Abstract: The prevalence of dependencies in REST API makes it difficult to generate a reasonable sequence of API calls with input parameters.Most existing approaches only consider one of these dependencies and require cumbersome manual preliminaries,thus the generated test cases are still less effective.To address the above problem,a test case generation method based on depen-dency model is proposed.By parsing the OpenAPI documentation,this method extracts the inter-operation dependencies and inter-parameter dependencies,establishes two dependency models,generates test cases from the models,and determines test oracles.Experimental results show that the proposed method achieves 100% input metric coverage,and 100%,91.67%,and 83.33% coverage for status code category,status code,and response resource type,respectively,and can detect internal interface defects within a limited time.Compared with RESTler and RESTest,the proposed method improves the maximum 36% of output metric coverage,triggeres the most number of abnormal response status codes,and detects a maximum of 10% increase in the percentage of abnormal responses.The method provides a valuable reference for the test case generation problem of REST API.

Key words: REST API, Test case generation, Inter-operation dependency, Inter-parameter dependency, BERT model