Gavel tells you whether an actual HTTP message is valid against an expected HTTP message.
npm install gavel# (Optional) Record HTTP messages
curl -s --trace - http://httpbin.org/ip | curl-trace-parser > expected
curl -s --trace - http://httpbin.org/ip | curl-trace-parser > actual
# Perform the validation
cat actual | gavel expectedGavel CLI is not supported on Windows. Example above uses
curl-trace-parser.
const gavel = require('gavel');
// Define HTTP messages
const expected = {
statusCode: 200,
headers: {
'Content-Type': 'application/json'
}
};
const actual = {
statusCode: 404,
headers: {
'Content-Type': 'application/json'
}
};
// Perform the validation
const result = gavel.validate(expected, actual);The code above would return the following validation result:
{
valid: false,
fields: {
statusCode: {
valid: false,
kind: 'text',
values: {
expected: '200',
actual: '404'
},
errors: [
{
message: `Expected status code '200', but got '404'.`
}
]
},
headers: {
valid: true,
kind: 'json',
values: {
expected: {
'Content-Type': 'application/json'
},
actual: {
'Content-Type': 'application/json'
}
},
errors: []
}
}
}When a parsable JSON body is expected without an explicit schema the default schema is inferred.
You can describe the body expectations using JSON Schema by providing a valid schema to the bodySchema property of the expected HTTP message:
const gavel = require('gavel');
const expected = {
bodySchema: {
type: 'object',
properties: {
fruits: {
type: 'array',
items: {
type: 'string'
}
}
}
}
};
const actual = {
body: JSON.stringify({
fruits: ['apple', 'banana', 2]
})
};
const result = gavel.validate(expected, actual);The validation result against the given JSON Schema will look as follows:
{
valid: false,
fields: {
body: {
valid: false,
kind: 'json',
values: {
actual: "{\"fruits\":[\"apple\",\"banana\",2]}"
},
errors: [
{
message: `At '/fruits/2' Invalid type: number (expected string)`,
location: {
pointer: '/fruits/2'
}
}
]
}
}
}Take a look at the Gherkin specification, which describes on examples how validation of each field behaves:
Gavel ships with TypeScript type definitions. Please refer to the definitions file for more details.
validate(expected: HttpMessage, actual: HttpMessage): ValidationResult