MIME of .mjs files

[benedictdudel]

Unfortunately skipper is serving .mjs files as application/octet-stream instead of application/javascript. The MIME used to identify .mjs files should be a web compatible JavaScript MIME Type.

Does anyone has a workaround to set the correct Content-Type header for *.mjs files with skipper in the meantime?

[AlexanderYastrebov]

Hello, how do you serve these files? Could you provide an example route maybe?

[benedictdudel]

@AlexanderYastrebov Unfortunately I have no public route available. I stumbled across the issue with the new storybook version which uses .mjs files. Here is the corresponding issue in Storybook with some more context (albeit using nginx).

[benedictdudel]

Here is some more context regarding to updates to ECMAScript media types.

[AlexanderYastrebov]

If we are talking about static filter then it uses https://pkg.go.dev/net/http#FileServer which internally uses https://pkg.go.dev/mime#TypeByExtension which relies on system mime files (see docs):

~$ grep mjs /usr/share/mime/globs2 
50:application/javascript:*.mjs

~$ mkdir /tmp/skipper2253
~$ echo "This is an .mjs file" > /tmp/skipper2253/test.mjs
~$ bin/skipper -inline-routes='* -> static("/tmp/skipper2253") -> <shunt>'

~$ curl -v localhost:9090/test.mjs 2>&1 | grep Content-Type
< Content-Type: text/javascript; charset=utf-8

[AlexanderYastrebov]

Actually mjs seems to be hardcoded which explains the result discrepancy (application/javascript vs text/javascript) in #2253 (comment)

[AlexanderYastrebov]

See related golang/go#32351

[benedictdudel]

Thank you for your fast response!