Just to be clear what I proposed was not a change in the compiler, just changing ExUnit's assert macro to emit the warning under that specific scenario.
> On 16 Aug 2022, at 11:59, Ben Wilson <[email protected]> wrote: > > To me this feels like a good use of credo or similar linter, not something > that the Elixir compiler itself should warn about. `assert %{} = x` isn't the > most idiomatic way to match but it isn't incoherent or invalid, just probably > not best practice. > > On Tuesday, August 16, 2022 at 5:55:09 AM UTC-4 [email protected] wrote: > Hi, > > Developers can easily shoot themselves in the foot if they write: > > assert %{} = x > > but really what they meant was to write: > > assert %{} == x > > The mistake is writing `=` instead of `==`, an easy one to make. The > difference is of course that the former will succeed on _any_ map and the > latter will _only_ succeed on an _empty_ map. > > I'd like to propose ExUnit warn on `assert %{} = x` and tell users to instead > write `assert is_map(x)`. > > Thoughts? > > P.S. In my projects I'd either write `assert actual == expected` OR `assert > expected = actual` and never `assert expected == actual` exactly because it > is easy to make the mistake. Maybe there is a Credo check to enforce such > style. > > -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/b70a4bb4-14d4-4ea3-8b49-45b408abf750n%40googlegroups.com > > <https://groups.google.com/d/msgid/elixir-lang-core/b70a4bb4-14d4-4ea3-8b49-45b408abf750n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/D3AD3ABD-1F0F-48F8-B9C2-A3E6B67E8EB1%40wojtekmach.pl.
