Dynamic Variables

KTestify processes dynamic variable placeholders in file content before sending or comparing. This lets you inject runtime values (current date, random IDs, environment-specific data) into your test payloads and expected files without hardcoding them.

All file reads go through FileUtils.getFileContent(), which transparently resolves placeholders before returning content.

Syntax

Placeholders use the form {{TYPE:format}} or {{TYPE}}:

{
  "orderId":   "{{RANDOM:UUID}}",
  "createdAt": "{{DATE:yyyy-MM-dd}}",
  "updatedAt": "{{TIMESTAMP:epoch}}",
  "envUser":   "{{ENV:CI_USER}}"
}

Available variable types

`{{DATE:format}}`

Current local date formatted with DateTimeFormatter.

Example	Output
`{{DATE:yyyy-MM-dd}}`	`2026-05-09`
`{{DATE:dd/MM/yyyy}}`	`09/05/2026`
`{{DATE:yyyyMMdd}}`	`20260509`

`{{TIMESTAMP:format}}`

Current UTC timestamp.

Example	Output
`{{TIMESTAMP:epoch}}`	`1746748800000` (milliseconds since epoch)
`{{TIMESTAMP:yyyy-MM-dd'T'HH:mm:ss'Z'}}`	`2026-05-09T10:00:00Z`

`{{RANDOM:type}}`

Generates a random value.

Example	Output
`{{RANDOM:UUID}}`	`f47ac10b-58cc-4372-a567-0e02b2c3d479`
`{{RANDOM:INT}}`	Random integer

`{{ENV:VARIABLE_NAME}}`

Reads a value from an environment variable at test runtime.

{
  "targetHost": "{{ENV:TARGET_HOST}}",
  "apiKey":     "{{ENV:API_KEY}}"
}

If the environment variable is not set, the placeholder is left as-is (no error is thrown). Use this to parameterise tests across CI environments.

Using dynamic variables in expected files

Dynamic variables work in expected files too, so you can assert against a computed value:

assets/expected/order-enriched.json
{
  "orderId":   "order-001",
  "processedAt": "{{DATE:yyyy-MM-dd}}",
  "status":    "PROCESSED"
}

This means the assertion is date-aware without you having to update the file daily.

Custom dynamic variables

To add your own variable type, implement DynamicVariable in ktestify-core and register it via DynamicVariableFactory. See Extend → Core concepts → for details.

Syntax​

Available variable types​

{{DATE:format}}​

{{TIMESTAMP:format}}​

{{RANDOM:type}}​

{{ENV:VARIABLE_NAME}}​

Using dynamic variables in expected files​

Custom dynamic variables​