Add support for component flags type

Flags are passed to/from Ruby as `Array<String>`, matching the
Wasmtime's `Val::Flags`.

Similar to enum types, the strings are not matched against valid flags
given the rust layer does when lowering the flags.

Author: jbourassa

ext/src/ruby_api/component/convert.rs

@@ -5,7 +5,9 @@ use crate::{define_rb_intern, err, error, not_implemented};
 use magnus::exception::type_error;
 use magnus::rb_sys::AsRawValue;
 use magnus::value::{IntoId, Lazy, ReprValue};
-use magnus::{prelude::*, value, Error, IntoValue, RArray, RClass, RHash, RString, Ruby, Value};
+use magnus::{
+    prelude::*, try_convert, value, Error, IntoValue, RArray, RClass, RHash, RString, Ruby, Value,
+};
 use wasmtime::component::{Type, Val};
 
 define_rb_intern!(
@@ -89,7 +91,7 @@ pub(crate) fn component_val_to_rb(val: Val, _store: &StoreContextValue) -> Resul
             };
             result_class(&ruby).funcall(ruby_method, (ruby_argument,))
         }
-        Val::Flags(_vec) => not_implemented!("Flags not implemented"),
+        Val::Flags(vec) => Ok(vec.into_value()),
         Val::Resource(_resource_any) => not_implemented!("Resource not implemented"),
     }
 }
@@ -275,7 +277,7 @@ pub(crate) fn rb_to_component_val(
                 }
             }
         }
-        Type::Flags(_flags) => not_implemented!("Flags not implemented"),
+        Type::Flags(_) => Vec::<String>::try_convert(value).map(Val::Flags),
         Type::Own(_resource_type) => not_implemented!("Resource not implemented"),
         Type::Borrow(_resource_type) => not_implemented!("Resource not implemented"),
     }

spec/unit/component/convert_spec.rb

@@ -32,8 +32,8 @@ module Component
           ["enum", "l"],
           ["option", 0, nil], # option<u32>
           ["result", Result.ok(1), Result.error(2)], # result<u32, u32>
-          ["result-unit", Result.ok(nil), Result.error(nil)]
-          # TODO flags
+          ["result-unit", Result.ok(nil), Result.error(nil)],
+          ["flags", [], ["read"], ["read", "write", "exec"]]
         ].each do |type, *values|
           values.each do |v|
             it "#{type} #{v.inspect}" do
@@ -89,7 +89,10 @@ module Component
           ["enum", "no", /enum variant name `no` is not valid/],
           ["result", nil, /undefined method `ok\?/],
           ["result-unit", Result.ok(""), /expected nil for result<_, E> ok branch/],
-          ["result-unit", Result.error(""), /expected nil for result<O, _> error branch/]
+          ["result-unit", Result.error(""), /expected nil for result<O, _> error branch/],
+          ["flags", ["no"], /unknown flag: `no`/],
+          ["flags", [1], /no implicit conversion of Integer into String/],
+          ["flags", 1, /no implicit conversion of Integer into Array/]
         ].each do |type, value, klass, msg|
           it "fails on #{type} #{value.inspect}" do
             expect { instance.invoke("id-#{type}", value) }.to raise_error(klass, msg)