D6877: merge: replace magic strings with NAMED_CONSTANTS (API)

[durin42 (Augie Fackler)]

durin42 created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  .. api::
  
    `mercurial.hg.update*` and `mercurial.merge.update` now expect a value
    from a set of NAMED_CONSTANTS (`merge.UPDATECHECK_*` constants)
    rather than a collection of magic strings. As of now, the values
    are the same, but code should be prepared for these values to
    change in the future.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D6877

AFFECTED FILES
  mercurial/hg.py
  mercurial/merge.py

CHANGE DETAILS

diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -1926,6 +1926,11 @@
         else:
             repo.dirstate.normal(f)
 
+UPDATECHECK_ABORT = 'abort'  # handled at higher layers
+UPDATECHECK_NONE = 'none'
+UPDATECHECK_LINEAR = 'linear'
+UPDATECHECK_NO_CONFLICT = 'noconflict'
+
 def update(repo, node, branchmerge, force, ancestor=None,
            mergeancestor=False, labels=None, matcher=None, mergeforce=False,
            updatecheck=None, wc=None):
@@ -1992,8 +1997,11 @@
         # and force=False pass a value for updatecheck. We may want to allow
         # updatecheck='abort' to better suppport some of these callers.
         if updatecheck is None:
-            updatecheck = 'linear'
-        assert updatecheck in ('none', 'linear', 'noconflict')
+            updatecheck = UPDATECHECK_LINEAR
+        assert updatecheck in (UPDATECHECK_NONE,
+                               UPDATECHECK_LINEAR,
+                               UPDATECHECK_NO_CONFLICT,
+        )
     # If we're doing a partial update, we need to skip updating
     # the dirstate, so make a note of any partial-ness to the
     # update here.
@@ -2050,7 +2058,7 @@
                 repo.hook('update', parent1=xp2, parent2='', error=0)
                 return updateresult(0, 0, 0, 0)
 
-            if (updatecheck == 'linear' and
+            if (updatecheck == UPDATECHECK_LINEAR and
                     pas not in ([p1], [p2])):  # nonlinear
                 dirty = wc.dirty(missing=True)
                 if dirty:
@@ -2087,7 +2095,7 @@
             repo, wc, p2, pas, branchmerge, force, mergeancestor,
             followcopies, matcher=matcher, mergeforce=mergeforce)
 
-        if updatecheck == 'noconflict':
+        if updatecheck == UPDATECHECK_NO_CONFLICT:
             for f, (m, args, msg) in actionbyfile.iteritems():
                 if m not in (ACTION_GET, ACTION_KEEP, ACTION_EXEC,
                              ACTION_REMOVE, ACTION_PATH_CONFLICT_RESOLVE):
diff --git a/mercurial/hg.py b/mercurial/hg.py
--- a/mercurial/hg.py
+++ b/mercurial/hg.py
@@ -897,21 +897,26 @@
     :clean: whether changes in the working directory can be discarded
     :updatecheck: how to deal with a dirty working directory
 
-    Valid values for updatecheck are (None => linear):
+    Valid values for updatecheck are the UPDATECHECK_* constants
+    defined in the merge module. Passing `None` will result in using the
+    configured default.
 
-     * abort: abort if the working directory is dirty
-     * none: don't check (merge working directory changes into destination)
-     * linear: check that update is linear before merging working directory
+     * ABORT: abort if the working directory is dirty
+     * NONE: don't check (merge working directory changes into destination)
+     * LINEAR: check that update is linear before merging working directory
                changes into destination
-     * noconflict: check that the update does not result in file merges
+     * NO_CONFLICT: check that the update does not result in file merges
 
     This returns whether conflict is detected at updating or not.
     """
     if updatecheck is None:
         updatecheck = ui.config('commands', 'update.check')
-        if updatecheck not in ('abort', 'none', 'linear', 'noconflict'):
+        if updatecheck not in (mergemod.UPDATECHECK_ABORT,
+                               mergemod.UPDATECHECK_NONE,
+                               mergemod.UPDATECHECK_LINEAR,
+                               mergemod.UPDATECHECK_NO_CONFLICT):
             # If not configured, or invalid value configured
-            updatecheck = 'linear'
+            updatecheck = mergemod.UPDATECHECK_LINEAR
     with repo.wlock():
         movemarkfrom = None
         warndest = False
@@ -923,9 +928,9 @@
         if clean:
             ret = _clean(repo, checkout)
         else:
-            if updatecheck == 'abort':
+            if updatecheck == mergemod.UPDATECHECK_ABORT:
                 cmdutil.bailifchanged(repo, merge=False)
-                updatecheck = 'none'
+                updatecheck = mergemod.UPDATECHECK_NONE
             ret = _update(repo, checkout, updatecheck=updatecheck)
 
         if not ret and movemarkfrom:



To: durin42, #hg-reviewers
Cc: mercurial-devel