diff tests/test-status-tracked-key.t @ 48684:568f63b5a30f

dirstate: introduce a "tracked-key" feature

A new format variant is introduced. When used, a `tracked-key` file will be
generated. That file will be update when the set of tracked file might have
changed. This will be useful for external automation (e.g. build tool) to be
notified when the set of relevant files changes.

One of the motivation for this changes is to mitigate effect dirstate-v2 has on
such automation. Since the dirstate file is updated much more frequently on
dirstate-v2, monitoring update to that file is no longer a viable strategy.

See the associated documentation for details about the feature

To prevent older client to update the repository without updating that file, a
new requirements is introduced.

The `postfinalizegenerators` business is a bit weird, so I'll likely clean that
up soon.

Differential Revision: https://phab.mercurial-scm.org/D12124

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-status-tracked-key.t	Mon Jan 31 08:44:48 2022 +0100
@@ -0,0 +1,163 @@
+==============================
+Test the "tracked key" feature
+==============================
+
+The tracked key feature provide a file that get updated when the set of tracked
+files get updated.
+
+basic setup
+
+  $ cat << EOF >> $HGRCPATH
+  > [format]
+  > exp-dirstate-tracked-key-version=1
+  > EOF
+
+  $ hg init tracked-key-test
+  $ cd tracked-key-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 key file should exist
+
+  $ ls -1 .hg/dirstate*
+  .hg/dirstate
+  .hg/dirstate-tracked-key
+
+key-file stay the same if the tracked set is unchanged
+------------------------------------------------------
+
+(copy its content for later comparison)
+
+  $ cp .hg/dirstate-tracked-key ../key-bck
+  $ echo foo >> nf0
+  $ sleep 1
+  $ hg status
+  M nf0
+  $ diff --brief .hg/dirstate-tracked-key ../key-bck
+  $ hg revert -C nf0
+  $ sleep 1
+  $ hg status
+  $ diff --brief .hg/dirstate-tracked-key ../key-bck
+
+key-file change if the tracked set is changed manually
+------------------------------------------------------
+
+adding a file to tracking
+
+  $ cp .hg/dirstate-tracked-key ../key-bck
+  $ echo x > x
+  $ hg add x
+  $ diff --brief .hg/dirstate-tracked-key ../key-bck
+  Files .hg/dirstate-tracked-key and ../key-bck differ
+  [1]
+
+remove a file from tracking
+(forget)
+
+  $ cp .hg/dirstate-tracked-key ../key-bck
+  $ hg forget x
+  $ diff --brief .hg/dirstate-tracked-key ../key-bck
+  Files .hg/dirstate-tracked-key and ../key-bck differ
+  [1]
+
+(remove)
+
+  $ cp .hg/dirstate-tracked-key ../key-bck
+  $ hg remove nf1
+  $ diff --brief .hg/dirstate-tracked-key ../key-bck
+  Files .hg/dirstate-tracked-key and ../key-bck differ
+  [1]
+
+key-file changes on revert (when applicable)
+--------------------------------------------
+
+  $ cp .hg/dirstate-tracked-key ../key-bck
+  $ hg status
+  R nf1
+  ? x
+  $ hg revert --all
+  undeleting nf1
+  $ hg status
+  ? x
+  $ diff --brief .hg/dirstate-tracked-key ../key-bck
+  Files .hg/dirstate-tracked-key and ../key-bck differ
+  [1]
+
+
+`hg update` does affect the key-file (when needed)
+--------------------------------------------------
+
+update changing the tracked set
+
+(removing)
+
+  $ cp .hg/dirstate-tracked-key ../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-key ../key-bck
+  Files .hg/dirstate-tracked-key and ../key-bck differ
+  [1]
+
+(adding)
+
+  $ cp .hg/dirstate-tracked-key ../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-key ../key-bck
+  Files .hg/dirstate-tracked-key and ../key-bck differ
+  [1]
+
+update not affecting the tracked set
+
+  $ echo foo >> nf0
+  $ hg commit -m foo
+
+  $ cp .hg/dirstate-tracked-key ../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-key ../key-bck