Title

test(graphs): add tests for Dijkstra, DijkstraSmallestPath, FloydWarshall, KruskalMST, and DFS

Description

• What’s added

  • Graphs/test/Dijkstra.test.js: Tests createGraph() and djikstra() from Graphs/Dijkstra.js with a weighted undirected graph; verifies shortest distances and parent initialization.
  • Graphs/test/DijkstraSmallestPath.test.js: Tests solve() from Graphs/DijkstraSmallestPath.js; asserts distances via dist property and validates path sequences via spread.
  • Graphs/test/FloydWarshall.test.js: Tests FloydWarshall() from Graphs/FloydWarshall.js; validates all-pairs shortest paths (including Infinity handling).
  • Graphs/test/KruskalMST.test.js: Tests GraphWeightedUndirectedAdjacencyList from Graphs/KruskalMST.js; verifies MST node set, edge count (nodes-1), total weight, and exclusion of heavy edge.
  • Graphs/test/DepthFirstSearchIterative.test.js: Tests GraphUnweightedUndirected.DFSIterative() from Graphs/DepthFirstSearchIterative.js; reachability positive/negative cases.
  • Graphs/test/DepthFirstSearchRecursive.test.js: Tests GraphUnweightedUndirected.DFSRecursive() from Graphs/DepthFirstSearchRecursive.js; reachability positive/negative cases.

• Why

  • Improves coverage and guards against regressions for core graph algorithms.
  • Aligns with CONTRIBUTING.md guidance to "write proper tests."

• How to run

npm ci
npm test -- Graphs

Changes

• Added test files only:
  • Graphs/test/Dijkstra.test.js
  • Graphs/test/DijkstraSmallestPath.test.js
  • Graphs/test/FloydWarshall.test.js
  • Graphs/test/KruskalMST.test.js
  • Graphs/test/DepthFirstSearchIterative.test.js
  • Graphs/test/DepthFirstSearchRecursive.test.js

No algorithm implementations or configs were modified.

Notes

• DijkstraSmallestPath constructs path arrays that also carry a dist property (e.g., ['B', dist: 1]). Tests assert dist separately (e.g., res.B.dist) and compare the path sequence using spread (e.g., expect([...res.B])).
• Tests use ES Modules and Vitest per repo standards.

Checklist

• I have read CONTRIBUTING.md.
• This pull request is all my own work — I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• All new JavaScript files are placed inside an existing directory.
• All filenames use the UpperCamelCase (PascalCase) style. There are no spaces in filenames.
• No already existing files modified.

Summary

• Added comprehensive tests for graph algorithms in Graphs/.
• No changes to algorithm code; tests pass locally.
• Ready for review and CI.