mocha failed and shows ERROR: null

[ramanarupa]

I'm using ts-mocha and put mistaken code like this:
this.logger?.error(e)

ts-mocha is failed, and after debugging code of mocha I've detected stupid reaction like this
(node:13116) ExperimentalWarning:--experimental-loadermay be removed in the future; instead useregister(): --import 'data:text/javascript,import { register } from "node:module"; import { pathToFileURL } from "node:url"; register("ts-node/esm", pathToFileURL("./"));' (Use node --trace-warnings ...` to show where the warning was created)
mocha inspect [spec..]

Run tests with Mocha

Rules & Behavior
--allow-uncaught Allow uncaught errors to propagate [boolean]
-A, --async-only Require all tests to use a callback (async) or
return a Promise [boolean]
-b, --bail Abort ("bail") after first test failure [boolean]
--check-leaks Check for global variable leaks [boolean]
--delay Delay initial execution of root suite [boolean]
--dry-run Report tests without executing them [boolean]
--exit Force Mocha to quit after tests complete [boolean]
--fail-zero Fail test run if no test(s) encountered [boolean]
--forbid-only Fail if exclusive test(s) encountered [boolean]
--forbid-pending Fail if pending test(s) encountered [boolean]
--global, --globals List of allowed global variables [array]
-j, --jobs Number of concurrent jobs for --parallel; use 1 to
run in serial
[number] [default: (number of CPU cores - 1)]
-p, --parallel Run tests in parallel [boolean]
--retries Retry failed tests this many times [number]
-s, --slow Specify "slow" test threshold (in milliseconds)
[string] [default: 75]
-t, --timeout, --timeouts Specify test timeout threshold (in milliseconds)
[string] [default: 2000]
-u, --ui Specify user interface [string] [default: "bdd"]

Reporting & Output
-c, --color, --colors Force-enable color output [boolean]
--diff Show diff on failure
[boolean] [default: true]
--full-trace Display full stack traces [boolean]
--inline-diffs Display actual/expected differences
inline within each string [boolean]
-R, --reporter Specify reporter to use
[string] [default: "spec"]
-O, --reporter-option, Reporter-specific options
--reporter-options (<k=v,[k1=v1,..]>) [array]

Configuration
--config Path to config file [string] [default: (nearest rc file)]
-n, --node-option Node or V8 option (no leading "--") [array]
--package Path to package.json for config [string]

File Handling
--extension File extension(s) to load
[array] [default: ["js","cjs","mjs"]]
--file Specify file(s) to be loaded prior to root suite
execution [array] [default: (none)]
--ignore, --exclude Ignore file(s) or glob pattern(s)
[array] [default: (none)]
--recursive Look for tests in subdirectories [boolean]
-r, --require Require module [array] [default: (none)]
-S, --sort Sort test files [boolean]
-w, --watch Watch files in the current working directory for
changes [boolean]
--watch-files List of paths or globs to watch [array]
--watch-ignore List of paths or globs to exclude from watching
[array] [default: ["node_modules",".git"]]

Test Filters
-f, --fgrep Only run tests containing this string [string]
-g, --grep Only run tests matching this string or regexp [string]
-i, --invert Inverts --grep and --fgrep matches [boolean]

Positional Arguments
spec One or more files, directories, or globs to test
[array] [default: ["test"]]

Other Options
-h, --help Show usage information & exit [boolean]
-V, --version Show version number & exit [boolean]
--list-interfaces List built-in user interfaces & exit [boolean]
--list-reporters List built-in reporters & exit [boolean]

× ERROR: null
`

[mklenbw]

I'm having the same issue with following configuration:

extensions:
  - "ts"
project: "./tsconfig.json"
spec:
  - "./**/*.test.ts"
require:
  - "ts-node/register"
  - "tsconfig-paths/register"
reporter: "dot"
node-option:
  - "experimental-specifier-resolution=node"
  - "loader=ts-node/esm"

[kuba-orlik]

I'm also experiencing this issue. I'm using node v21.4.0 and ts-node.

This command fails with "Error: null":

TS_NODE_PROJECT='./src/back/tsconfig.json' npx mocha --recursive --timeout 20000  --require ts-node/register src/back/some.test.ts

[tpluscode]

I found that this happens with recent versions of node. For example, worked find in 18.17 but is broken in 18.19

[tpluscode]

My problem is actually ts-node/esm loader. I switched to tsm and the tests work again.

[tpluscode]

Alternatively, see TypeStrong/ts-node#1007 (comment)

[ramanarupa]

I resolved this problem by changing "ts-node/esm" to "tsx/esm":

"node-option": [
"experimental-specifier-resolution=node",
"import=tsx/esm",
"trace-uncaught"
],

[tpluscode]

Where do you set this `node_option`? 

…

________________________________ From: Rustam108 ***@***.***> Sent: Wednesday, 3 January 2024 17:54 To: mochajs/mocha Cc: Tomasz Pluskiewicz; Manual Subject: Re: [mochajs/mocha] mocha failed and shows ERROR: null (Issue #5048) I resolved this problem by: changing "esm" to "tsx/esm": "node-option": [ "experimental-specifier-resolution=node", "import=tsx/esm", "trace-uncaught" ], — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[JoshuaKGoldberg]

The Mocha config file, such as .mocharc.json, I'm guessing.

See also:

• 🚀 Feature: Explicit --import support for Node ESM #5002 for more discussion around ESM support
• feat: added TypeScript + ts-node/esm and tsx/esm examples mocha-examples#76 for some more examples with ESM imports/loaders

This issue seems to have turned into a general Q&A, so I'm going to close it out as resolved. Glad things seem to have been figured out!

If there's still a bug you'd like to report (echoing ERROR: null?) please do file a new issue with our new bug report template. We'd be happy to take a look.

...and also, please, use ``` code blocks to capture monospace output. This issue was very difficult to read. https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/creating-and-highlighting-code-blocks

[ClementValot]

For whom it may help, I've had this issue because my tsconfig.json had "moduleResolution": "bundler"

Still, the ERROR: null is worth investigating 🤔