Automating API Test Script Generation: From Manual Coding to Tool‑Assisted Production

Pain Points

Interface automation test engineers spend a large portion of their time manually creating API classes and test cases, leading to repetitive work, low robustness, and difficulty in refactoring.

Solution Overview

Parse API documentation (Swagger, RAP, Wiki).

Identify scripts that are suitable for automatic generation.

Use a code‑generation tool to produce the scripts.

Document Parsing

For Wiki pages the team uses BeautifulSoup to extract HTML content, while for Swagger they directly parse the json definition.

from bs4 import BeautifulSoup
soup = BeautifulSoup(html_doc)
title_string = soup.title.string
# ... further parsing logic

Code Generation Engine

A lightweight backend generator is implemented in Python:

class CodeGeneratorBackend():
    def __init__(self):
        self.code = []
        self.tab = "\t"
        self.level = 0
    def begin(self, tab="\t"):
        self.code = []
        self.tab = tab
        self.level = 0
    def write(self, string):
        self.code.append(self.tab * self.level + string)
    def indent(self):
        self.level += 1
    def dedent(self):
        if self.level == 0:
            raise SyntaxError("internal error in code generator")
        self.level -= 1
    def end(self):
        return "".join(self.code)

Typical usage:

c = CodeGeneratorBackend()
c.begin(tab="    ")
c.write("def function(self):
")
c.indent()
# generate body
c.dedent()
print(c.end())

Generation Rules

Interface class scripts are generated by iterating over API objects and substituting placeholders.

Test case scripts consider special values (0, None, empty string), type‑based values, pagination parameters, and time range parameters.

Query‑type APIs generate single, combined, and full‑parameter queries; update‑type APIs generate per‑field and bulk updates.

Efficiency Results

For a coupon‑related feature with ~10 new APIs (≈250 parameters) the manual effort was 2 person‑days, while the tool reduced it to under an hour, achieving a 94 % efficiency gain for interface classes and a 50 % gain for robustness test cases, overall 74 % improvement.

Future Work

Expand multi‑parameter test case generation.

Invoke real APIs to capture expected results automatically.

Refine rule definitions through continuous collaboration with developers.