Capture

class aws_cdk.assertions.Capture(pattern=None)

Bases: Matcher

Capture values while matching templates.

Using an instance of this class within a Matcher will capture the matching value. The as*() APIs on the instance can be used to get the captured value.

ExampleMetadata:

infused

Example:

# Given a template -
# {
#   "Resources": {
#     "MyBar": {
#       "Type": "Foo::Bar",
#       "Properties": {
#         "Fred": "Flob",
#       }
#     },
#     "MyBaz": {
#       "Type": "Foo::Bar",
#       "Properties": {
#         "Fred": "Quib",
#       }
#     }
#   }
# }

fred_capture = Capture()
template.has_resource_properties("Foo::Bar", {
    "Fred": fred_capture
})

fred_capture.as_string() # returns "Flob"
fred_capture.next() # returns true
fred_capture.as_string()

Initialize a new capture.

Parameters:

pattern (Optional[Any]) – a nested pattern or Matcher. If a nested pattern is provided objectLike() matching is applied.

Methods

as_array()

Retrieve the captured value as an array.

An error is generated if no value is captured or if the value is not an array.

Return type:

List[Any]

as_boolean()

Retrieve the captured value as a boolean.

An error is generated if no value is captured or if the value is not a boolean.

Return type:

bool

as_number()

Retrieve the captured value as a number.

An error is generated if no value is captured or if the value is not a number.

Return type:

Union[int, float]

as_object()

Retrieve the captured value as a JSON object.

An error is generated if no value is captured or if the value is not an object.

Return type:

Mapping[str, Any]

as_string()

Retrieve the captured value as a string.

An error is generated if no value is captured or if the value is not a string.

Return type:

str

next()

When multiple results are captured, move the iterator to the next result.

Return type:

bool

Returns:

true if another capture is present, false otherwise

test(actual)

Test whether a target matches the provided pattern.

Every Matcher must implement this method. This method will be invoked by the assertions framework. Do not call this method directly.

Parameters:

actual (Any)

Return type:

MatchResult

Attributes

name

A name for the matcher.

This is collected as part of the result and may be presented to the user.

Static Methods

classmethod is_matcher(x)

Check whether the provided object is a subtype of the IMatcher.

Parameters:

x (Any)

Return type:

bool