Convert brew prune test to spec.

Library/Homebrew/test/cmd/prune_spec.rb

@@ -0,0 +1,28 @@
+describe "brew prune", :integration_test do
+  it "removes empty directories and broken symlinks" do
+    share = (HOMEBREW_PREFIX/"share")
+
+    (share/"pruneable/directory/here").mkpath
+    (share/"notpruneable/file").write "I'm here"
+    FileUtils.ln_s "/i/dont/exist/no/really/i/dont", share/"pruneable_symlink"
+
+    expect { brew "prune", "--dry-run" }
+      .to output(%r{Would remove \(empty directory\): .*/pruneable/directory/here}).to_stdout
+      .and not_to_output.to_stderr
+      .and be_a_success
+
+    expect { brew "prune" }
+      .to output(/Pruned 1 symbolic links and 3 directories/).to_stdout
+      .and not_to_output.to_stderr
+      .and be_a_success
+
+    expect(share/"pruneable").not_to be_a_directory
+    expect(share/"notpruneable").to be_a_directory
+    expect(share/"pruneable_symlink").not_to be_a_symlink
+
+    expect { brew "prune", "--verbose" }
+      .to output(/Nothing pruned/).to_stdout
+      .and not_to_output.to_stderr
+      .and be_a_success
+  end
+end

Library/Homebrew/test/prune_test.rb

@@ -1,21 +0,0 @@
-require "testing_env"
-
-class IntegrationCommandTestPrune < IntegrationCommandTestCase
-  def test_prune
-    share = (HOMEBREW_PREFIX/"share")
-
-    (share/"pruneable/directory/here").mkpath
-    (share/"notpruneable/file").write "I'm here"
-    FileUtils.ln_s "/i/dont/exist/no/really/i/dont", share/"pruneable_symlink"
-
-    assert_match %r{Would remove \(empty directory\): .*/pruneable/directory/here},
-      cmd("prune", "--dry-run")
-    assert_match "Pruned 1 symbolic links and 3 directories",
-      cmd("prune")
-    refute((share/"pruneable").directory?)
-    assert((share/"notpruneable").directory?)
-    refute((share/"pruneable_symlink").symlink?)
-
-    assert_match "Nothing pruned", cmd("prune", "--verbose")
-  end
-end