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expect-expand
expect-expand-once
expect-syntax-exn
7.1

9 Macro Expansion Expectations

procedure

(expect-expand exp [#:namespace ns])  expectation?

  exp : expectation?
  ns : namespace? = (current-namespace)
Returns an expectation that expects a syntax object object stx, then a thunk that evaluates (expand stx) is created and checked against exp. The call to expand is made with current-namespace parameterized to ns. Combine this with expect-raise to test that a specific syntax error is made, or combine with expect-return to test properties of the resulting fully expanded syntax. See also expect-syntax-exn.

Examples:
> (define success #f)
> (define-syntax-rule (foo (id v) ...) success)
> (expect! #'(foo (a 1) (b 2))
           (expect-expand (expect-return (expect-syntax 'success))))
> (expect! #'(foo a) (expect-expand expect-not-raise))

expected no value raised

  subject: #<syntax:eval:4:0 (foo a)>

  in: application to #<procedure:expand>

  in: the raised value

  expected: nothing

  actual: (exn:fail:syntax "eval:4:0: foo: use does not

match pattern: (foo (id v) ...)\n  in: (foo a)"

#<continuation-mark-set> '(#<syntax:eval:4:0 (foo a)>))

procedure

(expect-expand-once exp [#:namespace ns])  expectation?

  exp : expectation?
  ns : namespace? = (current-namespace)
Like expect-expand, but calls expand-once on the input syntax object instead of expand.

procedure

(expect-syntax-exn [msg-exp #:namespace ns])  expectation?

  msg-exp : (or/c string? regexp? expectation?) = expect-any
  ns : namespace? = (current-namespace)
Returns an expectation that expects a syntax object and expects that expanding that syntax object raises an exn:fail:syntax value whose message is checked against msg-exp. The syntax object is expanded with current-namespace parameterized to ns. If msg-exp is a regexp, it is converted to an expectation with expect-regexp-match. Otherwise, it is converted with ->expectation. This procedure is essentially sugar over combining expect-expand, expect-raise, expect-struct, and expect-regexp-match manually.

Example:
> (expect! #'(let ([a 1] [a 2]) (void)) (expect-syntax-exn #rx"duplicate"))