refactor: create a dedicated method for updating package.json (#527)

I'm aware of how much conflict this will create with #466 but oh well 🤷

template.rb

@@ -244,19 +244,23 @@ def build_engines_field
   }
 end
 
-def cleanup_package_json
-  package_json = JSON.parse(File.read("./package.json"))
+def update_package_json(&block)
+  package_json = JSON.load_file("./package.json").tap(&block)
 
-  # ensure that the package name is set based on the folder
-  package_json["name"] = File.basename(__dir__)
+  File.write("./package.json", "#{JSON.pretty_generate(package_json)}\n")
+end
 
-  # set engines constraint in package.json
-  package_json["engines"] = build_engines_field
+def cleanup_package_json
+  update_package_json do |package_json|
+    # ensure that the package name is set based on the folder
+    package_json["name"] = File.basename(__dir__)
 
-  # ensure that all dependency constraints are normalized
-  %w[dependencies devDependencies].each { |k| package_json[k] = normalize_dependency_constraints(package_json[k]) }
+    # set engines constraint in package.json
+    package_json["engines"] = build_engines_field
 
-  File.write("./package.json", JSON.pretty_generate(package_json))
+    # ensure that all dependency constraints are normalized
+    %w[dependencies devDependencies].each { |k| package_json[k] = normalize_dependency_constraints(package_json[k]) }
+  end
 
   run "npx -y sort-package-json"
 

variants/frontend-base-typescript/template.rb

@@ -55,9 +55,9 @@ def rename_js_file_to_ts(file)
 EO_TS_ENABLE_IMAGES
 gsub_file("app/frontend/packs/application.ts", js_load_images_chunk, ts_load_images_chunk, force: true)
 
-package_json = JSON.parse(File.read("./package.json"))
-package_json["scripts"]["typecheck"] = "tsc -p . --noEmit"
-File.write("./package.json", JSON.generate(package_json))
+update_package_json do |package_json|
+  package_json["scripts"]["typecheck"] = "tsc -p . --noEmit"
+end
 
 append_to_file "bin/ci-run" do
   <<~TYPECHECK

variants/frontend-base/js-lint/template.rb

@@ -15,19 +15,18 @@
 copy_file "variants/frontend-base/.eslintrc.js", ".eslintrc.js"
 template "variants/frontend-base/.prettierignore.tt", ".prettierignore"
 
-package_json = JSON.parse(File.read("./package.json"))
-package_json["prettier"] = "prettier-config-ackama"
-package_json["browserslist"] = ["defaults"]
-package_json["scripts"] = {
-  "js-lint" => "eslint . --ignore-pattern '!.eslintrc.js' --ext js,ts,tsx,jsx",
-  "js-lint-fix" => "eslint . --ignore-pattern '!.eslintrc.js' --ext js,ts,tsx,jsx --fix",
-  "format-check" => "prettier --check .",
-  "format-fix" => "prettier --write .",
-  "scss-lint" => "stylelint '**/*.{css,scss}'",
-  "scss-lint-fix" => "stylelint '**/*.{css,scss}' --fix"
-}
-
-File.write("./package.json", JSON.generate(package_json))
+update_package_json do |package_json|
+  package_json["prettier"] = "prettier-config-ackama"
+  package_json["browserslist"] = ["defaults"]
+  package_json["scripts"] = {
+    "js-lint" => "eslint . --ignore-pattern '!.eslintrc.js' --ext js,ts,tsx,jsx",
+    "js-lint-fix" => "eslint . --ignore-pattern '!.eslintrc.js' --ext js,ts,tsx,jsx --fix",
+    "format-check" => "prettier --check .",
+    "format-fix" => "prettier --write .",
+    "scss-lint" => "stylelint '**/*.{css,scss}'",
+    "scss-lint-fix" => "stylelint '**/*.{css,scss}' --fix"
+  }
+end
 
 append_to_file "bin/ci-run" do
   <<~ESLINT

variants/frontend-react/template.rb

@@ -80,9 +80,7 @@
   ERB
 end
 
-package_json = JSON.parse(File.read("./package.json"))
-
-# we've replaced this with a babel.config.js
-package_json.delete "babel"
-
-File.write("./package.json", JSON.generate(package_json))
+update_package_json do |package_json|
+  # we've replaced this with a babel.config.js
+  package_json.delete "babel"
+end

variants/frontend-stimulus-typescript/template.rb

@@ -16,12 +16,10 @@
 
 copy_file "babel.config.js", force: true
 
-package_json = JSON.parse(File.read("./package.json"))
-
-# we've replaced this with a babel.config.js
-package_json.delete "babel"
-
-File.write("./package.json", JSON.generate(package_json))
+update_package_json do |package_json|
+  # we've replaced this with a babel.config.js
+  package_json.delete "babel"
+end
 
 remove_file "app/frontend/stimulus/controllers/hello_controller.js", force: true
 copy_file "app/frontend/stimulus/controllers/hello_controller.ts"

variants/frontend-stimulus/template.rb

@@ -65,15 +65,14 @@
 copy_file ".eslintrc.js", force: true
 copy_file "jest.config.js"
 
-package_json = JSON.parse(File.read("./package.json"))
-package_json["scripts"] = package_json["scripts"].merge(
-  {
-    "test" => "jest",
-    "watch-tests" => "jest --watch"
-  }
-)
-
-File.write("./package.json", JSON.generate(package_json))
+update_package_json do |package_json|
+  package_json["scripts"] = package_json["scripts"].merge(
+    {
+      "test" => "jest",
+      "watch-tests" => "jest --watch"
+    }
+  )
+end
 
 append_to_file "bin/ci-run" do
   <<~JEST