Define and test the rotating file sink

Author: Tastyep

lua/structlog/sinks/console.lua

@@ -16,6 +16,7 @@ setmetatable(Console, {
 -- @param opts Optional parameters
 -- @param opts.async Make the logger async, default: True
 -- @param opts.processors The list of processors to chain the log entries in
+-- @param opts.formatter The formatter to format the log entries
 function Console:new(opts)
   opts = opts or {}
 

lua/structlog/sinks/file.lua

@@ -15,6 +15,7 @@ setmetatable(File, {
 -- @param path The path to the logging file
 -- @param opts Optional parameters
 -- @param opts.processors The list of processors to chain the log entries in
+-- @param opts.formatter The formatter to format the log entries
 function File:new(path, opts)
   opts = opts or {}
 

lua/structlog/sinks/init.lua

@@ -8,9 +8,11 @@
 -- @table M
 -- @field Console The class to write to nvim console.
 -- @field File The class to write to a file.
+-- @field RotatingFile The class to write to a rotating file.
 local M = {
   Console = require("structlog.sinks.console"),
   File = require("structlog.sinks.file"),
+  RotatingFile = require("structlog.sinks.rotating_file"),
 }
 
 return M

lua/structlog/sinks/rotating_file.lua

@@ -0,0 +1,65 @@
+--- Write log entries to a rotating file.
+
+--- The Rotating File sink class.
+-- @type RotatingFile
+local RotatingFile = {}
+local File = require("structlog.sinks.file")
+
+setmetatable(RotatingFile, {
+  __call = function(cls, ...)
+    return cls:new(...)
+  end,
+})
+
+--- Create a new rotating file writer.
+-- @param path The path to the logging file
+-- @param opts Optional parameters
+-- @param opts.processors The list of processors to chain the log entries in
+-- @param opts.formatter The formatter to format the log entries
+-- @param opts.max_size Maximum size of the file in bytes
+-- @param opts.max_age Maximum age of the file is seconds
+-- @param opts.time_format The time format used for renaming the log, default: "%F-%H:%M:%S"
+function RotatingFile:new(path, opts)
+  opts = opts or {}
+
+  local file = {}
+
+  file.sink = File(path, opts)
+  file.path = path
+  file.max_size = opts.max_size
+  file.max_age = opts.max_age
+  file.time_format = opts.time_format or "%F-%H:%M:%S"
+
+  file.uv = opts.uv or vim.loop
+
+  RotatingFile.__index = RotatingFile
+  setmetatable(file, self)
+
+  return file
+end
+
+function RotatingFile:write(message)
+  local stat = self.uv.fs_stat(self.path)
+  if stat then
+    local cu_time = os.time()
+    if
+      (self.max_size and stat.size >= self.max_size)
+      or (self.max_age and cu_time >= stat.birthtime.sec + self.max_age)
+    then
+      cu_time = os.date(self.time_format, cu_time)
+
+      local parts = { self.path:match("(.*)%.(.*)$") }
+      local archive_file
+      if #parts == 2 then
+        archive_file = string.format("%s-%s.%s", parts[1], cu_time, parts[2])
+      else
+        archive_file = string.format("%s-%s", self.path, cu_time)
+      end
+      self.uv.fs_rename(self.path, archive_file)
+    end
+  end
+
+  self.sink:write(message)
+end
+
+return RotatingFile

test/unit/sinks/rotating_file_spec.lua

@@ -0,0 +1,103 @@
+local log = require("structlog")
+local RotatingFile = log.sinks.RotatingFile
+
+local stub = require("luassert.stub")
+local match = require("luassert.match")
+
+describe("RotatingFile", function()
+  local fp = {}
+  stub(fp, "write")
+  stub(fp, "close")
+
+  local iolib = {
+    open = function()
+      return fp
+    end,
+  }
+
+  local stat = {
+    atime = {
+      nsec = 862184517,
+      sec = 1629806034,
+    },
+    birthtime = {
+      nsec = 862184517,
+      sec = 1629806034,
+    },
+    blksize = 4096,
+    blocks = 8,
+    ctime = {
+      nsec = 862184517,
+      sec = 1629806034,
+    },
+    dev = 2049,
+    flags = 0,
+    gen = 0,
+    gid = 1000,
+    ino = 11698217,
+    mode = 33188,
+    mtime = {
+      nsec = 862184517,
+      sec = 1629806034,
+    },
+    nlink = 1,
+    rdev = 0,
+    size = 5,
+    type = "file",
+    uid = 1000,
+  }
+
+  local uv = {
+    fs_stat = function(_)
+      return stat
+    end,
+  }
+  stub(uv, "fs_rename")
+
+  local file_path = "./path.log"
+
+  it("should use the io lib to write to the file sink", function()
+    local file = RotatingFile(file_path, { iolib = iolib })
+    file:write("test")
+
+    assert.stub(fp.write).was_called_with(match.is_ref(fp), "test")
+    assert.stub(fp.write).was_called_with(match.is_ref(fp), "\n")
+    assert.stub(fp.close).called()
+  end)
+  it("should not rotate the file if stat returns nil", function()
+    local uv_cpy = {
+      fs_stat = function(_)
+        return nil
+      end,
+    }
+    stub(uv_cpy, "fs_rename")
+    local file = RotatingFile(file_path, { max_size = 0, iolib = iolib, uv = uv_cpy })
+    file:write("test")
+
+    assert.stub(uv_cpy.fs_rename).was_not_called()
+  end)
+  it("should not rotate the file if max_size is not exceeded", function()
+    local file = RotatingFile(file_path, { max_size = math.huge, iolib = iolib, uv = uv })
+    file:write("test")
+
+    assert.stub(uv.fs_rename).was_not_called()
+  end)
+  it("should not rotate the file if max_age is not exceeded", function()
+    local file = RotatingFile(file_path, { max_age = math.huge, iolib = iolib, uv = uv })
+    file:write("test")
+
+    assert.stub(uv.fs_rename).was_not_called()
+  end)
+  it("should rotate the file if max_size is exceeded", function()
+    local file = RotatingFile(file_path, { max_size = 0, iolib = iolib, uv = uv })
+    file:write("test")
+
+    assert.stub(uv.fs_rename).was_called()
+  end)
+  it("should rotate the file if max_age is exceeded", function()
+    local file = RotatingFile(file_path, { max_age = 0, iolib = iolib, uv = uv })
+    file:write("test")
+
+    assert.stub(uv.fs_rename).was_called()
+  end)
+end)