Use snake case for module names

Summary:
no-op

Use snake case for module names:
- Our style guide says to use Jane Street style for anything not otherwise covered in the style guide. Jane Street style is to snake it up: `Let_syntax`, `Monad_infix`.
- For consistency: in OCaml, a module is a file. Our file names are typically snake case, including for the files edited in this diff. By being consistent, we avoid switching conventions three times in the same compound name: `Typing_warning.CastNonPrimitive.cast_hint`
- Ease of refactoring: it's an implementation detail whether a module lives in another file or corresponds directly to a file. Moving a module to/from a file shouldn't require painful, manual, global renames.

mnemonic: no "camel" in "OCaml"

Reviewed By: vassilmladenov

Differential Revision: D65134093

fbshipit-source-id: 7455ef7b32a5a876e6bc2c5d9c948675244b9ab1

hphp/hack/src/typing/tast_check/cast_non_primitive.ml

@@ -90,7 +90,7 @@ let handler ~as_lint =
           ( pos,
             Typing_warning.Cast_non_primitive,
             {
-              Typing_warning.CastNonPrimitive.cast_hint =
+              Typing_warning.Cast_non_primitive.cast_hint =
                 Env.print_hint env hint;
               ty = Env.print_ty env ty;
             } )

hphp/hack/src/typing/tast_check/disjoint_types.ml

@@ -34,7 +34,7 @@ let add_warning env p name ty1 ty2 ~dynamic ~as_lint =
     ( p,
       warning_kind,
       {
-        Typing_warning.NonDisjointCheck.name = Utils.strip_ns name;
+        Typing_warning.Non_disjoint_check.name = Utils.strip_ns name;
         dynamic;
         ty1 = Env.print_ty env ty1;
         ty2 = Env.print_ty env ty2;

hphp/hack/src/typing/tast_check/duplicate_properties.ml

@@ -108,7 +108,7 @@ let add_warning
     ( pos,
       warning_kind,
       {
-        Typing_warning.DuplicateProperties.class_name;
+        Typing_warning.Duplicate_properties.class_name;
         prop_name;
         class_names;
         initialized_with_constant;

hphp/hack/src/typing/tast_check/equality_check.ml

@@ -69,7 +69,7 @@ let add_warning env ~as_lint pos kind ty1 ty2 =
         Some None
       else
         None)
-    (pos, warning_kind, { Typing_warning.EqualityCheck.kind; ty1; ty2 })
+    (pos, warning_kind, { Typing_warning.Equality_check.kind; ty1; ty2 })
 
 let error_if_inequatable env ty1 ty2 err =
   let expand_tydef =
@@ -100,21 +100,21 @@ let ensure_valid_equality_check env ~as_lint p bop e1 e2 =
        env
        ~as_lint
        p
-       (Typing_warning.EqualityCheck.Equality (equal_bop bop Diff2)))
+       (Typing_warning.Equality_check.Equality (equal_bop bop Diff2)))
 
 let ensure_valid_contains_check env ~as_lint p trv_val_ty val_ty =
   error_if_inequatable
     env
     trv_val_ty
     val_ty
-    (add_warning env ~as_lint p Typing_warning.EqualityCheck.Contains)
+    (add_warning env ~as_lint p Typing_warning.Equality_check.Contains)
 
 let ensure_valid_contains_key_check env ~as_lint p trv_key_ty key_ty =
   error_if_inequatable
     env
     trv_key_ty
     key_ty
-    (add_warning env ~as_lint p Typing_warning.EqualityCheck.Contains_key)
+    (add_warning env ~as_lint p Typing_warning.Equality_check.Contains_key)
 
 let handler ~as_lint =
   object

hphp/hack/src/typing/tast_check/is_check.ml

@@ -75,7 +75,7 @@ let trivial_check ~as_lint pos env lhs_ty rhs_ty ~always_kind ~never_kind =
         ( pos,
           warning_kind,
           {
-            Typing_warning.IsAsAlways.kind;
+            Typing_warning.Is_as_always.kind;
             lhs_ty = print_ty lhs_ty;
             rhs_ty = print_ty rhs_ty;
           } )
@@ -101,8 +101,8 @@ let handler ~as_lint =
           env
           lhs_ty
           hint_ty
-          ~always_kind:Typing_warning.IsAsAlways.Is_is_always_true
-          ~never_kind:Typing_warning.IsAsAlways.Is_is_always_false
+          ~always_kind:Typing_warning.Is_as_always.Is_is_always_true
+          ~never_kind:Typing_warning.Is_as_always.Is_is_always_false
       | ( _,
           p,
           As
@@ -120,13 +120,13 @@ let handler ~as_lint =
           lhs_ty
           hint_ty
           ~always_kind:
-            (Typing_warning.IsAsAlways.As_always_succeeds
+            (Typing_warning.Is_as_always.As_always_succeeds
                {
                  Typing_warning.can_be_captured =
                    Aast_utils.can_be_captured lhs_expr;
                  original_pos = p;
                  replacement_pos = lhs_pos;
                })
-          ~never_kind:Typing_warning.IsAsAlways.As_always_fails
+          ~never_kind:Typing_warning.Is_as_always.As_always_fails
       | _ -> ()
   end

hphp/hack/src/typing/tast_check/sketchy_null_check.ml

@@ -55,7 +55,7 @@ let sketchy_null_check env ~as_lint (ty, p, e) kind =
           ( p,
             warning_kind,
             {
-              Typing_warning.SketchyNullCheck.name;
+              Typing_warning.Sketchy_null_check.name;
               kind;
               ty = Tast_env.print_ty env ty;
             } )
@@ -75,16 +75,16 @@ let handler ~as_lint =
           env
           ~as_lint
           e
-          Typing_warning.SketchyNullCheck.Coalesce
+          Typing_warning.Sketchy_null_check.Coalesce
       | Unop (Unot, e)
       | Binop { bop = Eqeq; lhs = (_, _, Null); rhs = e }
       | Binop { bop = Eqeq; lhs = e; rhs = (_, _, Null) } ->
-        sketchy_null_check env ~as_lint e Typing_warning.SketchyNullCheck.Eq
+        sketchy_null_check env ~as_lint e Typing_warning.Sketchy_null_check.Eq
       | Eif (e, Some _, _) ->
-        sketchy_null_check env ~as_lint e Typing_warning.SketchyNullCheck.Neq
+        sketchy_null_check env ~as_lint e Typing_warning.Sketchy_null_check.Neq
       | Binop { bop = Ampamp | Barbar; lhs = e1; rhs = e2 } ->
-        sketchy_null_check env ~as_lint e1 Typing_warning.SketchyNullCheck.Neq;
-        sketchy_null_check env ~as_lint e2 Typing_warning.SketchyNullCheck.Neq
+        sketchy_null_check env ~as_lint e1 Typing_warning.Sketchy_null_check.Neq;
+        sketchy_null_check env ~as_lint e2 Typing_warning.Sketchy_null_check.Neq
       | _ -> ()
 
     method! at_stmt env x =
@@ -93,6 +93,6 @@ let handler ~as_lint =
       | Do (_, e)
       | While (e, _)
       | For (_, Some e, _, _) ->
-        sketchy_null_check env ~as_lint e Typing_warning.SketchyNullCheck.Neq
+        sketchy_null_check env ~as_lint e Typing_warning.Sketchy_null_check.Neq
       | _ -> ()
   end

hphp/hack/src/typing/tast_check/truthiness_test.ml

@@ -33,27 +33,41 @@ let add_warning env ~as_lint pos kind ty e not =
         None)
     ( pos,
       Typing_warning.Truthiness_test,
-      { Typing_warning.TruthinessTest.kind; ty; expr = get_lvar_name e; not } )
+      { Typing_warning.Truthiness_test.kind; ty; expr = get_lvar_name e; not }
+    )
 
 let truthiness_test env ~as_lint (ty, p, e) ~not : unit =
-  let module TruthinessTest = Typing_warning.TruthinessTest in
   let prim_to_string prim =
     Env.print_error_ty env (MakeType.prim_type (get_reason ty) prim)
   in
   List.iter (Tast_utils.find_sketchy_types env ty) ~f:(function
       | Tast_utils.String ->
         let tystr = prim_to_string Aast_defs.Tstring in
-        add_warning env ~as_lint p TruthinessTest.(Sketchy String) tystr e not
+        add_warning
+          env
+          ~as_lint
+          p
+          Typing_warning.Truthiness_test.(Sketchy String)
+          tystr
+          e
+          not
       | Tast_utils.Arraykey ->
         let tystr = prim_to_string Aast_defs.Tarraykey in
-        add_warning env ~as_lint p TruthinessTest.(Sketchy Arraykey) tystr e not
+        add_warning
+          env
+          ~as_lint
+          p
+          Typing_warning.Truthiness_test.(Sketchy Arraykey)
+          tystr
+          e
+          not
       | Tast_utils.Stringish ->
         let tystr = Utils.strip_ns SN.Classes.cStringish in
         add_warning
           env
           ~as_lint
           p
-          TruthinessTest.(Sketchy Stringish)
+          Typing_warning.Truthiness_test.(Sketchy Stringish)
           tystr
           e
           not
@@ -63,7 +77,7 @@ let truthiness_test env ~as_lint (ty, p, e) ~not : unit =
           env
           ~as_lint
           p
-          TruthinessTest.(Sketchy Xhp_child)
+          Typing_warning.Truthiness_test.(Sketchy Xhp_child)
           tystr
           e
           not
@@ -72,7 +86,7 @@ let truthiness_test env ~as_lint (ty, p, e) ~not : unit =
           env
           ~as_lint
           p
-          TruthinessTest.(Sketchy Traversable)
+          Typing_warning.Truthiness_test.(Sketchy Traversable)
           tystr
           e
           not);
@@ -82,7 +96,7 @@ let truthiness_test env ~as_lint (ty, p, e) ~not : unit =
       env
       ~as_lint
       p
-      TruthinessTest.(Invalid { truthy = true })
+      Typing_warning.Truthiness_test.(Invalid { truthy = true })
       (Env.print_ty env ty)
       e
       not
@@ -91,7 +105,7 @@ let truthiness_test env ~as_lint (ty, p, e) ~not : unit =
       env
       ~as_lint
       p
-      TruthinessTest.(Invalid { truthy = false })
+      Typing_warning.Truthiness_test.(Invalid { truthy = false })
       (Env.print_ty env ty)
       e
       not

hphp/hack/src/typing/typing_equality_check.ml

@@ -39,7 +39,7 @@ let trivial_comparison_error
       ( pos,
         Typing_warning.Sketchy_equality,
         {
-          Typing_warning.SketchyEquality.result;
+          Typing_warning.Sketchy_equality.result;
           left;
           right;
           left_trail;

hphp/hack/src/typing/typing_warning.ml

@@ -16,7 +16,7 @@ type quickfix = {
   replacement_pos: Pos.t;
 }
 
-module IsAsAlways = struct
+module Is_as_always = struct
   type kind =
     | Is_is_always_true
     | Is_is_always_false
@@ -30,7 +30,7 @@ module IsAsAlways = struct
   }
 end
 
-module SketchyNullCheck = struct
+module Sketchy_null_check = struct
   type kind =
     | Coalesce
     | Eq
@@ -43,7 +43,7 @@ module SketchyNullCheck = struct
   }
 end
 
-module NonDisjointCheck = struct
+module Non_disjoint_check = struct
   type t = {
     name: string;
     ty1: string;
@@ -52,7 +52,7 @@ module NonDisjointCheck = struct
   }
 end
 
-module SketchyEquality = struct
+module Sketchy_equality = struct
   type t = {
     result: bool;
     left: Pos_or_decl.t Message.t list Lazy.t;
@@ -62,14 +62,14 @@ module SketchyEquality = struct
   }
 end
 
-module CastNonPrimitive = struct
+module Cast_non_primitive = struct
   type t = {
     cast_hint: string;
     ty: string;
   }
 end
 
-module TruthinessTest = struct
+module Truthiness_test = struct
   type sketchy_kind =
     | String
     | Arraykey
@@ -89,7 +89,7 @@ module TruthinessTest = struct
   }
 end
 
-module EqualityCheck = struct
+module Equality_check = struct
   type kind =
     | Equality of bool
     | Contains
@@ -102,7 +102,7 @@ module EqualityCheck = struct
   }
 end
 
-module DuplicateProperties = struct
+module Duplicate_properties = struct
   type t = {
     class_name: string;
     prop_name: string;
@@ -112,13 +112,13 @@ module DuplicateProperties = struct
 end
 
 type (_, _) kind =
-  | Sketchy_equality : (SketchyEquality.t, warn) kind
-  | Is_as_always : (IsAsAlways.t, migrated) kind
-  | Sketchy_null_check : (SketchyNullCheck.t, migrated) kind
-  | Non_disjoint_check : (NonDisjointCheck.t, migrated) kind
-  | Cast_non_primitive : (CastNonPrimitive.t, migrated) kind
-  | Truthiness_test : (TruthinessTest.t, migrated) kind
-  | Equality_check : (EqualityCheck.t, migrated) kind
-  | Duplicate_properties : (DuplicateProperties.t, migrated) kind
+  | Sketchy_equality : (Sketchy_equality.t, warn) kind
+  | Is_as_always : (Is_as_always.t, migrated) kind
+  | Sketchy_null_check : (Sketchy_null_check.t, migrated) kind
+  | Non_disjoint_check : (Non_disjoint_check.t, migrated) kind
+  | Cast_non_primitive : (Cast_non_primitive.t, migrated) kind
+  | Truthiness_test : (Truthiness_test.t, migrated) kind
+  | Equality_check : (Equality_check.t, migrated) kind
+  | Duplicate_properties : (Duplicate_properties.t, migrated) kind
 
 type ('x, 'a) t = Pos.t * ('x, 'a) kind * 'x