json-path-comparison

Comparison of the different implementations of JSONPath and language agnostic test suite.

See https://cburgmer.github.io/json-path-comparison/ for the table generated from the queries in ./queries.

Goals

• Show implementation status of well established implementations.
• Inform emerging specification on existing de facto standard.
• Support implementers with test cases.

How to

Regression test suite

If you are an author of an upstream implementation, you can use the report generated here to test for regressions in your logic. The regression_suite/regression_suite.yaml holds all queries and includes a consensus where one exists. Additionally a report is generated for every implementation which contains current results for queries where the consensus isn't matched or no consensus exists (see e.g. regression_suite/Clojure_json-path.yaml).

See for example the Clojure json-path regression test on how those files can be put to use.

(Re-)Run the comparison locally

To update the reports checked into Git under ./docs and others, run:

./src/with_native.sh ninja
open docs/index.html

Alternatively, you can use Docker to provide the dependencies via

./src/with_docker.sh ninja

This will take a while and some network bandwidth but has the benefit that you won't have to install anything locally.

One-off comparisons

You can quickly execute a query against all implementations by running:

echo '{"a": 1}' | ./src/with_native.sh ./src/one_off.sh '$.a'

(Or use ./src/with_docker.sh if you prefer Docker.)

Errors

Some of the complexity sadly brings its own set of errors

• If Ninja fails, the failing step is unlikely to be the last (as it will let parallel requests finish first). Search for FAILED to identify the failing step. The error is most likely captured in the output file (the part behind the >). Debug from there.
• Some executions might run into timeouts rather randomly (especially when the machine is under high load). The timeout mechanism is necessary as not all implementations play nice, however will sometimes skew the results. Currently the best fix is to remove the output of the query that ran into a timeout, e.g. rm -r build/results/bracket_notation_with_number_on_short_array for a whole query, and re-running Ninja to force a re-build.
• Docker might fail building on re-runs due to an outdated package index. Quickest fix is to run docker rmi json-path-comparison and start from scratch.
• Out of memory on Docker: Some compile steps (looking at you, Haskell) seem to need a lot of memory. Increasing the available memory for Docker should help.