erquhart•8mo ago

convex-test handling dates differently than convex runtime

I've encountered the following two so far: - local timezone is used instead of UTC (this is a big one) - Date.prototype.toString() and Date.prototype.toISOString() both work as expected (timezone aside), but when a Date is coerced to a string without directly calling one of these methods, the mock test environment seems to use toISOString(), whereas the convex runtime correctly produces the result of toString().

13 Replies

erquhartOP•8mo ago

Ah actually it seems that second point reflects the convex runtime being more similar to a browser environment, while the mock environment is based on Node, maybe? Is the convex runtime v8 based and the mock is node based perhaps? Tangentially, I'm a bit curious why the actual convex runtime can't be used in convex-test, but I'm guessing that would require provisioning convex locally.

lee•8mo ago

convex-test is a more like a library that provides mocks of ctx than a full runtime. the runtime is determined by how you run tests, like jest or vitest, which is probably Node. I suppose the package could mock out Date stuff too, but mocking a full convex runtime within Node sounds tricky. If you want the actual Convex runtime, that would run separately like https://stack.convex.dev/testing-with-local-oss-backend

Stack

Running tests using a local open-source backend

Convex recently released an open source version of the backend. We can use this to unit test Convex functions by running them with a local backend. Th...

ballingt•8mo ago

Are you using "edge-runtime," that should help with this https://docs.convex.dev/testing/convex-test#multiple-environments

convex-test | Convex Developer Hub

The convex-test library provides a mock implementation of the Convex backend

erquhartOP•8mo ago

Ah okay, that makes sense Yes, using edge runtime per the docs

ballingt•8mo ago

There's an environment variable to set for timezone stuff, https://stackoverflow.com/a/9849524/398212

Stack Overflow

How can I set the default timezone in node.js?

How do I set the default timezone in node.js?

ballingt•8mo ago

But the print interesting, I hope the convex runtime matches the chrome browser. If it does then toString isn't standardized, toISOstring should always be used for portable code. If it's not, the Convex runtime is deviating from standard and we need to look into it.

erquhartOP•8mo ago

Convex runtime does match chrome, it's node that does it different

ballingt•8mo ago

that's annoying then but at least consistent

erquhartOP•8mo ago

Yeah, agreed. The real issue is time not being in UTC, that will probably lead to false negatives in tests (as it is currently for me). oh env var, just saw your other comment will try that This solution from another SO post should be added to the convex-test getting started guide: Create a file vitest.global-setup.ts

export const setup = () => {
  process.env.TZ = 'UTC'
}

export const setup = () => {
  process.env.TZ = 'UTC'
}

Then add it to test.globalSetup in vitest.config.ts

export default defineConfig({
  test: {
    globalSetup: './vitest.global-setup.ts',
    // ...
  },
})

export default defineConfig({
  test: {
    globalSetup: './vitest.global-setup.ts',
    // ...
  },
})

SO answer: https://stackoverflow.com/a/76971168/1556245 (which borrowed from a GitHub issue) Tested and working for the issue I was experiencing.

Michal Srb•8mo ago

Nice! Can you write an example of a test where this matters?

erquhartOP•8mo ago

I have a lot of date based functionality, and I use simple ISO's (yyyy-MM-dd) everywhere. So there's a lot of conversion between string dates and js Dates. Because Convex runtime only supports number dates in new Date(), this is everywhere:

const someDateString = '2024-05-05'
new Date(Date.parse(someDateString))
// Sun May 05 2024 00:00:00 GMT+0000 (Coordinated Universal Time)

const someDateString = '2024-05-05'
new Date(Date.parse(someDateString))
// Sun May 05 2024 00:00:00 GMT+0000 (Coordinated Universal Time)

Notice Date.parse() creates a Date with time set to midnight in the local timezone. In Convex, that's UTC, but for my local that's EST. And May 5th at midnight EST is May 4th at 9pm UTC. A whole lot of date calculations and comparisons go off by one.

Michal Srb•8mo ago

Is your Convex code hardcoding the UTC timezone somewhere? What I'm looking for is: 1. This is my convex-test test 2. This is my Convex function 3. This test (say) fails in convex-test but passes when running against a real convex backend That'll help explain it in docs

erquhartOP•8mo ago

hmmm it looks like I'm using date parsing from date-fns in a lot of places, that's the rub the method above is timezone agnostic, there's is not okay, good point, this does appear to be a me problem I'd still say the timezone diff is worth noting in the docs, but it was really only exposing a flaw in my code in this case. cannot overstate how much I dislike how dates work in js

convex-test handling dates differently than convex runtime

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