jackwener/OpenCLI · error · ArgumentError

bilibili follow target cannot be empty

Error message

bilibili follow target cannot be empty

What it means

resolveTargetMid normalizes the follow target with String(raw ?? '').trim(); if the result is empty it throws this ArgumentError. The guard exists so a blank target is never forwarded to the user-search endpoint, which would return useless results.

Source

Thrown at clis/bilibili/follow.js:23

 * Accepts target as: numeric uid, username, or a space.bilibili.com profile URL.
 * Pre-checks the current relation so the result row reports `already-following`
 * accurately instead of relying on the modify API's idempotent silent success.
 */
import { cli, Strategy } from '@jackwener/opencli/registry';
import { ArgumentError, CommandExecutionError, EmptyResultError } from '@jackwener/opencli/errors';
import { parseSpaceMidUrl, fetchRelationAttribute, waitForRelation } from './relation.js';
import { apiPost, getSelfUid, requireOkPayload, resolveUid } from './utils.js';

/**
 * Pull a uid out of a `space.bilibili.com/<uid>` URL before falling back to the
 * generic resolver. `resolveUid` only handles bare digits or usernames; without
 * this short-circuit a profile URL would get sent to the user-search endpoint
 * and likely return nothing.
 */
async function resolveTargetMid(page, raw) {
    const trimmed = String(raw ?? '').trim();
    if (!trimmed) {
        throw new ArgumentError('bilibili follow target cannot be empty');
    }
    if (/^(?:https?:\/\/)?space\.bilibili\.com\//i.test(trimmed)) {
        const mid = parseSpaceMidUrl(trimmed);
        if (!mid) {
            throw new ArgumentError('bilibili follow target must be a valid space.bilibili.com/<uid> URL');
        }
        return mid;
    }
    try {
        return await resolveUid(page, trimmed);
    } catch (error) {
        if (error instanceof EmptyResultError) throw error;
        throw new ArgumentError(
            `Cannot resolve Bilibili target from input: ${trimmed}`,
            error instanceof Error ? error.message : String(error),
        );
    }
}

View on GitHub (pinned to 49907e53dc)

Solutions

1. Pass a non-empty target: UID, username, or a space.bilibili.com/<uid> URL.
2. Check the variable feeding the argument is set before invoking the CLI.
3. Add a shell-level guard: [ -n "$TARGET" ] || { echo 'target required'; exit 1; }

Example fix

// before
await cli({ args: { target: process.env.TARGET } });
// after
if (!process.env.TARGET) throw new Error('TARGET env var required');
await cli({ args: { target: process.env.TARGET } });

const target = (process.argv.target ?? '').trim();
if (!target) throw new Error('--target is required');

function hasTarget(v) {
  return typeof v === 'string' && v.trim().length > 0;
}

try {
  await follow(kwargs.target);
} catch (e) {
  if (e instanceof ArgumentError && e.message.includes('cannot be empty')) {
    console.error('Usage: bilibili follow --target <uid|username|space-url>');
    process.exitCode = 2;
    return;
  }
  throw e;
}

When it happens

Trigger: Running bilibili follow without the --target argument, or passing a value that is only whitespace / an empty string after shell expansion (e.g. TARGET="" bilibili follow).

Common situations: Scripting the CLI with an unset environment variable, forgetting the required positional/flag argument, or a config file with an empty target field.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• archive search sort must be one of ${SORT_OPTIONS.join(', ')
• archive search mediatype must be one of ${MEDIATYPES.join(',
• archive search limit must be a positive integer
• archive search limit must be <= 100
• archive search query must not be empty

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/19d066d022239b8b. Report an issue: GitHub.