Add simple ppx test.

Author: cristianoc

tests/tools_tests/ppx/TestPpx.res

@@ -0,0 +1,6 @@
+Console.log("ppx test")
+
+type t = [ #A | #B ]
+
+let a: t = #A
+let b: t = #B

tests/tools_tests/src/expected/TestPpx.res.jsout

@@ -0,0 +1,15 @@
+// Generated by ReScript, PLEASE EDIT WITH CARE
+'use strict';
+
+
+console.log("ppx test");
+
+console.log("ppx test");
+
+let a = "A";
+
+let b = "B";
+
+exports.a = a;
+exports.b = b;
+/*  Not a pure module */

tests/tools_tests/test.sh

@@ -7,6 +7,15 @@ for file in src/*.{res,resi}; do
   fi
 done
 
+for file in ppx/*.res; do
+  output="src/expected/$(basename $file).jsout"
+  ../../cli/bsc -ppx "../../_build/install/default/bin/rescript-tools ppx" $file > $output
+  # # CI. We use LF, and the CI OCaml fork prints CRLF. Convert.
+  if [ "$RUNNER_OS" == "Windows" ]; then
+    perl -pi -e 's/\r\n/\n/g' -- $output
+  fi
+done
+
 warningYellow='\033[0;33m'
 successGreen='\033[0;32m'
 reset='\033[0m'

tools/bin/main.ml

@@ -56,6 +56,26 @@ let main () =
          (Tools.extractEmbedded
             ~extensionPoints:(extPointNames |> String.split_on_char ',')
             ~filename))
+  | ["ppx"; file_in; file_out] ->
+    let ic = open_in_bin file_in in
+    let magic =
+      really_input_string ic (String.length Config.ast_impl_magic_number)
+    in
+    let loc = input_value ic in
+    let ast0 : Parsetree0.structure = input_value ic in
+    let prefix =
+      match ast0 with
+      | c1 :: c2 :: _ -> [c1; c2]
+      | _ -> []
+    in
+    let ast = prefix @ ast0 in
+    close_in ic;
+    let oc = open_out_bin file_out in
+    output_string oc magic;
+    output_value oc loc;
+    output_value oc ast;
+    close_out oc;
+    exit 0
   | ["-h"] | ["--help"] -> logAndExit (Ok help)
   | ["-v"] | ["--version"] -> logAndExit (Ok version)
   | _ -> logAndExit (Error help)