Objectify Function Params

When your function has many optional parameters, define the params as an object.

A real-life example from Azure DevOps's Node.js API package that I recently had to endure:

const response = await gitApi.getItems(
  repoId,
  undefined,
  undefined,
  undefined,
  undefined,
  undefined,
  undefined,
  undefined,
  {
    versionType: GitVersionType.Branch,
    version: branchName,
  },
);

Just do this instead, please:

const response = await gitApi.getItems({
  repoId,
  versionDescriptor: {
    versionType: GitVersionType.Branch,
    version: branchName,
  },
});

It gets even worse when you want to pass that 9th parameter conditionally. If branchName is an optional parameter and isn't passed in the function call, we end up with atrocities like:

// using Function.prototype.apply()
const response = await gitApi.getItems.apply(
  gitApi.getItems,
  ...(branchName
    ? [
        repoId,
        undefined,
        undefined,
        undefined,
        undefined,
        undefined,
        undefined,
        undefined,
        {
          versionType: GitVersionType.Branch,
          version: branchName,
        },
      ]
    : [repoId]),
);

// or just the good old if/else
if (branchName) {
  // ugly call goes here
} else {
  // not-so-ugly call goes here
}

The same thing could be easily done with a single object as the param:

const response = await gitApi.getItems.apply({
  repoId,
  ...(branchName
    ? {
        versionType: GitVersionType.Branch,
        version: branchName,
      }
    : {}),
});

Much neater, right? I don't like writing undefined so many times, even if I can copy/paste it or know some cool keyboard shortcut to duplicate it in my IDE. So please don't make me write undefined 7 times just because I want to pass an optional param that might be... *sigh*, undefined.