CODEWITHSUNDEEP
pythonmercurial
Industrial
Industrial

Reputation: 42798

How can I write a basic mercurial extension?

So, I would like to make a basic mercurial extension that appends a string to the commit message. Below shown code is placed in a file - myextension.py and included by .hgrc.

When I run hg commit -m "A message", the commit editor opens with the message "A message APPENDED" shown as expected. If I however try to abort the commit by pressing CTRL+X, the commit still occurs with the full, now appended message.

What am I doing wrong here?

from mercurial import commands, extensions

def commit(originalcommit, ui, repo, *pats, **opts):

    if not opts["message"]:
        return originalcommit(ui, repo, *pats, **opts)
    else:
        opts["force_editor"] = True
        opts["message"] += " APPENDED"
        return originalcommit(ui, repo, *pats, **opts)

def uisetup(ui):
    extensions.wrapcommand(commands.table, 'commit', commit)

Upvotes: 2

Views: 442

Answers (1)

gvalkov
gvalkov

Reputation: 4107

I think this is the correct behaviour, since the temporary file that mercurial passes to your editor already contains a commit message. You can override this to some extend by monkey-patching the cmdutil.commitforceeditor function:

from mercurial import commands, extensions, cmdutil, util

cfe = cmdutil.commitforceeditor

def commitforceeditor(repo, ctx, subs):
    text = cfe(repo, ctx, subs)

    # Do not commit unless the commit message differs from 
    # the one you specified on the command line
    if ctx.description() == text.strip():
        raise util.Abort("empty commit message")
    else:
        return text

def commit(originalcommit, ui, repo, *pats, **opts):
    if not opts["message"]:
        return originalcommit(ui, repo, *pats, **opts)
    else:
        opts["force_editor"] = True
        opts["message"] += " APPENDED"

        # monkey-patch
        cmdutil.commitforceeditor = commitforceeditor

        return originalcommit(ui, repo, *pats, **opts)

def uisetup(ui):
    extensions.wrapcommand(commands.table, 'commit', commit)

Upvotes: 1

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