Don't report on module bindings coming from the type of first-class modules.

Fixes #107

Author: cristianoc

Changes.md

@@ -1,4 +1,5 @@
 # master
+- Don't report on module bindings coming from the type of first-class modules (see https://github.com/reason-association/reanalyze/issues/107).
 - Fix issue where `emptyArray` was reported unused for lowercase components without children. (See https://github.com/reason-association/reanalyze/issues/85).
 
 # 2.12.0

examples/deadcode/src/FC.bs.js

@@ -0,0 +1,11 @@
+module type ReplacebleComponent = {
+  [@react.component]
+  let make: unit => React.element;
+};
+
+let foo = (~impl: (module ReplacebleComponent)) => {
+  let (module X) = impl;
+  X.make;
+};
+
+Js.log(foo);

examples/deadcode/src/FC.re

@@ -425,6 +425,12 @@
   addValueDeclaration +x EverythingLiveHere.re:1:4 path:+EverythingLiveHere
   addValueDeclaration +y EverythingLiveHere.re:3:4 path:+EverythingLiveHere
   addValueDeclaration +z EverythingLiveHere.re:5:4 path:+EverythingLiveHere
+  Scanning FC.cmt Source:FC.re
+  addValueDeclaration +foo FC.re:6:4 path:+FC
+  addValueReference FC.re:7:14 --> FC.re:6:12
+  addValueReference FC.re:6:4 --> FC.re:2:2
+  addValueReference FC.re:6:4 --> FC.re:7:6
+  addValueReference FC.re:11:7 --> FC.re:6:4
   Scanning FirstClassModules.cmt Source:FirstClassModules.re
   addValueDeclaration +y FirstClassModules.re:17:6 path:+FirstClassModules.M
   addValueDeclaration +k FirstClassModules.re:21:8 path:+FirstClassModules.M.InnerModule2
@@ -1889,6 +1895,7 @@ File References
   ErrorHandler.re -->> 
   ErrorHandler.rei -->> ErrorHandler.re
   EverythingLiveHere.re -->> 
+  FC.re -->> 
   FirstClassModules.re -->> 
   FirstClassModulesInterface.re -->> 
   FirstClassModulesInterface.rei -->> FirstClassModulesInterface.re
@@ -2102,6 +2109,7 @@ File References
   Dead Value +EverythingLiveHere.+z: 0 references () [0]
   Dead Value +EverythingLiveHere.+y: 0 references () [0]
   Dead Value +EverythingLiveHere.+x: 0 references () [0]
+  Live Value +FC.+foo: 1 references (FC.re:11:7) [0]
   Live Value +FirstClassModules.+someFunctorAsFunction: 0 references () [0]
   Live Value +FirstClassModules.SomeFunctor.+ww: 1 references (FirstClassModules.re:46:20) [0]
   Live Value +FirstClassModules.+testConvert: 0 references () [0]

examples/deadcode/src/deadcode.txt

@@ -48,7 +48,13 @@ let collectValueBinding = (super, self, vb: Typedtree.value_binding) => {
         };
       let currentModulePath = ModulePath.getCurrent();
       let path = currentModulePath.path @ [Common.currentModuleName^];
-      if (!exists) {
+
+      let isFirstClassModule =
+        switch (vb.vb_expr.exp_type.desc) {
+        | Tpackage(_) => true
+        | _ => false
+        };
+      if (!exists && !isFirstClassModule) {
         // This is never toplevel currently
         let isToplevel = oldLastBinding == Location.none;
         let sideEffects = SideEffects.checkExpr(vb.vb_expr);