Refactor unpack strategy specs.

Library/Homebrew/test/unpack_strategy_spec.rb

@@ -1,127 +1,192 @@
 require "unpack_strategy"
 
-describe UnpackStrategy, :focus do
+RSpec.shared_examples "UnpackStrategy::detect" do
-  matcher :be_detected_as_a do |klass|
+  it "is correctly detected" do
-    match do |expected|
+    expect(UnpackStrategy.detect(path)).to be_a described_class
-      @detected = described_class.detect(expected)
+  end
-      @detected.is_a?(klass)
+end
-    end
 
-    failure_message do
+RSpec.shared_examples "#extract" do |children: []|
-      <<~EOS
+  specify "#extract" do
-        expected: #{klass}
+    mktmpdir do |unpack_dir|
-        detected: #{@detected}
+      described_class.new(path).extract(to: unpack_dir)
-      EOS
+      expect(unpack_dir.children(false).map(&:to_s)).to match_array children
     end
   end
+end
 
-  describe "::detect" do
+describe UncompressedUnpackStrategy do
-    it "correctly detects JAR files" do
+  let(:path) {
-      expect(TEST_FIXTURE_DIR/"test.jar").to be_detected_as_a UncompressedUnpackStrategy
+    (mktmpdir/"test").tap do |path|
+      FileUtils.touch path
     end
+  }
 
-    it "correctly detects ZIP files" do
+  include_examples "UnpackStrategy::detect"
-      expect(TEST_FIXTURE_DIR/"cask/MyFancyApp.zip").to be_detected_as_a ZipUnpackStrategy
+end
-    end
 
-    it "correctly detects BZIP2 files" do
+describe P7ZipUnpackStrategy do
-      expect(TEST_FIXTURE_DIR/"cask/container.bz2").to be_detected_as_a Bzip2UnpackStrategy
+  let(:path) { TEST_FIXTURE_DIR/"cask/container.7z" }
-    end
 
-    it "correctly detects GZIP files" do
+  include_examples "UnpackStrategy::detect"
-      expect(TEST_FIXTURE_DIR/"cask/container.gz").to be_detected_as_a GzipUnpackStrategy
+end
-    end
 
-    it "correctly detects compressed TAR files" do
+describe XarUnpackStrategy do
-      expect(TEST_FIXTURE_DIR/"cask/container.tar.gz").to be_detected_as_a TarUnpackStrategy
+  let(:path) { TEST_FIXTURE_DIR/"cask/container.xar" }
-    end
 
-    it "correctly detects 7-ZIP files" do
+  include_examples "UnpackStrategy::detect"
-      expect(TEST_FIXTURE_DIR/"cask/container.7z").to be_detected_as_a P7ZipUnpackStrategy
+  include_examples "#extract", children: ["container"]
-    end
+end
 
-    it "correctly detects XAR files" do
+describe XzUnpackStrategy do
-      expect(TEST_FIXTURE_DIR/"cask/container.xar").to be_detected_as_a XarUnpackStrategy
+  let(:path) { TEST_FIXTURE_DIR/"cask/container.xz" }
-    end
 
-    it "correctly detects XZ files" do
+  include_examples "UnpackStrategy::detect"
-      expect(TEST_FIXTURE_DIR/"cask/container.xz").to be_detected_as_a XzUnpackStrategy
+end
-    end
 
-    it "correctly detects RAR files" do
+describe RarUnpackStrategy do
-      expect(TEST_FIXTURE_DIR/"cask/container.rar").to be_detected_as_a RarUnpackStrategy
+  let(:path) { TEST_FIXTURE_DIR/"cask/container.rar" }
-    end
 
-    it "correctly detects LZIP files" do
+  include_examples "UnpackStrategy::detect"
-      expect(TEST_FIXTURE_DIR/"test.lz").to be_detected_as_a LzipUnpackStrategy
+end
-    end
 
-    it "correctly detects LHA files" do
+describe LzipUnpackStrategy do
-      expect(TEST_FIXTURE_DIR/"test.lha").to be_detected_as_a LhaUnpackStrategy
+  let(:path) { TEST_FIXTURE_DIR/"test.lz" }
-    end
 
-    it "correctly detects Git repositories" do
+  include_examples "UnpackStrategy::detect"
-      mktmpdir do |repo|
+end
-        system "git", "-C", repo, "init"
 
-        expect(repo).to be_detected_as_a GitUnpackStrategy
+describe LhaUnpackStrategy do
+  let(:path) { TEST_FIXTURE_DIR/"test.lha" }
+
+  include_examples "UnpackStrategy::detect"
+end
+
+describe JarUnpackStrategy do
+  let(:path) { TEST_FIXTURE_DIR/"test.jar" }
+
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: ["test.jar"]
+end
+
+describe ZipUnpackStrategy do
+  let(:path) { TEST_FIXTURE_DIR/"cask/MyFancyApp.zip" }
+
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: ["MyFancyApp"]
+
+  context "when ZIP archive is corrupted" do
+    let(:path) {
+      (mktmpdir/"test.zip").tap do |path|
+        FileUtils.touch path
       end
-    end
+    }
 
-    it "correctly detects Subversion repositories" do
+    include_examples "UnpackStrategy::detect"
-      mktmpdir do |path|
+  end
-        repo = path/"repo"
+end
-        working_copy = path/"working_copy"
 
-        system "svnadmin", "create", repo
+describe GzipUnpackStrategy do
-        system "svn", "checkout", "file://#{repo}", working_copy
+  let(:path) { TEST_FIXTURE_DIR/"cask/container.gz" }
 
-        expect(working_copy).to be_detected_as_a SubversionUnpackStrategy
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: ["container"]
+end
+
+describe Bzip2UnpackStrategy do
+  let(:path) { TEST_FIXTURE_DIR/"cask/container.bz2" }
+
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: ["container"]
+end
+
+describe TarUnpackStrategy do
+  let(:path) { TEST_FIXTURE_DIR/"cask/container.tar.gz" }
+
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: ["container"]
+
+  context "when TAR archive is corrupted" do
+    let(:path) {
+      (mktmpdir/"test.tar").tap do |path|
+        FileUtils.touch path
       end
-    end
+    }
+
+    include_examples "UnpackStrategy::detect"
   end
 end
 
 describe GitUnpackStrategy do
-  describe "#extract" do
+  let(:repo) {
-    it "correctly extracts a Subversion repository" do
+    mktmpdir.tap do |repo|
-      mktmpdir do |path|
+      system "git", "-C", repo, "init"
-        repo = path/"repo"
 
-        repo.mkpath
+      FileUtils.touch repo/"test"
-
+      system "git", "-C", repo, "add", "test"
-        system "git", "-C", repo, "init"
+      system "git", "-C", repo, "commit", "-m", "Add `test` file."
-
-        FileUtils.touch repo/"test"
-        system "git", "-C", repo, "add", "test"
-        system "git", "-C", repo, "commit", "-m", "Add `test` file."
-
-        unpack_dir = path/"unpack_dir"
-        GitUnpackStrategy.new(repo).extract(to: unpack_dir)
-        expect(unpack_dir.children(false).map(&:to_s)).to match_array [".git", "test"]
-      end
     end
-  end
+  }
+  let(:path) { repo }
+
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: [".git", "test"]
 end
 
 describe SubversionUnpackStrategy do
-  describe "#extract" do
+  let(:repo) {
-    it "correctly extracts a Subversion repository" do
+    mktmpdir.tap do |repo|
-      mktmpdir do |path|
+      system "svnadmin", "create", repo
-        repo = path/"repo"
-        working_copy = path/"working_copy"
-
-        system "svnadmin", "create", repo
-        system "svn", "checkout", "file://#{repo}", working_copy
-
-        FileUtils.touch working_copy/"test"
-        system "svn", "add", working_copy/"test"
-        system "svn", "commit", working_copy, "-m", "Add `test` file."
-
-        unpack_dir = path/"unpack_dir"
-        SubversionUnpackStrategy.new(working_copy).extract(to: unpack_dir)
-        expect(unpack_dir.children(false).map(&:to_s)).to match_array ["test"]
-      end
     end
-  end
+  }
+  let(:working_copy) {
+    mktmpdir.tap do |working_copy|
+      system "svn", "checkout", "file://#{repo}", working_copy
+
+      FileUtils.touch working_copy/"test"
+      system "svn", "add", working_copy/"test"
+      system "svn", "commit", working_copy, "-m", "Add `test` file."
+    end
+  }
+  let(:path) { working_copy }
+
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: ["test"]
+end
+
+describe CvsUnpackStrategy do
+  let(:repo) {
+    mktmpdir.tap do |repo|
+      FileUtils.touch repo/"test"
+      (repo/"CVS").mkpath
+    end
+  }
+  let(:path) { repo }
+
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: ["CVS", "test"]
+end
+
+describe BazaarUnpackStrategy do
+  let(:repo) {
+    mktmpdir.tap do |repo|
+      FileUtils.touch repo/"test"
+      (repo/".bzr").mkpath
+    end
+  }
+  let(:path) { repo }
+
+  include_examples "UnpackStrategy::detect"
+  include_examples "#extract", children: ["test"]
+end
+
+describe MercurialUnpackStrategy do
+  let(:repo) {
+    mktmpdir.tap do |repo|
+      (repo/".hg").mkpath
+    end
+  }
+  let(:path) { repo }
+
+  include_examples "UnpackStrategy::detect"
 end

Library/Homebrew/unpack_strategy.rb

@@ -31,7 +31,7 @@ class UnpackStrategy
     magic_number = if path.directory?
       ""
     else
-      File.binread(path, MAX_MAGIC_NUMBER_LENGTH)
+      File.binread(path, MAX_MAGIC_NUMBER_LENGTH) || ""
     end
 
     strategy = strategies.detect do |s|
@@ -40,7 +40,7 @@ class UnpackStrategy
 
     # This is so that bad files produce good error messages.
     strategy ||= case path.extname
-    when ".tar.gz", ".tgz", ".tar.bz2", ".tbz", ".tar.xz", ".txz"
+    when ".tar", ".tar.gz", ".tgz", ".tar.bz2", ".tbz", ".tar.xz", ".txz"
       TarUnpackStrategy
     when ".zip"
       ZipUnpackStrategy
@@ -58,16 +58,11 @@ class UnpackStrategy
   end
 
   def extract(to: nil, basename: nil)
+    basename ||= path.basename
     unpack_dir = Pathname(to || Dir.pwd).expand_path
     unpack_dir.mkpath
     extract_to_dir(unpack_dir, basename: basename)
   end
-
-  private
-
-  def extract_to_dir(_unpack_dir, basename:)
-    raise NotImplementedError
-  end
 end
 
 class DirectoryUnpackStrategy < UnpackStrategy
@@ -83,10 +78,6 @@ class DirectoryUnpackStrategy < UnpackStrategy
 end
 
 class UncompressedUnpackStrategy < UnpackStrategy
-  def self.can_extract?(path:, magic_number:)
-    false
-  end
-
   private
 
   def extract_to_dir(unpack_dir, basename:)