diff --git a/data/tests/composer.json b/.data/tests/composer.json
similarity index 100%
rename from data/tests/composer.json
rename to .data/tests/composer.json
diff --git a/data/tests/lorem-ipsum.txt b/.data/tests/lorem-ipsum.txt
similarity index 100%
rename from data/tests/lorem-ipsum.txt
rename to .data/tests/lorem-ipsum.txt
diff --git a/data/tests/minion.jpg b/.data/tests/minion.jpg
similarity index 100%
rename from data/tests/minion.jpg
rename to .data/tests/minion.jpg
diff --git a/.gitignore b/.gitignore
index e2116fb..0bd0569 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,7 +14,7 @@
 # ----------------------------------------------------------------------------------------------------------------------
 ### Phing
 # ----------------------------------------------------------------------------------------------------------------------
-/phing/properties
+/.phing/properties
 
 
 # ----------------------------------------------------------------------------------------------------------------------
@@ -32,13 +32,13 @@
 # ----------------------------------------------------------------------------------------------------------------------
 ### Build files
 # ----------------------------------------------------------------------------------------------------------------------
-/build/
+/.build/
 
 
 # ----------------------------------------------------------------------------------------------------------------------
 ### Generated databases
 # ----------------------------------------------------------------------------------------------------------------------
-/data/tmp
+/.data/tmp
 *.sql
 *.sqlite
 
diff --git a/phing/app.xml b/.phing/app.xml
similarity index 93%
rename from phing/app.xml
rename to .phing/app.xml
index 2acceef..028fe2b 100644
--- a/phing/app.xml
+++ b/.phing/app.xml
@@ -2,12 +2,12 @@
 <project name="Meritoo Package" basedir="." default="build:main" phingVersion="2.14.0">
     <!-- Properties -->
     <if>
-        <available file="phing/properties" property="custom.properties.available"/>
+        <available file=".phing/properties" property="custom.properties.available"/>
         <then>
-            <property file="phing/properties" />
+            <property file=".phing/properties" />
         </then>
         <else>
-            <property file="phing/properties.dist" />
+            <property file=".phing/properties.dist" />
         </else>
     </if>
 
diff --git a/phing/properties.dist b/.phing/properties.dist
similarity index 97%
rename from phing/properties.dist
rename to .phing/properties.dist
index ae06943..992dbb6 100644
--- a/phing/properties.dist
+++ b/.phing/properties.dist
@@ -59,7 +59,7 @@ composer.validate = false
 
 # System directories
 #
-dir.data = ${project.basedir}/data
+dir.data = ${project.basedir}/.data
 dir.src = ${project.basedir}/src
 dir.tests = ${project.basedir}/tests
 
@@ -67,7 +67,7 @@ dir.tests = ${project.basedir}/tests
 # Build directories
 # --------------------------------------------------------------------------------
 
-dir.build = ${project.basedir}/build
+dir.build = ${project.basedir}/.build
 dir.reports = ${dir.build}/logs
 dir.reports.pdepend = ${dir.reports}/pdepend
 dir.reports.coverage = ${dir.reports}/phpunit_coverage
diff --git a/phing/tests.xml b/.phing/tests.xml
similarity index 98%
rename from phing/tests.xml
rename to .phing/tests.xml
index 0ab44df..4567626 100644
--- a/phing/tests.xml
+++ b/.phing/tests.xml
@@ -11,12 +11,12 @@
 
     <!-- Properties -->
     <if>
-        <available file="phing/properties" property="custom.properties.available"/>
+        <available file=".phing/properties" property="custom.properties.available"/>
         <then>
-            <property file="phing/properties" />
+            <property file=".phing/properties" />
         </then>
         <else>
-            <property file="phing/properties.dist" />
+            <property file=".phing/properties.dist" />
         </else>
     </if>
 
diff --git a/build.xml b/build.xml
index 928bc93..fccc179 100644
--- a/build.xml
+++ b/build.xml
@@ -2,12 +2,12 @@
 <project name="Meritoo Package" basedir="." default="build:main" phingVersion="2.14.0">
     <!-- Properties -->
     <if>
-        <available file="phing/properties" property="custom.properties.available"/>
+        <available file=".phing/properties" property="custom.properties.available"/>
         <then>
-            <property file="phing/properties" />
+            <property file=".phing/properties" />
         </then>
         <else>
-            <property file="phing/properties.dist" />
+            <property file=".phing/properties.dist" />
         </else>
     </if>
 
@@ -18,12 +18,12 @@
 
     <!-- Build app -->
     <target name="build:app" description="Prepares app to build and tests">
-        <phing phingfile="phing/app.xml" haltonfailure="true" />
+        <phing phingfile=".phing/app.xml" haltonfailure="true" />
     </target>
 
     <!-- Build tests -->
     <target name="build:tests" description="Runs all tests, checks and creates docs">
-        <phing phingfile="phing/tests.xml" haltonfailure="true" />
+        <phing phingfile=".phing/tests.xml" haltonfailure="true" />
 
         <!--
         Conditional running of tests.
@@ -35,7 +35,7 @@
         <if>
             <equals arg1="${env}" arg2="test" />
             <then>
-                <phing phingfile="phing/tests.xml" haltonfailure="true" />
+                <phing phingfile=".phing/tests.xml" haltonfailure="true" />
             </then>
             <else>
                 <echo message="[Skipped] Running tests, checks and creating docs, because it's a not 'test' environment..." />
diff --git a/composer.json b/composer.json
index e943541..94ecf60 100644
--- a/composer.json
+++ b/composer.json
@@ -2,7 +2,7 @@
     "name": "meritoo/common-library",
     "description": "Useful classes, methods, extensions etc.",
     "license": "MIT",
-    "version": "0.0.14",
+    "version": "0.0.15",
     "authors": [
         {
             "name": "Meritoo.pl",
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 4c43916..fd0219d 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -30,6 +30,6 @@
     </groups>
 
     <logging>
-        <log type="coverage-html" target="./build/logs/phpunit_coverage/html" />
+        <log type="coverage-html" target="./.build/logs/phpunit_coverage/html" />
     </logging>
 </phpunit>
diff --git a/src/Test/Base/BaseTestCase.php b/src/Test/Base/BaseTestCase.php
index ee7db79..0027bd9 100644
--- a/src/Test/Base/BaseTestCase.php
+++ b/src/Test/Base/BaseTestCase.php
@@ -25,6 +25,13 @@ use ReflectionMethod;
  */
 abstract class BaseTestCase extends TestCase
 {
+    /**
+     * Path of directory with data used by test cases
+     *
+     * @var string
+     */
+    private static $testsDataDirPath = '.data/tests';
+
     /**
      * Provides an empty value
      *
@@ -98,7 +105,7 @@ abstract class BaseTestCase extends TestCase
 
     /**
      * Returns path of file used by tests.
-     * It should be placed in /data/tests directory of this project.
+     * It should be placed in /.data/tests directory of this project.
      *
      * @param string $fileName      Name of file
      * @param string $directoryPath (optional) Path of directory containing the file
@@ -110,7 +117,7 @@ abstract class BaseTestCase extends TestCase
 
         $paths = [
             $rootPath,
-            'data/tests',
+            self::$testsDataDirPath,
             $directoryPath,
             $fileName,
         ];
@@ -218,4 +225,14 @@ abstract class BaseTestCase extends TestCase
 
         static::assertNull($constructor);
     }
+
+    /**
+     * Sets path of directory with data used by test cases
+     *
+     * @param string $testsDataDirPath Path of directory with data used by test cases
+     */
+    protected static function setTestsDataDirPath($testsDataDirPath)
+    {
+        static::$testsDataDirPath = $testsDataDirPath;
+    }
 }