tests/test-mq-qrefresh-interactive.t

filemerge: add support for partial conflict resolution by external tool

A common class of merge conflicts is in imports/#includes/etc. It's
relatively easy to write a tool that can resolve these conflicts,
perhaps by naively just unioning the statements and leaving any
cleanup to other tools to do later [1]. Such specialized tools cannot
generally resolve all conflicts in a file, of course. Let's therefore
call them "partial merge tools". Note that the internal simplemerge
algorithm is such a partial merge tool - one that only resolves
trivial "conflicts" where one side is unchanged or both sides change
in the same way.

One can also imagine having smarter language-aware partial tools that
merge the AST. It may be useful for such tools to interactively let
the user resolve any conflicts it can't resolve itself. However,
having the option of implementing it as a partial merge tool means
that the developer doesn't *need* to create a UI for it. Instead, the
user can resolve any remaining conflicts with their regular merge tool
(e.g. `:merge3` or `meld).

We don't currently have a way to let the user define such partial
merge tools. That's what this patch addresses. It lets the user
configure partial merge tools to run. Each tool can be configured to
run only on files matching certain patterns (e.g. "*.py"). The tool
takes three inputs (local, base, other) and resolves conflicts by
updating these in place. For example, let's say the inputs are these:


base:
```
import sys

def main():
  print('Hello')
```

local:
```
import os
import sys

def main():
  print('Hi')
```

other:
```
import re
import sys

def main():
  print('Howdy')
```

A partial merge tool could now resolve the conflicting imports by
replacing the import statements in *all* files by the following
snippet, while leaving the remainder of the files unchanged.

```
import os
import re
import sys
```

As a result, simplemerge and any regular merge tool that runs after
the partial merge tool(s) will consider the imports to be
non-conflicting and will only present the conflict in `main()` to the
user.

Differential Revision: https://phab.mercurial-scm.org/D12356

Create configuration

  $ echo "[ui]" >> $HGRCPATH
  $ echo "interactive=true" >> $HGRCPATH

help qrefresh (no record)

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ hg help qrefresh
  hg qrefresh [-I] [-X] [-e] [-m TEXT] [-l FILE] [-s] [FILE]...
  
  update the current patch
  
      If any file patterns are provided, the refreshed patch will contain only
      the modifications that match those patterns; the remaining modifications
      will remain in the working directory.
  
      If -s/--short is specified, files currently included in the patch will be
      refreshed just like matched files and remain in the patch.
  
      If -e/--edit is specified, Mercurial will start your configured editor for
      you to enter a message. In case qrefresh fails, you will find a backup of
      your message in ".hg/last-message.txt".
  
      hg add/remove/copy/rename work as usual, though you might want to use git-
      style patches (-g/--git or [diff] git=1) to track copies and renames. See
      the diffs help topic for more information on the git diff format.
  
      Returns 0 on success.
  
  options ([+] can be repeated):
  
   -e --edit                invoke editor on commit messages
   -g --git                 use git extended diff format
   -s --short               refresh only files already in the patch and
                            specified files
   -U --currentuser         add/update author field in patch with current user
   -u --user USER           add/update author field in patch with given user
   -D --currentdate         add/update date field in patch with current date
   -d --date DATE           add/update date field in patch with given date
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
   -m --message TEXT        use text as commit message
   -l --logfile FILE        read commit message from file
  
  (some details hidden, use --verbose to show complete help)

help qrefresh (record)

  $ echo "record=" >> $HGRCPATH
  $ hg help qrefresh
  hg qrefresh [-I] [-X] [-e] [-m TEXT] [-l FILE] [-s] [FILE]...
  
  update the current patch
  
      If any file patterns are provided, the refreshed patch will contain only
      the modifications that match those patterns; the remaining modifications
      will remain in the working directory.
  
      If -s/--short is specified, files currently included in the patch will be
      refreshed just like matched files and remain in the patch.
  
      If -e/--edit is specified, Mercurial will start your configured editor for
      you to enter a message. In case qrefresh fails, you will find a backup of
      your message in ".hg/last-message.txt".
  
      hg add/remove/copy/rename work as usual, though you might want to use git-
      style patches (-g/--git or [diff] git=1) to track copies and renames. See
      the diffs help topic for more information on the git diff format.
  
      Returns 0 on success.
  
  options ([+] can be repeated):
  
   -e --edit                invoke editor on commit messages
   -g --git                 use git extended diff format
   -s --short               refresh only files already in the patch and
                            specified files
   -U --currentuser         add/update author field in patch with current user
   -u --user USER           add/update author field in patch with given user
   -D --currentdate         add/update date field in patch with current date
   -d --date DATE           add/update date field in patch with given date
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
   -m --message TEXT        use text as commit message
   -l --logfile FILE        read commit message from file
   -i --interactive         interactively select changes to refresh
  
  (some details hidden, use --verbose to show complete help)

  $ hg init a
  $ cd a

Base commit

  $ cat > 1.txt <<EOF
  > 1
  > 2
  > 3
  > 4
  > 5
  > EOF
  $ cat > 2.txt <<EOF
  > a
  > b
  > c
  > d
  > e
  > f
  > EOF

  $ mkdir dir
  $ cat > dir/a.txt <<EOF
  > hello world
  > 
  > someone
  > up
  > there
  > loves
  > me
  > EOF

  $ hg add 1.txt 2.txt dir/a.txt
  $ hg commit -m aaa
  $ hg qrecord --config ui.interactive=false patch
  abort: running non-interactively, use qnew instead
  [10]
  $ hg qnew -i --config ui.interactive=false patch
  abort: running non-interactively
  [10]
  $ hg qnew -d '0 0' patch

Changing files

  $ sed -e 's/2/2 2/;s/4/4 4/' 1.txt > 1.txt.new
  $ sed -e 's/b/b b/' 2.txt > 2.txt.new
  $ sed -e 's/hello world/hello world!/' dir/a.txt > dir/a.txt.new

  $ mv -f 1.txt.new 1.txt
  $ mv -f 2.txt.new 2.txt
  $ mv -f dir/a.txt.new dir/a.txt

Whole diff

  $ hg diff --nodates
  diff -r ed27675cb5df 1.txt
  --- a/1.txt
  +++ b/1.txt
  @@ -1,5 +1,5 @@
   1
  -2
  +2 2
   3
  -4
  +4 4
   5
  diff -r ed27675cb5df 2.txt
  --- a/2.txt
  +++ b/2.txt
  @@ -1,5 +1,5 @@
   a
  -b
  +b b
   c
   d
   e
  diff -r ed27675cb5df dir/a.txt
  --- a/dir/a.txt
  +++ b/dir/a.txt
  @@ -1,4 +1,4 @@
  -hello world
  +hello world!
   
   someone
   up

partial qrefresh

  $ hg qrefresh -i --config ui.interactive=false
  abort: running non-interactively
  [10]
  $ hg qrefresh -i -d '0 0' <<EOF
  > y
  > y
  > n
  > y
  > y
  > n
  > EOF
  diff --git a/1.txt b/1.txt
  2 hunks, 2 lines changed
  examine changes to '1.txt'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,3 +1,3 @@
   1
  -2
  +2 2
   3
  record change 1/4 to '1.txt'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -3,3 +3,3 @@
   3
  -4
  +4 4
   5
  record change 2/4 to '1.txt'?
  (enter ? for help) [Ynesfdaq?] n
  
  diff --git a/2.txt b/2.txt
  1 hunks, 1 lines changed
  examine changes to '2.txt'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,5 +1,5 @@
   a
  -b
  +b b
   c
   d
   e
  record change 3/4 to '2.txt'?
  (enter ? for help) [Ynesfdaq?] y
  
  diff --git a/dir/a.txt b/dir/a.txt
  1 hunks, 1 lines changed
  examine changes to 'dir/a.txt'?
  (enter ? for help) [Ynesfdaq?] n
  

After partial qrefresh 'tip'

  $ hg tip -p
  changeset:   1:0738af1a8211
  tag:         patch
  tag:         qbase
  tag:         qtip
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     [mq]: patch
  
  diff -r 1fd39ab63a33 -r 0738af1a8211 1.txt
  --- a/1.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/1.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,5 +1,5 @@
   1
  -2
  +2 2
   3
   4
   5
  diff -r 1fd39ab63a33 -r 0738af1a8211 2.txt
  --- a/2.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/2.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,5 +1,5 @@
   a
  -b
  +b b
   c
   d
   e
  
After partial qrefresh 'diff'

  $ hg diff --nodates
  diff -r 0738af1a8211 1.txt
  --- a/1.txt
  +++ b/1.txt
  @@ -1,5 +1,5 @@
   1
   2 2
   3
  -4
  +4 4
   5
  diff -r 0738af1a8211 dir/a.txt
  --- a/dir/a.txt
  +++ b/dir/a.txt
  @@ -1,4 +1,4 @@
  -hello world
  +hello world!
   
   someone
   up

qrefresh interactively everything else

  $ hg qrefresh -i -d '0 0' <<EOF
  > y
  > y
  > y
  > y
  > EOF
  diff --git a/1.txt b/1.txt
  1 hunks, 1 lines changed
  examine changes to '1.txt'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,5 +1,5 @@
   1
   2 2
   3
  -4
  +4 4
   5
  record change 1/2 to '1.txt'?
  (enter ? for help) [Ynesfdaq?] y
  
  diff --git a/dir/a.txt b/dir/a.txt
  1 hunks, 1 lines changed
  examine changes to 'dir/a.txt'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,4 +1,4 @@
  -hello world
  +hello world!
   
   someone
   up
  record change 2/2 to 'dir/a.txt'?
  (enter ? for help) [Ynesfdaq?] y
  

After final qrefresh 'tip'

  $ hg tip -p
  changeset:   1:2c3f66afeed9
  tag:         patch
  tag:         qbase
  tag:         qtip
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     [mq]: patch
  
  diff -r 1fd39ab63a33 -r 2c3f66afeed9 1.txt
  --- a/1.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/1.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,5 +1,5 @@
   1
  -2
  +2 2
   3
  -4
  +4 4
   5
  diff -r 1fd39ab63a33 -r 2c3f66afeed9 2.txt
  --- a/2.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/2.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,5 +1,5 @@
   a
  -b
  +b b
   c
   d
   e
  diff -r 1fd39ab63a33 -r 2c3f66afeed9 dir/a.txt
  --- a/dir/a.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/dir/a.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,4 +1,4 @@
  -hello world
  +hello world!
   
   someone
   up
  

After qrefresh 'diff'

  $ hg diff --nodates

  $ cd ..