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/**
* Rule: prefer-await-to-then
* Discourage using then() and instead use async/await.
*/
'use strict'
const getDocsUrl = require('./lib/get-docs-url')
module.exports = {
meta: {
docs: {
url: getDocsUrl('prefer-await-to-then')
}
},
create(context) {
/** Returns true if node is inside yield or await expression. */
function isInsideYieldOrAwait() {
return context.getAncestors().some(parent => {
return (
parent.type === 'AwaitExpression' || parent.type === 'YieldExpression'
)
})
}
/**
* Returns true if node is created at the top-level scope.
* Await statements are not allowed at the top level,
* only within function declarations.
*/
function isTopLevelScoped() {
return context.getScope().block.type === 'Program'
}
return {
MemberExpression(node) {
if (isTopLevelScoped() || isInsideYieldOrAwait()) {
return
}
// if you're a then expression then you're probably a promise
if (node.property && node.property.name === 'then') {
context.report({
node: node.property,
message: 'Prefer await to then().'
})
}
}
}
}
}