[Truffle] add RubyFiletypeDetector

jruby · Sep 7, 2015 · 410350c · 410350c
1 parent 6bae7a6
commit 410350c
Showing 2 changed files with 52 additions and 0 deletions.
diff --git a/core/src/main/java/org/jruby/util/RubyFiletypeDetector.java b/core/src/main/java/org/jruby/util/RubyFiletypeDetector.java
@@ -0,0 +1,51 @@
+package org.jruby.util;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.spi.FileTypeDetector;
+import java.util.Locale;
+import java.util.regex.Pattern;
+
+public final class RubyFiletypeDetector extends FileTypeDetector {
+
+    private static final String[] KNOWN_RUBY_FILES = new String[]{ "Gemfile", "Rakefile", "Mavenfile" };
+    private static final String[] KNOWN_RUBY_SUFFIXES = new String[]{ ".rb", ".rake", ".gemspec" };
+    private static final String RUBY_MIME = "application/x-ruby";
+    private static final Pattern SHEBANG_REGEXP = Pattern.compile("^#! ?/usr/bin/(env +ruby|ruby).*");
+
+    @Override
+    public String probeContentType(Path path) throws IOException {
+        final Path fileNamePath = path.getFileName();
+        if (fileNamePath == null) {
+            return null;
+        }
+
+        final String fileName = fileNamePath.toString();
+        final String lowerCaseFileName = fileName.toLowerCase(Locale.ROOT);
+
+        for (String candidate : KNOWN_RUBY_SUFFIXES) {
+            if (lowerCaseFileName.endsWith(candidate)) {
+                return RUBY_MIME;
+            }
+        }
+
+        for (String candidate : KNOWN_RUBY_FILES) {
+            if (fileName.equals(candidate)) {
+                return RUBY_MIME;
+            }
+        }
+
+        try (BufferedReader fileContent = Files.newBufferedReader(path, StandardCharsets.UTF_8)) {
+            final String firstLine = fileContent.readLine();
+            if (firstLine != null && SHEBANG_REGEXP.matcher(firstLine).matches()) {
+                return RUBY_MIME;
+            }
+        }
+
+        return null;
+    }
+}
+
diff --git a/core/src/main/resources/META-INF/services/java.nio.file.spi.FileTypeDetector b/core/src/main/resources/META-INF/services/java.nio.file.spi.FileTypeDetector
@@ -0,0 +1 @@
+org.jruby.util.RubyFiletypeDetector