fswatch: move-to <=> change (close #1171).

lua/luasnip/loaders/fs_watchers.lua

@@ -185,9 +185,21 @@ function TreeWatcher:fs_event_callback(err, relpath, events)
 			end
 
 			if f_type == "file" then
-				self:new_file(relpath, full_path)
+				if self.files[relpath] then
+					-- rename and file exists => a new file was moved into its
+					-- place => handle as changed file.
+					self:change_file(relpath, full_path)
+				else
+					self:new_file(relpath, full_path)
+				end
 				return
 			elseif f_type == "directory" then
+				if self.dir_watchers[relpath] then
+					-- rename and directory exists => directory is overwritten
+					-- => stop recursively, clear, and start a new watcher.
+					self.dir_watchers[relpath]:stop()
+					self.dir_watchers[relpath] = nil
+				end
 				self:new_dir(relpath, full_path)
 				return
 			end

tests/helpers.lua

@@ -374,6 +374,13 @@ end
 function M.scratch_mkdir(scratch_rel)
 	os.execute(('mkdir -p "%s/%s"'):format(scratchdir_path, scratch_rel))
 end
+function M.scratch_mv(scratch_from, scratch_to)
+	os.execute(('mv "%s/%s" "%s/%s"'):format(scratchdir_path, scratch_from, scratchdir_path, scratch_to))
+end
+-- mv -T
+function M.scratch_mv_T(scratch_from, scratch_to)
+	os.execute(('mv -T "%s/%s" "%s/%s"'):format(scratchdir_path, scratch_from, scratchdir_path, scratch_to))
+end
 function M.scratch_touch(scratch_rel)
 	os.execute(('touch "%s/%s"'):format(scratchdir_path, scratch_rel))
 end

tests/unit/fswatcher_spec.lua

@@ -3,6 +3,8 @@ local exec_lua = ls_helpers.exec_lua
 local mkdir = ls_helpers.scratch_mkdir
 local touch = ls_helpers.scratch_touch
 local edit = ls_helpers.scratch_edit
+local mv = ls_helpers.scratch_mv
+local mv_T = ls_helpers.scratch_mv_T
 
 describe("fs_events", function()
 	before_each(function()
@@ -205,6 +207,65 @@ describe("fs_events", function()
 		}, exec_lua([[return {seen_files, seen_dirs, changed}]]))
 	end)
 
+	it("libuv triggers change on overwriting existing entry.", function()
+		mkdir("a")
+		touch("a/a")
+		touch("a/b")
+		mkdir("a/c")
+		touch("a/c/e")
+		mkdir("a/d")
+
+		exec_lua([[
+			changed = {
+				["a/a"] = 0,
+				["a/b"] = 0,
+				["a/c/e"] = 0,
+				["a/d/e"] = 0,
+			}
+			seen = {
+				["a/a"] = 0,
+				["a/b"] = 0,
+				["a/c/e"] = 0,
+				["a/d/e"] = 0,
+			}
+
+			ls.log.set_loglevel("debug")
+			watcher = scratch_tree_watcher("a", 3, {
+				change_file = function(path)
+					changed[path] = changed[path] + 1
+				end,
+				new_file = function(path)
+					seen[path] = seen[path] + 1
+				end
+			}, {lazy=false, fs_event_providers = {libuv = true} } )
+			ls.log.set_loglevel("warn")
+		]])
+
+		-- make sure a/b is marked as changed.
+		mv("a/a", "a/b")
+		-- make sure a/d/e is seen.
+		mv_T("a/c", "a/d")
+
+		assert.are.same({
+			{
+				["a/b"] = 1,
+				-- we don't handle file-removal, it's currently out of scope
+				-- for the loaders to remove snippets when the file is removed,
+				-- so we don't have to handle it here.
+				["a/a"] = 0,
+				-- both are only created, not changed.
+				["a/c/e"] = 0,
+				["a/d/e"] = 0,
+			},
+			{
+				["a/a"] = 1,
+				["a/b"] = 1,
+				["a/c/e"] = 1,
+				["a/d/e"] = 1
+			}
+		}, exec_lua([[return {changed, seen}]]))
+	end)
+
 	it("lazy registration works with libuv.", function()
 		mkdir("a")