Fix: --source-type is now honoured for stdin and for existing non-.java files

[lutzleonhardt]

Closes #1975

🐞 Problem

Scenario	Expected	Current behaviour
pbpaste | jbang --source-type=java -	Treated as Java source	Piped script cached as .jsh and executed via JShell
jbang --source-type=java myscript.jsh	Compiled as Java (or rejected)	File copied as myscript.jsh.java → javac “bad file name” error

🔧 What changed

• LiteralScriptResourceResolver
  • Accepts the forceType parameter and always prefers it over auto-detection when caching stdin.
  • Keeps the existing “prepend underscore if the name starts with a digit” safeguard.
• RenamingScriptResourceResolver
  • When --source-type is supplied, we strip the original extension before adding the forced one
    (myscript.jsh ➜ myscript.java instead of myscript.jsh.java).

✅ Tests

• Added TestSourceType with two cases:

  1. stdinHonoursForceType() – verifies that piping to - is handled as Java when requested.
  2. forceJavaOnJshFile() – verifies that forcing Java on a .jsh file succeeds and does not generate a .jsh.jar.

• Manual test
  

♻ Regression risk

Localised to two resolvers; no logic elsewhere changed. Existing behaviour for regular .java, .jsh, remote, and gav resources stays untouched.

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🙌 Credits

Most of the root-cause analysis was assisted by Brokk AI.
If you’re curious, I recorded the full debugging session:
https://youtu.be/t_7MqowT638?si=QVySbqoy0mqLcljz
(24 min video – optional to watch, of course).

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📋 Checklist

• Code builds and all existing tests pass
• New unit-tests added
• --enable-preview workflow verified manually
• Release notes updated (if required)

Summary by Sourcery

Fix handling of --source-type for piped input and existing non-.java scripts by propagating the forced source type through both LiteralScriptResourceResolver and RenamingScriptResourceResolver, and add tests to verify the corrected behavior.

Bug Fixes:

• Honor --source-type when caching stdin scripts instead of defaulting to .jsh
• Strip existing file extensions before applying a forced source type to avoid generating ".jsh.java" filenames

Enhancements:

• Allow LiteralScriptResourceResolver to accept and use a forceType parameter for consistent type enforcement

Tests:

• Add TestSourceType to verify enforced Java source type for stdin input and on .jsh files

[sourcery-ai]

Reviewer's Guide

This PR introduces a forceType override for both stdin-based and existing non-.java scripts by extending the resource resolvers to honor --source-type, updating caching and renaming logic accordingly, and adds tests to validate the new behavior.

File-Level Changes

Change	Details	Files
Enable --source-type override for stdin in LiteralScriptResourceResolver	Add forceType field and constructor to resolver Pass forceType from ProjectBuilder to LiteralScriptResourceResolver Overload stringToResourceRef to accept forceType Adjust suffix and basename logic to prefer forceType and prefix underscore for invalid Java identifiers	src/main/java/dev/jbang/source/resolvers/LiteralScriptResourceResolver.java src/main/java/dev/jbang/source/ProjectBuilder.java
Strip original extension before appending forced type in RenamingScriptResourceResolver	When forceType is set, remove existing file extension using regex Append the forced extension instead of simply adding to the original name Retain fallback behavior when no forceType is provided	src/main/java/dev/jbang/source/resolvers/RenamingScriptResourceResolver.java
Add unit tests for source-type enforcement	Test that piping code via stdin honors --source-type=java without using JShell Verify forcing Java on a .jsh file succeeds and does not produce a .jsh.jar	src/test/java/dev/jbang/cli/TestSourceType.java

Assessment against linked issues

Issue	Objective	Addressed	Explanation
#1975	Ensure that when running a script from stdin with jbang --source-type=java -, the script is treated as Java source code and not as a JShell script.	✅
#1975	Ensure that when running jbang --source-type=java myscript.jsh, the script is compiled as Java (or rejected if it's not valid Java) and not treated as a JShell script.	✅

Possibly linked issues

• source-type not honored #1975: The PR modifies script resolvers to correctly handle --source-type for piped input and existing non-.java files.
• source-type not honored #1975: The PR modifies source resolvers to correctly handle --source-type for stdin and non-java files, resolving the issue.

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[sourcery-ai]

Hey @lutzleonhardt - I've reviewed your changes and they look great!

Here's what I looked at during the review

• 🟡 General issues: 1 issue found
• 🟢 Security: all looks good
• 🟡 Testing: 1 issue found
• 🟢 Documentation: all looks good

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[quintesse]

Looks really good, just a couple of small changes and questions.

[lutzleonhardt]

@quintesse Thanks for your feedback. I have implemented your suggestions so far. Let me know if something is wrong or missing -thx.

[quintesse]

Still some minor changes to be made, but almost there!

[lutzleonhardt]

Let's iterate on it until it's satisfying :) Thanks for you input, let me know when something is missing

[lutzleonhardt]

@quintesse Anything missing here from my side? Thanks

[quintesse]

@lutzleonhardt if you have the time you can take a look at why the IT tests are failing. If not I'll look into it as soon as aI have some time.

[maxandersen]

just testing this and at first glance it solves the reported bug (good) but it also introduce a regression and fail at handling this:

jbang --code "$(cat itests/helloworld.java)" jbangtest

it does not save as a helloworld.java file but instead _helloworld.java which worked previously. Thats what the failed itests is about.

[maxandersen]

I've added code to detect identifers so it wont add _ unless really need to. wdyt?

@quintesse wiremock generated new files from foojay. expected i guess?

[maxandersen]

the pr was blocked/failing due to bad formatting. pushed update with that done.

[maxandersen]

lgtm