subst.js

Synopsis:

var subst = require('subst');
var newValue = subst(value, data);

Replaces placeholders in strings:

subst("cp $(src) $(dst)", { '$(src)': 'file1', '$(dst)': 'file2'});
// returns: "cp file1 file2"

and arrays:

subst(["perl", "-i$(ext)", "$(args)", "script.pl"], { '$(ext)': '.bak', '$(args)': ['-p', '-w'] });
// returns: ["perl", "-i.bak", "-p", "-w", "script.pl"]

and objects:

subst({cmd: "ls", "dir": "$(project)/lib"}, { '$(project)': '~/woot' })
// returns: {cmd: "ls", dir: "~/woot/lib"}

To avoid prefixing and suffixing the keys, use .wrap:

var subst = require('subst').wrap("$(", ")");
subst("cp $(src) $(dst)", { src: 'file1', dst: 'file2'});
// returns: "cp file1 file2"

Installation

npm install subst

Running tests

npm install               # just once
npm test                  # see package.json for the test command
REPORTER=dot npm test     # override the reporter

Spec

subst
  ✓ should substitute placeholders in string values
  ✓ should support keys with funny characters like $([{hello}])
  ✓ should substitute placeholders in array items
  ✓ should splice substituted array items into the value array
  ✓ should recurse into nested array items
  ✓ should substitute placeholders in object keys
  ✓ should substitute placeholders in object values
  ✓ should recurse into nested objects
  ✓ should pass through null values
  ✓ should pass through undefined values
  ✓ should pass through numeric values
  ✓ should pass through Date values
  ✓ should pass through custom objects
  .wrap('{', '}')
    ✓ should substitute placeholder '{foo}' with the value of key 'foo'

License

© 2012, Andrey Tarantsov. Distributed under the MIT license.