Do not instrument React.forwardRef and React.memo

Fixes #375.
aantron · May 4, 2021 · 6b50f77 · 6b50f77
1 parent 21b037f
commit 6b50f77
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Showing 2 changed files with 40 additions and 1 deletion.
diff --git a/src/ppx/instrument.ml b/src/ppx/instrument.ml
@@ -1094,7 +1094,9 @@ class instrumenter =
         | [%expr ignore]
         | [%expr Sys.opaque_identity]
         | [%expr Obj.magic]
-        | [%expr (##)] -> true
+        | [%expr (##)]
+        | [%expr React.forwardRef]
+        | [%expr React.memo] -> true
         | _ -> false)
       in
 

diff --git a/test/instrument/attribute.t b/test/instrument/attribute.t
@@ -80,3 +80,40 @@ Non-coverage attributes are preserved uninstrumented.
   let _ = () [@@foo print_endline "bar"]
   
   let _ = () [@foo print_endline "bar"]
+
+
+Let-bindings with [@@react.component] are not instrumented at their top level.
+
+  $ bash test.sh <<'EOF'
+  > module React = struct let forwardRef f = f () end
+  > 
+  > let make1 = fun () -> ignore ignore
+  >   [@@react.component]
+  > 
+  > let make2 () = ignore ignore
+  >   [@@react.component]
+  > 
+  > let make3 = React.forwardRef (fun r -> ignore r)
+  >   [@@react.component]
+  > EOF
+  module React = struct
+    let forwardRef f =
+      ___bisect_visit___ 0;
+      f ()
+  end
+  
+  let make1 () =
+    ___bisect_visit___ 1;
+    ignore ignore
+    [@@react.component]
+  
+  let make2 () =
+    ___bisect_visit___ 2;
+    ignore ignore
+    [@@react.component]
+  
+  let make3 =
+    React.forwardRef (fun r ->
+        ___bisect_visit___ 3;
+        ignore r)
+    [@@react.component]