jsos-util

JSOS Utility belt with minimal 3rd party dependencies. This is mainly meant to be reused with JSOS, but because of no inter-dependencies, the utilities are largely reusable elsewhere.

Example

var util = require('jsos-util');

Members

• util.substitute(str, [dict])
• util.mapNested(source, fun)
• util.merge(source, ...sourceN)
• util.parseConfig(...path, [defaults])

util.substitute(str, [dict])

Substitute the values in the string based on the given dictionary. Based on https://github.com/npm/npmconf/blob/master/npmconf.js

Params

• str string - The string to substitute
• [dict={}] Object - dict The dictionary to use for substitution

Returns: string - The string after substitutions; str if str is not a string
Example

var value = substitute('${HOME}/.jsos/cache', process.env);
// 'home/lauri/.jsos/cache'
console.log(value);

util.mapNested(source, fun)

Walks through the whole object, including its nested properties in the same way as Array.forEach. Note that it does not function for objects having loops and will eventually fail in stack overflow.

Params

• source Object - The object to visit/walk through
• fun function - The function to execute

Returns: Object - A new Object with the same structure as source and fun executed for each member
Example

// baz says Hello
mapNested({ foo: { bar: { baz: 'Hello'}}], function(key, value) {
  console.log(key, 'says', value);
});

util.merge(source, ...sourceN)

Merge several objects into one, prioritising the values of former over the latter and recursing into subobjects.

Params

• source Object - Object The first object to merge
• ...sourceN Object - One or more objects to merge to the source

Returns: Object - The results of merging the objects
Example

var value = merge({ foo: { bar: { text2: 'World'}}, { foo: { bar: { text: 'Hello', text2: 'WTF' }})
// { foo: { bar: { text: 'Hello', text2: 'World' }}}
console.log(value);

util.parseConfig(...path, [defaults])

Parses one or many file configurations, supplemented by defaults. The defaults given in the end are optional.

Params

• ...path string - Zero or more configuration file paths to parse
• [defaults={}] Object - The configuration defaults

Returns: Object - All the configurations flattened into one object
Example

parseConfig('.jsos-initc', '/etc/jsos-initrc', { foo: 'bar' });
parseConfig('.jsos-initc', '/etc/jsos-initrc');