Minitest Rails Assertions (table)

#ruby #rails #testing #softwaredevelopment

Minitest is the default testing library used by Ruby on Rails. Here's a synopsis of the available api.

Available Assertions

From Minitest:

Assertion	Purpose
`assert( test, [msg] )`	Ensures that `test` is true.
`assert_not( test, [msg] )`	Ensures that `test` is false.
`assert_equal( expected, actual, [msg] )`	Ensures that `expected == actual` is true.
`assert_not_equal( expected, actual, [msg] )`	Ensures that `expected != actual` is true.
`assert_same( expected, actual, [msg] )`	Ensures that `expected.equal?(actual)` is true.
`assert_not_same( expected, actual, [msg] )`	Ensures that `expected.equal?(actual)` is false.
`assert_nil( obj, [msg] )`	Ensures that `obj.nil?` is true.
`assert_not_nil( obj, [msg] )`	Ensures that `obj.nil?` is false.
`assert_empty( obj, [msg] )`	Ensures that `obj` is `empty?`.
`assert_not_empty( obj, [msg] )`	Ensures that `obj` is not `empty?`.
`assert_match( regexp, string, [msg] )`	Ensures that a string matches the regular expression.
`assert_no_match( regexp, string, [msg] )`	Ensures that a string doesn't match the regular expression.
`assert_includes( collection, obj, [msg] )`	Ensures that `obj` is in `collection`.
`assert_not_includes( collection, obj, [msg] )`	Ensures that `obj` is not in `collection`.
`assert_in_delta( expected, actual, [delta], [msg] )`	Ensures that the numbers `expected` and `actual` are within `delta` of each other.
`assert_not_in_delta( expected, actual, [delta], [msg] )`	Ensures that the numbers `expected` and `actual` are not within `delta` of each other.
`assert_in_epsilon ( expected, actual, [epsilon], [msg] )`	Ensures that the numbers `expected` and `actual` have a relative error less than `epsilon`.
`assert_not_in_epsilon ( expected, actual, [epsilon], [msg] )`	Ensures that the numbers `expected` and `actual` have a relative error not less than `epsilon`.
`assert_throws( symbol, [msg] ) { block }`	Ensures that the given block throws the symbol.
`assert_raises( exception1, exception2, ... ) { block }`	Ensures that the given block raises one of the given exceptions.
`assert_instance_of( class, obj, [msg] )`	Ensures that `obj` is an instance of `class`.
`assert_not_instance_of( class, obj, [msg] )`	Ensures that `obj` is not an instance of `class`.
`assert_kind_of( class, obj, [msg] )`	Ensures that `obj` is an instance of `class` or is descending from it.
`assert_not_kind_of( class, obj, [msg] )`	Ensures that `obj` is not an instance of `class` and is not descending from it.
`assert_respond_to( obj, symbol, [msg] )`	Ensures that `obj` responds to `symbol`.
`assert_not_respond_to( obj, symbol, [msg] )`	Ensures that `obj` does not respond to `symbol`.
`assert_operator( obj1, operator, [obj2], [msg] )`	Ensures that `obj1.operator(obj2)` is true.
`assert_not_operator( obj1, operator, [obj2], [msg] )`	Ensures that `obj1.operator(obj2)` is false.
`assert_predicate ( obj, predicate, [msg] )`	Ensures that `obj.predicate` is true, e.g. `assert_predicate str, :empty?`
`assert_not_predicate ( obj, predicate, [msg] )`	Ensures that `obj.predicate` is false, e.g. `assert_not_predicate str, :empty?`
`assert_error_reported(class) { block }`	Ensures that the error class has been reported, e.g. `assert_error_reported IOError { Rails.error.report(IOError.new("Oops")) }`
`assert_no_error_reported { block }`	Ensures that no errors have been reported, e.g. `assert_no_error_reported { perform_service }`
`flunk( [msg] )`	Ensures failure. This is useful to explicitly mark a test that isn't finished yet.

From Rails:

Assertion	Purpose
`assert_difference(expressions, difference = 1, message = nil) {...}`	Test numeric difference between the return value of an expression as a result of what is evaluated in the yielded block.
`assert_no_difference(expressions, message = nil, &block)`	Asserts that the numeric result of evaluating an expression is not changed before and after invoking the passed in block.
`assert_changes(expressions, message = nil, from:, to:, &block)`	Test that the result of evaluating an expression is changed after invoking the passed in block.
`assert_no_changes(expressions, message = nil, &block)`	Test the result of evaluating an expression is not changed after invoking the passed in block.
`assert_nothing_raised { block }`	Ensures that the given block doesn't raise any exceptions.
`assert_recognizes(expected_options, path, extras={}, message=nil)`	Asserts that the routing of the given path was handled correctly and that the parsed options (given in the expected_options hash) match path. Basically, it asserts that Rails recognizes the route given by expected_options.
`assert_generates(expected_path, options, defaults={}, extras = {}, message=nil)`	Asserts that the provided options can be used to generate the provided path. This is the inverse of assert_recognizes. The extras parameter is used to tell the request the names and values of additional request parameters that would be in a query string. The message parameter allows you to specify a custom error message for assertion failures.
`assert_response(type, message = nil)`	Asserts that the response comes with a specific status code. You can specify `:success` to indicate 200-299, `:redirect` to indicate 300-399, `:missing` to indicate 404, or `:error` to match the 500-599 range. You can also pass an explicit status number or its symbolic equivalent. For more information, see full list of status codes and how their mapping works.
`assert_redirected_to(options = {}, message=nil)`	Asserts that the response is a redirect to a URL matching the given options. You can also pass named routes such as `assert_redirected_to root_path` and Active Record objects such as `assert_redirected_to @article`.
`assert_queries_count(count = nil, include_schema: false, &block)`	Asserts that `&block` generates an `int` number of SQL queries.
`assert_no_queries(include_schema: false, &block)`	Asserts that `&block` generates no SQL queries.
`assert_queries_match(pattern, count: nil, include_schema: false, &block)`	Asserts that `&block` generates SQL queries that match the pattern.
`assert_no_queries_match(pattern, &block)`	Asserts that `&block` generates no SQL queries that match the pattern.