function explainFailure
explainFailure(
packageInput: string,
coderName: string,
error: unknown
): Promise<string>

Explains a failure that only surfaced once the package was imported.

A run reaches import() only when discovery vouched for the coder, or when discovery was unavailable and the name was taken on trust; either way the package can still turn out to be unloadable, or the export can still fail to behave. This runs the listing after the fact and answers with the same guidance an incomplete invocation would have given, falling back to the raw error when neither the package nor the coder is at fault — a malformed input, say.

An UnverifiedArityError is answered without running the listing. It is raised only on the trusted path, where discovery has already failed once, and asking again buys nothing but a second wait — up to another thirty seconds of it when the first attempt timed out.

The guides it renders carry no header: the caller announced the specifier before the run started, and repeating it makes every failure open with the same line twice.

Examples

A misspelled coder is answered with the listing and a suggestion

import { assertStringIncludes } from "@std/assert";
import { explainFailure } from "./cli.ts";

const text = await explainFailure(
  import.meta.resolve("../arp/mod.ts"),
  "arpDatum",
  new Error("Coder 'arpDatum' not found"),
);

assertStringIncludes(text, "no coder named 'arpDatum'");
assertStringIncludes(text, "did you mean 'arpData'?");

Parameters

packageInput: string

The package as typed, or its resolved specifier

coderName: string

The coder that was asked for

error: unknown

What the run threw

Return Type

Promise<string>

The text to write to stderr, without a trailing newline

Usage

import { explainFailure } from "cli.ts";