Regression testing is specifically designed to detect the re-emergence of previously fixed defects after code changes, upgrades, or component reintegration. By executing a maintained suite of regression tests every time earlier versions or modules are merged into the current code base, the team verifies that earlier fixes (such as the RBAC segmentation control) still hold, preventing the reintroduction of old bugs in a multitenant SaaS environment.

B. Code signing – Verifies publisher authenticity and integrity of delivered binaries; it does not test for functional defects.

C. Automated test and retest – Generic phrase; without a focused regression test suite it may miss previously resolved issues.

D. User acceptance testing – Confirms user requirements in production-like conditions, not systematic detection of resurrected internal bugs.

E. Software composition analysis – Scans third-party libraries for known vulnerabilities/licensing issues, not logic flaws introduced by integrating earlier in-house code.

1. SWEBOK v3.0

Ch. 4 “Software Testing”

§4.1.4 Regression Testing

p. 43-44: describes purpose of regression testing to detect re-introduced faults after changes.

2. IEEE Std 29119-1:2013

§7.2.7 Regression Testing: mandates executing regression suites whenever existing software components are modified or integrated.

3. MIT OpenCourseWare 6.005 “Software Construction”

Lecture notes 12 “Regression Testing”

slides 3-5: explains preventing old bugs from resurfacing via automated regression tests.

4. NIST Special Publication 500-291 (Software Assurance Metrics)

§5.3.2: highlights regression tests in continuous integration pipelines to ensure fixes remain effective after updates.