text: //@flow
  "use strict";
  
  import {test} from "tape";
  import {SPACE, EMPTY_STRING, isEmptyString} from "../src/string";
  
  test("Custom error classes", function(t) {
  
    t.ok(typeof isEmptyString === "function",
        "Function customError is imported.");
  
    t.ok(typeof EMPTY_STRING === "string",
      "EMPTY_STRING is imported.");
  
    t.equal(EMPTY_STRING, "", "EMPTY_STRING === ''");
  
    let str = EMPTY_STRING;
    t.true(isEmptyString(str), `isEmptyString('${str}') returns true`);
  
    str = "foo";
    t.false(isEmptyString(str), `isEmptyString('${str}') returns false`);
  
    str = "  ";
    t.true(isEmptyString(str), `isEmptyString('${str}') returns true`);
  
    t.true(isEmptyString("\n"), "isEmptyString('\\n') returns true");
    t.true(isEmptyString("\t"), "isEmptyString('\\t') returns true");
    t.true(isEmptyString("\t\n\t"), "isEmptyString('\\t\\n\\t') returns true");
  
    t.equal(SPACE, " ", "A space > <.");
    t.notEqual(SPACE, EMPTY_STRING, "SPACE is not an EMPTY_STRING.");
    t.true(isEmptyString(SPACE), "SPACE is an empty string.");
  
    // --------------------------------------------------------------------------
    t.end();
  
  });
  