This project is part of the @thi.ng/umbrella monorepo.
Types & basis infrastructure for arbitrary logging (w/ default impls).
The types & implementations provided by this package are used in various places throughout the thi.ng/umbrella ecosystem and can be swapped out on demand to customize users' needs.
All loggers based on this basic framework provided by this package support the
following LogLevels
(in order of importance):
FINEDEBUGINFOWARNSEVERE
Logging calls targetting lower levels than configured in the logger will be ignored.
The following logger implementations are provided:
ConsoleLogger: writes output toconsoleMemoryLogger: writes output to in-memory journalNULL_LOGGER: no-op logger, suppresses all output
Log messages can contain any number & types of arguments. No-arg functions can be provided as message arg to avoid evaluation of potentially costly message formatting for suppressed log levels. For example:
import { ConsoleLogger, LogLevel } from "@thi.ng/logger";
const logger = new ConsoleLogger("app", LogLevel.INFO);
const name = "thi.ng";
// eager (standard) arg evaluation
logger.info(`hello, ${name}`);
// [INFO] app: hello, thi.ng
// eager (standard) arg evaluation, but suppressed output
logger.debug("result is", 23 + 42);
// lazy arg evaluation
logger.info("result is", () => 23 + 42);
// [INFO] app: result is 65STABLE - used in production
Search or submit any issues for this package
- @thi.ng/rstream-log - Structured, multilevel & hierarchical loggers based on @thi.ng/rstream
yarn add @thi.ng/loggerES module import:
<script type="module" src="https://cdn.skypack.dev/@thi.ng/logger"></script>For Node.js REPL:
const logger = await import("@thi.ng/logger");Package sizes (brotli'd, pre-treeshake): ESM: 476 bytes
None
TODO
If this project contributes to an academic publication, please cite it as:
@misc{thing-logger,
title = "@thi.ng/logger",
author = "Karsten Schmidt",
note = "https://thi.ng/logger",
year = 2016
}© 2016 - 2023 Karsten Schmidt // Apache License 2.0