chore: do not depend on ocamlformat in tests (#10745)

Signed-off-by: Etienne Millon <me@emillon.org>

Makefile

@@ -54,7 +54,7 @@ install-ocamlformat:
 	opam install -y ocamlformat.$$(awk -F = '$$1 == "version" {print $$2}' .ocamlformat)
 
 .PHONY: dev-deps
-dev-deps: install-ocamlformat
+dev-deps:
 	opam install -y . --deps-only --with-dev-setup
 
 .PHONY: coverage-deps

test/blackbox-tests/test-cases/dialects/dune

@@ -0,0 +1,7 @@
+(env
+ (_
+  (binaries ../../utils/ocamlformat.exe)))
+
+(cram
+ (applies_to :whole_subtree)
+ (deps %{bin:ocamlformat}))

test/blackbox-tests/test-cases/dialects/no_impl.t/run.t

@@ -3,4 +3,13 @@ Test the (dialect ...) stanza inside the `dune-project` file.
   $ dune exec ./main.exe
 
   $ dune build @fmt
+  fake ocamlformat is running: "--impl" "fmt.ml"
+  fake ocamlformat is running: "--impl" "main.ml"
   Formatting main.mfi
+  File "fmt.ml", line 1, characters 0-0:
+  Error: Files _build/default/fmt.ml and _build/default/.formatted/fmt.ml
+  differ.
+  File "main.ml", line 1, characters 0-0:
+  Error: Files _build/default/main.ml and _build/default/.formatted/main.ml
+  differ.
+  [1]

test/blackbox-tests/test-cases/dialects/no_intf_good.t/run.t

@@ -3,4 +3,9 @@ Test the (dialect ...) stanza inside the dune-project file.
   $ dune exec ./main.exe
 
   $ dune build @fmt
+  fake ocamlformat is running: "--impl" "fmt.ml"
   Formatting main.mf
+  File "fmt.ml", line 1, characters 0-0:
+  Error: Files _build/default/fmt.ml and _build/default/.formatted/fmt.ml
+  differ.
+  [1]

test/blackbox-tests/test-cases/formatting/dune

@@ -0,0 +1,7 @@
+(env
+ (_
+  (binaries ../../utils/ocamlformat.exe)))
+
+(cram
+ (applies_to :whole_subtree)
+ (deps %{bin:ocamlformat}))

test/blackbox-tests/test-cases/formatting/feature.t/run.t

@@ -225,6 +225,7 @@ Formatting can also be set in the (env ...) stanza
   > EOF
   $ touch using-env/.ocamlformat
   $ (cd using-env && dune build @fmt)
+  fake ocamlformat is running: "--impl" "subdir/foo.ml"
   File "subdir/foo.ml", line 1, characters 0-0:
   Error: Files _build/default/subdir/foo.ml and
   _build/default/subdir/.formatted/foo.ml differ.

test/blackbox-tests/test-cases/formatting/load-automatic-dirs.t

@@ -12,6 +12,7 @@
   > (library (name lib_reason))
   > EOF
   $ dune build ./bin/.formatted/ocaml_file.ml
+  fake ocamlformat is running: "--impl" "bin/ocaml_file.ml"
 
 .formatted dir is loaded
 

test/blackbox-tests/test-cases/formatting/no-gen.t

@@ -57,10 +57,15 @@ Now we add [mli] files for the two modules whose implementation is generated:
 
 We format again.
   $ dune build @fmt
+  fake ocamlformat is running: "--intf" "other_gen.mli"
   Warning: one state end-of-stream conflict was arbitrarily resolved.
   File "parser_raw.mly", line 5, characters 4-7:
   Warning: production prog -> EOL is never reduced.
   Warning: in total, 1 production is never reduced.
+  fake ocamlformat is running: "--intf" "parser_raw.mli"
+  File "other_gen.mli", line 1, characters 0-0:
+  Error: Files _build/default/other_gen.mli and
+  _build/default/.formatted/other_gen.mli differ.
   File "parser_raw.mli", line 1, characters 0-0:
   Error: Files _build/default/parser_raw.mli and
   _build/default/.formatted/parser_raw.mli differ.

test/blackbox-tests/utils/dune

@@ -38,3 +38,7 @@
  (modules ocaml_index)
  (name ocaml_index)
  (libraries cmdliner))
+
+(executable
+ (modules ocamlformat)
+ (name ocamlformat))

test/blackbox-tests/utils/ocamlformat.ml

@@ -0,0 +1,16 @@
+(* This can be used when testing formatting rules instead of calling the real
+   ocamlformat binary. But when doing so, be careful not to expose it to too
+   many tests because it will be also be used by `@fmt` in dune itself.
+*)
+
+let () =
+  let args =
+    Sys.argv
+    |> Array.to_list
+    |> List.tl
+    |> List.map (fun s -> Printf.sprintf "%S" s)
+    |> String.concat " "
+  in
+  Printf.eprintf "fake ocamlformat is running: %s\n" args;
+  Printf.printf "(* fake ocamlformat output *)"
+;;