Another language's API: null or === in Python, .strip(), None or len() in JavaScript, null in Go

Calls and packages that do not exist: one of the ways AI coding agents bloat software, from lessloc's pattern catalog. lessloc catches it as made-up-api.

What makes another language's API a bad practice?

The standard that calls it a bad practice: Sonar's quality profile for agent-written code targets "hallucinated APIs"; a call that does not exist fails the first time it runs.

What does lessloc do about another language's API?

lessloc catches it as made-up-api.

• made-up-api (tier 1): Another language's API, such as null in Python, len() in JavaScript or None in Go, or an import that no manifest declares and the platform does not provide.

Examples

Caught as made-up-api:

def first(xs):
    if len(xs) === 0:
        return null
    return xs[0]

Written well:

def first(xs):
    return xs[0] if xs else None

Caught as made-up-api:

def test_load():
    doc = load("[a]\nb = 1\n")
    assert doc["a"] != null

Written well:

def test_load():
    doc = load("""\
[a]
smooth = true
""")
    assert doc["a"]["smooth"] is True

Caught as made-up-api:

export const clean = s => s.strip();

Written well:

export const clean = s => s.trim();

Related patterns

The other patterns in Calls and packages that do not exist:

• Imports of packages no manifest declares: lessloc catches it as made-up-api: checked against every package.json, Python manifest, the standard library and the project's own modules.