[litho] support optional Prop's

Summary: Don't want to warn when `Prop(optional = true)`'s aren't provided to the `Builder`.

Reviewed By: jeremydubreil

Differential Revision: D6741579

fbshipit-source-id: b1ae3ed

infer/src/checkers/Litho.ml

@@ -99,11 +99,24 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
 
 
   let get_required_props typename tenv =
+    let is_required_prop annotations =
+      List.exists
+        ~f:(fun ({Annot.class_name; parameters}, _) ->
+          String.is_suffix class_name ~suffix:Annotations.prop
+          && (* Don't count as required if it's @Prop(optional = true). Note: this is a hack. We
+                only translate boolean parameters at the moment, and we only translate the value of
+                the parameter (as a string, lol), not its name. In this case, the only boolean
+                parameter of @Prop is optional, and its default value is false. So it suffices to
+                do the "one parameter true" check *)
+             not (List.exists ~f:(fun annot_string -> String.equal annot_string "true") parameters)
+          )
+        annotations
+    in
     match Tenv.lookup tenv typename with
     | Some {fields} ->
         List.filter_map
-          ~f:(fun (fieldname, _, annot) ->
+          ~f:(fun (fieldname, _, annotation) ->
-            if Annotations.ia_is_prop annot then Some (Typ.Fieldname.Java.get_field fieldname)
+            if is_required_prop annotation then Some (Typ.Fieldname.Java.get_field fieldname)
             else None )
           fields
     | None ->
@@ -139,7 +152,8 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
               let prop_set =
                 List.fold prop_setter_calls
                   ~f:(fun acc pname -> String.Set.add acc (Typ.Procname.get_method pname))
-                  ~init:String.Set.empty in
+                  ~init:String.Set.empty
+              in
               List.iter
                 ~f:(fun required_prop ->
                   if not (String.Set.mem prop_set required_prop) then

infer/src/checkers/annotations.mli

@@ -25,6 +25,8 @@ val performance_critical : string
 
 val present : string
 
+val prop : string
+
 val for_non_ui_thread : string
 
 val for_ui_thread : string

infer/tests/codetoanalyze/java/litho/RequiredProps.java

@@ -1,3 +1,5 @@
+package codetoanalyze.java.litho;
+
 /*
  * Copyright (c) 2018 - present Facebook, Inc.
  * All rights reserved.
@@ -80,8 +82,8 @@ public class RequiredProps {
         .build();
   }
 
-  // need to parse optional boolean for this to work
+  // prop 2 is optional
-  public MyComponent FP_buildWithRequiredOk() {
+  public MyComponent buildWithout2Ok() {
     return
       mMyComponent
         .create()
@@ -90,6 +92,7 @@ public class RequiredProps {
         .build();
   }
 
+  // prop 1 is required
   public MyComponent buildWithout1Bad() {
     return
       mMyComponent
@@ -99,12 +102,13 @@ public class RequiredProps {
         .build();
   }
 
-  public MyComponent buildWithout2Bad() {
+  // prop3 is required
+  public MyComponent buildWithout3Bad() {
     return
       mMyComponent
         .create()
         .prop1(new Object())
-        .prop3(new Object())
+        .prop2(new Object())
         .build();
   }
 

infer/tests/codetoanalyze/java/litho/issues.exp

@@ -1,8 +1,7 @@
 codetoanalyze/java/litho/RequiredProps.java, MyComponent RequiredProps.FP_buildSuffix(MyComponent$Builder), 1, MISSING_REQUIRED_PROP, [@Prop prop1 is required, but not set before the call to build()]
-codetoanalyze/java/litho/RequiredProps.java, MyComponent RequiredProps.FP_buildWithRequiredOk(), 6, MISSING_REQUIRED_PROP, [@Prop prop2 is required, but not set before the call to build()]
 codetoanalyze/java/litho/RequiredProps.java, MyComponent RequiredProps.FP_setRequiredOnBothBranchesOk(boolean), 7, MISSING_REQUIRED_PROP, [@Prop prop1 is required, but not set before the call to build()]
 codetoanalyze/java/litho/RequiredProps.java, MyComponent RequiredProps.buildWithout1Bad(), 6, MISSING_REQUIRED_PROP, [@Prop prop1 is required, but not set before the call to build()]
-codetoanalyze/java/litho/RequiredProps.java, MyComponent RequiredProps.buildWithout2Bad(), 6, MISSING_REQUIRED_PROP, [@Prop prop2 is required, but not set before the call to build()]
+codetoanalyze/java/litho/RequiredProps.java, MyComponent RequiredProps.buildWithout3Bad(), 6, MISSING_REQUIRED_PROP, [@Prop prop3 is required, but not set before the call to build()]
 codetoanalyze/java/litho/RequiredProps.java, MyComponent RequiredProps.setProp3InCalleeButForgetProp1Bad(), 4, MISSING_REQUIRED_PROP, [@Prop prop1 is required, but not set before the call to build()]
 codetoanalyze/java/litho/RequiredProps.java, MyComponent RequiredProps.setRequiredOnOneBranchBad(boolean), 5, MISSING_REQUIRED_PROP, [@Prop prop1 is required, but not set before the call to build()]
 codetoanalyze/java/litho/ShouldUpdate.java, void LithoTest.onCreateLayout(), 0, GRAPHQL_FIELD_ACCESS, [&story.getActors().get(...)]