bottle: add test for writing part

In preparation for https://github.com/Homebrew/brew/issues/9315

Library/Homebrew/test/.rubocop_todo.yml

@@ -11,6 +11,7 @@
 RSpec/ExampleLength:
   Exclude:
     - 'rubocops/patches_spec.rb'
+    - 'dev-cmd/bottle_spec.rb'
 
 # Offense count: 6
 # Configuration parameters: AssignmentOnly.

Library/Homebrew/test/dev-cmd/bottle_spec.rb

@@ -42,9 +42,6 @@ describe "brew bottle", :integration_test do
   end
 end
 
-describe Homebrew do
-  subject(:homebrew) { described_class }
-
 def stub_hash(parameters)
   <<~EOS
     {
@@ -54,7 +51,7 @@ describe Homebrew do
             "path":"#{parameters[:path]}"
          },
          "bottle":{
-              "root_url":"https://homebrew.bintray.com/bottles",
+            "root_url":"#{HOMEBREW_BOTTLE_DEFAULT_DOMAIN}",
             "prefix":"/usr/local",
             "cellar":"#{parameters[:cellar]}",
             "rebuild":0,
@@ -75,6 +72,9 @@ describe Homebrew do
   EOS
 end
 
+describe Homebrew do
+  subject(:homebrew) { described_class }
+
   let(:hello_hash_big_sur) {
     JSON.parse(
       stub_hash(
@@ -194,3 +194,106 @@ describe Homebrew do
     )
   end
 end
+
+describe "brew bottle --merge", :integration_test, :needs_linux do
+  it "adds the bottle block to a formula that has none" do
+    core_tap = CoreTap.new
+    core_tap.path.cd do
+      system "git", "init"
+      setup_test_formula "testball"
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "testball 0.1"
+    end
+
+    Pathname("testball-1.0.big_sur.bottle.json").write(
+      stub_hash(
+        {
+          "name":           "testball",
+          "version":        "1.0",
+          "path":           "#{core_tap.path}/Formula/testball.rb",
+          "cellar":         "any_skip_relocation",
+          "os":             "big_sur",
+          "filename":       "hello-1.0.big_sur.bottle.tar.gz",
+          "local_filename": "hello--1.0.big_sur.bottle.tar.gz",
+          "sha256":         "a0af7dcbb5c83f6f3f7ecd507c2d352c1a018f894d51ad241ce8492fa598010f",
+        },
+      ),
+    )
+
+    Pathname("testball-1.0.catalina.bottle.json").write(
+      stub_hash(
+        {
+          "name":           "testball",
+          "version":        "1.0",
+          "path":           "#{core_tap.path}/Formula/testball.rb",
+          "cellar":         "any_skip_relocation",
+          "os":             "catalina",
+          "filename":       "testball-1.0.catalina.bottle.tar.gz",
+          "local_filename": "testball--1.0.catalina.bottle.tar.gz",
+          "sha256":         "5334dd344986e46b2aa4f0471cac7b0914bd7de7cb890a34415771788d03f2ac",
+        },
+      ),
+    )
+
+    expect {
+      brew "bottle",
+           "--merge",
+           "--write",
+           "testball-1.0.big_sur.bottle.json",
+           "testball-1.0.catalina.bottle.json"
+    }.to output(
+      <<~EOS,
+        ==> testball
+          bottle do
+            root_url "#{HOMEBREW_BOTTLE_DEFAULT_DOMAIN}"
+            cellar :any_skip_relocation
+            sha256 "a0af7dcbb5c83f6f3f7ecd507c2d352c1a018f894d51ad241ce8492fa598010f" => :big_sur
+            sha256 "5334dd344986e46b2aa4f0471cac7b0914bd7de7cb890a34415771788d03f2ac" => :catalina
+          end
+      EOS
+    ).to_stdout
+
+    FileUtils.rm_f "testball-1.0.catalina.bottle.json"
+    FileUtils.rm_f "testball-1.0.big_sur.bottle.json"
+
+    tarball = if OS.linux?
+      TEST_FIXTURE_DIR/"tarballs/testball-0.1-linux.tbz"
+    else
+      TEST_FIXTURE_DIR/"tarballs/testball-0.1.tbz"
+    end
+
+    expect((core_tap.path/"Formula/testball.rb").read).to eq(
+      <<~EOS,
+        class Testball < Formula
+          desc "Some test"
+          homepage "https://brew.sh/testball"
+          url "file://#{tarball}"
+          sha256 "#{tarball.sha256}"
+
+          bottle do
+            root_url "#{HOMEBREW_BOTTLE_DEFAULT_DOMAIN}"
+            cellar :any_skip_relocation
+            sha256 "a0af7dcbb5c83f6f3f7ecd507c2d352c1a018f894d51ad241ce8492fa598010f" => :big_sur
+            sha256 "5334dd344986e46b2aa4f0471cac7b0914bd7de7cb890a34415771788d03f2ac" => :catalina
+          end
+
+          option "with-foo", "Build with foo"
+
+          def install
+            (prefix/"foo"/"test").write("test") if build.with? "foo"
+            prefix.install Dir["*"]
+            (buildpath/"test.c").write \
+            "#include <stdio.h>\\nint main(){printf(\\"test\\");return 0;}"
+            bin.mkpath
+            system ENV.cc, "test.c", "-o", bin/"test"
+          end
+
+
+
+          # something here
+
+        end
+      EOS
+    )
+  end
+end