README.md in diff_matcher-2.7.0 vs README.md in diff_matcher-2.7.1
- old
+ new
@@ -3,25 +3,27 @@
[](https://travis-ci.org/diff-matcher/diff_matcher)
[](http://badge.fury.io/rb/diff_matcher)
[](https://gemnasium.com/diff-matcher/diff_matcher)
[](http://stillmaintained.com/diff-matcher/diff_matcher)
+[](https://www.omniref.com/ruby/gems/diff_matcher)
Generates a diff by matching against user-defined matchers written in ruby.
DiffMatcher matches input data (eg. from a JSON API) against values,
-ranges, classes, regexes, procs, custom matchers and/or easily composed,
+ranges, classes, regexes, procs, custom matchers, RSpec matchers and/or easily composed,
nested combinations thereof to produce an easy to read diff string.
Actual input values are matched against expected matchers in the following way:
``` ruby
-actual.is_a? expected # when expected is a class
-expected.match actual # when expected is a regexp
-expected.call actual # when expected is a proc
-actual == expected # when expected is anything else
-expected.diff actual # when expected is a built-in DiffMatcher
+actual.is_a? expected # when expected is a class
+expected.match actual # when expected is a regexp
+expected.call actual # when expected is a proc
+expected.matches? actual # when expected implements an RSpec Matcher interface
+actual == expected # when expected is anything else
+expected.diff actual # when expected is a built-in DiffMatcher
```
Using these building blocks, more complicated nested matchers can be
composed.
eg.
@@ -198,10 +200,47 @@
# => - Float+ "3"
# => ]
# => Where, - 1 missing, + 1 additional, | 2 match_matcher
```
+When `actual` is matched against some custom logic, an object with an RSpec Matcher
+interface can be used. (NB. `#mathches?(actual)`, `#description` and `#failure_message`
+methods must be implemented.)
+
+So you can use one of the RSpec matchers or you can implement your own.
+
+```ruby
+class BeAWeekend
+ def matches?(day)
+ @day = day
+ %w{Sat Sun}.include?(day)
+ end
+
+ def description
+ 'be a weekend day'
+ end
+
+ def failure_message
+ "expected #{@day} to #{description}"
+ end
+end
+
+be_a_weekend = BeAWeekend.new
+puts DiffMatcher::difference(be_a_weekend, 'Mon')
+# => - expected Mon to be a weekend day+ "Mon"
+# => Where, - 1 missing, + 1 additional
+
+
+all_be_weekends = DiffMatcher::AllMatcher.new(be_a_weekend)
+puts DiffMatcher::difference(all_be_weekends, ['Sat', 'Mon'])
+# => [
+# => R "Sat" be a weekend day,
+# => - expected Mon to be a weekend day+ "Mon"
+# => ]
+# => Where, - 1 missing, + 1 additional, R 1 match_rspec
+```
+
### Matcher options
Matcher options can be passed to `DiffMatcher::difference` or `DiffMatcher::Matcher#diff`
or instances of `DiffMatcher::Matcher`
@@ -282,10 +321,11 @@
match regexp => "~ "
match class => ": "
match matcher => "| "
match range => ". "
match proc => "{ "
+ match rspec => "R "
#### Colours
Colours (defined in colour schemes) can also appear in the difference.
@@ -298,9 +338,10 @@
match regexp => green
match class => blue
match matcher => blue
match range => cyan
match proc => cyan
+ match rspec => cyan
Other colour schemes, eg. `:color_scheme=>:white_background` will use different colour mappings.