Stack filter

Version:
See buster-test
Module:
require("buster-test").stackFilter;
In browsers:
buster.stackFilter;

Stack traces contain some interesting information and (often) lots of noise. The stack filter helps reduce the noise to help you find errors faster. It can do so by:

  1. stripping the current working directory from paths, and
  2. removing lines from inside buster (or other libraries not of your interest).

Methods

stackFilter()
var lines = buster.stackFilter(stack[, cwd]);

Trims a stack trace by removing lines that match stackFilter.filters. stack is a string containing the entire stack trace. The optional cwd argument is a string containing the current working directory. When provided, it is stripped from all lines in the resulting stack trace.

The function returns an array of stack trace lines. Given the following stack trace:

var stack = 'AssertionError: [assert.equals] Expected "Something" to be equal to "Other"' +
  'at Function.fail (/home/christian/buster/node_modules/buster-assert/lib/buster-assert.js:147:25)' +
  'at fail (/home/christian/buster/node_modules/buster-assert/lib/buster-assert.js:61:16)' +
  'at Function.equals (/home/christian/buster/node_modules/buster-assert/lib/buster-assert.js:237:13)' +
  'at Object.<anonymous> (/home/christian/buster/doc/samples/test-case.js:101:23)' +
  'at asyncFunction (/home/christian/buster/node_modules/buster-test/lib/buster-test/runner.js:79:21)' +
  'at Object.runTestFunction (/home/christian/buster/node_modules/buster-test/lib/buster-test/runner.js:312:26)' +
  'at /home/christian/buster/node_modules/buster-core/lib/buster-core.js:45:31' +
  'at EventEmitter._tickCallback (node.js:108:26)';

stackFilter() would reduce it like so:

var lines = buster.stackFilter(stack, "/home/christian/buster");
// lines:
// ['AssertionError: [assert.equals] Expected "Something" to be equal to "Other"',
//  'at Object.<anonymous> (doc/samples/test-case.js:101:23)',
//  'at runOne (node_modules/buster-promise/lib/buster-promise.js:89:35',
//  'at Array.0 (node_modules/buster-promise/lib/buster-promise.js:75:47']
stackFilter.match()
var isMatch = buster.stackFilter.match(line);

Helper function used by stackFilter(). Returns true if line matches any of stackFilter.filters.

Properties

stackFilter.filters

The stackFilter.filters property is an array of strings to match against lines in a stack trace. Any stack trace line that match one of these filters will be stripped. The default value is an array of core buster modules. If you are developing add-ons to Buster, and don’t want long traces from inside these libraries in test reports, add entries to this array.

The buster-sinon module adds the core Sinon.JS libraries to the array to avoid them getting in the way of finding where in your test and implementation a failure originated. (Note that the added entry filters out lines from both Sinon.JS and the buster-sinon adapter.)

buster.stackFilter.filters.push("lib/sinon");

If you want the full traces, you can simply wipe the filters array in your tests:

delete buster.stackFilter.filters;

Table Of Contents

Related Topics

This Page