Spacing around block comments

[MichaReiser]

Rome always inserts a whitespace character before and after a block comment. Prettier doesn't do so:

• Leading whitespace: if the comment is directly following a ( token
• Trailing whitespace: if the comment is immediately followed by a ( or ) token.

Playground

Input

// Prettier doesn't insert a whitespace before a block comment if it is after a `(` token
// Prettier doesn't insert a whitespace character after a block comment if it is immediately followed by a `(` or `)` token

class C {
  name/*comment*/() {
  }
};


({
  name/*comment*/() {
  }
});

class Foo {
  f(/* ... */) {}
  f() /* ... */ {}
  f = (/* ... */) => {};
  static f(/* ... */) {};
  static f = (/* ... */) => {};
  static f = function(/* ... */) {};
  static f = function f(/* ... */) {};
}

let f1 = (/* ... */) => {}
(function (/* ... */) {})(/* ... */)
function f2(/* ... */) {}

const obj = {
  f(/* ... */) {},
  f: (/* ... */) => {},
  f: function(/* ... */) {},
  f: function f(/* ... */) {}
}

f(/* ... */);
f(a, /* ... */);
f(a, /* ... */ b);
f(/* ... */ a, b);

let f3 = () => import(a /* ... */);
let f4 = () => doThing(a, /* ... */ b);

if (code === 92 /* '\' */) {}
if (code === 92 /* '\' */ /* '\' */) {}

if (code === 92) /* '\' */ {}
if (code === 92) { /* '\' */ }

if (
  1
  // Comment
) {
  a;
}

Prettier

// Prettier doesn't insert a whitespace before a block comment if it is after a `(` token
// Prettier doesn't insert a whitespace character after a block comment if it is immediately followed by a `(` or `)` token

class C {
  name /*comment*/() {}
}

({
  name /*comment*/() {},
});

class Foo {
  f(/* ... */) {}
  f() /* ... */ {}
  f = (/* ... */) => {};
  static f(/* ... */) {}
  static f = (/* ... */) => {};
  static f = function (/* ... */) {};
  static f = function f(/* ... */) {};
}

let f1 = (/* ... */) => {};
(function (/* ... */) {})(/* ... */);
function f2(/* ... */) {}

const obj = {
  f(/* ... */) {},
  f: (/* ... */) => {},
  f: function (/* ... */) {},
  f: function f(/* ... */) {},
};

f(/* ... */);
f(a /* ... */);
f(a, /* ... */ b);
f(/* ... */ a, b);

let f3 = () => import(a /* ... */);
let f4 = () => doThing(a, /* ... */ b);

if (code === 92 /* '\' */) {
}
if (code === 92 /* '\' */ /* '\' */) {
}

if (code === 92) {
  /* '\' */
}
if (code === 92) {
  /* '\' */
}

if (
  1
  // Comment
) {
  a;
}

Rome

// Prettier doesn't insert a whitespace before a block comment if it is after a `(` token
// Prettier doesn't insert a whitespace character after a block comment if it is immediately followed by a `(` or `)` token

class C {
  name /*comment*/ () {}
}

({ name /*comment*/ () {} });

class Foo {
  f( /* ... */ ) {}
  f() /* ... */ {}
  f = ( /* ... */ ) => {};
  static f( /* ... */ ) {}
  static f = ( /* ... */ ) => {};
  static f = function ( /* ... */ ) {};
  static f = function f( /* ... */ ) {};
}

let f1 = ( /* ... */ ) => {};
(function ( /* ... */ ) {})( /* ... */ );
function f2( /* ... */ ) {}

const obj = {
  f( /* ... */ ) {},
  f: ( /* ... */ ) => {},
  f: function ( /* ... */ ) {},
  f: function f( /* ... */ ) {},
};

f( /* ... */ );
f(a /* ... */ );
f(a, /* ... */ b);
f( /* ... */ a, b);

let f3 = () => import(a /* ... */ );
let f4 = () => doThing(a, /* ... */ b);

if (code === 92 /* '\' */ ) {
}
if (code === 92 /* '\' */ /* '\' */ ) {
}

if (code === 92) /* '\' */ {
}
if (code === 92) {
  /* '\' */
}

if (
  1
  // Comment
) {
  a;
}

Expected

Rome's formatting to match Prettier's

[MichaReiser]

Prettier's rule is more generic than this and overall, uses very different rules for formatting comments than Rome. I'm currently looking into this as part of making our comment formatting more predictable.