- Avoid mutations in attribute parameters #29

"ppx_deriving" {with-test}

(* don't mutate attribute parameters such as 'false' in [@@deriving show {with_path=false}] *)

method! attributes _ctx attrs = return attrs

Let us try something:

$ ls ../filter_dune_build.sh

../filter_dune_build.sh

Create a file with a deriving show attribute https://github.com/jmid/mutaml/issues/28

$ cat > test.ml << EOF

> type some_type = A | B [@@deriving show {with_path = false}]

> type another_type = C | D of some_type [@@deriving show {with_path = false}]

> ;;

> assert (show_another_type C = "C")

> EOF

Create the dune files:

$ cat > dune-project << EOF

> (lang dune 2.9)

> EOF

$ cat > dune <<'EOF'

> (executable

> (name test)

> (preprocess (pps ppx_deriving.show))

> (instrumentation (backend mutaml))

> )

> EOF

Check that files were created as expected:

$ ls dune* test.ml

dune

dune-project

test.ml

Set seed and (full) mutation rate as environment variables, for repeatability

$ export MUTAML_SEED=896745231

$ export MUTAML_MUT_RATE=100

$ ../filter_dune_build.sh ./test.exe --instrument-with mutaml

Running mutaml instrumentation on "test.ml"

Randomness seed: 896745231 Mutation rate: 100 GADTs enabled: true

Created 0 mutations of test.ml

Writing mutation info to test.muts

$ ls _build

default

log

$ ls _build/default

mutaml-mut-files.txt

test.exe

test.ml

test.muts

test.pp.ml

$ mutaml-runner _build/default/test.exe

read mut file test.muts

Warning: No mutations were listed in test.muts

Did not find any mutations across the files listed in mutaml-mut-files.txt

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