I want to start by saying that I do not want to diminish or disparage the work that Russ, Rob, Laurent, and others have done. It has made the Google code base better. That is an inarguable fact. Nor do I want to pick on buildifier or gofmt or any other tool as a singleton problem. I'll talk about buildifier because that is what I personally fight with. Others may have different demons. (YDMV - "your daemon may vary". I'm taking the authorship of that one now, in case it ever takes off).

But back to the point... formatting rules without firm, incredibly strict enforcement ends up being a tax on the janitors - the people who clean the code base and do large scale changes. That makes me sad. These are the people who care a great deal about code health, and their work is hindered by the lint checks that we have imposed.

Let me give an example.

I'm trying to eliminate a constraint in the build system. It's a "small" large change - only O(30K) instances. (Yeah, Google scale is different). I have an incredible wealth of tools available to me to automate the process. For the benefit of the Googlers, I can identify Blaze targets to change, use buildozer to fix them, and ship off CLs to review. But the changes I want to make are often ones which should be reviewed by the code owners, and not globally approved. So possibly O(10K) individuals might be involved in reviews.

Let's explore the problem. First, shouts to y2mango for bringing up incremental formatters. This should be the default for all tools. And another to flymasterv for raising the question of "why not just format as each person touches a BUILD file". Here's the situation.

1. buildozer is really good at rewriting BUILD files syntactically correctly.
2. It has an unfortunate side effect of not being incremental. It calls buildifier to rewrite the entire file.
3. We update the formatting rules to make them stricter over time. That means that a "correct" BUILD file on January 1, might require changes on March 1.
4. Buildifier findings are advisory, rather than mandatory.
5. No team is staffed with repeating the monumental work this post started with.

The reality on the ground is that little touched BUILD files become stale, and would require a formatting update over time. It is actually worse than that, because many teams take the path of ignoring buildifier warnings and committing their working code anyway. Without continual BUILD file reformatting there is a lot of stale floating around. [Root cause: We could fix this by promoting people for doing that repeat work. But we don't. We promote for the initial sprint.]

And then a janitor comes along.

I use bulldozer to fix a problem. It reformats an ancient BUILD file completely (not incremental). I send it to the code owner. They see changes far beyond my 2 line fix. They reject it, or ask for a change to only the two lines that actually mattered. Sure. I can hand build the change once or twice. But not for a few hundred, or thousands files. So.... I have to hack up an incremental format. Or, it turns out that users are very happy if I don't bother with formatting at all, and just change single lines. It's not that any individual is right or wrong. It is that they all have a choice and a preference and Google created a policy that allowed individual teams to have a choice of strict compliance or not. That is the failure.

If you are going to have a policy about code formatting:
- make it hard mandatory for everything except a "break glass" situation
- if the policy can evolve, staff a team with enforcing it globally

The fact that Google, as a company, does not reward this behavior does not take away from any individual's accomplishments. This post may sound grumpy to an outsider, but I am constantly amazed at the tools I have available to fix things on an enormous scale. The friction is usually only where we have good intentions, without the policy teeth to enforce alignment with the intentions. That's a management problem, not a technical one.