Options
August 30, 2021 ยท View on GitHub
Options
Contents
- Introduction
- Fluent Interface
- Reporters
- Scrubbers
- File Options
- Defaults
- Adding to Existing Options object
Introduction
There are many things you might want to tweak with Approval Tests. Options is the entry-point for many of the changes.
It is on all verify() methods, as an optional parameter.
Note: If you are interested in why we moved from "optional Reporter arguments" to "optional Options arguments", see Why We Are Converting To Options.
Fluent Interface
Options utilizes a fluent interface, allowing you to chain together commands. Each returned object is a new copy.
ApprovalTests::Options()
.withReporter(ApprovalTests::QuietReporter())
.withScrubber(ApprovalTests::Scrubbers::scrubGuid)
.fileOptions().withFileExtension(".json")
Reporters
Reporters launch diff tools upon failure. There are two ways to set a Reporter.
- Pass in a Reporter object to the Options constructor, for example:
using namespace ApprovalTests;
Approvals::verify("text to be verified", Options(Windows::AraxisMergeReporter()));
- Call
.withReporter()on an existing Options object, for example:
using namespace ApprovalTests;
Approvals::verify("text to be verified",
Options().withReporter(Mac::AraxisMergeReporter()));
Scrubbers
Scrubbers clean output to help remove inconsistent pieces of text, such as dates. There are two ways to set a Scrubber.
- Pass in a function pointer to the Options constructor, for example:
using namespace ApprovalTests;
Approvals::verifyAll("IDs", v, Options(Scrubbers::scrubGuid));
- Call
.withScrubber()with a function pointer, for example:
using namespace ApprovalTests;
Approvals::verifyAll("IDs", v, Options().withScrubber(Scrubbers::scrubGuid));
File Options
The Options::FileOptions class exists to customise the .approved and .received files in various ways.
For now, it just controls the file extension.
File Extensions
If you want to change the file extension of both the approved and received files, use withFileExtension().
using namespace ApprovalTests;
Approvals::verify("text to be verified",
Options().fileOptions().withFileExtension(".xyz"));
Note: withFileExtension() returns an Options object, so it's possible to keep appending more with...() calls.
Defaults
The default constructor for Options does:
- no scrubbing
- uses file extension
.txt - uses whatever is currently set as the default reporter.
Adding to Existing Options object
Because of the fluent options, you can modify a specific option from an existing Options object, while retaining all other settings, and not changing the original object.
verifyWithQuietReporter(std::string text, const Options& o)
{
Approvals::verify(text, o.withReporter(QuietReporter());
}