Extractors

An Extractor is what makes it possible to capture data from one API response and reuse it in later steps.

You never create an Extractor directly, instead you use the .saveAs(...) method on Step.

Saving a Value

When you write:

Step.of("create user", "USER_DATA", "Alice")
    .expectedStatus(201)
    .saveAs("userId", "$.id");

YetiFramework creates an Extractor behind the scenes with:

• variableName = "userId"
• expression = "$.id" (a JSONPath expression)

After the step executes:

• The response body is evaluated with JSONPath.
• The result is stored in the scenario's VariableContext.

Reusing the Value

Later steps can use the extracted variable as a placeholder:

Step.of("Fetch user", "GET_USER", null)
    .wtithPathParam("id", "${userId}")
    .expectStatus(200);

JSONPath Support

Extractors use JSONPath to navigate the response body.

Examples:

• $.id → extract the top-level id field
• $.user.email → nested fields
• $.items[0].name → first element in an array

Summary

• Extractors are created by calling .saveAs(variable, jsonPath) on a step.
• They pull values out of the response body with JSONPath.
• Results are stored in scenario's VariableContext.
• Variables can then be referenced with ${variable} in later steps.