Method [kGetDisplayPos]

lib/internal/readline/interface.js:1178–1213

(str)

  // Returns the last character's display position of the given string
  [kGetDisplayPos](str) {
    let offset = 0;
    const col = this.columns;
    let rows = 0;
    str = stripVTControlCharacters(str);

    for (const char of new SafeStringIterator(str)) {
      if (char === '\n') {
        // Rows must be incremented by 1 even if offset = 0 or col = +Infinity.
        rows += MathCeil(offset / col) || 1;
        // Only add prefix offset for continuation lines in user input (not prompts)
        offset = this[kIsMultiline] ? kMultilinePrompt.description.length : 0;
        continue;
      }
      // Tabs must be aligned by an offset of the tab size.
      if (char === '\t') {
        offset += this.tabSize - (offset % this.tabSize);
        continue;
      }
      const width = getStringWidth(char, false /* stripVTControlCharacters */);
      if (width === 0 || width === 1) {
        offset += width;
      } else {
        // width === 2
        if ((offset + 1) % col === 0) {
          offset++;
        }
        offset += 2;
      }
    }

    const cols = offset % col;
    rows += (offset - cols) / col;

    return { cols, rows };
  }

  /**
   * Returns the real position of the cursor in relation