how elm-format and prettier deal with ambiguity

nudge-formatter.md

Case Study: how to branch without options

elm-format inspired prettier to let the user branch between two different formatters without the use of explicit options, by taking cues from the source's original formatting. (see multi-line objects)

• Context: an object literal is sometimes better displayed on multiple lines even it can fit on one
• Problem: it was deemed impossible for the formatter to know when multiline is preferable
• Solution: allow the user to insert a newline after the first curly to force multiline

// before
const a = {foo:1, bar:2};  // <-- no newline after curly allows default formatting

// after
const a = { foo: 1, bar: 2 };

// before
const a = {                // <-- newline after the curly forces MULTILINE formatting
foo:1, bar:2};

// after:
const a = {
  foo:1,
  bar:2
};