now-flow/src/resolve.js

Add deployment workflows to Zeit now

// Utilities
const resolvers = require('./resolvers')

const resolverNames = Object.keys(resolvers)

module.exports = async (param, opts) => {
	for (const name of resolverNames) {
		const resolver = resolvers[name]
		let resolved

		// give the caller the ability to create
		// nicer errors by attaching the resolver name
		try {
			resolved = await resolver(param, opts)
		} catch (err) {
			err.resolverName = name
			throw err
		}

		if (resolved !== null) {
			return resolved
		}

		// otherwise continue onto the next resolver
		// note: if a resolver throws, we consider that
		// unexpected. a resolver should return `null`
		// when the parameter is unresolvable instead
	}

	return null
}