UnhandledPromiseRejectionWarning during Mocha unit:test --watch

After editing a component while running unit:test --watch, vuetify-loader causes an UnhandledPromiseRejectionWarning, and the webpack compile/rebuild hangs.

(node:8087) UnhandledPromiseRejectionWarning: TypeError [ERR_INVALID_ARG_TYPE]: The "from" argument must be of type string. Received type function
    at validateString (internal/validators.js:125:11)
    at Object.relative (path.js:1162:5)
    at JSON.stringify.splitted.map (~/loader-promise-rejection/node_modules/loader-utils/lib/stringifyRequest.js:30:29)
    at Array.map (<anonymous>)
    at Object.stringifyRequest (~/loader-promise-rejection/node_modules/loader-utils/lib/stringifyRequest.js:23:8)
    at install (~/loader-promise-rejection/node_modules/vuetify-loader/lib/loader.js:38:57)
    at Object.module.exports (~/loader-promise-rejection/node_modules/vuetify-loader/lib/loader.js:106:15)
    at process._tickCallback (internal/process/next_tick.js:68:7)
(node:8087) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:8087) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Simple steps to reproduce: vue --version 3.7.0

vue create my-app “Manually select features”, add Unit Testing, choose “Mocha + Chai” when prompted, everything else defaults.

cd my-app vue add vuetify

Steps to here are in https://github.com/ajhoddinott/vuetify-loader-promise-rejection.

yarn test:unit --watch

vue add vuetify has made changes to HelloWorld.vue without corresponding changes to example.spec.js, so the test fails.

Touch example.spec.js, the webpack rebuild completes and the test is run (and fails) again as expected.

Touch HelloWorld.vue, the webpack rebuild starts, but hangs/dies with the UnhandledPromiseRejectionWarning.

[jcono]

We are also seeing this issue and while I don’t fully understand what the problem is I can at least recap what I discovered in case it’s useful.

First of all, the problem only shows up for us under these conditions:

• running test:unit --watch as outlined above (it succeeds on the initial run)
• a vue component that uses vuetify components (e.g. v-layout)
• modify the vue component file and save it to trigger the watcher

If the component doesn’t have use any vuetify components we don’t see the error.

Investigating into this a little the problem originates in the vuetify-loader/lib/loader.js file. Specifically (in v1.2.2 anyway) in the lines that install the components / directives line 106 / 107.

content = install('installComponents', content, getMatches.call(this, 'Tag', tags, options.match, component));
content = install('installDirectives', content, getMatches.call(this, 'Attr', attrs, options.attrsMatch, component));

The only thing I discovered about this call was that there seems to be a difference in the context that this code runs in the 2nd time through (upon saving the file). More specifically inspecting this at the point this code fails seems to indicate that this refers to the global object which causes the trouble once the install function calls stringifyRequest(this, ...).

So I think the solution is to make sure that the install function is called with the correct this context much like is done with the getMatches.call on those lines of code.

Anyway, if I manually modify that loader.js file like this (note the .call(this, modification):

content = install.call(this, 'installComponents', content, getMatches.call(this, 'Tag', tags, options.match, component));
content = install.call(this, 'installDirectives', content, getMatches.call(this, 'Attr', attrs, options.attrsMatch, component));

Then everything seems to work and error goes away.

However having not spent a lot of time understanding the vuetify-loader codebase I’m not certain about the ramifications of this and can’t be sure it doesn’t have other side effects that we’ve not seen yet.

I hope this helps. I’m happy to make a PR if this is the correct fix or for someone else to add it in if it is.

[gdandy]

I’m experiencing the same/similar issue. It’s annoying to have to terminate the test watching and start it back up every time. I’m not sure if its vueitfy related though but I am using vuetify in the project. The only error I get is:

[===                      ] 10% (building)(node:27400) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): TypeError: Path must be a string. Received { [Function] skip: [Function], only: [Function] }
(node:27400) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.