Issue 4940: Add skip deployment flag for PR bot tests

[stuart-bass-cgi]

Resolves #4940

What is being addressed

PR bot /test and /test-extended commands currently always run the full validation flow, including build and deployment jobs, even when the PR validation environment has already been deployed. This makes it slow to re-run smoke or extended E2E tests after transient test failures or test-only changes.

How is this addressed

• Adds a skip_deployment flag for the /test and /test-extended PR bot commands.
• Passes the parsed flag from the PR comment bot into the reusable TRE deployment workflow.
• When skip_deployment is true, skips the deployment/build/register jobs and allows the smoke and requested custom E2E jobs to run against the existing deterministic PR validation environment.
• Keeps the existing external PR SHA validation in place, including when skip_deployment is supplied.
• Updates PR bot command documentation with the new syntax and fork PR examples.
• Adds unit test coverage for the new command parsing behaviour.

[Copilot]

Pull request overview

Adds a skip_deployment flag to PR comment bot /test and /test-extended commands so maintainers can rerun smoke/extended E2E tests against an already-deployed deterministic PR validation environment, avoiding the full build/deploy pipeline when appropriate.

Changes:

• Extended PR bot command parsing to recognize skip_deployment and pass it through to the reusable deployment workflow.
• Updated the reusable workflow to conditionally bypass deployment/build stages and still run smoke/custom E2E jobs.
• Updated developer docs and added unit tests covering the new command parsing behavior.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
docs/tre-developers/github-pr-bot-commands.md	Documents the new skip_deployment flag syntax and fork PR examples for /test and /test-extended.
.github/workflows/pr_comment_bot.yml	Plumbs skipDeployment output from the parsing script into the reusable workflow call.
.github/workflows/deploy_tre_reusable.yml	Adds skipDeployment input and adjusts E2E job conditions to allow running tests when deployment is skipped.
.github/scripts/build.js	Parses skip_deployment, emits skipDeployment output, and updates external-PR SHA extraction to ignore the flag.
.github/scripts/build.test.js	Adds unit tests validating skipDeployment output behavior for internal and external PR command forms.

[stuart-bass-cgi]

@microsoft-github-policy-service agree company="CGI"

[marrobi]

@stuart-bass-cgi thanks for the PR.

A review with Opus 4.8 says:

I

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Overall: Well-structured, focused change that solves a real developer pain point (re-running smoke/extended E2E tests without a full redeploy). Good test coverage and docs, plus a couple of nice opportunistic bug fixes. A few items to confirm before approval.

🟢 Done well

• Clean separation of commandHasSkipDeploymentFlag() and getShaFromCommandParts() — correctly supports passing a SHA and the flag in any order on fork PRs.
• Good unit-test coverage for internal true/default-false, fork /test <sha> skip_deployment, and /test-extended.
• Fixes real pre-existing bugs: branchRefid → branchRefId typo, and the debug echo that printed prRefId under the branchRefId label.
• Docs updated in step with the code, including fork examples.

🟠 To address

1. Check status reporting on skip-deployment runs. With skipDeployment == true, deploy_management is skipped, so the entire needs chain feeding e2e_tests_smoke/e2e_tests_custom is skipped. The always() && (inputs.skipDeployment || ...) guards make the tests run, which works — but please confirm the summary job still reports the "Deploy PR / Run E2E Tests (Smoke)" check back to the PR head SHA so the PR status check updates correctly. A short code comment explaining why always() + skipped upstreams produces the intended behavior would help future maintainers.
2. skip_deployment is silently ignored by /test-extended-aad and /test-shared-services. The flag is only wired into /test and /test-extended. A user appending it to the other commands gets a full deploy with no feedback. Consider warning on unsupported use, or confirm this asymmetry is intentional (docs already omit it for those commands).

🟡 Nits

• skip_deployment is a magic string in multiple places — consider a shared constant to avoid drift.
• const { create } = require('domain'); (build.js) is unused dead code; low-risk cleanup while you're here.
• The string→bool round-trip (== 'true') for the typed workflow input is correct — just flagging it's intentional.

Verdict: LGTM pending confirmation of (1) smoke-test check reporting and (2) the intentional flag asymmetry.

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Let me know if you agree!