cli-legend
Version:
"A fun command-line rogurelike dungeon game"
111 lines (110 loc) • 5.34 kB
JavaScript
import * as readline from 'node:readline';
import { AsyncResource } from 'node:async_hooks';
import MuteStream from 'mute-stream';
import { onExit as onSignalExit } from 'signal-exit';
import ScreenManager from './screen-manager.js';
import { PromisePolyfill } from './promise-polyfill.js';
import { withHooks, effectScheduler } from './hook-engine.js';
import { AbortPromptError, CancelPromptError, ExitPromptError } from './errors.js';
function getCallSites() {
const _prepareStackTrace = Error.prepareStackTrace;
let result = [];
try {
Error.prepareStackTrace = (_, callSites) => {
const callSitesWithoutCurrent = callSites.slice(1);
result = callSitesWithoutCurrent;
return callSitesWithoutCurrent;
};
// eslint-disable-next-line @typescript-eslint/no-unused-expressions, unicorn/error-message
new Error().stack;
}
catch {
// An error will occur if the Node flag --frozen-intrinsics is used.
// https://nodejs.org/api/cli.html#--frozen-intrinsics
return result;
}
Error.prepareStackTrace = _prepareStackTrace;
return result;
}
export function createPrompt(view) {
const callSites = getCallSites();
const prompt = (config, context = {}) => {
// Default `input` to stdin
const { input = process.stdin, signal } = context;
const cleanups = new Set();
// Add mute capabilities to the output
const output = new MuteStream();
output.pipe(context.output ?? process.stdout);
const rl = readline.createInterface({
terminal: true,
input,
output,
});
const screen = new ScreenManager(rl);
const { promise, resolve, reject } = PromisePolyfill.withResolver();
const cancel = () => reject(new CancelPromptError());
if (signal) {
const abort = () => reject(new AbortPromptError({ cause: signal.reason }));
if (signal.aborted) {
abort();
return Object.assign(promise, { cancel });
}
signal.addEventListener('abort', abort);
cleanups.add(() => signal.removeEventListener('abort', abort));
}
cleanups.add(onSignalExit((code, signal) => {
reject(new ExitPromptError(`User force closed the prompt with ${code} ${signal}`));
}));
// Re-renders only happen when the state change; but the readline cursor could change position
// and that also requires a re-render (and a manual one because we mute the streams).
// We set the listener after the initial workLoop to avoid a double render if render triggered
// by a state change sets the cursor to the right position.
const checkCursorPos = () => screen.checkCursorPos();
rl.input.on('keypress', checkCursorPos);
cleanups.add(() => rl.input.removeListener('keypress', checkCursorPos));
return withHooks(rl, (cycle) => {
// The close event triggers immediately when the user press ctrl+c. SignalExit on the other hand
// triggers after the process is done (which happens after timeouts are done triggering.)
// We triggers the hooks cleanup phase on rl `close` so active timeouts can be cleared.
const hooksCleanup = AsyncResource.bind(() => effectScheduler.clearAll());
rl.on('close', hooksCleanup);
cleanups.add(() => rl.removeListener('close', hooksCleanup));
cycle(() => {
try {
const nextView = view(config, (value) => {
setImmediate(() => resolve(value));
});
// Typescript won't allow this, but not all users rely on typescript.
// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
if (nextView === undefined) {
const callerFilename = callSites[1]?.getFileName?.();
throw new Error(`Prompt functions must return a string.\n at ${callerFilename}`);
}
const [content, bottomContent] = typeof nextView === 'string' ? [nextView] : nextView;
screen.render(content, bottomContent);
effectScheduler.run();
}
catch (error) {
reject(error);
}
});
return Object.assign(promise
.then((answer) => {
effectScheduler.clearAll();
return answer;
}, (error) => {
effectScheduler.clearAll();
throw error;
})
// Wait for the promise to settle, then cleanup.
.finally(() => {
cleanups.forEach((cleanup) => cleanup());
screen.done({ clearContent: Boolean(context.clearPromptOnDone) });
output.end();
})
// Once cleanup is done, let the expose promise resolve/reject to the internal one.
.then(() => promise), { cancel });
});
};
return prompt;
}