add option to show diff before asking to overwrite

README.md

@@ -610,6 +610,7 @@ the following entries:
   * `keepdot`: preserve leading dot when importing hidden file in the `dotpath` (default *false*)
   * `link_by_default`: when importing a dotfile set `link` to that value per default (default *false*)
   * `workdir`: directory where templates are installed before being symlink when using `link` (default *~/.config/dotdrop*)
+  * `showdiff`: on install show a diff before asking to overwrite (see `--showdiff`) (default *false*)
 
 * **dotfiles** entry: a list of dotfiles
   * When `link` is true, dotdrop will create a symlink instead of copying (default *false*).

dotdrop/config.py

@@ -29,6 +29,7 @@ class Cfg:
     key_banner = 'banner'
     key_long = 'longkey'
     key_keepdot = 'keepdot'
+    key_showdiff = 'showdiff'
     key_deflink = 'link_by_default'
     key_workdir = 'workdir'
 
@@ -64,6 +65,7 @@ class Cfg:
     default_link = False
     default_longkey = False
     default_keepdot = False
+    default_showdiff = False
     default_link_by_default = False
     default_workdir = '~/.config/dotdrop'
 
@@ -315,6 +317,8 @@ class Cfg:
             self.lnk_settings[self.key_deflink] = self.default_link_by_default
         if self.key_workdir not in self.lnk_settings:
             self.lnk_settings[self.key_workdir] = self.default_workdir
+        if self.key_showdiff not in self.lnk_settings:
+            self.lnk_settings[self.key_showdiff] = self.default_showdiff
 
     def abs_dotpath(self, path):
         """transform path to an absolute path based on config path"""

dotdrop/dotdrop.py

@@ -42,26 +42,26 @@ USAGE = """
 {}
 
 Usage:
-  dotdrop install   [-tfndVb] [-c <path>] [-p <profile>] [<key>...]
-  dotdrop import    [-ldVb]   [-c <path>] [-p <profile>] <paths>...
-  dotdrop compare   [-Vb]     [-c <path>] [-p <profile>]
-                              [-o <opts>] [-i <name>...]
-                              [--files=<files>]
-  dotdrop update    [-fdVb]   [-c <path>] <paths>...
-  dotdrop listfiles [-VTb]    [-c <path>] [-p <profile>]
-  dotdrop list      [-Vb]     [-c <path>]
+  dotdrop install   [-tfndVbD] [-c <path>] [-p <profile>] [<key>...]
+  dotdrop import    [-ldVb]    [-c <path>] [-p <profile>] <paths>...
+  dotdrop compare   [-Vb]      [-c <path>] [-p <profile>]
+                               [-o <opts>] [-C <files>] [-i <name>...]
+  dotdrop update    [-fdVb]    [-c <path>] <paths>...
+  dotdrop listfiles [-VTb]     [-c <path>] [-p <profile>]
+  dotdrop list      [-Vb]      [-c <path>]
   dotdrop --help
   dotdrop --version
 
 Options:
   -p --profile=<profile>  Specify the profile to use [default: {}].
   -c --cfg=<path>         Path to the config [default: config.yaml].
-  --files=<files>         Comma separated list of files to compare.
+  -C --files=<files>      Comma separated list of files to compare.
   -i --ignore=<name>      File name to ignore when diffing.
   -o --dopts=<opts>       Diff options [default: ].
   -n --nodiff             Do not diff when installing.
   -t --temp               Install to a temporary directory for review.
   -T --template           Only template dotfiles.
+  -D --showdiff           Show a diff before overwriting.
   -l --link               Import and link.
   -f --force              Do not warn if exists.
   -V --verbose            Be verbose.
@@ -94,9 +94,10 @@ def install(opts, conf, temporary=False, keys=[]):
     if temporary:
         tmpdir = get_tmpdir()
     inst = Installer(create=opts['create'], backup=opts['backup'],
-                     dry=opts['dry'], safe=opts['safe'], base=opts['dotpath'],
-                     workdir=opts['workdir'], diff=opts['installdiff'],
-                     debug=opts['debug'], totemp=tmpdir)
+                     dry=opts['dry'], safe=opts['safe'],
+                     base=opts['dotpath'], workdir=opts['workdir'],
+                     diff=opts['installdiff'], debug=opts['debug'],
+                     totemp=tmpdir, showdiff=opts['showdiff'])
     installed = []
     for dotfile in dotfiles:
         preactions = []
@@ -361,6 +362,7 @@ def main():
     opts['link'] = args['--link']
     opts['debug'] = args['--verbose']
     opts['variables'] = conf.get_variables()
+    opts['showdiff'] = opts['showdiff'] or args['--showdiff']
 
     if opts['debug']:
         LOG.dbg('config file: {}'.format(args['--cfg']))

dotdrop/installer.py

@@ -20,7 +20,7 @@ class Installer:
 
     def __init__(self, base='.', create=True, backup=True,
                  dry=False, safe=False, workdir='~/.config/dotdrop',
-                 debug=False, diff=True, totemp=None):
+                 debug=False, diff=True, totemp=None, showdiff=False):
         self.create = create
         self.backup = backup
         self.dry = dry
@@ -30,6 +30,7 @@ class Installer:
         self.debug = debug
         self.diff = diff
         self.totemp = totemp
+        self.showdiff = showdiff
         self.comparing = False
         self.action_executed = False
         self.log = Logger()
@@ -125,7 +126,7 @@ class Installer:
             self.log.err('source dotfile does not exist: {}'.format(src))
             return []
         st = os.stat(src)
-        ret = self._write(dst, content, st.st_mode, actions=actions)
+        ret = self._write(src, dst, content, st.st_mode, actions=actions)
         if ret < 0:
             self.log.err('installing {} to {}'.format(src, dst))
             return []
@@ -164,7 +165,7 @@ class Installer:
             cur = f.read()
         return cur == content
 
-    def _write(self, dst, content, rights, actions=[]):
+    def _write(self, src, dst, content, rights, actions=[]):
         """write content to file
         return  0 for success,
                 1 when already exists
@@ -178,9 +179,17 @@ class Installer:
                 if self.debug:
                     self.log.dbg('{} is the same'.format(dst))
                 return 1
-            if self.safe and not self.log.ask('Overwrite \"{}\"'.format(dst)):
-                self.log.warn('ignoring {}, already present'.format(dst))
-                return 1
+            if self.safe:
+                if self.debug:
+                    self.log.dbg('change detected for {}'.format(dst))
+                if self.showdiff:
+                    comp = Comparator(debug=self.debug)
+                    diff = comp.compare(src, dst)
+                    self.log.log('diff \"{}\" VS \"{}\"'.format(src, dst))
+                    self.log.emph(diff)
+                if not self.log.ask('Overwrite \"{}\"'.format(dst)):
+                    self.log.warn('ignoring {}'.format(dst))
+                    return 1
         if self.backup and os.path.lexists(dst):
             self._backup(dst)
         base = os.path.dirname(dst)

tests/helpers.py

@@ -80,6 +80,7 @@ def load_config(confpath, profile):
     opts['safe'] = True
     opts['installdiff'] = True
     opts['link'] = False
+    opts['showdiff'] = True
     opts['debug'] = True
     opts['dopts'] = ''
     opts['variables'] = {}

tests/test_install.py

@@ -174,6 +174,7 @@ exec bspwm
         conf, opts = load_config(confpath, profile)
         opts['safe'] = False
         opts['debug'] = True
+        opts['showdiff'] = True
         opts['variables'] = {}
         install(opts, conf)