From 79c9c0747e876c0b97a4fb3fe91fa9825e462722 Mon Sep 17 00:00:00 2001
From: Anton Khirnov <anton@khirnov.net>
Date: Sun, 15 Nov 2020 16:25:57 +0100
Subject: Add a dry run mode.

---
 dotbot/plugins/link.py | 50 +++++++++++++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 21 deletions(-)

(limited to 'dotbot/plugins/link.py')

diff --git a/dotbot/plugins/link.py b/dotbot/plugins/link.py
index 411a0ef..5e2bd90 100644
--- a/dotbot/plugins/link.py
+++ b/dotbot/plugins/link.py
@@ -11,7 +11,7 @@ class Link(dotbot.Plugin):
 
     _directive = 'link'
 
-    def handle(self, directive, links):
+    def handle(self, directive, links, dry_run):
         success = True
         defaults = self._context.defaults().get('link', {})
         for destination, source in links.items():
@@ -47,12 +47,20 @@ class Link(dotbot.Plugin):
                     (destination, path))
                 continue
             if force or relink:
-                success &= self._delete(path, destination, relative, canonical_path, force)
-            success &= self._link(path, destination, relative, canonical_path, ignore_missing)
-        if success:
-            self._log.verbose('All links have been set up')
+                success &= self._delete(path, destination, relative, canonical_path, force, dry_run)
+            success &= self._link(path, destination, relative, canonical_path, ignore_missing, dry_run)
+
+        if dry_run:
+            if success:
+                self._log.verbose('link/dry run: nothing to do')
+            else:
+                self._log.verbose('link/dry run: some targets are missing')
         else:
-            self._log.error('Some links were not successfully set up')
+            if success:
+                self._log.verbose('All links have been set up')
+            else:
+                self._log.error('Some links were not successfully set up')
+
         return success
 
     def _test_success(self, command):
@@ -91,7 +99,7 @@ class Link(dotbot.Plugin):
         path = os.path.expanduser(path)
         return os.path.exists(path)
 
-    def _delete(self, source, path, relative, canonical_path, force):
+    def _delete(self, source, path, relative, canonical_path, force, dry_run):
         success = True
         source = os.path.join(self._context.base_directory(canonical_path=canonical_path), source)
         fullpath = os.path.expanduser(path)
@@ -99,7 +107,11 @@ class Link(dotbot.Plugin):
             source = self._relative_path(source, fullpath)
         if ((self._is_link(path) and self._link_destination(path) != source) or
                 (self._exists(path) and not self._is_link(path))):
-            removed = False
+            self._log.info('Removing %s' % path)
+
+            if dry_run:
+                return False
+
             try:
                 if os.path.islink(fullpath):
                     os.unlink(fullpath)
@@ -107,16 +119,12 @@ class Link(dotbot.Plugin):
                 elif force:
                     if os.path.isdir(fullpath):
                         shutil.rmtree(fullpath)
-                        removed = True
                     else:
                         os.remove(fullpath)
-                        removed = True
             except OSError:
                 self._log.warning('Failed to remove %s' % path)
                 success = False
-            else:
-                if removed:
-                    self._log.info('Removing %s' % path)
+
         return success
 
     def _relative_path(self, source, destination):
@@ -127,7 +135,7 @@ class Link(dotbot.Plugin):
         destination_dir = os.path.dirname(destination)
         return os.path.relpath(source, destination_dir)
 
-    def _link(self, source, link_name, relative, canonical_path, ignore_missing):
+    def _link(self, source, link_name, relative, canonical_path, ignore_missing, dry_run):
         '''
         Links link_name to source.
 
@@ -149,13 +157,13 @@ class Link(dotbot.Plugin):
         # directory, and if source is relative, it will be relative to the
         # destination directory
         elif not self._exists(link_name) and (ignore_missing or self._exists(absolute_source)):
-            try:
-                os.symlink(source, destination)
-            except OSError:
-                self._log.warning('Linking failed %s -> %s' % (link_name, source))
-            else:
-                self._log.verbose('Creating link %s -> %s' % (link_name, source))
-                success = True
+            self._log.verbose('Creating link %s -> %s' % (link_name, source))
+            if not dry_run:
+                try:
+                    os.symlink(source, destination)
+                    success = True
+                except OSError:
+                    self._log.warning('Linking failed %s -> %s' % (link_name, source))
         elif self._exists(link_name) and not self._is_link(link_name):
             self._log.warning(
                 '%s already exists but is a regular file or directory' %
-- 
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