Assertions and scripts

What a request checks about its response, and the JavaScript that runs before a request is sent and after its response came.

Assertions

A line ?? SUBJECT [ARGUMENT] PREDICATE [VALUE] checks the response:

Subject	Value
status	The status
header NAME	The header’s value
body	The body; body PATH a value of the JSON body ($.items[0].id, items[0].id or /items/0/id)
duration	The time to the response, in milliseconds
js EXPRESSION	The value of a JavaScript expression with the scripts’ API

Predicates: ==, !=, >, >=, <, <= (numbers when both sides are numbers), startsWith, endsWith, includes (or contains), matches (a regular expression, /.../flags too), exists, isArray, isBoolean, isNumber, isString, isTrue and isFalse. A js subject without a predicate must be true. Variables are substituted in the argument and the value.

Scripts

{{ and }} on lines of their own enclose an httpYac script: before the request line it runs before the request is sent, after it once the response came. JetBrains handlers work too: < {% ... %} before the request line, > {% ... %} after it. Scripts run in a sandboxed JavaScript engine (QuickJS) with no file system or network access, five seconds each. Both flavours get the same API:

Name	What it is
response.status, response.statusCode	The status
response.headers	Headers by lower-case name; headers.valueOf(name), headers.valuesOf(name)
response.body	The body, parsed when it is JSON; response.parsedBody, response.rawBody
response.contentType.mimeType, .charset	The media type
response.duration	Milliseconds
request.method, request.url, request.headers, request.body	The request as written
request.variables.set(name, value), .get(name)	Variables of this request (pre-request scripts)
exports.name = value, client.global.set(name, value)	Variables of the following requests
client.global.get(name), request.environment.get(name)	A variable
test(name, fn), client.test(name, fn)	A named check: it fails when fn throws (or its promise rejects)
test.status(code), test.header(name, value), test.headerContains(name, text), test.hasResponseBody(), test.totalTime(ms)	httpYac’s shortcuts
assert(value, message), client.assert(...), assert.equal, assert.strictEqual, assert.deepStrictEqual, assert.notEqual, assert.fail	Throws when the check fails
console.log, console.warn, …, client.log	Lines of the request’s log (--verbose, the reports)

Variables are also local names of scripts when they are identifiers. A script that throws fails its request. Changes an ordinary pre-request script makes to request are not sent: set variables instead. Imported files opt into the header-addition API described below.