refactoring testball case to make it more readable

Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb

@@ -135,11 +135,17 @@ RSpec.shared_context "integration test" do # rubocop:disable RSpec/ContextWordin
     case name
     when /^testball/
       case name
-      when "testball4", "testball5", "testball2"
+      when "testball4", "testball5"
         prefix = name
+        program_name = name
+      when "testball2"
+        prefix = name
+        program_name = "test"
       else
         prefix = "testball"
+        program_name = "test"
       end
+
       tarball_name = "#{prefix}-0.1#{'-linux' if OS.linux?}.tbz"
       tarball = TEST_FIXTURE_DIR / "tarballs/#{tarball_name}"
 
@@ -151,14 +157,13 @@ RSpec.shared_context "integration test" do # rubocop:disable RSpec/ContextWordin
 
       option "with-foo", "Build with foo"
       #{bottle_block}
-
       def install
-      (prefix/"foo"/"#{prefix}").write("#{prefix}") if build.with? "foo"
+        (prefix/"foo"/"#{program_name}").write("#{program_name}") if build.with? "foo"
         prefix.install Dir["*"]
-      (buildpath/"#{prefix}.c").write \\
-        "#include <stdio.h>\\nint main(){printf(\\"#{prefix}\\");return 0;}"
+        (buildpath/"#{program_name}.c").write \
+          "#include <stdio.h>\\nint main(){printf(\\"#{program_name}\\");return 0;}"
         bin.mkpath
-      system ENV.cc, "#{prefix}.c", "-o", bin/"#{prefix}"
+        system ENV.cc, "#{program_name}.c", "-o", bin/"#{program_name}"
       end
 
       #{content}