However when I then run Mocha, it's not finding new files. They're there, it's just reporting that it can't find them. I don't know if it's looking in the wrong place, or it's refusing to update some internal cache, or what.

What can I pare back to work towards finding the source of the problem? Should I try creating a .js file in my ./lib file and seeing if Mocha can find that?

I have

"lib": "./lib", "test": "."

in my package.json, but I don't know what they're for or if they're right.

I haven't defined any "dependencies": everything is defined in "devDependencies".

The error message always looks like this: TypeError: Unable to require file: lib/test/mocha/pulumi/FileThatExists.spec.d.ts

I had some tweaks to defaults (e.g. location of .mocharc.json file) that I removed; I think everything is now in npm's and Mocha's opinionate preference locations. No more complaining about not finding files that exist.

Unfortunately, I'm now getting compile errors, but only if I specify a single spec file (

npm run test --spec **/Si*.spec.ts

). If I use a slightly broader ant-expression that finds more than one file (

npm run test --spec **/S*.spec.ts

) then everything is fine, even the tests in the file that previously didn't compile

Weeeeird.

All the compile failures strictly sensible: I'm using code like

expect(bucketUnderTest.bucket.serverSideEncryptionConfiguration!.rule.applyServerSideEncryptionByDefault.sseAlgorithm.promise()).to.eventually.contain("kms")

and it's complaining with this:

error TS2339: Property 'rule' does not exist on type 'Output<BucketServerSideEncryptionConfiguration | undefined>'.

Property 'rule' does not exist on type 'OutputInstance<BucketServerSideEncryptionConfiguration | undefined>'.

No idea why the complaints go away when I run the tests in more than one file, though.

Or how to fix the issue: the serverSideEncryptionConfiguration does exist, but I suppose the type can't be lifted out of

Output<BucketServerSideEncryptionConfiguration | undefined>

so TypeScript / tslint has a rant.

If anyone comes across this thread and has a suggestion, I'd love to hear it. For now, I'm going to lower the strictness of my linting when running tests. Which isn't ideal..