Add backward compatibility

lib/install/config/shakapacker.yml

@@ -45,6 +45,9 @@ default: &default
   # Select whether the compiler will use SHA digest ('digest' option) or most most recent modified timestamp ('mtime') to determine freshness
   compiler_strategy: digest
 
+  # Set whether the compiler should be sensitive to the provided asset host
+  compiler_strategy_asset_host_sensitive: false
+
   # Select whether the compiler will always use a content hash and not just in production
   # Don't use contentHash except for production for performance
   # https://webpack.js.org/guides/build-performance/#avoid-production-specific-tooling

lib/shakapacker/digest_strategy.rb

@@ -53,7 +53,10 @@ def record_compilation_digest
       end
 
       def compilation_digest_path
-        config.cache_path.join("last-compilation-digest-#{Shakapacker.env}-#{generate_host_hash}")
+        path = "last-compilation-digest-#{Shakapacker.env}"
+        path += "-#{generate_host_hash}" if Shakapacker.config.fetch(:compiler_strategy_asset_host_sensitive)
+
+        config.cache_path.join(path)
       end
 
       def generate_host_hash(*keys)

spec/shakapacker/digest_strategy_spec.rb

@@ -29,6 +29,9 @@ def remove_compilation_digest_path
   end
 
   it "is stale when host changes" do
+    allow(Shakapacker.config).to receive(:fetch).with(any_args).and_call_original
+    allow(Shakapacker.config).to receive(:fetch).with(:compiler_strategy_asset_host_sensitive).and_return(true)
+
     ENV["SHAKAPACKER_ASSET_HOST"] = "the-host"
 
     @digest_strategy.after_compile_hook
@@ -38,12 +41,24 @@ def remove_compilation_digest_path
     expect(@digest_strategy.stale?).to be true
     expect(@digest_strategy.fresh?).to be_falsey
 
-    ENV["SHAKAPACKER_ASSET_HOST"] = ""
+    ENV["SHAKAPACKER_ASSET_HOST"] = nil
   end
 
   it "generates correct compilation_digest_path" do
     actual_path = @digest_strategy.send(:compilation_digest_path).basename.to_s
-    host_hash = Digest::SHA1.hexdigest("")
+    expected_path = "last-compilation-digest-#{Shakapacker.env}"
+
+    expect(actual_path).to eq expected_path
+  end
+
+  it "generates correct compilation_digest_path with " do
+    allow(Shakapacker.config).to receive(:fetch).with(any_args).and_call_original
+    allow(Shakapacker.config).to receive(:fetch).with(:compiler_strategy_asset_host_sensitive).and_return(true)
+
+    ENV["SHAKAPACKER_ASSET_HOST"] = "custom-path"
+
+    actual_path = @digest_strategy.send(:compilation_digest_path).basename.to_s
+    host_hash = Digest::SHA1.hexdigest("-custom-path")
     expected_path = "last-compilation-digest-#{Shakapacker.env}-#{host_hash}"
 
     expect(actual_path).to eq expected_path