Introduce StreamProvider

src/main/java/org/editorconfig/core/EditorConfig.java

@@ -1,5 +1,8 @@
 package org.editorconfig.core;
 
+import org.editorconfig.core.provider.FileStreamProvider;
+import org.editorconfig.core.provider.StreamProvider;
+
 import java.io.*;
 import java.util.*;
 import java.util.regex.Matcher;
@@ -29,6 +32,7 @@ public class EditorConfig {
 
   private final String configFilename;
   private final String version;
+  private final StreamProvider provider;
 
   /**
    * Creates EditorConfig handler with default configuration filename (.editorconfig) and
@@ -38,6 +42,13 @@ public EditorConfig() {
     this(".editorconfig", VERSION);
   }
 
+  /**
+   * Creates EditorConfig handler with specified StreamProvider
+   */
+  public EditorConfig(StreamProvider provider){
+    this(".editorconfig", VERSION, provider);
+  }
+
   /**
    * Creates EditorConfig handler with specified configuration filename and version.
    * Used mostly for debugging/testing.
@@ -47,6 +58,20 @@ public EditorConfig() {
   public EditorConfig(String configFilename, String version) {
     this.configFilename = configFilename;
     this.version = version;
+    this.provider = new FileStreamProvider();
+  }
+
+  /**
+   * Creates EditorConfig handler with specified configuration filename and version.
+   * Used mostly for debugging/testing.
+   * @param configFilename configuration file name to be searched for instead of .editorconfig
+   * @param version required version
+   * @param provider stream provider
+   */
+  public EditorConfig(String configFilename, String version, StreamProvider provider) {
+    this.configFilename = configFilename;
+    this.version = version;
+    this.provider = provider;
   }
 
   /**
@@ -83,25 +108,26 @@ public List<OutPair> getProperties(String filePath, Set<String> explicitRootDirs
     Map<String, String> options = new LinkedHashMap<String, String>();
     try {
       boolean root = false;
-      String dir = new File(filePath).getParent();
+      String dir = provider.getParent(filePath);
       while (dir != null && !root) {
-        File configFile = new File(dir, configFilename);
-        if (configFile.exists()) {
-          BufferedReader bufferedReader = null;
-          try {
-            bufferedReader = new BufferedReader(new InputStreamReader(new FileInputStream(configFile), "UTF-8"));
+        String configFilePath = provider.combinePath(dir, configFilename);
+        BufferedReader bufferedReader = null;
+        try {
+          InputStream inputStream = provider.openStream(configFilePath);
+          if(inputStream != null){
+            bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
             root = parseFile(bufferedReader, dir + "/", filePath, options);
-          } finally {
-            if (bufferedReader != null) {
-                bufferedReader.close();
-            }
+          }
+        } finally {
+          if (bufferedReader != null) {
+              bufferedReader.close();
           }
         }
         options.putAll(oldOptions);
         oldOptions = options;
         options = new LinkedHashMap<String, String>();
         root |= explicitRootDirs.contains(dir);
-        dir = new File(dir).getParent();
+        dir = provider.getParent(dir);
       }
     } catch (IOException e) {
       throw new EditorConfigException(null, e);

src/main/java/org/editorconfig/core/provider/FileStreamProvider.java

@@ -0,0 +1,33 @@
+package org.editorconfig.core.provider;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.InputStream;
+
+public class FileStreamProvider implements StreamProvider {
+  @Override
+  public String getParent(String filePath) {
+    return new File(filePath).getParent();
+  }
+
+  @Override
+  public String combinePath(String dirPath, String filePath) {
+    return new File(dirPath, filePath).getPath();
+  }
+
+  @Override
+  public InputStream openStream(String filePath) {
+    try{
+      if (new File(filePath).exists()){
+        return new FileInputStream(filePath);
+      }
+      else {
+        return null;
+      }
+    }
+    catch (FileNotFoundException ex){
+      return null;
+    }
+  }
+}

src/main/java/org/editorconfig/core/provider/StreamProvider.java

@@ -0,0 +1,27 @@
+package org.editorconfig.core.provider;
+
+import java.io.InputStream;
+
+public interface StreamProvider {
+  /**
+   * get Parent directory
+   * @param filePath
+   * @return parent direcoty path by String
+   */
+  String getParent(String filePath);
+
+  /**
+   * combine Path
+   * @param dirPath directory path
+   * @param filePath file path
+   * @return dirPath + filePath
+   */
+  String combinePath(String dirPath, String filePath);
+
+  /**
+   * open InputStream for specified path
+   * @param filePath file path to open file.
+   * @return opened InputStream
+   */
+  InputStream openStream(String filePath);
+}