combineLatest.js

/**
 * This codemod refactors calls like combineLatest(stream1$, stream2$, ...) to combineLatest([stream1$, stream2$, ...]) as
 * the first call signature was deprecated in rxjs 6.5 (see the reason here: https://github.com/reactivex/rxjs/commit/6661c79).
 * I run this with jscodeshift (for Typescript files): jscodeshift -t combineLatest.js PATH --parser ts --extensions=ts
 */
module.exports = function(file, api) {
    const j = api.jscodeshift;
    const root = j(file.source);

    const calls = root
        .find(j.CallExpression, {
            callee: {
                name: 'combineLatest'
            }
        })
        .filter(
            p =>
                p.value.arguments.length > 1 ||
                (p.value.arguments[0].type !== 'ArrayExpression' && p.value.arguments[0].type !== 'SpreadElement')
        );

    calls.forEach(p => {
        p.value.arguments = [j.arrayExpression([...p.value.arguments])];
    });

    console.log(`Transformed ${calls.length} instances of combineLatest()`);
    return root.toSource();
};