Files
vanillajs-seed/node_modules/errlop/source/index.ts
2020-05-26 10:37:57 +02:00

129 lines
3.8 KiB
TypeScript

'use strict'
type PotentialError = Errlop | Error | ErrorCodeHolder | string
interface ErrorCodeHolder {
exitCode?: string | number
errno?: string | number
code?: string | number
}
/** Only accept codes that are numbers, otherwise discard them */
function parseCode(code: any): number | null {
const number = Number(code)
if (isNaN(number)) return null
return number
}
/** Fetch the code from the value */
function fetchCode(value: any): string | number | null {
return (
value &&
(parseCode(value.exitCode) ||
parseCode(value.errno) ||
parseCode(value.code))
)
}
/** Prevent [a weird error on node version 4](https://github.com/bevry/errlop/issues/1) and below. */
function isValid(value: any): boolean {
/* eslint no-use-before-define:0 */
return value instanceof Error || Errlop.isErrlop(value)
}
export default class Errlop extends Error {
/** Duck typing as node 4 and intanceof does not work for error extensions */
public klass: typeof Errlop
/**
* The parent error if it was provided.
* If a parent was provided, then use that, otherwise use the input's parent, if it exists.
*/
public parent?: Errlop | Error
/** An array of all the ancestors. From parent, to grand parent, and so on. */
public ancestors: Array<Errlop | Error>
/**
* A numeric code to use for the exit status if desired by the consumer.
* It cycles through [input, this, ...ancestors] until it finds the first [exitCode, errno, code] that is valid.
*/
public exitCode?: string | number
/**
* The stack for our instance alone, without any parents.
* If the input contained a stack, then use that.
*/
public orphanStack: string
/**
* The stack which now contains the accumalated stacks of its ancestors.
* This is used instead of an alias like `fullStack` or the like, to ensure existing code that uses `err.stack` doesn't need to be changed to remain functional.
*/
public stack: string
/**
* Syntatic sugar for Errlop class creation.
* Enables `Errlop.create(...args)` to achieve `new Errlop(...args)`
*/
static create(input: PotentialError, parent?: Errlop | Error): Errlop {
return new this(input, parent)
}
/**
* Create an instance of an error, using a message, as well as an optional parent.
* If the parent is provided, then the `fullStack` property will include its stack too
*/
constructor(input: PotentialError, parent?: Errlop | Error) {
if (!input) throw new Error('Attempted to create an Errlop without a input')
// Instantiate with the above
super((input as any).message || input)
// Apply
this.klass = Errlop
this.parent = parent || (input as Errlop).parent
this.ancestors = []
let ancestor = this.parent
while (ancestor) {
this.ancestors.push(ancestor)
ancestor = (ancestor as Errlop).parent
}
// this code must support node 0.8, as well as prevent a weird bug in node v4
// https://travis-ci.org/bevry/editions/jobs/408828147
let exitCode = fetchCode(input)
if (exitCode == null) exitCode = fetchCode(this)
for (
let index = 0;
index < this.ancestors.length && exitCode == null;
++index
) {
const error = this.ancestors[index]
if (isValid(error)) exitCode = fetchCode(error)
}
// Apply
if (exitCode != null) {
this.exitCode = exitCode
}
this.orphanStack = ((input as any).stack || (this as any).stack).toString()
this.stack = this.ancestors.reduce<string>(
(accumulator, error) =>
`${accumulator}\n↳ ${
(error as Errlop).orphanStack || (error as Error).stack || error
}`,
this.orphanStack
)
}
/** Check whether or not the value is an Errlop instance */
static isErrlop(value: any): boolean {
return value && (value instanceof this || value.klass === this)
}
/** Ensure that the value is an Errlop instance */
static ensure(value: any): Errlop {
return this.isErrlop(value) ? value : this.create(value)
}
}