diff --git a/test/lib/fluentd_ui_test.rb b/test/lib/fluentd_ui_test.rb
new file mode 100644
index 0000000..6ab7b23
--- /dev/null
+++ b/test/lib/fluentd_ui_test.rb
@@ -0,0 +1,36 @@
+require "test_helper"
+
+class FluentdUITest < ActiveSupport::TestCase
+  sub_test_case ".update_available?" do
+    setup do
+      @current_version = FluentdUI::VERSION
+    end
+
+    test "unavailable" do
+      FluentdUI.latest_version = @current_version
+      assert do
+        !FluentdUI.update_available?
+      end
+    end
+
+    test "available" do
+      FluentdUI.latest_version = @current_version.succ
+      assert do
+        FluentdUI.update_available?
+      end
+    end
+  end
+
+  sub_test_case ".fluentd_version" do
+    test "not ready" do
+      stub(Fluentd).instance { nil }
+      assert_nil(FluentdUI.fluentd_version)
+    end
+
+    test "ready" do
+      target = FactoryBot.build(:fluentd)
+      stub(Fluentd).instance{ target }
+      assert_equal(target.agent.version, FluentdUI.fluentd_version)
+    end
+  end
+end
diff --git a/test/lib/regexp_preview/multi_line_test.rb b/test/lib/regexp_preview/multi_line_test.rb
new file mode 100644
index 0000000..8b546ea
--- /dev/null
+++ b/test/lib/regexp_preview/multi_line_test.rb
@@ -0,0 +1,86 @@
+require "test_helper"
+
+module RegexpPreview
+  class MultilineTest < ActiveSupport::TestCase
+    test "simple usage" do
+      config = {
+        "format_firstline" => "/foo/",
+        "time_format" => "time_format",
+      }
+      config["format1"] = "/(?<foo>foo)\n/"
+      config["format2"] = "/(?<bar>bar)/"
+      3.upto(Fluentd::Setting::InTail::MULTI_LINE_MAX_FORMAT_COUNT) do |i|
+        config["format#{i}"] = "//"
+      end
+      preview = RegexpPreview::MultiLine.new(fixture_path("error0.log"), "multiline", config)
+      matches = [
+        {
+          whole: "foo\nbar\nbaz\n1\n2\n3\n4\n5\n6\n10\n11\n12",
+          matches: [
+            { key: "foo", matched: "foo", pos: [0, 3] },
+            { key: "bar", matched: "bar", pos: [4, 7] }
+          ]
+        }
+      ]
+      assert_equal(matches, preview.matches[:matches])
+    end
+
+    test "detect only continuous patterns" do
+      config = {
+        "format_firstline" => "/foo/",
+        "time_format" => "time_format",
+      }
+      config["format1"] = "/(?<foo>foo)\n/"
+      config["format2"] = "/(?<bar>baz)/"
+      3.upto(Fluentd::Setting::InTail::MULTI_LINE_MAX_FORMAT_COUNT) do |i|
+        config["format#{i}"] = "//"
+      end
+      preview = RegexpPreview::MultiLine.new(fixture_path("error0.log"), "multiline", config)
+      assert_equal([], preview.matches[:matches])
+    end
+
+    # http://docs.fluentd.org/articles/in_tail
+    test "example on document" do
+      config = {
+        "format_firstline" => "/\\d{4}-\\d{1,2}-\\d{1,2}/",
+        "format1" => "/^(?<time>\\d{4}-\\d{1,2}-\\d{1,2} \\d{1,2}:\\d{1,2}:\\d{1,2}) \\[(?<thread>.*)\\] (?<level>[^\\s]+)(?<message>.*)/",
+        "time_format" => "%Y-%m-%d %H:%M:%S",
+        "keep_time_key" => true
+      }
+      2.upto(Fluentd::Setting::InTail::MULTI_LINE_MAX_FORMAT_COUNT) do |i|
+        config["format#{i}"] = "//"
+      end
+      preview = RegexpPreview::MultiLine.new(fixture_path("multiline_example.log"), "multiline", config)
+      matches = [
+            {
+              whole: "2013-3-03 14:27:33 [main] INFO  Main - Start\n",
+              matches: [
+                { key: "time", matched: "2013-3-03 14:27:33", pos: [0, 18] },
+                { key: "thread", matched: "main", pos: [20, 24] },
+                { key: "level", matched: "INFO", pos: [26, 30] },
+                { key: "message", matched: "  Main - Start\n", pos: [30, 45] }
+              ]
+            },
+            {
+              whole: "2013-3-03 14:27:33 [main] ERROR Main - Exception\njavax.management.RuntimeErrorException: null\n    at Main.main(Main.java:16) ~[bin/:na]\n",
+              matches: [
+                { key: "time", matched: "2013-3-03 14:27:33", pos: [0, 18] },
+                { key: "thread", matched: "main", pos: [20, 24] },
+                { key: "level", matched: "ERROR", pos: [26, 31] },
+                { key: "message", matched: " Main - Exception\njavax.management.RuntimeErrorException: null\n    at Main.main(Main.java:16) ~[bin/:na]\n", pos: [31, 136] },
+              ]
+            },
+            {
+              whole: "2013-3-03 14:27:33 [main] INFO  Main - End",
+              matches: [
+                { key: "time", matched: "2013-3-03 14:27:33", pos: [0, 18] },
+                { key: "thread", matched: "main", pos: [20, 24] },
+                { key: "level", matched: "INFO", pos: [26, 30] },
+                { key: "message", matched: "  Main - End", pos: [30, 42] },
+              ]
+            }
+      ]
+      assert_equal(matches, preview.matches[:matches])
+    end
+  end
+end
diff --git a/test/lib/regexp_preview/single_line_test.rb b/test/lib/regexp_preview/single_line_test.rb
new file mode 100644
index 0000000..10b2069
--- /dev/null
+++ b/test/lib/regexp_preview/single_line_test.rb
@@ -0,0 +1,87 @@
+require "test_helper"
+require "fluent/plugin/parser_apache"
+require "fluent/plugin/parser_nginx"
+
+module RegexpPreview
+  class SingleLineTest < ActiveSupport::TestCase
+    data("regexp" => ["regexp", Fluent::Plugin::RegexpParser, { "expression" => "(?<catefory>\[.+\])", "time_format" => "%Y/%m/%d" }],
+         "ltsv" => ["ltsv", Fluent::Plugin::LabeledTSVParser, {}],
+         "json" => ["json", Fluent::Plugin::JSONParser, {}],
+         "csv" => ["csv", Fluent::Plugin::CSVParser, { "keys" => "column1,column2" }],
+         "tsv" => ["tsv", Fluent::Plugin::TSVParser, { "keys" => "column1,column2" }],
+         "syslog" => ["syslog", Fluent::Plugin::SyslogParser, {}],
+         "apache" => ["apache", Fluent::Plugin::ApacheParser, {}],
+         "nginx" => ["nginx", Fluent::Plugin::NginxParser, {}])
+    test "create parser plugin instance from selected plugin name" do |(name, klass, config)|
+      preview = RegexpPreview::SingleLine.new("log_file.log", name, config)
+      assert_instance_of(klass, preview.plugin)
+    end
+
+    sub_test_case "#matches" do
+      test "regexp" do
+        config = {
+          "expression" => "(?<regexp>bar)", # bar from error0.log
+          "time_format" => "time_format",
+        }
+        preview = RegexpPreview::SingleLine.new(fixture_path("error0.log"), "regexp", config)
+        matches = [
+          {
+            whole: "bar",
+            matches: [
+              { key: "regexp", matched: "bar", pos: [0, 3] }
+            ]
+          }
+        ]
+        assert_equal(config, preview.matches[:pluginConfig])
+        assert_equal(matches,preview.matches[:matches])
+      end
+
+      test "csv" do
+        config = { "keys" => "column1,column2" }
+        preview = RegexpPreview::SingleLine.new(fixture_path("error0.log"), "csv", config)
+        assert do
+          preview.matches[:matches].empty?
+        end
+      end
+
+      test "syslog" do
+        config = {
+          "time_format" => "%Y-%m-%d %H:%M:%S %z",
+          "keep_time_key" => true
+        }
+        preview = RegexpPreview::SingleLine.new(fixture_path("error4.log"), "syslog", config)
+        matches = [
+          {
+            whole: "2014-05-27 10:54:37 +0900 [info]: listening fluent socket on 0.0.0.0:24224",
+            matches: [
+              { key: "time", matched: "2014-05-27 10:54:37 +0900", pos: [0, 25] },
+              { key: "host", matched: "[info]:", pos: [26, 33] },
+              { key: "ident", matched: "listening", pos: [34, 43] },
+              { key: "message", matched: "24224", pos: [69, 74] }
+            ]
+          }
+        ]
+        assert_equal(matches, preview.matches[:matches])
+      end
+
+      test "syslog when keep_time_key is false" do
+        config = {
+          "time_format" => "%Y-%m-%d %H:%M:%S %z",
+          "keep_time_key" => false
+        }
+        preview = RegexpPreview::SingleLine.new(fixture_path("error4.log"), "syslog", config)
+        matches = [
+          {
+            whole: "2014-05-27 10:54:37 +0900 [info]: listening fluent socket on 0.0.0.0:24224",
+            matches: [
+              { key: "host", matched: "[info]:", pos: [26, 33] },
+              { key: "ident", matched: "listening", pos: [34, 43] },
+              { key: "message", matched: "24224", pos: [69, 74] }
+            ]
+          }
+        ]
+        assert_equal(matches, preview.matches[:matches])
+      end
+    end
+  end
+end