Map Tests to Code with vg tests

Knowing which tests exercise a given piece of code lets you run the right tests instead of the whole suite. vg tests maps tests to a node via call or coverage linkage, finds gaps, and can run exactly the tests that matter.

Prerequisites

• A built code graph from vg build
• A test suite in the repository

Steps

1. Build the graph

vg build

2. List tests for a node

vg tests

vg tests shows which tests cover the node via call or coverage linkage.

3. Find untested nodes

Surface nearby code that has no test coverage:

vg tests --missing

--missing highlights untested nodes near the one you queried — your coverage gaps.

4. Print the minimal command

Get the minimal command to exercise exactly the relevant tests:

vg tests --run

--run prints the command so you can review it before running.

5. Execute the minimal tests

Run those tests directly:

vg tests --exec

--exec runs the minimal command, exercising only the tests tied to the node.

Verification

Confirm vg tests lists covering tests for the node, that --missing surfaces gaps, and that --run prints a command which --exec executes successfully.

Next Steps

• Combine with vg impact --tests before shipping
• Find central, must-test nodes with vg hubs
• Explain a node with vg show