Add curl -H/--header option to add a request header one each request

[jcamiel]

Add support for curl -H/--header option to add a request header on each request:

$ hurl --header "foo: bar" test.hurl

Adding multiple header is possible:

$ hurl --header "foo: bar" --header "bar: baz" test.hurl

To define: while redundant with header, per request header option should be also possible ?

GET https://foo.com
[Options]
header: "foo: bar"
HTTP 200

[jcamiel]

@theoforger if you're interesting by this issue, you're good to go!

This option is a curl option and it makes sense to be exposed by Hurl.

For a start, we could implement in a first PR this option:

$ hurl --header "foo: bar" test.hurl

Multiple headers could be added

$ hurl --header "foo: bar" --header "baz:bar" test.hurl

That will a a request header foo:bar to every request of a Hurl file.

It will make also sense to implement it on [Options]section (in another PRs of course):

GET https://foo.com
[Options]
header: toto:tutu
HTTP 200

This can be redundant with our header syntax

GET https://foo.com
toto: tutu
HTTP 200

But in the future we plan to implement [Options] section at the start of a Hurl file that will be apply to every entry of a file. For instance:

[Options]
insecure: true
header: token:xxx

GET https://foo.com

GET https://bar.com

GET https://baz.com

Will add a header on every request of the Hurl file

[theoforger]

@jcamiel Sounds good! I'll take this one 😆

[theoforger]

@jcamiel I noticed that the curl option also supports input through a file:

curl -H @filename https://example.com

or through stdin:

curl -H @- https://example.com

Do we want to implement them as well?

[jcamiel]

For the moment, it doesn't seem necessary. We can implement it later if someone has a strong need of it!

[theoforger]

@jcamiel Hello again! I just submitted a PR for this. Any feedback is appreciated 🙏