Add unit test

build.gradle

@@ -3,6 +3,7 @@ plugins {
     id "com.github.jruby-gradle.base" version "0.1.5"
     id "java"
     id "checkstyle"
+    id "jacoco"
 }
 import com.github.jrubygradle.JRubyExec
 repositories {

src/test/java/org/embulk/input/sftp/TestFileList.java

@@ -1,7 +1,87 @@
 package org.embulk.input.sftp;
 
-/**
- * Created by satoshi on 2016/03/17.
- */
-public class TestFileList {
+import org.embulk.EmbulkTestRuntime;
+import org.embulk.config.ConfigSource;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class TestFileList
+{
+    @Rule
+    public EmbulkTestRuntime runtime = new EmbulkTestRuntime();
+
+    private ConfigSource config;
+
+    @Before
+    public void createConfigSource()
+    {
+        config = runtime.getExec().newConfigSource();
+    }
+
+    @Test
+    public void checkMinTaskSize()
+            throws Exception
+    {
+        { // not specify min_task_size
+            FileList fileList = newFileList(config.deepCopy(),
+                    "sample_00", 100L,
+                    "sample_01", 150L,
+                    "sample_02", 350L);
+
+            assertEquals(3, fileList.getTaskCount());
+            assertEquals("sample_00", fileList.get(0).get(0));
+            assertEquals("sample_01", fileList.get(1).get(0));
+            assertEquals("sample_02", fileList.get(2).get(0));
+        }
+
+        {
+            FileList fileList = newFileList(config.deepCopy().set("min_task_size", 100),
+                    "sample_00", 100L,
+                    "sample_01", 150L,
+                    "sample_02", 350L);
+
+            assertEquals(3, fileList.getTaskCount());
+            assertEquals("sample_00", fileList.get(0).get(0));
+            assertEquals("sample_01", fileList.get(1).get(0));
+            assertEquals("sample_02", fileList.get(2).get(0));
+        }
+
+        {
+            FileList fileList = newFileList(config.deepCopy().set("min_task_size", 200),
+                    "sample_00", 100L,
+                    "sample_01", 150L,
+                    "sample_02", 350L);
+
+            assertEquals(2, fileList.getTaskCount());
+            assertEquals("sample_00", fileList.get(0).get(0));
+            assertEquals("sample_01", fileList.get(0).get(1));
+            assertEquals("sample_02", fileList.get(1).get(0));
+        }
+
+        {
+            FileList fileList = newFileList(config.deepCopy().set("min_task_size", 700),
+                    "sample_00", 100L,
+                    "sample_01", 150L,
+                    "sample_02", 350L);
+
+            assertEquals(1, fileList.getTaskCount());
+            assertEquals("sample_00", fileList.get(0).get(0));
+            assertEquals("sample_01", fileList.get(0).get(1));
+            assertEquals("sample_02", fileList.get(0).get(2));
+        }
+    }
+
+    private static FileList newFileList(ConfigSource config, Object... nameAndSize)
+    {
+        FileList.Builder builder = new FileList.Builder(config);
+
+        for (int i = 0; i < nameAndSize.length; i += 2) {
+            builder.add((String) nameAndSize[i], (long) nameAndSize[i + 1]);
+        }
+
+        return builder.build();
+    }
 }