'use strict'
// hoisted due to circular dependency on command.
module.exports = {
applyMiddleware,
commandMiddlewareFactory,
globalMiddlewareFactory
}
const isPromise = require('./is-promise')
const argsert = require('./argsert')
function globalMiddlewareFactory (globalMiddleware, context) {
return function (callback, applyBeforeValidation = false) {
argsert('<array|function> [boolean]', [callback, applyBeforeValidation], arguments.length)
if (Array.isArray(callback)) {
for (let i = 0; i < callback.length; i++) {
if (typeof callback[i] !== 'function') {
throw Error('middleware must be a function')
}
callback[i].applyBeforeValidation = applyBeforeValidation
}
Array.prototype.push.apply(globalMiddleware, callback)
} else if (typeof callback === 'function') {
callback.applyBeforeValidation = applyBeforeValidation
globalMiddleware.push(callback)
}
return context
}
}
function commandMiddlewareFactory (commandMiddleware) {
if (!commandMiddleware) return []
return commandMiddleware.map(middleware => {
middleware.applyBeforeValidation = false
return middleware
})
}
function applyMiddleware (argv, yargs, middlewares, beforeValidation) {
const beforeValidationError = new Error('middleware cannot return a promise when applyBeforeValidation is true')
return middlewares
.reduce((accumulation, middleware) => {
if (middleware.applyBeforeValidation !== beforeValidation) {
return accumulation
}
if (isPromise(accumulation)) {
return accumulation
.then(initialObj =>
Promise.all([initialObj, middleware(initialObj, yargs)])
)
.then(([initialObj, middlewareObj]) =>
Object.assign(initialObj, middlewareObj)
)
} else {
const result = middleware(argv, yargs)
if (beforeValidation && isPromise(result)) throw beforeValidationError
return isPromise(result)
? result.then(middlewareObj => Object.assign(accumulation, middlewareObj))
: Object.assign(accumulation, result)
}
}, argv)
}
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