@ethereum-waffle/chai/src/matchers/hexEqual.ts

A sweet set of chai matchers for your blockchain testing needs.

export function supportHexEqual(Assertion: Chai.AssertionStatic) {
  Assertion.addMethod('hexEqual', function (this: any, other: string) {
    const subject = this._obj;
    const isNegated = this.__flags.negate === true;
    const isHex = (a: string) => /^0x[0-9a-fA-F]*$/.test(a);
    for (const element of [subject, other]) {
      if (!isHex(element)) {
        this.assert(
          isNegated,
          `Expected "${subject}" to be a hex string equal to "${other}", but "${element}" is not a valid hex string`,
          `Expected "${subject}" not to be a hex string equal to "${other}", but "${element}" is not a valid hex string`
        );
      }
    }
    const extractNumeric = (hex: string) => hex.replace(/^0x0*/, '');
    this.assert(
      extractNumeric(subject.toLowerCase()) === extractNumeric(other.toLowerCase()),
      `Expected "${subject}" to be a hex string equal equal to "${other}"`,
      `Expected "${subject}" not to a hex string equal be equal to "${other}", but it was`,
      `Hex string representing the same number as ${other}`,
      subject
    );
  });
}