remoteconfig --dry-run does not validate condition expression syntax

[Ryu0118]

[REQUIRED] Environment info

firebase-tools: 15.30.2

Platform: macOS

[REQUIRED] Test case

Set a Remote Config condition's expression to an invalid string:

{ "conditions": [{ "name": "test", "expression": "this is not valid syntax at all !!!" }] }

Run: firebase deploy --only remoteconfig --dry-run

[REQUIRED] Steps to reproduce

1. Add the above condition to a remoteconfig template JSON referenced by firebase.json's remoteconfig.template
2. Run firebase deploy --only remoteconfig --dry-run

[REQUIRED] Expected behavior

Dry-run should report the invalid expression syntax as an error (or the CLI should document that remoteconfig dry-run does not perform this check).

[REQUIRED] Actual behavior

Dry-run prints "Dry run complete!" and exits 0. A subsequent real firebase deploy --only remoteconfig (no --dry-run) with the same broken expression is the first point where the error surfaces, server-side, on publish.

Root cause:

• src/deploy/remoteconfig/functions.ts's validateInputRemoteConfigTemplate() only checks that etag is a non-empty string and conditions is an array. It never inspects expression content.
• src/deploy/index.ts (around line 220): when options.dryRun is true, the deploys and releases phases are skipped entirely for every target. For remoteconfig, the release phase (the actual template PUT) is the only place server-side validation happens — so dry-run performs no expression validation at all.
• This does not appear to be intentional: PR Add --dry-run to deploy #7574 ("Add --dry-run to deploy") added dedicated dry-run validation logic to database, dataconnect, and extensions (e.g. database/prepare.ts always calls rtdb.updateRules(..., { dryRun: true }) to check rules syntax server-side; dataconnect/prepare.ts calls diffSchema → upsertSchema(schema, validateOnly: true) when options.dryRun is set). remoteconfig was not touched by that PR and has no equivalent validation path.
• The Remote Config REST API supports ?validate_only=true on the template PUT endpoint, which would let remoteconfig follow the same pattern, but the CLI never calls it.

[aalej]

Thanks for the detailed report and for opening a PR for this @Ryu0118! I was able to reproduce the issue. I'll mark this as reproducible and discuss this with our engineering team to see if anyone can review the PR.