function matchReadonlyArray()

in src/rules/expectRule.ts [306:349]

• 34 lines of code
• 13 McCabe index (conditional complexity)

function matchReadonlyArray(actual: string, expected: string) {
    if (!(/\breadonly\b/.test(actual) && /\bReadonlyArray\b/.test(expected))) return false;
    const readonlyArrayRegExp = /\bReadonlyArray</y;
    const readonlyModifierRegExp = /\breadonly /y;

    // A<ReadonlyArray<B<ReadonlyArray<C>>>>
    // A<readonly B<readonly C[]>[]>

    let expectedPos = 0;
    let actualPos = 0;
    let depth = 0;
    while (expectedPos < expected.length && actualPos < actual.length) {
        const expectedChar = expected.charAt(expectedPos);
        const actualChar = actual.charAt(actualPos);
        if (expectedChar === actualChar) {
            expectedPos++;
            actualPos++;
            continue;
        }

        // check for end of readonly array
        if (depth > 0 && expectedChar === ">" && actualChar === "[" && actualPos < actual.length - 1 &&
            actual.charAt(actualPos + 1) === "]") {
            depth--;
            expectedPos++;
            actualPos += 2;
            continue;
        }

        // check for start of readonly array
        readonlyArrayRegExp.lastIndex = expectedPos;
        readonlyModifierRegExp.lastIndex = actualPos;
        if (readonlyArrayRegExp.test(expected) && readonlyModifierRegExp.test(actual)) {
            depth++;
            expectedPos += 14; // "ReadonlyArray<".length;
            actualPos += 9; // "readonly ".length;
            continue;
        }

        return false;
    }

    return true;
}