issue#58 implement Node#select

https://github.com/puppeteer/puppeteer/blob/c510df8d8e52fa361c26f6db011aaa9410c8996a/src/common/JSHandle.ts#L561-L605

Author: Mifrill

lib/ferrum/node.rb

@@ -139,6 +139,30 @@ def selected
       page.evaluate_func(function, self)
     end
 
+    def select(*values)
+      tap do
+        function = <<~JS
+          function(element, values) {
+            if (element.nodeName.toLowerCase() !== 'select') {
+              throw new Error('Element is not a <select> element.');
+            }
+            const options = Array.from(element.options);
+            element.value = undefined;
+            for (const option of options) {
+              option.selected = values.includes(option.value);
+              if (option.selected && !element.multiple) break;
+            }
+            element.dispatchEvent(new Event('input', { bubbles: true }));
+            element.dispatchEvent(new Event('change', { bubbles: true }));
+            return options
+              .filter((option) => option.selected)
+              .map((option) => option.value);
+          }
+        JS
+        page.evaluate_func(function, self, values.join(','))
+      end
+    end
+
     def evaluate(expression)
       page.evaluate_on(node: self, expression: expression)
     end

spec/node_spec.rb

@@ -112,6 +112,33 @@ module Ferrum
       end
     end
 
+    describe "#select" do
+      before do
+        browser.goto("/ferrum/form")
+      end
+
+      it "picks option in select by match string argument" do
+        expect(browser.at_xpath("//*[@id='form_title']").select("Miss").value).to eq("Miss")
+      end
+
+      context "when select has multiple property" do
+        it "picks options in select by match arguments as array" do
+          expect(browser.at_xpath("//*[@id='form_languages']").select(%w[SQL Ruby]).selected).to eq(%w[Ruby SQL])
+        end
+
+        it "picks options in select by match arguments as string" do
+          expect(browser.at_xpath("//*[@id='form_languages']").select("SQL, Ruby").selected).to eq(%w[Ruby SQL])
+        end
+      end
+
+      context "when selector is not <select>" do
+        it "raises JavaScriptError with proper message" do
+          expect { browser.at_xpath("//*[@id='customer_name']").select(anything) }.
+            to raise_exception(Ferrum::JavaScriptError, /Element is not a <select> element/)
+        end
+      end
+    end
+
     context "when the element is not in the viewport" do
       before do
         browser.go_to("/ferrum/with_js")