Fix variance of built in dict type

CHANGELOG.md

@@ -12,6 +12,10 @@
 
 # 11.1.0-rc.7 (Unreleased)
 
+#### :bug: Bug Fix
+
+- Fixes variance setting for builtin dict. Fixes issues around inference. https://github.com/rescript-lang/rescript-compiler/pull/6707 
+
 # 11.1.0-rc.6
 
 #### :rocket: New Feature

jscomp/build_tests/super_errors/expected/dict_inference.res.expected

@@ -0,0 +1,13 @@
+
+  We've found a bug for you!
+  /.../fixtures/dict_inference.res:4:31-33
+
+  2 │ dict->Js.Dict.set("someKey1", 1)
+  3 │ dict->Js.Dict.set("someKey2", 2)
+  4 │ dict->Js.Dict.set("someKey2", "2")
+  5 │ 
+
+  This has type: string
+  But this function argument is expecting: int
+
+  You can convert string to int with Belt.Int.fromString.

jscomp/build_tests/super_errors/fixtures/dict_inference.res

@@ -0,0 +1,4 @@
+let dict = Js.Dict.empty()
+dict->Js.Dict.set("someKey1", 1)
+dict->Js.Dict.set("someKey2", 2)
+dict->Js.Dict.set("someKey2", "2")

jscomp/ml/predef.ml

@@ -238,7 +238,7 @@ let common_initial_env add_type add_extension empty_env =
     {decl_abstr with
       type_params = [tvar];
       type_arity = 1;
-      type_variance = [Variance.covariant]}
+      type_variance = [Variance.full]}
   and decl_uncurried =
     let tvar1, tvar2 = newgenvar(), newgenvar() in
     {decl_abstr with

jscomp/runtime/release.ninja

@@ -25,7 +25,7 @@ o runtime/caml_exceptions.cmj : cc_cmi runtime/caml_exceptions.res | runtime/cam
 o runtime/caml_exceptions.cmi : cc runtime/caml_exceptions.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_float.cmj : cc_cmi runtime/caml_float.res | runtime/caml_float.cmi runtime/caml_float_extern.cmj
 o runtime/caml_float.cmi : cc runtime/caml_float.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_format.cmj : cc_cmi runtime/caml_format.ml | runtime/caml.cmj runtime/caml_float.cmj runtime/caml_float_extern.cmj runtime/caml_format.cmi runtime/caml_int64.cmj runtime/caml_int64_extern.cmj runtime/caml_nativeint_extern.cmj runtime/caml_string_extern.cmj
+o runtime/caml_format.cmj : cc_cmi runtime/caml_format.ml | runtime/caml_float.cmj runtime/caml_float_extern.cmj runtime/caml_format.cmi runtime/caml_int64.cmj runtime/caml_int64_extern.cmj runtime/caml_nativeint_extern.cmj runtime/caml_string_extern.cmj
 o runtime/caml_format.cmi : cc runtime/caml_format.mli | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_hash.cmj : cc_cmi runtime/caml_hash.res | runtime/caml_hash.cmi runtime/caml_hash_primitive.cmj runtime/caml_nativeint_extern.cmj runtime/js.cmj
 o runtime/caml_hash.cmi : cc runtime/caml_hash.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
@@ -41,7 +41,7 @@ o runtime/caml_md5.cmj : cc_cmi runtime/caml_md5.res | runtime/caml_array_extern
 o runtime/caml_md5.cmi : cc runtime/caml_md5.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_module.cmj : cc_cmi runtime/caml_module.res | runtime/caml_array_extern.cmj runtime/caml_module.cmi runtime/caml_obj.cmj
 o runtime/caml_module.cmi : cc runtime/caml_module.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_obj.cmj : cc_cmi runtime/caml_obj.res | runtime/caml.cmj runtime/caml_array_extern.cmj runtime/caml_obj.cmi runtime/caml_option.cmj runtime/js.cmj
+o runtime/caml_obj.cmj : cc_cmi runtime/caml_obj.res | runtime/caml_array_extern.cmj runtime/caml_obj.cmi runtime/caml_option.cmj runtime/js.cmj
 o runtime/caml_obj.cmi : cc runtime/caml_obj.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_option.cmj : cc_cmi runtime/caml_option.res | runtime/caml_option.cmi runtime/caml_undefined_extern.cmj runtime/js.cmj
 o runtime/caml_option.cmi : cc runtime/caml_option.resi | runtime/bs_stdlib_mini.cmi runtime/caml_undefined_extern.cmj runtime/js.cmi runtime/js.cmj
@@ -58,7 +58,7 @@ o runtime/caml_bigint_extern.cmi runtime/caml_bigint_extern.cmj : cc runtime/cam
 o runtime/caml_external_polyfill.cmi runtime/caml_external_polyfill.cmj : cc runtime/caml_external_polyfill.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_float_extern.cmi runtime/caml_float_extern.cmj : cc runtime/caml_float_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_int64_extern.cmi runtime/caml_int64_extern.cmj : cc runtime/caml_int64_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_js_exceptions.cmi runtime/caml_js_exceptions.cmj : cc runtime/caml_js_exceptions.res | runtime/bs_stdlib_mini.cmi runtime/caml_exceptions.cmj runtime/caml_option.cmj runtime/js.cmi runtime/js.cmj
+o runtime/caml_js_exceptions.cmi runtime/caml_js_exceptions.cmj : cc runtime/caml_js_exceptions.res | runtime/bs_stdlib_mini.cmi runtime/caml_exceptions.cmj runtime/js.cmi runtime/js.cmj
 o runtime/caml_nativeint_extern.cmi runtime/caml_nativeint_extern.cmj : cc runtime/caml_nativeint_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_string_extern.cmi runtime/caml_string_extern.cmj : cc runtime/caml_string_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_undefined_extern.cmi runtime/caml_undefined_extern.cmj : cc runtime/caml_undefined_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj

jscomp/test/DictInference.res

@@ -0,0 +1,4 @@
+let dict = Js.Dict.empty()
+dict->Js.Dict.set("someKey1", 1)
+dict->Js.Dict.set("someKey2", 2)
+let asArray = dict->Js.Dict.values