Assertions - In Nutshell

Asserting Mechanism	Description
PROPERTY CONTENT
Contains	Searches for the existence of the specified string. It also supports regular expression.
Not Contains	Searches for the Non-existence of the specified string. It also supports regular expression.
XPath Match	Uses XPath expression to select the target node and its values.
XQuery Match	Uses an Xquery expression to select content from the target property.
Compliance , Status, Standards
HTTP Download all resource	Validates the HTML Document after downloading and it holds good to any property containing HTML.
Invalid HTTP Status Codes	Verifies if the HTML response contains a status code that is not in the list of defined codes.
Not SOAP Fault	Verifies if the last received message is not a SOAP Fault. It is very obvious that it is applicable only for SOAP Test Steps.
Schema Compliance	Verifies if the last received message is compliant with the WSDL or WADL standard schema definition. Holds good for SOAP and REST Test Steps.
SOAP Fault	Verifies if the last received message is a SOAP Fault. It is the inverse of 'NOT SOAP' Fault Assertions.
SOAP Response	Verifies if the last received response is a valid SOAP Response and holds good for SOAP Test Request Steps only.
Valid HTTP Status Codes	Verifies if the HTML response contains a status code that is in the list of defined codes. It is the inverse of 'Invalid HTTP Status Codes' Assertion.
WS-Addressing Request	Verifies if the last received request contains appropriate WS-Addressing Headers.
WS-Addressing Response	Verifies if the last received response contains appropriate WS-Addressing Headers.
WS-Security Status	Validates if the last received message contains valid WS-Security headers and holds good only for SOAP Requests.
Script
Script Assertion	Allows users to execute a custom script to perform user defined validations.
SLA
Response SLA	Validates if the response time of the last received response was within the defined limit.
JMS
JMS Status	Verifies if the JMS request of the Test Step has executed successfully and holds good for Test Steps with a JMS endpoint.
JMS Timeout	Verifies if that the JMS response of a test step did not took longer than the specified duration.
Security
Sensitive Information Exposure	Verifies if the response message does not expose sensitive information about the target system. We can use this assertion for REST, SOAP and HTTP Test Steps.