Add specs for rb_get_kwargs.

Author: aardvark179

spec/ruby/optional/capi/ext/util_spec.c

@@ -44,6 +44,30 @@ VALUE util_spec_rb_scan_args(VALUE self, VALUE argv, VALUE fmt, VALUE expected,
   return INT2NUM(result);
 }
 
+static VALUE util_spec_rb_get_kwargs(VALUE self, VALUE keyword_hash, VALUE keys, VALUE required, VALUE optional) {
+  int req = FIX2INT(required);
+  int opt = FIX2INT(optional);
+  int len = RARRAY_LEN(keys);
+
+  int values_len = req + (opt < 0 ? -1 - opt : opt);
+  int i = 0;
+
+  ID *ids = malloc(sizeof(VALUE) * len);
+  VALUE *results = malloc(sizeof(VALUE) * values_len);
+  int extracted = 0;
+  VALUE ary = Qundef;
+
+  for (i = 0; i < len; i++) {
+    ids[i] = SYM2ID(rb_ary_entry(keys, i));
+  }
+
+  extracted = rb_get_kwargs(keyword_hash, ids, req, opt, results);
+  ary = rb_ary_new_from_values(extracted, results);
+  free(results);
+  free(ids);
+  return ary;
+}
+
 static VALUE util_spec_rb_long2int(VALUE self, VALUE n) {
   return INT2NUM(rb_long2int(NUM2LONG(n)));
 }
@@ -64,6 +88,7 @@ static VALUE util_spec_rb_sourceline(VALUE self) {
 void Init_util_spec(void) {
   VALUE cls = rb_define_class("CApiUtilSpecs", rb_cObject);
   rb_define_method(cls, "rb_scan_args", util_spec_rb_scan_args, 4);
+  rb_define_method(cls, "rb_get_kwargs", util_spec_rb_get_kwargs, 4);
   rb_define_method(cls, "rb_long2int", util_spec_rb_long2int, 1);
   rb_define_method(cls, "rb_iter_break", util_spec_rb_iter_break, 0);
   rb_define_method(cls, "rb_sourcefile", util_spec_rb_sourcefile, 0);

spec/ruby/optional/capi/util_spec.rb

@@ -154,6 +154,50 @@
     end
   end
 
+  describe "rb_get_kwargs" do
+    it "extracts required arguments in the order requested" do
+      h = { :a => 7, :b => 5 }
+      @o.rb_get_kwargs(h, [:b, :a], 2, 0).should == [5, 7]
+      h.should == {}
+    end
+
+    it "extracts required and optional arguments in the order requested" do
+      h = { :a => 7, :c => 12, :b => 5 }
+      @o.rb_get_kwargs(h, [:b, :a, :c], 2, 1).should == [5, 7, 12]
+      h.should == {}
+    end
+
+    it "accepts nil instead of a hash when only optional arguments are requested" do
+      h = nil
+      @o.rb_get_kwargs(h, [:b, :a, :c], 0, 3).should == []
+      h.should == nil
+    end
+
+    it "raises an error if a required argument is not in the hash" do
+      h = { :a => 7, :c => 12, :b => 5 }
+      lambda { @o.rb_get_kwargs(h, [:b, :d], 2, 0) }.should raise_error(ArgumentError, /missing keyword: d/)
+      h.should == {:a => 7, :c => 12}
+    end
+
+    it "does not raise an error for an optional argument not in the hash" do
+      h = { :a => 7, :b => 5 }
+      @o.rb_get_kwargs(h, [:b, :a, :c], 2, 1).should == [5, 7]
+      h.should == {}
+    end
+
+    it "raises an error if there are additional arguments  and optional is positive" do
+      h = { :a => 7, :c => 12, :b => 5 }
+      lambda { @o.rb_get_kwargs(h, [:b, :a], 2, 0) }.should raise_error(ArgumentError, /unknown keyword: c/)
+      h.should == {:c => 12}
+    end
+
+    it "leaves additional arguments in the hash if optional is negative" do
+      h = { :a => 7, :c => 12, :b => 5 }
+      @o.rb_get_kwargs(h, [:b, :a], 2, -1).should == [5, 7]
+      h.should == {:c => 12}
+    end
+  end
+
   platform_is wordsize: 64 do
     describe "rb_long2int" do
       it "raises a RangeError if the value is outside the range of a C int" do