Document typeCheck option.

[mikelehen]

I seem to be confused about what this option does. My tests (written in typescript and executed via mocha with --require ts-node/register) run just as fast with or without typeChecking (~23 seconds after clearing the cache) and catch simple type errors I've tried introducing, regardless of whether I use the typeCheck option or not.

I've tried enabling / disabling it both via the require entrypoints (ts-node/register vs ts-node/register/typeCheck) and via the environment variable (TS_NODE_TYPE_CHECK) and haven't been able to detect any difference in behavior.

Could you add some documentation on what the typeCheck option actually does and how to decide whether to enable it or not? Thanks!

[mikelehen]

Okay, this is really weird. When I was clearing the cache between runs, ts-node/register and ts-node/register/typecheck both took 23 seconds. But if instead I set TS_NODE_CACHE=NO, then ts-node/register/typecheck only takes 9 seconds, while ts-node/register still takes 23 seconds (which is the opposite of what I would expect!).

My package.json has:

    "test:node":           "TS_NODE_CACHE=NO nyc --reporter lcovonly -- mocha 'test/{,!(browser)/**/}*.test.ts' --require ts-node/register --require index.node.ts --retries 5 --timeout 5000 --exit",
    "test:node:typecheck": "TS_NODE_CACHE=NO nyc --reporter lcovonly -- mocha 'test/{,!(browser)/**/}*.test.ts' --require ts-node/register/type-check --require index.node.ts --retries 5 --timeout 5000 --exit",

And here are my timings:

~/src/firebase-js-sdk/packages/firestore (mikelehen/ts-node-caching) $ time yarn test:node
yarn run v1.2.1
$ TS_NODE_CACHE=NO nyc --reporter lcovonly -- mocha 'test/{,!(browser)/**/}*.test.ts' --require ts-node/register --require index.node.ts --retries 5 --timeout 5000 --exit
No IndexedDB. Skipping EncodedResourcePath tests.
No IndexedDB. Skipping LocalStore w/ IndexedDB persistence tests.
No IndexedDB. Skipping IndexedDbMutationQueue tests.
No IndexedDB. Skipping IndexedDbQueryCache tests.
No IndexedDB. Skipping IndexedDbRemoteDocumentCache tests.
No IndexedDB. Skipping RemoteDocumentChangeBuffer tests.
Skipping SimpleDb tests due to lack of indexedDB support.


  (Persistence=false) Database batch writes
    ✓ can set documents (865ms)


  1 passing (968ms)

✨  Done in 22.21s.

real	0m22.556s
user	0m24.243s
sys	0m1.180s


~/src/firebase-js-sdk/packages/firestore (mikelehen/ts-node-caching) $ time yarn test:node:typecheck
yarn run v1.2.1
$ TS_NODE_CACHE=NO nyc --reporter lcovonly -- mocha 'test/{,!(browser)/**/}*.test.ts' --require ts-node/register/type-check --require index.node.ts --retries 5 --timeout 5000 --exit
No IndexedDB. Skipping EncodedResourcePath tests.
No IndexedDB. Skipping LocalStore w/ IndexedDB persistence tests.
No IndexedDB. Skipping IndexedDbMutationQueue tests.
No IndexedDB. Skipping IndexedDbQueryCache tests.
No IndexedDB. Skipping IndexedDbRemoteDocumentCache tests.
No IndexedDB. Skipping RemoteDocumentChangeBuffer tests.
Skipping SimpleDb tests due to lack of indexedDB support.


  (Persistence=false) Database batch writes
    ✓ can set documents (834ms)


  1 passing (839ms)

✨  Done in 8.99s.

real	0m9.324s
user	0m10.935s
sys	0m0.423s

[ws-ono]

It seems current version 4.1.0 released on npm still has old options in the help.

> ts-node --help

Usage: ts-node [options] [ -e script | script.ts ] [arguments]

Options:

-e, --eval [code] Evaluate code
-p, --print [code] Evaluate code and print result
-r, --require [path] Require a node module for execution
-C, --compiler [name] Specify a custom TypeScript compiler
-I, --ignoreWarnings [code] Ignore TypeScript warnings by diagnostic code
-P, --project [path] Path to TypeScript project (or false)
-O, --compilerOptions [opts] JSON object to merge with compiler options
-F, --fast Run TypeScript compilation in transpile mode
--ignore [regexp], --no-ignore Set the ignore check (default: /node_modules/)
--no-cache Disable the TypeScript cache
--cache-directory Configure the TypeScript cache directory

[blakeembrey]

Added with #536.