[PATCH 4 of 4] commands: add template support for config

[Mathias De Maré]

# HG changeset patch
# User Mathias De Maré <mathias.demare at gmail.com>
# Date 1470324689 -7200
#      Thu Aug 04 17:31:29 2016 +0200
# Node ID c497d3c35883e43599d0a9f07f0894a582c4aede
# Parent  74056050d1bd9069f0dfaed861162ee65a77032d
commands: add template support for config

Example output:
hg config -Tjson ui.username
[
 {
  "value": "Mathias De Maré <mathias.demare at gmail.com>"
 }
]

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1787,7 +1787,7 @@
     [('u', 'untrusted', None, _('show untrusted configuration options')),
      ('e', 'edit', None, _('edit user config')),
      ('l', 'local', None, _('edit repository config')),
-     ('g', 'global', None, _('edit global config'))],
+     ('g', 'global', None, _('edit global config'))] + formatteropts,
     _('[-u] [NAME]...'),
     optionalrepo=True)
 def config(ui, repo, *values, **opts):
@@ -1848,6 +1848,7 @@
                   onerr=error.Abort, errprefix=_("edit failed"))
         return
 
+    fm = ui.formatter('config', opts)
     for f in scmutil.rcpath():
         ui.debug('read config from: %s\n' % f)
     untrusted = bool(opts.get('untrusted'))
@@ -1865,18 +1866,22 @@
                 if v == section:
                     ui.debug('%s: ' %
                              ui.configsource(section, name, untrusted))
-                    ui.write('%s=%s\n' % (sectname, value))
+                    fm.startitem()
+                    fm.write('section value', '%s=%s\n', sectname, value)
                     matched = True
                 elif v == sectname:
                     ui.debug('%s: ' %
                              ui.configsource(section, name, untrusted))
-                    ui.write(value, '\n')
+                    fm.startitem()
+                    fm.write('value', '%s\n', value)
                     matched = True
         else:
             ui.debug('%s: ' %
                      ui.configsource(section, name, untrusted))
-            ui.write('%s=%s\n' % (sectname, value))
+            fm.startitem()
+            fm.write('section value', '%s=%s\n', sectname, value)
             matched = True
+    fm.end()
     if matched:
         return 0
     return 1
diff --git a/tests/test-completion.t b/tests/test-completion.t
--- a/tests/test-completion.t
+++ b/tests/test-completion.t
@@ -232,7 +232,7 @@
   branches: active, closed, template
   bundle: force, rev, branch, base, all, type, ssh, remotecmd, insecure
   cat: output, rev, decode, include, exclude
-  config: untrusted, edit, local, global
+  config: untrusted, edit, local, global, template
   copy: after, force, include, exclude, dry-run
   debugancestor: 
   debugapplystreamclonebundle: 
diff --git a/tests/test-config.t b/tests/test-config.t
--- a/tests/test-config.t
+++ b/tests/test-config.t
@@ -54,6 +54,18 @@
   Section.KeY=Case Sensitive
   Section.key=lower case
 
+  $ hg showconfig Section -Tjson
+  [
+   {
+    "section": "Section.KeY",
+    "value": "Case Sensitive"
+   },
+   {
+    "section": "Section.key",
+    "value": "lower case"
+   }
+  ]
+
 Test "%unset"
 
   $ cat >> $HGRCPATH <<EOF