Concepts

TraceCov measures how thoroughly your tests cover your API specification, tracking validation logic at the schema level.

Coverage Dimensions

Dimension	What it tracks	Example
Operations	HTTP method + path combinations called	GET /users, POST /orders
Parameters	Path, query, header, cookie, body values	userId in /users/{userId}
Keywords	JSON Schema validation rules exercised	minLength, pattern, enum
Examples	Schema examples and defaults used	example: "john@example.com"
Responses	HTTP status codes returned	200, 404, 5XX

Keywords

Consider this schema:

{
  "type": "object",
  "properties": {
    "name": { "type": "string", "minLength": 1, "maxLength": 100 },
    "age": { "type": "integer", "minimum": 0, "maximum": 150 }
  }
}

TraceCov tracks each validation keyword separately: type, minLength, maxLength, minimum, maximum.

Why this matters: Hitting POST /users once with {"name": "Alice", "age": 30} gives you 100% endpoint coverage but poor keyword coverage - you haven't tested:

• Empty name (fails minLength)
• Name too long (fails maxLength)
• Negative age (fails minimum)
• Age over 150 (fails maximum)

Keywords like title, description, default, and x-* extensions are excluded since they don't affect validation.

Coverage States

Each keyword tracks two counters:

State	Meaning	Example
Valid	Input passed validation	"hello" passes minLength: 3
Invalid	Input failed validation	"hi" fails minLength: 3

Full coverage means testing both valid and invalid inputs for each keyword.

Satisfiability

Some schema constraints can only be tested one way:

Type	Can Pass?	Can Fail?	Example
Normal	Yes	Yes	minLength: 5
Positive-only	Yes	No	minLength: 0 (can't have negative length)
Negative-only	No	Yes	{"not": {}} (rejects everything)

TraceCov detects these cases automatically and excludes them from coverage calculations.

Coverage Percentage

The report shows separate percentages for each dimension:

• Operations - called / total operations
• Parameters - tested / total parameters
• Keywords - (partial + full) / total
• Examples - used / total schema examples and defaults
• Responses - seen / documented status codes