tests/test-config.t

wireproto: define and implement HTTP handshake to upgrade protocol

When clients connect to repositories over HTTP, they issue a request
to the well-known URL "?cmd=capabilities" to fetch the repository
capabilities. This is the handshake portion of the HTTP protocol.

This commit defines a mechanism to use that HTTP request to return
information about modern server features.

If a client sends an X-HgUpgrade-* header containing a list of
client-supported API names, the server responds with a response
containing information about available services. This includes
the normal capabilities string. So if the server doesn't support
any newer services, the client can easily fall back.

By advertising supported services from clients, server operators
can see and log what client support exists in the wild. This will
also help with debugging.

The response contains the base path to API services. We know there
are potential issues with the <repo>/api/ URL space conflicting with
hgwebdir and subrepos. By making the API URL dynamic from the
perspective of the client, the URL for APIs is not subject to backwards
compatibility concerns - at least as long as a ?cmd=capabilities request
is made.

We've also defined the ``cbor`` client capability for the X-HgProto-*
header. This MUST be sent in order to get the modern response from
"?cmd=capabilities". During implementation, I initially always sent
an application/mercurial-cbor response. However, the handshake
mechanism will be more future compatible if the client is in charge
of which formats to request. We already perform content negotiation
from X-HgProto-*, so keying off this for the capabilities response
feels appropriate.

In addition, I initially used application/cbor. However, it is
conceivable that a non-Mercurial server could serve application/cbor.
To rule out this possibility, I've invented a new media type that
is Mercurial specific and can't be confused for generic CBOR.

Differential Revision: https://phab.mercurial-scm.org/D3242

hide outer repo
  $ hg init

Invalid syntax: no value

  $ cat > .hg/hgrc << EOF
  > novaluekey
  > EOF
  $ hg showconfig
  hg: parse error at $TESTTMP/.hg/hgrc:1: novaluekey
  [255]

Invalid syntax: no key

  $ cat > .hg/hgrc << EOF
  > =nokeyvalue
  > EOF
  $ hg showconfig
  hg: parse error at $TESTTMP/.hg/hgrc:1: =nokeyvalue
  [255]

Test hint about invalid syntax from leading white space

  $ cat > .hg/hgrc << EOF
  >  key=value
  > EOF
  $ hg showconfig
  hg: parse error at $TESTTMP/.hg/hgrc:1:  key=value
  unexpected leading whitespace
  [255]

  $ cat > .hg/hgrc << EOF
  >  [section]
  > key=value
  > EOF
  $ hg showconfig
  hg: parse error at $TESTTMP/.hg/hgrc:1:  [section]
  unexpected leading whitespace
  [255]

Reset hgrc

  $ echo > .hg/hgrc

Test case sensitive configuration

  $ cat <<EOF >> $HGRCPATH
  > [Section]
  > KeY = Case Sensitive
  > key = lower case
  > EOF

  $ hg showconfig Section
  Section.KeY=Case Sensitive
  Section.key=lower case

  $ hg showconfig Section -Tjson
  [
   {
    "name": "Section.KeY",
    "source": "*.hgrc:*", (glob)
    "value": "Case Sensitive"
   },
   {
    "name": "Section.key",
    "source": "*.hgrc:*", (glob)
    "value": "lower case"
   }
  ]
  $ hg showconfig Section.KeY -Tjson
  [
   {
    "name": "Section.KeY",
    "source": "*.hgrc:*", (glob)
    "value": "Case Sensitive"
   }
  ]
  $ hg showconfig -Tjson | tail -7
   },
   {
    "name": "*", (glob)
    "source": "*", (glob)
    "value": "*" (glob)
   }
  ]

Test empty config source:

  $ cat <<EOF > emptysource.py
  > def reposetup(ui, repo):
  >     ui.setconfig(b'empty', b'source', b'value')
  > EOF
  $ cp .hg/hgrc .hg/hgrc.orig
  $ cat <<EOF >> .hg/hgrc
  > [extensions]
  > emptysource = `pwd`/emptysource.py
  > EOF

  $ hg config --debug empty.source
  read config from: * (glob)
  none: value
  $ hg config empty.source -Tjson
  [
   {
    "name": "empty.source",
    "source": "",
    "value": "value"
   }
  ]

  $ cp .hg/hgrc.orig .hg/hgrc

Test "%unset"

  $ cat >> $HGRCPATH <<EOF
  > [unsettest]
  > local-hgrcpath = should be unset (HGRCPATH)
  > %unset local-hgrcpath
  > 
  > global = should be unset (HGRCPATH)
  > 
  > both = should be unset (HGRCPATH)
  > 
  > set-after-unset = should be unset (HGRCPATH)
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > [unsettest]
  > local-hgrc = should be unset (.hg/hgrc)
  > %unset local-hgrc
  > 
  > %unset global
  > 
  > both = should be unset (.hg/hgrc)
  > %unset both
  > 
  > set-after-unset = should be unset (.hg/hgrc)
  > %unset set-after-unset
  > set-after-unset = should be set (.hg/hgrc)
  > EOF

  $ hg showconfig unsettest
  unsettest.set-after-unset=should be set (.hg/hgrc)

Test exit code when no config matches

  $ hg config Section.idontexist
  [1]

sub-options in [paths] aren't expanded

  $ cat > .hg/hgrc << EOF
  > [paths]
  > foo = ~/foo
  > foo:suboption = ~/foo
  > EOF

  $ hg showconfig paths
  paths.foo:suboption=~/foo
  paths.foo=$TESTTMP/foo

edit failure

  $ HGEDITOR=false hg config --edit
  abort: edit failed: false exited with status 1
  [255]

config affected by environment variables

  $ EDITOR=e1 VISUAL=e2 hg config --debug | grep 'ui\.editor'
  $VISUAL: ui.editor=e2

  $ VISUAL=e2 hg config --debug --config ui.editor=e3 | grep 'ui\.editor'
  --config: ui.editor=e3

  $ PAGER=p1 hg config --debug | grep 'pager\.pager'
  $PAGER: pager.pager=p1

  $ PAGER=p1 hg config --debug --config pager.pager=p2 | grep 'pager\.pager'
  --config: pager.pager=p2

verify that aliases are evaluated as well

  $ hg init aliastest
  $ cd aliastest
  $ cat > .hg/hgrc << EOF
  > [ui]
  > user = repo user
  > EOF
  $ touch index
  $ unset HGUSER
  $ hg ci -Am test
  adding index
  $ hg log --template '{author}\n'
  repo user
  $ cd ..

alias has lower priority

  $ hg init aliaspriority
  $ cd aliaspriority
  $ cat > .hg/hgrc << EOF
  > [ui]
  > user = alias user
  > username = repo user
  > EOF
  $ touch index
  $ unset HGUSER
  $ hg ci -Am test
  adding index
  $ hg log --template '{author}\n'
  repo user
  $ cd ..