@definitelytyped/perf

Performance measuring utilities for DefinitelyTyped.

Usage

This is not currently designed for public consumption, so docs, tests, and usage help are very light. The utility is used only in Azure Pipelines for DefinitelyTyped and TypeScript. There are three main functions that run in CI:

1. Every night, see what packages on DefinitelyTyped haven’t been benchmarked with the current version of TypeScript since their last change, and benchmark them. The CLI entrypoint getPackagesToBenchmark queries the Cosmos DB instance to see what packages need to be benchmarked, then generates a file specifying what to run. In another phase, a large number of build agents read that file with the benchmark entrypoint and benchmark the packages in parallel. After a new TypeScript release, it takes several weeks of running this nightly to cover all of DefinitelyTyped.
2. On every PR to DefinitelyTyped, pull the benchmarks for changed packages. If they haven’t been run or aren’t up-to-date, run them on master. Then, benchmark the PR, and compare. Post the summary of the results in a comment on the PR. This is done with the compare CLI entrypoint.
3. Every night, find existing benchmarks that have been run with the latest TypeScript version, run them with typescript@master, and compare. This is done with the compareTypeScript CLI entrypoint. Results are uploaded to the typeScriptComparisons collection in the database.

The package registers a bin called definitely-not-slow upon installation:

npx definitely-not-slow compare --package react/v16 --upload false

Installation and publishing

This utility isn’t published to npm; rather, a GitHub workflow produces branches that include the compiled code:

npm install github:andrewbranch/definitely-not-slow#production # Published on every tag
npm install github:andrewbranch/definitely-not-slow#beta # Published on every push to master

It can be useful to queue a Pipelines build manually against a real DefinitelyTyped PR with the variables COMMENT=false and DNS_VERSION=beta (definitely-not-slow—bad acronym, sorry) to test changes to definitely-not-slow on real code.