Merge pull request #2041 from github/emacs-vim-mode-lines

Emacs vim modelines

lib/linguist/language.rb

@@ -11,6 +11,7 @@ require 'linguist/samples'
 require 'linguist/file_blob'
 require 'linguist/blob_helper'
 require 'linguist/strategy/filename'
+require 'linguist/strategy/modeline'
 require 'linguist/shebang'
 
 module Linguist
@@ -94,6 +95,7 @@ module Linguist
     end
 
     STRATEGIES = [
+      Linguist::Strategy::Modeline,
       Linguist::Strategy::Filename,
       Linguist::Shebang,
       Linguist::Heuristics,

lib/linguist/strategy/modeline.rb

@@ -0,0 +1,30 @@
+module Linguist
+  module Strategy
+    class Modeline
+      EmacsModeline = /-\*-\s*(?:mode:)?\s*(\w+);?\s*-\*-/
+      VimModeline = /\/\*\s*vim:\s*set\s*(?:ft|filetype)=(\w+):\s*\*\//
+
+      # Public: Detects language based on Vim and Emacs modelines
+      #
+      # blob               - An object that quacks like a blob.
+      #
+      # Examples
+      #
+      #   Modeline.call(FileBlob.new("path/to/file"))
+      #
+      # Returns an Array with one Language if the blob has a Vim or Emacs modeline
+      # that matches a Language name or alias. Returns an empty array if no match.
+      def self.call(blob, _ = nil)
+        Array(Language.find_by_alias(modeline(blob.data)))
+      end
+
+      # Public: Get the modeline from the first n-lines of the file
+      #
+      # Returns a String or nil
+      def self.modeline(data)
+        match = data.match(EmacsModeline) || data.match(VimModeline)
+        match[1] if match
+      end
+    end
+  end
+end

test/fixtures/Data/Modelines/example_smalltalk.md

@@ -0,0 +1 @@
+; -*-Smalltalk-*-

test/fixtures/Data/Modelines/iamphp.inc

@@ -0,0 +1 @@
+; -*- mode: php;-*-

test/fixtures/Data/Modelines/not_perl.pl

@@ -0,0 +1,3 @@
+/* vim: set filetype=prolog: */
+
+# I am Prolog

test/fixtures/Data/Modelines/ruby

@@ -0,0 +1,3 @@
+/* vim: set filetype=ruby: */
+
+# I am Ruby

test/fixtures/Data/Modelines/seeplusplus

@@ -0,0 +1,3 @@
+/* vim: set ft=cpp: */
+
+I would like to be C++ please.

test/helper.rb

@@ -2,3 +2,21 @@ require "bundler/setup"
 require "minitest/autorun"
 require "mocha/setup"
 require "linguist"
+
+def fixtures_path
+  File.expand_path("../fixtures", __FILE__)
+end
+
+def fixture_blob(name)
+  name = File.join(fixtures_path, name) unless name =~ /^\//
+  Linguist::FileBlob.new(name, fixtures_path)
+end
+
+def samples_path
+  File.expand_path("../../samples", __FILE__)
+end
+
+def sample_blob(name)
+  name = File.join(samples_path, name) unless name =~ /^\//
+  Linguist::FileBlob.new(name, samples_path)
+end

test/test_blob.rb

@@ -14,24 +14,6 @@ class TestBlob < Minitest::Test
     Encoding.default_external = @original_external
   end
 
-  def samples_path
-    File.expand_path("../../samples", __FILE__)
-  end
-
-  def fixtures_path
-    File.expand_path("../fixtures", __FILE__)
-  end
-
-  def sample_blob(name)
-    name = File.join(samples_path, name) unless name =~ /^\//
-    FileBlob.new(name, samples_path)
-  end
-
-  def fixture_blob(name)
-    name = File.join(fixtures_path, name) unless name =~ /^\//
-    FileBlob.new(name, fixtures_path)
-  end
-
   def script_blob(name)
     blob = sample_blob(name)
     blob.instance_variable_set(:@name, 'script')

test/test_classifier.rb

@@ -3,10 +3,6 @@ require_relative "./helper"
 class TestClassifier < Minitest::Test
   include Linguist
 
-  def samples_path
-    File.expand_path("../../samples", __FILE__)
-  end
-
   def fixture(name)
     File.read(File.join(samples_path, name))
   end

test/test_generated.rb

@@ -3,10 +3,6 @@ require_relative "./helper"
 class TestGenerated < Minitest::Test
   include Linguist
 
-  def samples_path
-    File.expand_path("../../samples", __FILE__)
-  end
-
   class DataLoadedError < StandardError; end
 
   def generated_without_loading_data(name)

test/test_heuristics.rb

@@ -3,10 +3,6 @@ require_relative "./helper"
 class TestHeuristcs < Minitest::Test
   include Linguist
 
-  def samples_path
-    File.expand_path("../../samples", __FILE__)
-  end
-
   def fixture(name)
     File.read(File.join(samples_path, name))
   end

test/test_modelines.rb

@@ -0,0 +1,25 @@
+require_relative "./helper"
+
+class TestModelines < Minitest::Test
+  include Linguist
+
+  def assert_modeline(language, blob)
+    assert_equal language, Linguist::Strategy::Modeline.call(blob).first
+  end
+
+  def test_modeline_strategy
+    assert_modeline Language["Ruby"], fixture_blob("Data/Modelines/ruby")
+    assert_modeline Language["C++"], fixture_blob("Data/Modelines/seeplusplus")
+    assert_modeline Language["Prolog"], fixture_blob("Data/Modelines/not_perl.pl")
+    assert_modeline Language["Smalltalk"], fixture_blob("Data/Modelines/example_smalltalk.md")
+    assert_modeline Language["PHP"], fixture_blob("Data/Modelines/iamphp.inc")
+  end
+
+  def test_modeline_languages
+    assert_equal Language["Ruby"], fixture_blob("Data/Modelines/ruby").language
+    assert_equal Language["C++"], fixture_blob("Data/Modelines/seeplusplus").language
+    assert_equal Language["Prolog"], fixture_blob("Data/Modelines/not_perl.pl").language
+    assert_equal Language["Smalltalk"], fixture_blob("Data/Modelines/example_smalltalk.md").language
+    assert_equal Language["PHP"], fixture_blob("Data/Modelines/iamphp.inc").language
+  end
+end

test/test_tokenizer.rb

@@ -3,10 +3,6 @@ require_relative "./helper"
 class TestTokenizer < Minitest::Test
   include Linguist
 
-  def samples_path
-    File.expand_path("../../samples", __FILE__)
-  end
-
   def tokenize(data)
     data = File.read(File.join(samples_path, data.to_s)) if data.is_a?(Symbol)
     Tokenizer.tokenize(data)