Rebar3 Proper Plugin

Run PropEr test suites.

By default, will look for all modules starting in prop_ in the test/ directories of a rebar3 project, and running all properties (functions of arity 0 with a prop_ prefix) in them.

Todo/Gotchas

• No automated tests yet since this repo runs tests for a living

Use

Add the plugin to your rebar config:

%% the plugin itself
{plugins, [rebar3_proper]}.
%% The PropEr dependency is still required to compile the test cases
{profiles,
    [{test, [
        {deps, [{proper, "1.1.1-beta"}]}
    ]}
]}.

Then just call your plugin directly in an existing application:

Usage: rebar3 proper [-d <dir>] [-m <module>] [-p <properties>]
                     [-n <numtests>] [-v <verbose>] [-c [<cover>]]
                     [--retry [<retry>]] [--regressions [<regressions>]]
                     [--store [<store>]] [--long_result <long_result>]
                     [--start_size <start_size>] [--max_size <max_size>]
                     [--max_shrinks <max_shrinks>]
                     [--noshrink <noshrink>]
                     [--constraint_tries <constraint_tries>]
                     [--spec_timeout <spec_timeout>]
                     [--any_to_integer <any_to_integer>]

  -d, --dir           directory where the property tests are located
                      (defaults to "test")
  -m, --module        name of one or more modules to test (comma-separated)
  -p, --prop          name of properties to test within a specified module
                      (comma-separated)
  -n, --numtests      number of tests to run when testing a given property
  -v, --verbose       each propertie tested shows its output or not
                      (defaults to true)
  -c, --cover         generate cover data [default: false]
  --retry             If failing test case counterexamples have been
                      stored, they are retried [default: false]
  --regressions       replays the test cases stored in the regression
                      file. [default: false]
  --store             stores the last counterexample into the regression
                      file. [default: false]
  --long_result       enables long-result mode, displaying
                      counter-examples on failure rather than just false
  --start_size        specifies the initial value of the size parameter
  --max_size          specifies the maximum value of the size parameter
  --max_shrinks       specifies the maximum number of times a failing test
                      case should be shrunk before returning
  --noshrink          instructs PropEr to not attempt to shrink any
                      failing test cases
  --constraint_tries  specifies the maximum number of tries before the
                      generator subsystem gives up on producing an
                      instance that satisfies a ?SUCHTHAT constraint
  --spec_timeout      duration, in milliseconds, after which PropEr
                      considers an input to be failing
  --any_to_integer    converts instances of the any() type to integers in
                      order to speed up execution

All of PropEr's standard configurations that can be put in a consult file can be put in {proper_opts, [Options]}. in your rebar.config file.

Workflow

A workflow to handle errors and do development is being experimented with:

1. Run any properties with rebar3 proper
2. On a test failure, replay the last failing cases with rebar3 proper --retry
3. Call rebar3 proper --store if the cases are interesting and you want to keep them for the future. The entries will be appended in a proper-regressions.consult file in your configured test directory. Check in that file or edit it as you wish.
4. Use rebar3 proper --regressions to prevent regressions from happening by testing your code against all stored counterexamples

Changelog

• 0.8.0: storage and replay of counterexamples
• 0.7.2: rely on a non-beta PropEr version
• 0.7.1: fix bug regarding lib and priv directories in code path
• 0.7.0: fix bug with include paths of hrl files from parent apps, support counterexamples with --retry
• 0.6.3: fix bug with cover-compiling in rebar 3.2.0 and above again
• 0.6.2: fix bug with cover-compiling in rebar 3.2.0 and above
• 0.6.1: fix bug on option parsing in config files
• 0.5.0: switches to package dependencies
• 0.4.0: switches license to BSD with templates
• 0.3.0: code coverage supported
• 0.2.0: basic functionality
• 0.1.0: first commits