embedded:network/http/client requires headers in lower case

[tve]

Build environment: Linux
Moddable SDK version: idf-v5 branch
Target device: esp32-c3

Description
Looking at https://419.ecma-international.org/#-20-http-client-class-pattern I do not see the requirement that the headers passed to the request method be all lower case. I passed ["Content-Length": ...] and this caused no onWritable callback due to the lower-case equality check in https://github.com/Moddable-OpenSource/moddable/blob/public/examples/io/tcp/httpclient/httpclient.js#L343 . Note the same issue for transfer-encoding.

Expected behavior
I expected a case-insensitive comparison or a sentence in the spec to state that the headers must be all lower-case. (I bet the latter is there somewhere and I just haven't seen it....)

[phoddie]

The implementation certainly expects lowercase header names on input and generates lowercase headers names on output. When used with Header as the fetch() implementation does, this happens automatically. The spec doesn't say anything about the input headers being lowercase though. The fix is easy, as I'm sure you found. Add the following before line 343:

name = name.toLowerCase();

This allows the script to control the case of the headers sent, in case it matters (it shouldn't).. Alternatively, the toLowerCase() could be done in the assignment in line 341.

I'll commit that so no one else has to trip over this.

Using Map, there is the messy case where it can contain "Content-Length", "content-length", "CONTENT-LENGTH", and more. There's no point in handling that, so I think the spec should just note it as an undefined behavior.

What do you think?

[phoddie]

Also.... the HTTP 1.1 specification states:

All transfer-coding names are case-insensitive...

I think that means that the chunked check needs to be updated as well (not that anyone uses "CHUNKED"):

if ("chunked" === item.value[1].toLowerCase())

[phoddie]

Fix committed. Closing. (If problem persists, please reopen.)