histedit: add support to output nodechanges using formatter

The JSON output of nodechanges will help in automation and to improve editor
integrations such as for Nuclide.

Differential Revision: https://phab.mercurial-scm.org/D1348

tests/test-histedit-templates.t

@@ -0,0 +1,54 b''
+Testing templating for histedit command
+
+Setup
+
+  $ cat >> $HGRCPATH <<EOF
+  > [extensions]
+  > histedit=
+  > [experimental]
+  > evolution=createmarkers
+  > EOF
+
+  $ hg init repo
+  $ cd repo
+  $ for ch in a b c d; do echo foo > $ch; hg commit -Aqm "Added "$ch; done
+
+  $ hg log -G -T "{rev}:{node|short} {desc}"
+  @  3:62615734edd5 Added d
+  |
+  o  2:28ad74487de9 Added c
+  |
+  o  1:29becc82797a Added b
+  |
+  o  0:18d04c59bb5d Added a
+  
+Getting the JSON output for nodechanges
+
+  $ hg histedit -Tjson --commands - 2>&1 <<EOF
+  > pick 28ad74487de9 Added c
+  > pick 62615734edd5 Added d
+  > pick 18d04c59bb5d Added a
+  > pick 29becc82797a Added b
+  > EOF
+  [
+   {
+    "nodechanges": {"18d04c59bb5d2d4090ad9a5b59bd6274adb63add": ["109f8ec895447f81b380ba8d4d8b66539ccdcb94"], "28ad74487de9599d00d81085be739c61fc340652": ["bff9e07c1807942b161dab768aa793b48e9a7f9d"], "29becc82797a4bc11ec8880b58eaecd2ab3e7760": ["f5dcf3b4db23f31f1aacf46c33d1393de303d26f"], "62615734edd52f06b6fb9c2beb429e4fe30d57b8": ["201423b441c84d9e6858daed653e0d22485c1cfa"]}
+   }
+  ]
+
+  $ hg log -G -T "{rev}:{node|short} {desc}"
+  @  7:f5dcf3b4db23 Added b
+  |
+  o  6:109f8ec89544 Added a
+  |
+  o  5:201423b441c8 Added d
+  |
+  o  4:bff9e07c1807 Added c
+  
+  $ hg histedit -T "{nodechanges|json}" --commands - 2>&1 <<EOF
+  > pick bff9e07c1807 Added c
+  > pick 201423b441c8 Added d
+  > pick 109f8ec89544 Added a
+  > roll f5dcf3b4db23 Added b
+  > EOF
+  {"109f8ec895447f81b380ba8d4d8b66539ccdcb94": ["8d01470bfeab64d3de13c49adb79d88790d38396"], "f3ec56a374bdbdf1953cacca505161442c6f3a3e": [], "f5dcf3b4db23f31f1aacf46c33d1393de303d26f": ["8d01470bfeab64d3de13c49adb79d88790d38396"]} (no-eol)

hgext/histedit.py

@@ -917,7 +917,8 b' def findoutgoing(ui, repo, remote=None, '
      ('o', 'outgoing', False, _('changesets not found in destination')),
      ('f', 'force', False,
       _('force outgoing even for unrelated repositories')),
-     ('r', 'rev', [], _('first revision to be edited'), _('REV'))],
+     ('r', 'rev', [], _('first revision to be edited'), _('REV'))] +
+    cmdutil.formatteropts,
      _("[OPTIONS] ([ANCESTOR] | --outgoing [URL])"))
 def histedit(ui, repo, *freeargs, **opts):
     """interactively edit changeset history
@@ -1095,6 +1096,8 b' def _validateargs(ui, repo, state, freea'
 
 def _histedit(ui, repo, state, *freeargs, **opts):
     opts = pycompat.byteskwargs(opts)
+    fm = ui.formatter('histedit', opts)
+    fm.startitem()
     goal = _getgoal(opts)
     revs = opts.get('rev', [])
     rules = opts.get('commands', '')
@@ -1117,7 +1120,8 b' def _histedit(ui, repo, state, *freeargs'
         _newhistedit(ui, repo, state, revs, freeargs, opts)
 
     _continuehistedit(ui, repo, state)
-    _finishhistedit(ui, repo, state)
+    _finishhistedit(ui, repo, state, fm)
+    fm.end()
 
 def _continuehistedit(ui, repo, state):
     """This function runs after either:
@@ -1164,7 +1168,7 b' def _continuehistedit(ui, repo, state):'
     state.write()
     ui.progress(_("editing"), None)
 
-def _finishhistedit(ui, repo, state):
+def _finishhistedit(ui, repo, state, fm):
     """This action runs when histedit is finishing its session"""
     repo.ui.pushbuffer()
     hg.update(repo, state.parentctxnode, quietempty=True)
@@ -1198,6 +1202,13 b' def _finishhistedit(ui, repo, state):'
     mapping = {k: v for k, v in mapping.items()
                if k in nodemap and all(n in nodemap for n in v)}
     scmutil.cleanupnodes(repo, mapping, 'histedit')
+    hf = fm.hexfunc
+    fl = fm.formatlist
+    fd = fm.formatdict
+    nodechanges = fd({hf(oldn): fl([hf(n) for n in newn], name='node')
+                      for oldn, newn in mapping.iteritems()},
+                     key="oldnode", value="newnodes")
+    fm.data(nodechanges=nodechanges)
 
     state.clear()
     if os.path.exists(repo.sjoin('undo')):