From 1742d0c3c10fb9df5b7181bf537270aabad39426 Mon Sep 17 00:00:00 2001 From: Stephen Buchanan Date: Tue, 16 Jan 2018 11:16:23 +0100 Subject: [PATCH] clear example of usage and notice about file extensions, in README --- README.md | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 77 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index 65a5f06..d73e45e 100644 --- a/README.md +++ b/README.md @@ -59,7 +59,7 @@ so that sources **earlier** in this list override later ones. ## Configuration File Formats -Configuration files (e.g. `.appnamerc`) may be in either [json](http://json.org/example) or [ini](http://en.wikipedia.org/wiki/INI_file) format. The example configurations below are equivalent: +Configuration files (e.g. `.appnamerc`) may be in either [json](http://json.org/example) or [ini](http://en.wikipedia.org/wiki/INI_file) format. **No** file extension (`.json` or `.ini`) should be used. The example configurations below are equivalent: #### Formatted as `ini` @@ -115,6 +115,82 @@ Comments are stripped from JSON config via [strip-json-comments](https://github. > Since ini, and env variables do not have a standard for types, your application needs be prepared for strings. +## Simple example demonstrating precedence +Assume you have an application like this (notice the hard-coded defaults passed to rc): +``` +const conf = require('rc')('myapp', { + port: 12345, + mode: 'test' +}); + +console.log(JSON.stringify(conf, null, 2)); +``` +You also have a file `config.json`, with these contents: +``` +{ + "port": 9000, + "foo": "from config json", + "something": "else" +} +``` +And a file `.myapprc` in the same folder, with these contents: +``` +{ + "port": "3001", + "foo": "bar" +} +``` +Here is the expected output from various commands: + +`node .` +``` +{ + "port": "3001", + "mode": "test", + "foo": "bar", + "_": [], + "configs": [ + "/Users/stephen/repos/conftest/.myapprc" + ], + "config": "/Users/stephen/repos/conftest/.myapprc" +} +``` +*Default `mode` from hard-coded object is retained, but port is overridden by `.myapprc` file (automatically found based on appname match), and `foo` is added.* + + +`node . --foo baz` +``` +{ + "port": "3001", + "mode": "test", + "foo": "baz", + "_": [], + "configs": [ + "/Users/stephen/repos/conftest/.myapprc" + ], + "config": "/Users/stephen/repos/conftest/.myapprc" +} +``` +*Same result as above but `foo` is overridden because command-line arguments take precedence over `.myapprc` file.* + +`node . --foo barbar --config config.json` +``` +{ + "port": 9000, + "mode": "test", + "foo": "barbar", + "something": "else", + "_": [], + "config": "config.json", + "configs": [ + "/Users/stephen/repos/conftest/.myapprc", + "config.json" + ] +} +``` +*Now the `port` comes from the `config.json` file specified (overriding the value from `.myapprc`), and `foo` value is overriden by command-line despite also being specified in the `config.json` file.* + + ## Advanced Usage