validation.ts

/**
 * Validates a table name. <br>
 * Throws an error if table name is invalid.
 *
 * @param {string} name - The table name to validate.
 * @param {number} maxNameLength - The maximum length of table names.
 */
function validateTableName(name: string, maxNameLength: number) {
  const len = name.length;
  if (len > maxNameLength) {
    throw new Error(`Table name is too long, max length is ${maxNameLength}`);
  }
  if (len === 0) {
    throw new Error("Empty string is not allowed as table name");
  }
  for (let i = 0; i < len; i++) {
    const ch = name[i];
    switch (ch) {
      case ".":
        if (i === 0 || i === len - 1 || name[i - 1] === ".")
          // single dot is allowed in the middle only
          // starting with a dot hides directory in Linux
          // ending with a dot can be trimmed by some Windows versions / file systems
          // double or triple dot looks suspicious
          // single dot allowed as compatibility,
          // when someone uploads 'file_name.csv' the file name used as the table name
          throw new Error(
            "Table name cannot start or end with a dot, and only a single dot allowed",
          );
        break;
      case "?":
      case ",":
      case "'":
      case '"':
      case "\\":
      case "/":
      case ":":
      case ")":
      case "(":
      case "+":
      case "*":
      case "%":
      case "~":
      case "\u0000":
      case "\u0001":
      case "\u0002":
      case "\u0003":
      case "\u0004":
      case "\u0005":
      case "\u0006":
      case "\u0007":
      case "\u0008":
      case "\u0009": // control characters, except \n.
      case "\u000B": // new line allowed for compatibility, there are tests to make sure it works
      case "\u000c":
      case "\r":
      case "\n":
      case "\u000e":
      case "\u000f":
      case "\u007f":
      case "\ufeff": // UTF-8 BOM (Byte Order Mark) can appear at the beginning of a character stream
        throw new Error(`Invalid character in table name: ${ch}`);
    }
  }
}

/**
 * Validates a column name. <br>
 * Throws an error if column name is invalid.
 *
 * @param {string} name - The column name to validate.
 * @param {number} maxNameLength - The maximum length of column names.
 */
function validateColumnName(name: string, maxNameLength: number) {
  const len = name.length;
  if (len > maxNameLength) {
    throw new Error(`Column name is too long, max length is ${maxNameLength}`);
  }
  if (len === 0) {
    throw new Error("Empty string is not allowed as column name");
  }
  for (const ch of name) {
    switch (ch) {
      case "?":
      case ".":
      case ",":
      case "'":
      case '"':
      case "\\":
      case "/":
      case ":":
      case ")":
      case "(":
      case "+":
      case "-":
      case "*":
      case "%":
      case "~":
      case "\u0000":
      case "\u0001":
      case "\u0002":
      case "\u0003":
      case "\u0004":
      case "\u0005":
      case "\u0006":
      case "\u0007":
      case "\u0008":
      case "\u0009": // control characters, except \n
      case "\u000B":
      case "\u000c":
      case "\r":
      case "\n":
      case "\u000e":
      case "\u000f":
      case "\u007f":
      case "\ufeff": // UTF-8 BOM (Byte Order Mark) can appear at the beginning of a character stream
        throw new Error(`Invalid character in column name: ${ch}`);
    }
  }
}

export { validateTableName, validateColumnName };