| name | json-crawl-testing |
| description | Use when adding or changing json-crawl unit tests — crawl order, hook lifecycle, path rules, and clone/transform assertions. |
Testing json-crawl
Tests are Jest + ts-jest configured in package.json (npm test). The points
below are project-specific; they are not implied by a generic Jest setup.
Import from relative src
Tests in this repository import through ../src (or ../src/rules, etc.), not the
published package name. Keep new tests consistent with neighbouring files.
Where each kind of test goes
| File | Scope |
|---|
test/crawl.test.ts | Visit order, root vs skip-root, sparse/symbol array keys. |
test/clone.test.ts | Deep clone independence, hook interaction with clone state. |
test/equal.test.ts | equal() helper edge cases. |
test/rules.test.ts | End-to-end rules with syncClone + custom rule fields on CrawlRules. |
test/prefix-rules.test.ts | getNodeRules directly — prefix longest-match, global propagation. |
test/breadth-first-traverse.test.ts | BFS order vs DFS; do not assume shared state unless explicitly testing absence. |
Add focused cases to the existing file that matches the behaviour. New
top-level files are fine when the surface area is large (as with prefix rules).
Console noise
crawl.test.ts swaps global.console in beforeEach/afterEach to keep hook
debug output quiet. Follow that pattern if a new test intentionally logs.
Asserting crawl order
Depth-first walks visit a node before its descendants and finish a subtree
(exitHook) before siblings at the same level. Count hook invocations or collect
(key, value) pairs — for arrays, expect keys from anyArrayKeys semantics
(see the sparse-array case in crawl.test.ts: indices 0, 2, 4, -4, symbols,
and undefined at root).
Rules fixtures
For getNodeRules unit tests, build minimal CrawlRules<{ rule?: string }>
objects inline — no external fixtures directory. When testing rules through
syncClone, pair a SyncCloneHook that reads ctx.rules with a source object
small enough to assert the full output JSON (rules.test.ts pattern).
Prefix tests must cover: exact /key beats prefix; longest prefix beats shorter;
empty prefix keys are ignored; global /** re-attaches on the merged result.
Zero-deps constraint in tests
Do not import other @netcracker/* packages into this repository's tests — the
library itself has no runtime dependencies and tests should stay self-contained.
Before submitting
Run npm test from the repository root. Add or extend unit tests for any
behaviour change in src/; hook-order and rule-priority regressions are the
most common failure mode.
