Line breaks should favor method chaining for long statements

[tvolkert]

This following was formatted by dartfmt:

          expect(
              events[0],
              invokesMethod('file').on(fs).withPositionalArguments(
                  <String>['/foo']).withResult(isFile));

But there's clearly a method chain happening here, and it would be significantly more readable if it were expressed as:

          expect(
              events[0],
              invokesMethod('file')
                  .on(fs)
                  .withPositionalArguments(<String>['/foo'])
                  .withResult(isFile));

(separate issue is why events[0] is put on its own line, but that's lower priority).

[tvolkert]

@Hixie

[munificent]

Yeah, it would be nice if it recognized the chain better here. I think the problem is the list literal. When you have collection literals in a method chain, it also considers formatting it like:

method([
  stuff...
].method([
  more stuff...
]);

In theory, it can handle both styles, but determining which to choose is difficult for it and there may be some interaction between the two.

[munificent]

The forthcoming tall style handles this better and gives you:

          expect(
            events[0],
            invokesMethod('file')
                .on(fs)
                .withPositionalArguments(<String>['/foo'])
                .withResult(isFile),
          );