tests/test-phabricator.t

localrepo: create new function for instantiating a local repo object

Today, there is a single local repository class - localrepository. Its
__init__ is responsible for loading the .hg/requires file and taking
different actions depending on what is present.

In addition, extensions may define a "reposetup" function that
monkeypatches constructed repository instances, often by implementing
a derived type and changing the __class__ of the repo instance.

Work around alternate storage backends and partial clone has made it
clear to me that shoehorning all this logic into __init__ and operating
on an existing instance is too convoluted. For example, localrepository
assumes revlog storage and swapping in non-revlog storage requires
overriding e.g. file() to return something that isn't a revlog. I've
authored various patches that either:

a) teach various methods (like file()) about different states and
   taking the appropriate code path at run-time
b) create methods/attributes/callables used for instantiating things
   and populating these in __init__

"a" incurs run-time performance penalties and makes code more
complicated since various functions have a bunch of "if storage is X"
branches.

"b" makes localrepository quickly explode in complexity.

My plan for tackling this problem is to make the local repository type
more dynamic. Instead of a static localrepository class/type that
supports all of the local repository configurations (revlogs vs other,
revlogs with ellipsis, revlog v1 versus revlog v2, etc), we'll
dynamically construct a type providing the implementations that are
needed for the repository on disk, derived from the .hg/requires file
and configuration options. The constructed repository type will be
specialized and methods won't need to be taught about different
implementations nor overloaded.

We may also leverage this functionality for building types that don't
implement all attributes. For example, the "intents" feature allows
commands to declare that they are read only. By dynamically
constructing a repository type, we could return a repository instance
with no attributes related to mutating the repository. This could
include things like a "changelog" property implementation that doesn't
check whether it needs to invalidate the hidden revisions set on every
access.

This commit establishes a function for building a local repository
instance. Future commits will start moving functionality from
localrepository.__init__ to this function. Then we'll start dynamically
changing the returned type depending on options that are present.

This change may seem radical. But it should be fully compatible with
the reposetup() model - at least for now.

Differential Revision: https://phab.mercurial-scm.org/D4563

#require vcr
  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > phabricator = 
  > EOF
  $ hg init repo
  $ cd repo
  $ cat >> .hg/hgrc <<EOF
  > [phabricator]
  > url = https://phab.mercurial-scm.org/
  > callsign = HG
  > 
  > [auth]
  > hgphab.schemes = https
  > hgphab.prefix = phab.mercurial-scm.org
  > # When working on the extension and making phabricator interaction
  > # changes, edit this to be a real phabricator token. When done, edit
  > # it back, and make sure to also edit your VCR transcripts to match
  > # whatever value you put here.
  > hgphab.phabtoken = cli-hahayouwish
  > EOF
  $ VCR="$TESTDIR/phabricator"

Error is handled reasonably. We override the phabtoken here so that
when you're developing changes to phabricator.py you can edit the
above config and have a real token in the test but not have to edit
this test.
  $ hg phabread --config auth.hgphab.phabtoken=cli-notavalidtoken \
  >  --test-vcr "$VCR/phabread-conduit-error.json" D4480 | head
  abort: Conduit Error (ERR-INVALID-AUTH): API token "cli-notavalidtoken" has the wrong length. API tokens should be 32 characters long.

Basic phabread:
  $ hg phabread --test-vcr "$VCR/phabread-4480.json" D4480 | head
  # HG changeset patch
  exchangev2: start to implement pull with wire protocol v2
  
  Wire protocol version 2 will take a substantially different
  approach to exchange than version 1 (at least as far as pulling
  is concerned).
  
  This commit establishes a new exchangev2 module for holding
  code related to exchange using wire protocol v2. I could have
  added things to the existing exchange module. But it is already

phabupdate with an accept:
  $ hg phabupdate --accept D4564 \
  > -m 'I think I like where this is headed. Will read rest of series later.'\
  >  --test-vcr "$VCR/accept-4564.json"

Create a differential diff:
  $ echo alpha > alpha
  $ hg ci --addremove -m 'create alpha for phabricator test'
  adding alpha
  $ hg phabsend -r . --test-vcr "$VCR/phabsend-create-alpha.json"
  D4596 - created - 5206a4fa1e6c: create alpha for phabricator test
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/5206a4fa1e6c-dec9e777-phabsend.hg
  $ echo more >> alpha
  $ HGEDITOR=true hg ci --amend
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/d8f232f7d799-c573510a-amend.hg
  $ echo beta > beta
  $ hg ci --addremove -m 'create beta for phabricator test'
  adding beta
  $ hg phabsend -r ".^::" --test-vcr "$VCR/phabsend-update-alpha-create-beta.json"
  D4596 - updated - f70265671c65: create alpha for phabricator test
  D4597 - created - 1a5640df7bbf: create beta for phabricator test
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/1a5640df7bbf-6daf3e6e-phabsend.hg

Template keywords
  $ hg log -T'{rev} {phabreview|json}\n'
  1 {"id": "D4597", "url": "https://phab.mercurial-scm.org/D4597"}
  0 {"id": "D4596", "url": "https://phab.mercurial-scm.org/D4596"}

  $ hg log -T'{rev} {phabreview.url} {phabreview.id}\n'
  1 https://phab.mercurial-scm.org/D4597 D4597
  0 https://phab.mercurial-scm.org/D4596 D4596

  $ cd ..