annotate tests/test-status-tracked-key.t @ 50762:c51b178b0b7e

configitems: declare items in a TOML file

Mercurial ships with Rust code that also needs to read from the config.
Having a way of presenting `configitems` to both Python and Rust is needed
to prevent duplication, drift, and have the appropriate devel warnings.

Abstracting away from Python means choosing a config format. No single format
is perfect, and I have yet to come across a developer that doesn't hate all of
them in some way.
Since we have a strict no-dependencies policy for Mercurial, we either need
to use whatever comes with Python, vendor a library, or implement a custom
format ourselves.

Python stdlib means using JSON, which doesn't support comments and isn't great
for humans, or `configparser` which is an obscure, untyped format that nobody
uses and doesn't have a commonplace Rust parser.
Implementing a custom format is error-prone, tedious and subject to the
same issues as picking an existing format.

Vendoring opens us to the vast array of common config formats. The ones
being picked for most modern software are YAML and TOML. YAML is older and
common in the Python community, but TOML is much simpler and less error-prone.
I would much rather be responsible for the <1000 lines of `tomli`, on top of
TOML being the choice of the Rust community, with robust crates for reading it.

The structure of `configitems.toml` is explained inline.

===============================
Test the "tracked hint" feature
===============================

The tracked hint feature provide a file that get updated when the set of tracked
files get updated.

basic setup

  $ cat << EOF >> $HGRCPATH
  > [format]
  > use-dirstate-tracked-hint=yes
  > EOF

  $ hg init tracked-hint-test
  $ cd tracked-hint-test
  $ hg debugbuilddag '.+10' -n
  $ hg log -G -T '{rev} {desc} {files}\n'
  o  10 r10 nf10
  |
  o  9 r9 nf9
  |
  o  8 r8 nf8
  |
  o  7 r7 nf7
  |
  o  6 r6 nf6
  |
  o  5 r5 nf5
  |
  o  4 r4 nf4
  |
  o  3 r3 nf3
  |
  o  2 r2 nf2
  |
  o  1 r1 nf1
  |
  o  0 r0 nf0
  
  $ hg up tip
  11 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg files
  nf0
  nf1
  nf10
  nf2
  nf3
  nf4
  nf5
  nf6
  nf7
  nf8
  nf9

key-file exists
-----------

The tracked hint file should exist

  $ ls -1 .hg/dirstate*
  .hg/dirstate
  .hg/dirstate-tracked-hint

key-file stay the same if the tracked set is unchanged
------------------------------------------------------

(copy its content for later comparison)

  $ cp .hg/dirstate-tracked-hint ../key-bck
  $ echo foo >> nf0
  $ sleep 1
  $ hg status
  M nf0
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck
  $ hg revert -C nf0
  $ sleep 1
  $ hg status
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck

key-file change if the tracked set is changed manually
------------------------------------------------------

adding a file to tracking

  $ cp .hg/dirstate-tracked-hint ../key-bck
  $ echo x > x
  $ hg add x
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck
  Files .hg/dirstate-tracked-hint and ../key-bck differ
  [1]

remove a file from tracking
(forget)

  $ cp .hg/dirstate-tracked-hint ../key-bck
  $ hg forget x
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck
  Files .hg/dirstate-tracked-hint and ../key-bck differ
  [1]

(remove)

  $ cp .hg/dirstate-tracked-hint ../key-bck
  $ hg remove nf1
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck
  Files .hg/dirstate-tracked-hint and ../key-bck differ
  [1]

key-file changes on revert (when applicable)
--------------------------------------------

  $ cp .hg/dirstate-tracked-hint ../key-bck
  $ hg status
  R nf1
  ? x
  $ hg revert --all
  undeleting nf1
  $ hg status
  ? x
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck
  Files .hg/dirstate-tracked-hint and ../key-bck differ
  [1]


`hg update` does affect the key-file (when needed)
--------------------------------------------------

update changing the tracked set

(removing)

  $ cp .hg/dirstate-tracked-hint ../key-bck
  $ hg status --rev . --rev '.#generations[-1]'
  R nf10
  $ hg up '.#generations[-1]'
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck
  Files .hg/dirstate-tracked-hint and ../key-bck differ
  [1]

(adding)

  $ cp .hg/dirstate-tracked-hint ../key-bck
  $ hg status --rev . --rev '.#generations[1]'
  A nf10
  $ hg up '.#generations[1]'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck
  Files .hg/dirstate-tracked-hint and ../key-bck differ
  [1]

update not affecting the tracked set

  $ echo foo >> nf0
  $ hg commit -m foo

  $ cp .hg/dirstate-tracked-hint ../key-bck
  $ hg status --rev . --rev '.#generations[-1]'
  M nf0
  $ hg up '.#generations[-1]'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ diff --brief .hg/dirstate-tracked-hint ../key-bck

Test upgrade and downgrade
==========================

  $ test -f .hg/dirstate-tracked-hint
  $ hg debugrequires | grep 'tracked'
  dirstate-tracked-key-v1

downgrade

  $ hg debugupgraderepo --config format.use-dirstate-tracked-hint=no --run --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: * (glob)
     removed: dirstate-tracked-key-v1
  
  no revlogs to process
  
  $ test -f .hg/dirstate-tracked-hint
  [1]
  $ hg debugrequires | grep 'tracked'
  [1]

upgrade

  $ hg debugupgraderepo --config format.use-dirstate-tracked-hint=yes --run --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: * (glob)
     added: dirstate-tracked-key-v1
  
  no revlogs to process
  
  $ test -f .hg/dirstate-tracked-hint
  $ hg debugrequires | grep 'tracked'
  dirstate-tracked-key-v1
  $ cd ..

Test automatic upgrade and downgrade
------------------------------------

create an initial repository

  $ hg init auto-upgrade \
  > --config format.use-dirstate-tracked-hint=no
  $ hg debugbuilddag -R auto-upgrade --new-file .+5
  $ hg -R auto-upgrade update
  6 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugformat -R auto-upgrade | grep tracked
  tracked-hint:        no

upgrade it to dirstate-tracked-hint automatically

  $ hg status -R auto-upgrade \
  > --config format.use-dirstate-tracked-hint.automatic-upgrade-of-mismatching-repositories=yes \
  > --config format.use-dirstate-tracked-hint=yes
  automatically upgrading repository to the `tracked-hint` feature
  (see `hg help config.format.use-dirstate-tracked-hint` for details)
  $ hg debugformat -R auto-upgrade | grep tracked
  tracked-hint:       yes

rhg supports this feature

  $ hg status -R auto-upgrade \
  > --config format.use-dirstate-tracked-hint=yes --config rhg.on-unsupported=abort

downgrade it from dirstate-tracked-hint automatically

  $ hg status -R auto-upgrade \
  > --config format.use-dirstate-tracked-hint.automatic-upgrade-of-mismatching-repositories=yes \
  > --config format.use-dirstate-tracked-hint=no
  automatically downgrading repository from the `tracked-hint` feature
  (see `hg help config.format.use-dirstate-tracked-hint` for details)
  $ hg debugformat -R auto-upgrade | grep tracked
  tracked-hint:        no