source.md
In testthat: Unit Testing for R

source_file wraps error

Code
  source_file(test_path("reporters/error-setup.R"), wrap = FALSE)
Condition
  Error:
  ! Failed to evaluate 'reporters/error-setup.R'.
  Caused by error in `h()`:
  ! !

checks its inputs

Code
  source_file(1)
Condition
  Error:
  ! `path` must be a single string, not the number 1.
Code
  source_file("x")
Condition
  Error:
  ! `path` does not exist.
Code
  source_file(".", "x")
Condition
  Error:
  ! `env` must be an environment, not the string "x".

works on code like the describe() example

Code
  filter_desc(code, c("math library", "division()", "can handle division by 0"))
Condition
  Error:
  ! Failed to find test with description "can handle division by 0".

preserve srcrefs

Code
  filter_desc(code, "foo")
Output
  expression(test_that("foo", {
        # this is a comment
      }))

errors if zero or duplicate labels

Code
  filter_desc(code, "baz")
Condition
  Error:
  ! Found multiple tests with description "baz".
Code
  filter_desc(code, "missing")
Condition
  Error:
  ! Failed to find test with description "missing".