[Bug]: `HtmlRspackPlugin` escapes certain characters even when using `<%=`

[markmssd]

System Info

System:
OS: macOS 15.5
CPU: (10) arm64 Apple M1 Max
Memory: 715.94 MB / 32.00 GB
Shell: 5.9 - /bin/zsh
Binaries:
Node: 22.16.0 - ~/.nvm/versions/node/v22.16.0/bin/node
npm: 10.9.2 - ~/.nvm/versions/node/v22.16.0/bin/npm
pnpm: 9.15.4 - ~/Library/pnpm/pnpm
bun: 1.1.8 - ~/.bun/bin/bun
Browsers:
Brave Browser: 126.1.67.123
Chrome: 138.0.7204.50
Edge: 137.0.3296.93
Safari: 18.5
npmPackages:
@rspack/cli: ^1.4.1 => 1.4.1
@rspack/core: ^1.4.1 => 1.4.1

Details

When replacing HtmlWebpackPlugin with rspack.HtmlRspackPlugin.

There's a few things I wanted to point out about the Rspack version:

• In EJS, <%- is used for unescaped outputs and <%= for escaped, but in Rspack, it's the opposite: <%= for unescaped and <%- for escaped. Is that intended? EDIT: This is the same behaviour as HtmlWebpackPlugin

• When using <%= for outputting unescaped strings, <% still gets escaped as <%=. In the index.ejs template, we have <title><%= title %></title>, and in the rspack.HtmlRspackPlugin, we configured the templateParameter as title: '<%= title %>' (basically we don't want to change it, but it fails if we don't specify it, so we replace it with the same EJS string). Note that other characters like & also get escaped.

Reproduce link

https://github.com/markmssd/rspack-repro/tree/html-rspack-plugin-escaped-ejs

Reproduce Steps

git clone https://github.com/markmssd/rspack-repro/tree/html-rspack-plugin-escaped-ejs
pnpm install
pnpm build:rspack

Look at the src/index.ejs file. It has 2 title tags: one that should be escaped, and one that should not.

Now look at rspack.config.mjs. I have configured both HtmlWebpackPlugin and HtmlRspackPlugin, and each outputs in its own file.

Now, open both rspack-dist/html.index.ejs and rspack-dist/rspack.index.ejs. Notice that they are not the same. Rspack's one has both titles escaped.