diff hgext/phabricator.py @ 44717:3dc6a70779f2

phabricator: add an option to fold several commits into one review (issue6244)

Now that all of the pieces are in place, alter the user facing command to allow
it.  This is the default behavior when using `arc`, but I much prefer the 1:1
approach, and I'm tempted to mark this advanced to limit its abuse.  I started
out calling this `--no-stack` like the feature request suggested, but I found it
less obvious (especially when writing the code), so I went with the `hg fold`
analogue.

This will populate the `Commits` tab in the web UI with the hash of each commit
folded into the review.  From experimentation, it seems to list them in the
order they are received from the extension instead of the actual parent/child
relationship.  The extension sends them in sorted order, thanks to
`templatefilters.json()`.  Since there's enough info there for them to put
things in the right order, JSON is unordered aside from lists (IIUC), and there
doesn't seem to be any harmful side effects, I guess we write this off as their
bug.  It is simple enough to workaround by putting a check for `util.sortdict`
into `templatefilters.json()`, and don't resort in that case.

There are a handful of restrictions that are documented in the code, which
somebody could probably fix if they're interested.  Notably, this requires the
(default) `--amend` option, because there's not an easy way to apply a local tag
across several commits.  This also doesn't do preflight checking to ensure that
all previous commits that were part of a single review are selected when
updating.  That seems expensive.  What happens is the excluded commit is dropped
from the review, but it keeps the Differential Revision line in the commit
message.  Not everything can be edited, so it doesn't seem worth making the code
even more complicated to handle this edge case.

There are a couple of "obsolete feature not enabled but X markers found!"
messages that appeared on Windows but not macOS.  I have no idea what's going on
here, but that's an unrelated issue, so I conditionalized those lines.

Differential Revision: https://phab.mercurial-scm.org/D8314

--- a/hgext/phabricator.py	Wed Apr 08 17:07:19 2020 -0400
+++ b/hgext/phabricator.py	Wed Apr 08 17:30:10 2020 -0400
@@ -559,7 +559,11 @@
                 # and now resubmitted with --fold, the easiest thing to do is
                 # to leave the node clear.  This only results in creating a new
                 # diff for the _same_ Differential Revision if this commit is
-                # the first or last in the selected range.
+                # the first or last in the selected range.  If we picked a node
+                # from the list instead, it would have to be the lowest if at
+                # the beginning of the --fold range, or the highest at the end.
+                # Otherwise, one or more of the nodes wouldn't be considered in
+                # the diff, and the Differential wouldn't be properly updated.
                 # If this commit is the result of `hg split` in the same
                 # scenario, there is a single oldnode here (and multiple
                 # newnodes mapped to it).  That makes it the same as the normal
@@ -1250,6 +1254,7 @@
             _(b'add a comment to Revisions with new/updated Diffs'),
         ),
         (b'', b'confirm', None, _(b'ask for confirmation before sending')),
+        (b'', b'fold', False, _(b'combine the revisions into one review')),
     ],
     _(b'REV [OPTIONS]'),
     helpcategory=command.CATEGORY_IMPORT_EXPORT,
@@ -1278,6 +1283,12 @@
         [phabsend]
         confirm = true
 
+    By default, a separate review will be created for each commit that is
+    selected, and will have the same parent/child relationship in Phabricator.
+    If ``--fold`` is set, multiple commits are rolled up into a single review
+    as if diffed from the parent of the first revision to the last.  The commit
+    messages are concatenated in the summary field on Phabricator.
+
     phabsend will check obsstore and the above association to decide whether to
     update an existing Differential Revision, or create a new one.
     """
@@ -1291,6 +1302,44 @@
     if opts.get(b'amend'):
         cmdutil.checkunfinished(repo)
 
+    ctxs = [repo[rev] for rev in revs]
+
+    fold = opts.get(b'fold')
+    if fold:
+        if len(revs) == 1:
+            # TODO: just switch to --no-fold instead?
+            raise error.Abort(_(b"cannot fold a single revision"))
+
+        # There's no clear way to manage multiple commits with a Dxxx tag, so
+        # require the amend option.  (We could append "_nnn", but then it
+        # becomes jumbled if earlier commits are added to an update.)  It should
+        # lock the repo and ensure that the range is editable, but that would
+        # make the code pretty convoluted.  The default behavior of `arc` is to
+        # create a new review anyway.
+        if not opts.get(b"amend"):
+            raise error.Abort(_(b"cannot fold with --no-amend"))
+
+        # Ensure the local commits are an unbroken range
+        revrange = repo.revs(b'(first(%ld)::last(%ld))', revs, revs)
+        if any(r for r in revs if r not in revrange) or any(
+            r for r in revrange if r not in revs
+        ):
+            raise error.Abort(_(b"cannot fold non-linear revisions"))
+
+        # It might be possible to bucketize the revisions by the DREV value, and
+        # iterate over those groups when posting, and then again when amending.
+        # But for simplicity, require all selected revisions to be for the same
+        # DREV (if present).  Adding local revisions to an existing DREV is
+        # acceptable.
+        drevmatchers = [
+            _differentialrevisiondescre.search(ctx.description())
+            for ctx in ctxs
+        ]
+        if len({m.group('url') for m in drevmatchers if m}) > 1:
+            raise error.Abort(
+                _(b"cannot fold revisions with different DREV values")
+            )
+
     # {newnode: (oldnode, olddiff, olddrev}
     oldmap = getoldnodedrevmap(repo, [repo[r].node() for r in revs])
 
@@ -1323,17 +1372,25 @@
     # Send patches one by one so we know their Differential Revision PHIDs and
     # can provide dependency relationship
     lastrevphid = None
-    for rev in revs:
-        ui.debug(b'sending rev %d\n' % rev)
-        ctx = repo[rev]
+    for ctx in ctxs:
+        if fold:
+            ui.debug(b'sending rev %d::%d\n' % (ctx.rev(), ctxs[-1].rev()))
+        else:
+            ui.debug(b'sending rev %d\n' % ctx.rev())
 
         # Get Differential Revision ID
         oldnode, olddiff, revid = oldmap.get(ctx.node(), (None, None, None))
-        oldbasenode = oldnode
+        oldbasenode, oldbasediff, oldbaserevid = oldnode, olddiff, revid
+
+        if fold:
+            oldbasenode, oldbasediff, oldbaserevid = oldmap.get(
+                ctxs[-1].node(), (None, None, None)
+            )
+
         if oldnode != ctx.node() or opts.get(b'amend'):
             # Create or update Differential Revision
             revision, diff = createdifferentialrevision(
-                [ctx],
+                ctxs if fold else [ctx],
                 revid,
                 lastrevphid,
                 oldbasenode,
@@ -1342,7 +1399,13 @@
                 actions,
                 opts.get(b'comment'),
             )
-            diffmap[ctx.node()] = diff
+
+            if fold:
+                for ctx in ctxs:
+                    diffmap[ctx.node()] = diff
+            else:
+                diffmap[ctx.node()] = diff
+
             newrevid = int(revision[b'object'][b'id'])
             newrevphid = revision[b'object'][b'phid']
             if revid:
@@ -1352,18 +1415,19 @@
 
             # Create a local tag to note the association, if commit message
             # does not have it already
-            m = _differentialrevisiondescre.search(ctx.description())
-            if not m or int(m.group('id')) != newrevid:
-                tagname = b'D%d' % newrevid
-                tags.tag(
-                    repo,
-                    tagname,
-                    ctx.node(),
-                    message=None,
-                    user=None,
-                    date=None,
-                    local=True,
-                )
+            if not fold:
+                m = _differentialrevisiondescre.search(ctx.description())
+                if not m or int(m.group('id')) != newrevid:
+                    tagname = b'D%d' % newrevid
+                    tags.tag(
+                        repo,
+                        tagname,
+                        ctx.node(),
+                        message=None,
+                        user=None,
+                        date=None,
+                        local=True,
+                    )
         else:
             # Nothing changed. But still set "newrevphid" so the next revision
             # could depend on this one and "newrevid" for the summary line.
@@ -1374,6 +1438,15 @@
         drevids.append(newrevid)
         lastrevphid = newrevphid
 
+        if fold:
+            for c in ctxs:
+                if oldmap.get(c.node(), (None, None, None))[2]:
+                    action = b'updated'
+                else:
+                    action = b'created'
+                _print_phabsend_action(ui, c, newrevid, action)
+            break
+
         _print_phabsend_action(ui, ctx, newrevid, action)
 
     # Update commit messages and remove tags
@@ -1383,11 +1456,17 @@
         with repo.wlock(), repo.lock(), repo.transaction(b'phabsend'):
             wnode = unfi[b'.'].node()
             mapping = {}  # {oldnode: [newnode]}
+            newnodes = []
+
+            drevid = drevids[0]
+
             for i, rev in enumerate(revs):
                 old = unfi[rev]
-                drevid = drevids[i]
+                if not fold:
+                    drevid = drevids[i]
                 drev = [d for d in drevs if int(d[b'id']) == drevid][0]
-                newdesc = get_amended_desc(drev, old, False)
+
+                newdesc = get_amended_desc(drev, old, fold)
                 # Make sure commit message contain "Differential Revision"
                 if old.description() != newdesc:
                     if old.phase() == phases.public:
@@ -1414,21 +1493,57 @@
 
                     mapping[old.node()] = [newnode]
 
+                    if fold:
+                        # Defer updating the (single) Diff until all nodes are
+                        # collected.  No tags were created, so none need to be
+                        # removed.
+                        newnodes.append(newnode)
+                        continue
+
                     _amend_diff_properties(
                         unfi, drevid, [newnode], diffmap[old.node()]
                     )
-                # Remove local tags since it's no longer necessary
-                tagname = b'D%d' % drevid
-                if tagname in repo.tags():
-                    tags.tag(
-                        repo,
-                        tagname,
-                        nullid,
-                        message=None,
-                        user=None,
-                        date=None,
-                        local=True,
+
+                    # Remove local tags since it's no longer necessary
+                    tagname = b'D%d' % drevid
+                    if tagname in repo.tags():
+                        tags.tag(
+                            repo,
+                            tagname,
+                            nullid,
+                            message=None,
+                            user=None,
+                            date=None,
+                            local=True,
+                        )
+                elif fold:
+                    # When folding multiple commits into one review with
+                    # --fold, track even the commits that weren't amended, so
+                    # that their association isn't lost if the properties are
+                    # rewritten below.
+                    newnodes.append(old.node())
+
+            # If the submitted commits are public, no amend takes place so
+            # there are no newnodes and therefore no diff update to do.
+            if fold and newnodes:
+                diff = diffmap[old.node()]
+
+                # The diff object in diffmap doesn't have the local commits
+                # because that could be returned from differential.creatediff,
+                # not differential.querydiffs.  So use the queried diff (if
+                # present), or force the amend (a new revision is being posted.)
+                if not olddiff or set(newnodes) != getlocalcommits(olddiff):
+                    _debug(ui, b"updating local commit list for D%d\n" % drevid)
+                    _amend_diff_properties(unfi, drevid, newnodes, diff)
+                else:
+                    _debug(
+                        ui,
+                        b"local commit list for D%d is already up-to-date\n"
+                        % drevid,
                     )
+            elif fold:
+                _debug(ui, b"no newnodes to update\n")
+
             scmutil.cleanupnodes(repo, mapping, b'phabsend', fixphase=True)
             if wnode in mapping:
                 unfi.setparents(mapping[wnode][0])