deno fmt is too lax

[lucacasonato]

Here are some cases I have discovered, that I feel deno fmt is too lax about. What I mean with this, is that deno fmt likes to maintain what currently exists, over forcing a certain style. I think deno fmt should force a certain style more often.

This list is just a few examples. We should go through all dprint config options that are currently set to Maintain, and check if they should not be forcing a certain style instead. I think we should try to 1:1 match what prettier does.

Line breaks in function arguments

// Current options 

foo("foo bar", {
  why: "bar",
  bar: "foo",
});

foo(
  "foo bar",
  {
    why: "bar",
    bar: "foo",
  },
);

// Should always be

foo("foo bar", {
  why: "bar",
  bar: "foo",
});

// Current options

foo({
  foo: "bar",
  bar: "foo",
}, {
  why: "bar",
  bar: "foo",
});

foo(
  {
    foo: "bar",
    bar: "foo",
  },
  {
    why: "bar",
    bar: "foo",
  },
);

// Should always be

foo(
  {
    foo: "bar",
    bar: "foo",
  },
  {
    why: "bar",
    bar: "foo",
  }
);

// Current options

foo("foo", "bar", "foo", "nar");

foo(
  "foo",
  "bar",
  "foo",
  "nar",
);

// Should always be

foo("foo", "bar", "foo", "nar");

// Current
function name(
  item: string,
  foo: bar,
) {
}

// Should always be
function name(item: string, foo: bar) {}

For of loops

// Current
for (
  const iterator of {
    foo: bar,
  }
) {
}

// Should always be
for (const iterator of {
  foo: bar,
}) {
}

[lucacasonato]

I have discovered a good way to see this phenomenon is to go to repos formatted with deno fmt (e.g. https://github.com/denoland/deno_registry2) and run prettier on them, then run deno fmt again. There is a difference between old deno fmt and prettier, and differences between prettier and new deno fmt, and differences between old deno fmt and new deno fmt.

[dsherret]

Yeah, right now it's maintaining line breaks in many places. I wouldn't recommend turning on the "prefer single line" configuration yet as it still needs more work for some edge cases... and there are a lot of edge cases. I'm going to be slowly turning it on over time as things get better (ex. just recently turned it on for import and export declarations).