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Diffstat (limited to 'node_modules/yargs/lib/middleware.js')
-rw-r--r-- | node_modules/yargs/lib/middleware.js | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/node_modules/yargs/lib/middleware.js b/node_modules/yargs/lib/middleware.js new file mode 100644 index 000000000..56dab7527 --- /dev/null +++ b/node_modules/yargs/lib/middleware.js @@ -0,0 +1,64 @@ +'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) +} |