update types and add test

Author: graial

sig/ruby_wasm/build.rbs

@@ -251,6 +251,7 @@ module RubyWasm
     def ar: -> String
 
     def install: (_CommandExecutor executor) -> void
+    def wasi_sysroot?: -> bool
   end
 
   class WASISDK < Toolchain
@@ -268,6 +269,7 @@ module RubyWasm
     def download_url: () -> String
     def install_wasi_sdk: (_CommandExecutor executor) -> void
     def install: (_CommandExecutor executor) -> void
+    def wasi_sysroot?: -> bool
   end
 
   class Binaryen

test/toolchain_predicate_test.rb

@@ -0,0 +1,17 @@
+require "test-unit"
+require_relative "../lib/ruby_wasm/build/toolchain"
+# require "bundler"
+
+class ToolchainPredicateTest < Test::Unit::TestCase
+  def test_base_toolchain_is_not_wasi_sysroot
+    assert_equal false, Class.new(RubyWasm::Toolchain).allocate.wasi_sysroot?
+  end
+
+  def test_wasi_sdk_is_wasi_sysroot
+    assert_equal true, Class.new(RubyWasm::WASISDK).allocate.wasi_sysroot?
+  end
+
+  def test_emscripten_is_not_wasi_sysroot
+    assert_equal false, Class.new(RubyWasm::Emscripten).allocate.wasi_sysroot?
+  end
+end