JSONPath-Tester

Demo: extract user emails from a nested API response

A practical JSONPath review starts with a payload that looks like production but removes sensitive values. The tester should show both the matched values and the path shape so you can turn the expression into a test assertion.

• Use $..email when email fields can appear at different depths.
• Use $.users[*].email when the schema is stable and you want stricter matching.
• Prefer strict paths for tests and recursive paths for exploration.

$.users[*].email
{
  "users": [
    {"id": 1, "email": "ada@example.com"},
    {"id": 2, "email": "grace@example.com"}
  ]
}

The first line is the expression; the rest is the JSON payload to inspect.

JSONPath mistakes worth catching before code review

A JSONPath expression can look correct while selecting the wrong level of a nested payload. Previewing the result makes these mistakes visible before they become flaky tests or broken docs.

• Recursive selectors can match fields from unrelated objects.
• Array indexes such as [0] are fragile when examples do not represent production order.
• Filters should be checked against payloads with both matching and non-matching records.