plugins(chore): fix static check errors

plugins/calibrecompanion.koplugin/main.lua

@@ -1,12 +1,11 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
 local InfoMessage = require("ui/widget/infomessage")
 local UIManager = require("ui/uimanager")
-local util = require("ffi/util")
 local JSON = require("json")
 local DEBUG = require("dbg")
 local _ = require("gettext")
 
-local dummy = require("ffi/zeromq_h")
+require("ffi/zeromq_h")
 
 --[[
     This plugin implements a simple Calibre Companion protocol that communicates
@@ -66,14 +65,14 @@ function CalibreCompanion:find_calibre_server()
     udp:settimeout(3)
     for _, port in ipairs(self.broadcast_ports) do
         -- broadcast anything to calibre ports and listen to the reply
-        local sent, err = udp:sendto("hello", "255.255.255.255", port)
+        local _, err = udp:sendto("hello", "255.255.255.255", port)
         if not err then
             local dgram, host = udp:receivefrom()
             if dgram and host then
                 -- replied diagram has greet message from calibre and calibre hostname
                 -- calibre opds port and calibre socket port we will later connect to
-                local _, hostname, _, port = dgram:match("(.-)%(on (.-)%);(.-),(.-)$")
-                return host, port
+                local _, _, _, replied_port = dgram:match("(.-)%(on (.-)%);(.-),(.-)$")
+                return host, replied_port
             end
         end
     end
@@ -123,7 +122,6 @@ end
 
 -- will callback initCalibreMQ if inbox is confirmed to be set
 function CalibreCompanion:setInboxDir(host, port)
-    local lastdir = G_reader_settings:readSetting("lastdir") or "."
     local calibre_device = self
     require("ui/downloadmgr"):new{
         title = _("Choose inbox"),
@@ -173,7 +171,7 @@ function CalibreCompanion:onReceiveJSON(data)
         --DEBUG("buffer", self.buffer)
         local index = self.buffer:find('%[') or 1
         local size = tonumber(self.buffer:sub(1, index - 1))
-        local json_data = nil
+        local json_data
         if size and #self.buffer >= index - 1 + size then
             json_data = self.buffer:sub(index, index - 1 + size)
             --DEBUG("json_data", json_data)
@@ -295,7 +293,6 @@ end
 
 function CalibreCompanion:getBookCount(arg)
     DEBUG("GET_BOOK_COUNT", arg)
-    local option = arg
     local books = {
         willStream = true,
         willScan = true,
@@ -340,8 +337,8 @@ function CalibreCompanion:sendBook(arg)
                 timeout = 1,
             })
             -- switch to JSON data receiving mode
-            calibre_socket.receiveCallback = function(data)
-                calibre_device:onReceiveJSON(data)
+            calibre_socket.receiveCallback = function(json_data)
+                calibre_device:onReceiveJSON(json_data)
             end
             -- if calibre sends multiple files there may be left JSON data
             calibre_device.buffer = data:sub(#to_write_data + 1) or ""

plugins/evernote.koplugin/clip.lua

@@ -1,8 +1,6 @@
 local DocumentRegistry = require("document/documentregistry")
 local DocSettings = require("docsettings")
-local DEBUG = require("dbg")
 local md5 = require("ffi/MD5")
--- lfs
 
 local MyClipping = {
     my_clippings = "/mnt/us/documents/My Clippings.txt",
@@ -10,7 +8,7 @@ local MyClipping = {
 }
 
 function MyClipping:new(o)
-    o = o or {}
+    if o == nil then o = {} end
     setmetatable(o, self)
     self.__index = self
     return o
@@ -48,7 +46,6 @@ function MyClipping:parseMyClippings()
     local clippings = {}
     if file then
         local index = 1
-        local corrupted = false
         local title, author, info, text
         for line in file:lines() do
             line = line:match("^%s*(.-)%s*$") or ""
@@ -264,10 +261,10 @@ function MyClipping:parseHistory()
             if ok and stored.highlight then
                 local _, _, docname = path:find("%[.*%](.*)%.lua$")
                 local title, author = self:getTitle(docname)
-                local path = DocSettings:getPathFromHistory(f)
+                local docpath = DocSettings:getPathFromHistory(f)
                 local name = DocSettings:getNameFromHistory(f)
                 clippings[title] = {
-                    file = path .. "/" .. name,
+                    file = docpath .. "/" .. name,
                     title = title,
                     author = author,
                 }

plugins/evernote.koplugin/main.lua

@@ -6,7 +6,6 @@ local DataStorage = require("datastorage")
 local DocSettings = require("docsettings")
 local UIManager = require("ui/uimanager")
 local Screen = require("device").screen
-local Event = require("ui/event")
 local util = require("ffi/util")
 local Device = require("device")
 local DEBUG = require("dbg")
@@ -23,8 +22,8 @@ local EvernoteExporter = InputContainer:new{
     notemarks = _("Note: "),
     clipping_dir = DataStorage:getDataDir() .. "/clipboard",
 
-    evernote_token,
-    notebook_guid,
+    evernote_token = nil,
+    notebook_guid = nil,
 }
 
 function EvernoteExporter:init()
@@ -61,7 +60,7 @@ function EvernoteExporter:addToMainMenu(tab_item_table)
         sub_item_table = {
             {
                 text_func = function()
-                    local domain = nil
+                    local domain
                     if self.evernote_domain == "sandbox" then
                         domain = "Sandbox"
                     elseif self.evernote_domain == "yinxiang" then
@@ -212,7 +211,8 @@ function EvernoteExporter:doLogin(username, password)
         domain = self.evernote_domain,
         authToken = token,
     }
-    local ok, guid = pcall(self.getExportNotebook, self, client)
+    local guid
+    ok, guid = pcall(self.getExportNotebook, self, client)
     if not ok and guid and guid:find("Transport not open") then
         NetworkMgr:promptWifiOn()
         return

plugins/evernote.koplugin/slt2.lua

@@ -19,7 +19,7 @@ local function include_fold(template, start_tag, end_tag, fold_func, init_func)
     local start_tag_inc = start_tag..'include:'
 
     local start1, end1 = string.find(template, start_tag_inc, 1, true)
-    local start2 = nil
+    local start2
     local end2 = 0
 
     while start1 ~= nil do
@@ -101,7 +101,7 @@ function slt2.loadstring(template, start_tag, end_tag, tmpl_name)
     template = slt2.precompile(template, start_tag, end_tag)
 
     local start1, end1 = string.find(template, start_tag, 1, true)
-    local start2 = nil
+    local start2
     local end2 = 0
 
     local cEqual = string.byte('=', 1)

plugins/kosync.koplugin/KOSyncClient.lua

@@ -7,7 +7,7 @@ local KOSyncClient = {
 }
 
 function KOSyncClient:new(o)
-    local o = o or {}
+    if o == nil then o = {} end
     setmetatable(o, self)
     self.__index = self
     if o.init then o:init() end
@@ -21,7 +21,7 @@ function KOSyncClient:init()
         base_url = self.custom_url,
     })
     package.loaded['Spore.Middleware.GinClient'] = {}
-    require('Spore.Middleware.GinClient').call = function(self, req)
+    require('Spore.Middleware.GinClient').call = function(_, req)
         req.headers['accept'] = "application/vnd.koreader.v1+json"
     end
     package.loaded['Spore.Middleware.KOSyncAuth'] = {}

plugins/statistics.koplugin/main.lua

@@ -1,10 +1,8 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
 local MultiInputDialog = require("ui/widget/multiinputdialog")
-local CenterContainer = require("ui/widget/container/centercontainer")
 local KeyValuePage = require("ui/widget/keyvaluepage")
 local UIManager = require("ui/uimanager")
 local Screen = require("device").screen
-local Font = require("ui/font")
 local TimeVal = require("ui/timeval")
 local DataStorage = require("datastorage")
 local lfs = require("libs/libkoreader-lfs")
@@ -286,7 +284,7 @@ function ReaderStatistics:getCurrentStat()
     }
 end
 
-function generateReadBooksTable(title, dates)
+local function generateReadBooksTable(title, dates)
     local result = {}
     for k, v in tableutil.spairs(dates, function(t, a, b) return t[b].date < t[a].date end) do
         table.insert(result, {
@@ -298,7 +296,7 @@ function generateReadBooksTable(title, dates)
 end
 
 -- For backward compatibility
-function getDatesForBookOldFormat(book)
+local function getDatesForBookOldFormat(book)
     local dates = {}
 
     for k, v in pairs(book.details) do
@@ -330,7 +328,6 @@ function ReaderStatistics:getDatesFromAll(sdays, ptype)
     local dates = {}
     local sorted_performance_in_pages
     local diff
-    local book = {}
     local now_t = os.date("*t")
     local from_begin_day = now_t.hour *3600 + now_t.min*60 + now_t.sec
     local now_stamp = os.time()
@@ -399,7 +396,7 @@ function ReaderStatistics:getDatesFromAll(sdays, ptype)
     return generateReadBooksTable("", dates)
 end
 
-function getDatesForBook(book)
+local function getDatesForBook(book)
     local dates = {}
     local sorted_performance_in_pages = {}
     local diff

plugins/zsync.koplugin/main.lua

@@ -1,20 +1,9 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
-local FrameContainer = require("ui/widget/container/framecontainer")
-local VerticalGroup = require("ui/widget/verticalgroup")
-local VerticalSpan = require("ui/widget/verticalspan")
-local ButtonDialog = require("ui/widget/buttondialog")
 local InfoMessage = require("ui/widget/infomessage")
-local TextWidget = require("ui/widget/textwidget")
-local DocSettings = require("docsettings")
 local UIManager = require("ui/uimanager")
-local Screen = require("device").screen
-local Event = require("ui/event")
-local Font = require("ui/font")
 local ltn12 = require("ltn12")
 local DEBUG = require("dbg")
 local _ = require("gettext")
-local util = require("ffi/util")
--- lfs
 
 local ffi = require("ffi")
 ffi.cdef[[
@@ -22,7 +11,7 @@ int remove(const char *);
 int rmdir(const char *);
 ]]
 
-local dummy = require("ffi/zeromq_h")
+require("ffi/zeromq_h")
 local ZSync = InputContainer:new{
     name = "zsync",
 }

reader.lua

@@ -72,7 +72,6 @@ local function showusage()
     print("")
     print("This software is licensed under the AGPLv3.")
     print("See http://github.com/koreader/koreader for more info.")
-    return
 end
 
 -- should check DEBUG option in arg and turn on DEBUG before loading other