Fix yarn installation method for yarn > 1.x.x

This commit add a method to check if the yarn version need installation through Corepack instead of NPM.

Why? Because Yarn > 1.x.x isn't installable through NPM since 2019. Extract from Yarn documentation :
"Why is the yarn package on npm still on 1.x?

Modern releases of Yarn haven't been distributed on npm since 2019.

The reason is simple: because Yarn wasn't distributed alongside Node.js, many people relied on something like npm install -g yarn as part of their image building. It meant that any breaking change would make their way on everyone using this pattern, and break their deployments.

As a result, we decided to retire the yarn npm package and only use it for the few 1.x maintenance releases needed. Yarn is now installed directly from our website, via either Corepack or yarn set version."

Update railties/lib/rails/generators/app_base.rb

Co-authored-by: zzak <[email protected]>

combine RUN on single line

Author: BarnabeD

railties/lib/rails/generators/app_base.rb

@@ -539,6 +539,11 @@ def dockerfile_yarn_version
         "latest"
       end
 
+      def yarn_through_corepack?
+        true if dockerfile_yarn_version == "latest"
+        dockerfile_yarn_version >= "2"
+      end
+
       def dockerfile_bun_version
         using_bun? and `bun --version`[/\d+\.\d+\.\d+/]
       rescue

railties/lib/rails/generators/rails/app/templates/Dockerfile.tt

@@ -38,10 +38,17 @@ RUN apt-get update -qq && \
 ARG NODE_VERSION=<%= node_version %>
 ARG YARN_VERSION=<%= dockerfile_yarn_version %>
 ENV PATH=/usr/local/node/bin:$PATH
+<% if yarn_through_corepack? -%>
+RUN curl -sL https://github.com/nodenv/node-build/archive/master.tar.gz | tar xz -C /tmp/ && \
+    /tmp/node-build-master/bin/node-build "${NODE_VERSION}" /usr/local/node && \
+    rm -rf /tmp/node-build-master
+RUN corepack enable && yarn set version $YARN_VERSION
+<% else -%>
 RUN curl -sL https://github.com/nodenv/node-build/archive/master.tar.gz | tar xz -C /tmp/ && \
     /tmp/node-build-master/bin/node-build "${NODE_VERSION}" /usr/local/node && \
     npm install -g yarn@$YARN_VERSION && \
     rm -rf /tmp/node-build-master
+<% end -%>
 
 <% end -%>
 <% if using_bun? -%>
@@ -61,7 +68,7 @@ RUN bundle install && \
 <% if using_node? -%>
 # Install node modules
 COPY package.json yarn.lock ./
-RUN yarn install --frozen-lockfile
+RUN yarn install --immutable
 
 <% end -%>
 <% if using_bun? -%>