first commit

node_modules/errlop/source/index.ts

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+'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)
+	}
+}