param {RuleContext} context */
create(context) {
const sourceCode = context.getSourceCode()
return utils.defineTemplateBodyVisitor(context, {
/** @param {VDirective} node */
"VAttribute[directive=true][key.name.name='slot']"(node) {
const isDefaultSlot =
node.key.argument == null ||
(node.key.argument.type === 'VIdentifier' &&
node.key.argument.name === 'default')
const element = node.parent.parent
const parentElement = element.parent
const ownerElement =
element.name === 'template' ? parentElement : element
if (ownerElement.type === 'VDocumentFragment') {
return
}
const vSlotsOnElement = getSlotDirectivesOnElement(element)
const vSlotGroupsOnChildren = getSlotDirectivesOnChildren(ownerElement)
// Verify location.
if (!utils.isCustomComponent(ownerElement)) {
context.report({
node,
messageId: 'ownerMustBeCustomElement',
data: { name: ownerElement.rawName }
})
}
if (!isDefaultSlot && element.name !== 'template') {
context.report({
node,
messageId: 'namedSlotMustBeOnTemplate'
})
}
if (ownerElement === element && vSlotGroupsOnChildren.length >= 1) {
context.report({
node,
messageId: 'defaultSlotMustBeOnTemplate'
})
}
// Verify duplication.
if (vSlotsOnElement.length >= 2 && vSlotsOnElement[0] !== node) {
// E.g., <my-component #one #two>
context.report({
node,
messageId: 'disallowDuplicateSlotsOnElement'
})
}
if (ownerElement === parentElement) {
const vSlotGroupsOfSameSlot = filterSameSlot(
vSlotGroupsOnChildren,
node,
sourceCode
)
const vFor = utils.getDirective(element, 'for')
if (
vSlotGroupsOfSameSlot.length >= 2 &&
!vSlotGroupsOfSameSlot[0].includes(node)
) {
// E.g., <template #one></template>
// <template #one></template>
context.report({
node,
messageId: 'disallowDuplicateSlotsOnChildren'
})
}
if (vFor && !isUsingIterationVar(node.key.argument, element)) {
// E.g., <template v-for="x of xs" #one></template>
context.report({
node,
messageId: 'disallowDuplicateSlotsOnChildren'
})
}
}
// Verify argument.
if (isUsingScopeVar(node)) {
context.report({
node,
messageId: 'disallowArgumentUseSlotParams'
})
}
// Verify modifiers.
if (node.key.modifiers.length >= 1) {
context.report({
node,
messageId: 'disallowAnyModifier'
})
}
// Verify value.
if (
ownerElement === element &&
isDefaultSlot &&
(!node.value ||
utils.isEmptyValueDirective(node, context) ||
utils.isEmptyExpressionValueDirective(node, context))
) {
context.report({
node,
messageId: 'requireAttributeValue'
})
}
}
})
}
}