jackwener/OpenCLI · error · ArgumentError

--from and --to must differ (got ${fromName})

Error message

--from and --to must differ (got ${fromName})

What it means

Thrown by the ctrip train list command when the --from and --to values resolve to the same place name. The scraper needs an origin/destination pair to build a Ctrip train search URL; identical endpoints produce an invalid search. It is an ArgumentError because it is a caller input mistake, not a runtime failure.

Source

Thrown at clis/ctrip/train.js:48

    args: [
        { name: 'from', required: true, positional: true, help: 'Departure station or city name (e.g. 北京 / 上海虹桥)' },
        { name: 'to', required: true, positional: true, help: 'Arrival station or city name (e.g. 上海 / 杭州东)' },
        { name: 'date', required: true, help: 'Departure date (YYYY-MM-DD)' },
        { name: 'limit', default: 20, help: 'Number of trains (1-50)' },
    ],
    columns: [
        'rank',
        'trainNo',
        'departureTime', 'departureStation',
        'arrivalTime', 'arrivalStation',
        'duration', 'fromPrice', 'seats',
        'url',
    ],
    func: async (page, kwargs) => {
        const fromName = parsePlaceName('from', kwargs.from);
        const toName = parsePlaceName('to', kwargs.to);
        if (fromName === toName) {
            throw new ArgumentError(`--from and --to must differ (got ${fromName})`);
        }
        const date = parseIsoDate('date', kwargs.date);
        const limit = parseListLimit(kwargs.limit);

        const searchUrl = buildTrainListUrl(fromName, toName, date);
        await page.goto(searchUrl);
        const waitResult = await page.evaluate(WAIT_FOR_TRAINS_JS);
        if (waitResult === 'captcha') {
            throw new AuthRequiredError('trains.ctrip.com', 'Ctrip is asking for a captcha; complete it in your browser session and retry');
        }
        if (waitResult !== 'content') {
            throw new CommandExecutionError(`Ctrip train page did not render train cards (state=${String(waitResult)})`);
        }
        const renderedCardCount = await page.evaluate(buildScrollUntilJs('.card-white.list-item', limit));
        const raw = await page.evaluate(buildTrainExtractJs());
        if (!Array.isArray(raw)) {
            throw new CommandExecutionError('Ctrip train DOM extraction returned malformed rows');
        }

View on GitHub (pinned to 49907e53dc)

Solutions

  1. Pass distinct origin and destination values for --from and --to.
  2. Check how parsePlaceName normalizes input (trims, case, aliases) to understand why two different-looking strings collided.
  3. Add a pre-flight check in your script comparing normalized from/to before invoking the command.

Example fix

// before
await runTrainList({ from: '上海', to: '上海', date: '2026-09-01' });
// after
await runTrainList({ from: '上海', to: '北京', date: '2026-09-01' });
Defensive patterns

Strategy: validation

Validate before calling

function norm(s){return String(s).trim().toLowerCase();}
if (norm(opts.from) === norm(opts.to)) throw new Error('--from and --to must differ');

Type guard

const isDistinctPair = (from, to) => norm(from) !== norm(to);

Try / catch

try { await runTrainList(opts); } catch (e) { if (e instanceof ArgumentError && /must differ/.test(e.message)) { console.error('Fix from/to flags'); } else throw e; }

Prevention

When it happens

Trigger: Calling the train list command with --from and --to that normalize to the same string via parsePlaceName, e.g. --from '上海' --to '上海' or --from 'Shanghai' --to 'shanghai'.

Common situations: Copy-pasting the same station into both flags; scripting a loop where from/to variables are accidentally assigned the same value; case or whitespace differences that resolve to the same canonical name.

Related errors

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/bc9f264345feed8f. Report an issue: GitHub.