Anjali Dewangan — R51-T042: Define the supported boundaries of initCallbacks (breadthFirstSearch.js) [src/algorithms/graph/breadth-first-search] #42

Student: Anjali Dewangan

Task: R51-T042 · 2 of 10
Repository: https://github.com/S-AI-Projects/javascript-algorithms
Assigned working branch: student/e26b07f0661

Goal

Work on src/algorithms/graph/breadth-first-search/breadthFirstSearch.js. Identify the smallest supported domain around initCallbacks and make its boundary behavior explicit. Use edges A–B, A–C, B–D and an isolated E. From A, distances are 0 to A, 1 to B/C and 2 to D; E is unreachable. Fixture: Use edges A–B, A–C, B–D and an isolated E. From A, distances are 0 to A, 1 to B/C and 2 to D; E is unreachable.

Steps

1. Read src/algorithms/graph/breadth-first-search/breadthFirstSearch.js, especially initCallbacks near line 19. Record its public inputs, result, mutation behavior and any external dependencies before changing it.
2. Partition inputs into valid interior, valid boundary and explicitly unsupported values. Do not add rejection rules for behavior the source leaves undefined.
3. Place one test on each side of a documented boundary, including the exact exception or sentinel only when specified.
4. Implement work/R51-T042/check.py as a focused runner that executes the new checks and propagates failures. Native check to incorporate: run the repository test script in non-watch mode after installing from its lockfile; for browser-only code use a browser test instead of plain Node. Record the actual command and nonzero test count.
5. Create the checks specified below and run python3 work/R51-T042/check.py. Save inputs, expected versus actual results and tool versions in work/R51-T042/; a check must exit non-zero when an assertion fails.
6. Commit the repository change on branch R51-T042; prepare a PR to the organisation fork explaining the result and linking the checks. Keep each task independently reviewable. Remove work/R51-T042/ from a later upstream branch.

Done when

☐ The checked behavior is tied to initCallbacks in src/algorithms/graph/breadth-first-search/breadthFirstSearch.js; every assertion has an explicit expected value.
☐ Use edges A–B, A–C, B–D and an isolated E. From A, distances are 0 to A, 1 to B/C and 2 to D; E is unreachable.
☐ Existing supported behavior and the public interface are preserved unless a failing regression demonstrates and documents a defect.
☐ The boundary table cites the source contract, and every supported boundary is asserted.
☐ No arbitrary TypeError/RangeError policy is imposed across unrelated functions.

Submission checklist

• Complete this task and its checks.
• Add the required evidence and link your pull request here.
• Select this S-AI-Projects fork as the PR base repository.
• Request instructor review.

Keep this PR focused on this task. Do not submit assignment PRs to the upstream repository.