@inquirer/testing/dist/buffered-stream.js

Inquirer testing utilities

import { Stream } from 'node:stream';
import { stripVTControlCharacters } from 'node:util';
export class BufferedStream extends Stream.Writable {
    // Expose a large column width so cli-width (used by @inquirer/core's breakLines)
    // doesn't hard-wrap output at 80 columns. This prevents artificial line breaks
    // that would break assertions like toContain() in tests.
    columns = 10_000;
    #fullOutput = '';
    #chunks = [];
    #rawChunks = [];
    #writeCount = 0;
    get writeCount() {
        return this.#writeCount;
    }
    _write(chunk, _encoding, callback) {
        const str = chunk.toString();
        this.#fullOutput += str;
        // Keep track of every chunk sent through.
        this.#rawChunks.push(str);
        // Stripping the ANSI codes here because Inquirer will push commands ANSI (like cursor move.)
        // This is probably fine since we don't care about those for testing; but this could become
        // an issue if we ever want to test for those.
        if (stripVTControlCharacters(str).trim().length > 0) {
            this.#chunks.push(str);
            this.#writeCount++;
            this.emit('render');
        }
        callback();
    }
    getLastChunk({ raw } = {}) {
        const chunks = raw ? this.#rawChunks : this.#chunks;
        const lastChunk = chunks.at(-1);
        return lastChunk ?? '';
    }
    getFullOutput() {
        return this.#fullOutput;
    }
    clear() {
        this.#fullOutput = '';
        this.#chunks = [];
        this.#rawChunks = [];
    }
}