Deno test fails with inscrutable error when `assertSnapshot` is used in update mode but the `--allow-write` flag is missing about deno_std HOT 4 CLOSED

This issue is likely happening because the permissions error is thrown in the "unload" callback, where the snapshot is opened. To avoid this, we can either ensure that such errors are logged properly by deno test and/or assert that the required permissions are given before registering the callback in assertSnapshot.

Happy to raise a PR for the latter fix. I'm not 100% sure where to start with the former, but also happy to raise a PR if pointed in the right direction.

from deno_std.

I'm unable to reproduce the reported error on my machine. The behavior is as expected. By the way, it should throw a PermissionDenied error. Do you have any idea what the issue could be, @kt3k?

asher@Ashers-MacBook-Air x % deno test --allow-read -- -u
Check file:///Users/asher/Desktop/x/main_test.ts
running 1 test from ./main_test.ts
should match the snapshot ... FAILED (5ms)

 ERRORS 

should match the snapshot => ./main_test.ts:4:6
error: PermissionDenied: Requires write access to "/Users/asher/Desktop/x/__snapshots__", run again with the --allow-write flag
    await Deno.mkdir(dir, { recursive: true });
               ^
    at Object.mkdir (ext:deno_fs/30_fs.js:203:9)
    at ensureDir (https://jsr.io/@std/fs/1.0.0-rc.2/ensure_dir.ts:41:16)
    at eventLoopTick (ext:core/01_core.js:168:7)
    at async ensureFile (https://jsr.io/@std/fs/1.0.0-rc.2/ensure_file.ts:42:7)
    at async AssertSnapshotContext.#readSnapshotFile (https://jsr.io/@std/testing/0.225.3/snapshot.ts:402:7)
    at async AssertSnapshotContext.getSnapshot (https://jsr.io/@std/testing/0.225.3/snapshot.ts:471:23)
    at async assertSnapshot (https://jsr.io/@std/testing/0.225.3/snapshot.ts:585:20)
    at async file:///Users/asher/Desktop/x/main_test.ts:5:3

deno 1.44.4 (release, aarch64-apple-darwin)
v8 12.6.228.9
typescript 5.4.5

from deno_std.

I was able to reproduce the issue with the below steps:

• First create a snapshot file with -A option
• Run the same test with --allow-read option

$ deno test -A main_test.ts -- --update
running 1 test from ./main_test.ts
should match the snapshot ... ok (4ms)
------- post-test output -------

 > 1 snapshot updated.
----- post-test output end -----

ok | 1 passed | 0 failed (6ms)

$ deno test --allow-read main_test.ts -- --update
running 1 test from ./main_test.ts
should match the snapshot ... ok (2ms)
Uncaught error from ./main_test.ts FAILED

 ERRORS 

./main_test.ts (uncaught error)
error: null
This error was not caught from a test and caused the test runner to fail on the referenced module.
It most likely originated from a dangling promise, event/timeout handler or top-level code.

 FAILURES 

./main_test.ts (uncaught error)

FAILED | 1 passed | 1 failed (5ms)

error: Test failed

@bcheidemann

To avoid this, we can either ensure that such errors are logged properly by deno test and/or assert that the required permissions are given before registering the callback in assertSnapshot.

Happy to raise a PR for the latter fix.

The latter solution sounds good to me

from deno_std.

@kt3k thanks for expanding on the replication steps :)

To avoid this, we can either ensure that such errors are logged properly by deno test and/or assert that the required permissions are given before registering the callback in assertSnapshot.

Happy to raise a PR for the latter fix.

The latter solution sounds good to me

I have now implemented this in #5201

from deno_std.