Feature/#250 wait style (#255)

* Added support for parsed styles

* Added stdlib function.

* Added e2e tests

* Added e2e tests for STYLE_* functions

pkg/stdlib/html/attr_set.go

@@ -0,0 +1,50 @@
+package html
+
+import (
+	"context"
+
+	"github.com/MontFerret/ferret/pkg/runtime/core"
+	"github.com/MontFerret/ferret/pkg/runtime/values"
+	"github.com/MontFerret/ferret/pkg/runtime/values/types"
+)
+
+// AttributeSet sets or updates a single or more attribute(s) of a given element.
+// @param el (HTMLElement) - Target element.
+// @param nameOrObj (String | Object) - Attribute name or an object representing a key-value pair of attributes.
+// @param value (String) - If a second parameter is a string value, this parameter represent an attribute value.
+func AttributeSet(ctx context.Context, args ...core.Value) (core.Value, error) {
+	err := core.ValidateArgs(args, 2, core.MaxArgs)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	el, err := resolveElement(args[0])
+
+	if err != nil {
+		return values.None, err
+	}
+
+	switch arg1 := args[1].(type) {
+	case values.String:
+		// ATTR_SET(el, name, value)
+		err = core.ValidateArgs(args, 3, 3)
+
+		if err != nil {
+			return values.None, nil
+		}
+
+		arg2, ok := args[2].(values.String)
+
+		if !ok {
+			return values.None, core.TypeError(arg1.Type(), types.String, types.Object)
+		}
+
+		return values.None, el.SetAttribute(ctx, arg1, arg2)
+	case *values.Object:
+		// ATTR_SET(el, values)
+		return values.None, el.SetAttributes(ctx, arg1)
+	default:
+		return values.None, core.TypeError(arg1.Type(), types.String, types.Object)
+	}
+}