Table of Contents
Existing code → Baseline tests → Change → Validate → Repair / Regenerate → PR Protection
Result: Confident merge
Six steps.
One continuous flow.
Designed for how teams actually ship code.
You’re changing existing code, not starting fresh.
The code:
- Isn’t new
- Isn’t fully trusted
- Looks covered, but hides unknown behavior
The real risk
Not missing tests — implicit behavior no one can clearly explain.
Decision
Before changing anything:
What behavior must not change?
Freeze behavior before you touch the code.
A repo-level test generation agent analyzes existing code and produces tests that reflect current behavior, not intended design.
What this creates
- A behavioral baseline
- Protection for critical paths and public interfaces
- Tests that capture undocumented assumptions
Outcome
Uncertainty drops, even before any new code is written.
Focus on intent, not impact.
At this stage, developers:
- Add new functionality
- Modify existing logic
- Refactor to support the change
Key idea
This step is about expressing what should change.
Validation comes next.
Confidence comes from iteration, not a single green run.
Before opening a PR:
- Run all tests, including those generated around existing behavior
- Confirm nothing regressed
- Verify new functionality behaves as intended
Iteration continues until
- Existing behavior remains intact
- New behavior works correctly
This is where confidence is built — gradually and deliberately.
Failing tests are signals, not noise.
After a change, some tests will fail. That’s expected.
When a test fails:
- Repair it if structure changed but behavior didn’t
- Fix the code if a regression is exposed
- Regenerate it if behavior intentionally changed
Why this matters
Deleting failing tests hides risk and weakens the test suite over time.
Ownership
The agent surfaces the failure.
The developer decides what it means.
PRs should validate change, not the entire repository.
Global coverage metrics describe history, not risk.
In a PR, what matters is:
- New logic
- Modified behavior
- Untested paths introduced by the change
A PR-level test generation agent focuses only on the delta:
- Identifies risky, unprotected logic
- Generates tests scoped to the change
Review shifts from: “Coverage looks fine”
To: “The risky parts of this change are protected.”
Test generation agents don’t replace engineering judgment.
They make it scalable, exactly where change is risky and confidence matters most.
Result
Not more tests. Confidence at every change.
What This Flow Changes
Test generation agents don’t reduce the role of engineers, they deepen it.
As code changes accelerate, teams must engage more deliberately with the tools embedded in their PR workflow to validate and protect change.
Confidence doesn’t come from passive automation.
It comes from standardizing how judgment, validation, and responsibility show up in every PR.
Test generation agents don’t replace engineering judgment
They make it scalable, exactly where change is risky and confidence matters most
