Support minFirmwareVersion in bsconfig.json

[Copilot]

Adds a minFirmwareVersion bsconfig option that restricts which BrightScript features are permitted based on the target Roku OS version. This applies to both .brs and .bs files — features such as optional chaining are not transpiled by BrighterScript and are emitted as-is, so the target device must natively support them.

Changes

• BsConfig.ts — New optional minFirmwareVersion?: string property (semver-compatible string, e.g. "11.0.0")
• DiagnosticMessages.ts — New diagnostic featureRequiresMinFirmwareVersion (code 1146)
• BrsFileValidator.ts — Validates optional chaining operators (?., ?[, ?() in both .brs and .bs files against the configured version using semver.coerce + semver.lt; no-ops when minFirmwareVersion is unset
• bsconfig.schema.json / docs/bsconfig.md — Schema and docs updated
• package.json — semver promoted to explicit runtime dep; @types/semver added as dev dep

Example

Optional chaining was introduced in Roku OS 11. With minFirmwareVersion: "10.0.0":

' source/main.brs
sub main()
    value = obj?.name   ' Error: feature 'optional chaining' requires firmware 11.0.0, configured: 10.0.0
end sub

' source/main.bs — also produces an error, since optional chaining is not transpiled
sub main()
    value = obj?.name   ' Error: feature 'optional chaining' requires firmware 11.0.0, configured: 10.0.0
end sub

Features gated by firmware version (initial pass):

Feature	Min Version
Optional chaining (?., ?[, ?()	11.0.0

[TwitchBronBron]

So actually, we don't currently transpile optional chaining even in .bs files. So that feature needs to be locked behind a firmware flag for both brs and bs files. Fix that and the tests. And comments everywhere.

[Copilot]

So actually, we don't currently transpile optional chaining even in .bs files. So that feature needs to be locked behind a firmware flag for both brs and bs files. Fix that and the tests. And comments...

Fixed in 63f975f. Since optional chaining is emitted as-is (not transpiled to equivalent non-optional code), the firmware version check now applies to both .brs and .bs files. Added tests for both file types and updated the comments/docs accordingly.

[Copilot]

So actually, we don't currently transpile optional chaining even in .bs files. So that feature needs to be locked behind a firmware flag for both brs and bs files. Fix that and the tests. And comments...

Fixed in 63f975f. Removed the .brs-only guard from validateMinFirmwareVersionForOptionalChaining so the check now applies to both .brs and .bs files. Updated the JSDoc/inline comments throughout the method and the OPTIONAL_CHAINING_MIN_VERSION constant, and added matching .bs test cases (not set, 11.0.0, and below 11.0.0 for dotted get). Docs updated too.

[TwitchBronBron]

@copilot nu-uh. https://github.com/rokucommunity/brighterscript/actions/runs/25012570834/job/73251900142?pr=1676

[Copilot]

@copilot nu-uh. https://github.com/rokucommunity/brighterscript/actions/runs/25012570834/job/73251900142?pr=1676

The CI run you linked (25012570834) is for PR #1676 (fix/pass-through-sourcemaps), not this PR. Its lint failure is an import() type annotation in util.ts that I never touched.

My PR #1678's CI (commit 2da91539) is all green — ubuntu, macOS, and Windows all pass. All 2642 tests pass and lint is clean locally too. Is there something specific in my changes you'd like me to fix?