feat: Add missing newlines and add flag --no-trailing-newline port https://github.com/google/go-jsonnet/pull/843

[He-Pin]

refs: #592

[Copilot]

Pull request overview

This PR ports the --no-trailing-newline flag from upstream jsonnet implementations (google/go-jsonnet and google/jsonnet) to sjsonnet. By default, sjsonnet now adds trailing newlines to output (both stdout and files in multi mode), and the new flag allows users to suppress these trailing newlines. This brings sjsonnet's behavior in line with other jsonnet implementations.

Changes:

• Added --no-trailing-newline flag to suppress trailing newlines in output
• Updated default behavior to add trailing newlines to multi-mode file outputs
• Added validation to prevent using the flag with --yaml-stream mode

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
sjsonnet/src-jvm-native/sjsonnet/Config.scala	Adds the noTrailingNewline flag configuration parameter
sjsonnet/src-jvm-native/sjsonnet/SjsonnetMainBase.scala	Implements the flag logic for stdout, file writing, and yaml output; adds validation to reject the flag with yaml-stream
sjsonnet/test/src-jvm/sjsonnet/MainTests.scala	Updates existing tests to expect trailing newlines and adds comprehensive tests for the new flag across different output modes
sjsonnet/test/resources/db/multi_string.jsonnet	Adds test resource file for multi-file string output tests
readme.md	Documents the new --no-trailing-newline flag

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.