diff --git a/Library/Homebrew/test/dev-cmd/extract_spec.rb b/Library/Homebrew/test/dev-cmd/extract_spec.rb
index 5fd98eb940..fe91531dc8 100644
--- a/Library/Homebrew/test/dev-cmd/extract_spec.rb
+++ b/Library/Homebrew/test/dev-cmd/extract_spec.rb
@@ -1,13 +1,235 @@
 describe "brew extract", :integration_test do
-  it "extracts the most recent formula version without version argument" do
+  it "retrieves the most recent formula version without version argument" do
     path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
     (path/"Formula").mkpath
     target = Tap.from_path(path)
-    formula_file = setup_test_formula "foo"
-
-    expect { brew "extract", "foo", target.name }
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      formula_file = setup_test_formula "testball"
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+      contents = File.read(formula_file)
+      contents.gsub!("testball-0.1", "testball-0.2")
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.2"
+    end
+    expect { brew "extract", "testball", target.name }
       .to be_a_success
 
-    expect(path/"Formula/foo@1.0.rb").to exist
+    expect(path/"Formula/testball@0.2.rb").to exist
+
+    expect(Formulary.factory(path/"Formula/testball@0.2.rb").version).to be == "0.2"
+  end
+
+  it "does not overwrite existing files, except when running with --force" do
+    path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
+    (path/"Formula").mkpath
+    target = Tap.from_path(path)
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      formula_file = setup_test_formula "testball"
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+      contents = File.read(formula_file)
+      contents.gsub!("testball-0.1", "testball-0.2")
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.2"
+    end
+    expect { brew "extract", "testball", target.name }
+      .to be_a_success
+
+    expect(path/"Formula/testball@0.2.rb").to exist
+
+    expect { brew "extract", "testball", target.name }
+      .to be_a_failure
+
+    expect { brew "extract", "testball", target.name, "--force" }
+      .to be_a_success
+
+    expect { brew "extract", "testball", target.name, "--version=0.1" }
+      .to be_a_success
+
+    expect(path/"Formula/testball@0.2.rb").to exist
+
+    expect { brew "extract", "testball", "--version=0.1", target.name }
+      .to be_a_failure
+
+    expect { brew "extract", "testball", target.name, "--version=0.1", "--force" }
+      .to be_a_success
+  end
+
+  it "retrieves the specified formula version when given argument" do
+    path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
+    (path/"Formula").mkpath
+    target = Tap.from_path(path)
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      formula_file = setup_test_formula "testball"
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+      contents = File.read(formula_file)
+      contents.gsub!("testball-0.1", "testball-0.2")
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.2"
+    end
+    expect { brew "extract", "testball", target.name, "--version=0.1" }
+      .to be_a_success
+
+    expect { brew "extract", "testball", target.name, "--version=0.1", "--force" }
+      .to be_a_success
+
+    expect(Formulary.factory(path/"Formula/testball@0.1.rb").version).to be == "0.1"
+  end
+
+  it "retrieves most recent deleted formula when no argument is given" do
+    path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
+    (path/"Formula").mkpath
+    target = Tap.from_path(path)
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      formula_file = setup_test_formula "testball"
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+      contents = File.read(formula_file)
+      contents.gsub!("testball-0.1", "testball-0.2")
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.2"
+      File.delete(formula_file)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "Remove testball"
+    end
+
+    expect { brew "extract", "testball", target.name }
+      .to be_a_success
+
+    expect(path/"Formula/testball@0.2.rb").to exist
+
+    expect(Formulary.factory(path/"Formula/testball@0.2.rb").version).to be == "0.2"
+  end
+
+  it "retrieves old version of deleted formula when argument is given" do
+    path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
+    (path/"Formula").mkpath
+    target = Tap.from_path(path)
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      formula_file = setup_test_formula "testball"
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+      contents = File.read(formula_file)
+      contents.gsub!("testball-0.1", "testball-0.2")
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.2"
+      File.delete(formula_file)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "Remove testball"
+    end
+
+    expect { brew "extract", "testball", target.name, "--version=0.1" }
+      .to be_a_success
+
+    expect(path/"Formula/testball@0.1.rb").to exist
+
+    expect(Formulary.factory(path/"Formula/testball@0.1.rb").version).to be == "0.1"
+  end
+
+  it "retrieves old formulae that use outdated/missing blocks" do
+    path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
+    (path/"Formula").mkpath
+    target = Tap.from_path(path)
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      contents = <<~EOF
+        require 'brewkit'
+        class Testball < Formula
+          @url="file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
+          @md5='80a8aa0c5a8310392abf3b69f0319204'
+
+          def install
+            prefix.install "bin"
+            prefix.install "libexec"
+            Dir.chdir "doc"
+          end
+        end
+      EOF
+      formula_file = core_tap.path/"Formula/testball.rb"
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+      contents = File.read(formula_file)
+      contents.gsub!("testball-0.1", "testball-0.2")
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.2"
+      File.delete(formula_file)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "Remove testball"
+    end
+
+    expect { brew "extract", "testball", target.name, "--version=0.1" }
+      .to be_a_success
+
+    expect(path/"Formula/testball@0.1.rb").to exist
+  end
+
+  it "fails when formula does not exist" do
+    path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
+    (path/"Formula").mkpath
+    target = Tap.from_path(path)
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      formula_file = setup_test_formula "testball"
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+      contents = File.read(formula_file)
+      contents.gsub!("testball-0.1", "testball-0.2")
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.2"
+      File.delete(formula_file)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "Remove testball"
+    end
+    expect { brew "extract", "foo", target.name }
+      .to be_a_failure
+    expect(Dir.entries(path/"Formula").size).to be == 2
+  end
+
+  it "fails when formula does not have the specified version" do
+    path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
+    (path/"Formula").mkpath
+    target = Tap.from_path(path)
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      formula_file = setup_test_formula "testball"
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+      contents = File.read(formula_file)
+      contents.gsub!("testball-0.1", "testball-0.2")
+      File.write(formula_file, contents)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.2"
+      File.delete(formula_file)
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "Remove testball"
+    end
+
+    expect { brew "extract", "testball", target.name, "--version=0.3" }
+      .to be_a_failure
+
+    expect(path/"Formula/testball@0.3.rb").not_to exist
   end
 end