Tags Validation | Typescript and Python | Hivemind

Hello developers, I have been reading and comprehending the Python code of the Hivemind. I noticed that there are many reusable functions. Therefore, in this Hivemind series, I will attempt to share the useful functions provided by Hivemind in Python and convert them into Typescript. This conversion will enhance type handling and make them usable in Typescript or Javascript.

Today, we will explore Hivemind's validation of input tags and its implementation in Python. Additionally, we will convert it into Typescript. Let's delve into it.

GitHub

https://github.com/steemit/hivemind

Python

import re

def valid_tag(tag:str, allow_empty=False):
    """Returns validated tags or throws Assert."""
    if not tag:
        assert allow_empty, 'tag was blank'
        return ""
    assert isinstance(tag, str), 'tag must be a string'
    assert re.match('^[a-z0-9-_]+$', tag), 'invalid tag `%s`' % tag
    return tag
    

def valid_tags(tags:[], allow_empty=False):
    """Returns validated tag or throws Assert."""
    if not tags:
        assert allow_empty, 'empty tags'
        return []
    for tag in tags:
        assert isinstance(tag, str), 'tag must be a string'
        assert re.match('^[a-z0-9-_]+$', tag), 'invalid tag `%s`' % tag
    return tags

Example (Python)

print(valid_tag('steempro'))

print(valid_tags(['steempro','steemit']))

Typescript

function valid_tag(tag: string, allowEmpty: boolean = false): string {
    const regex = /^[a-z0-9-_]+$/;

    if (!tag) {
        if (!allowEmpty) {
            throw new Error('Empty tag');
        }
        return '';
    }

    if (typeof tag !== 'string') {
        throw new Error('Tag must be a string');
    }

    if (!regex.test(tag)) {
        throw new Error(`Invalid tag \`${tag}\``);
    }
    

    return tag;
}

function valid_tags(tags: string[], allowEmpty: boolean = false): string[] {
    const regex = /^[a-z0-9-_]+$/;

    if (!tags) {
        if (!allowEmpty) {
            throw new Error('Empty tags');
        }
        return [];
    }

    for (const tag of tags) {
        if (typeof tag !== 'string') {
            throw new Error('Tag must be a string');
        }

        if (!regex.test(tag)) {
            throw new Error(`Invalid tag \`${tag}\``);
        }
    }

    return tags;
}

Example (Typescript)

console.log(valid_tag('steempro'))

console.log(valid_tags(['steempro','steemit']))