Nim 中的编译时调用计数

Question

以下代码无法编译，但说明了我想做的事情：totalTests 应该保存 assertEquals() 被调用的次数（assertEquals() 可能应该是一个宏才能实现这一点，但我我还不熟悉 Nim 的这方面）。

知道应该如何修改此代码以使以下代码能够在每个测试报告行的开头打印 [1/2] 和 [2/2] 吗？

from strutils import format

var countTested = 0
var countFailed = 0
var countPassed = 0
let totalTests = 0 # <-- need let or other compile-time type here (?)

# using proc here... macro may be needed to be able to count calls (?)
proc assertEquals*[T](testName: string, expected: T, p: (proc(): T)) =
   countTested += 1
   totalTests += 1 # <-- compilation error (how can we increase each time it is called?)
   write(stdout, format("[$num/$total] $name: ", "num", countTested, "total", totalTests, "name", testName))
   var val = p()
   if val == expected:
     write(stdout, "passed\n")
     countPassed += 1
   else:
     write(stdout, "failed\n")
     countFailed += 1

when isMainModule:
  assertEquals("test #A", 12, proc(): int = 14-2)
  assertEquals("test #B", 12, proc(): int = 12-2)

编辑：在代码中添加了问题

Answer 1

这是一种方法。您可以使用宏或 static 语句在编译时执行代码。请注意，仍然无法跨多个模块可靠地计算这些。

import macros, strutils

proc beginTests()

var countTested = 0
var countFailed = 0
var countPassed = 0
var totalTests = 0
var totalTestsCT {.compiletime.} = 0

macro endTests(): stmt =
  quote do:
    proc beginTests() =
      totalTests = `totalTestsCT`

proc assertEqualsImpl*[T](testName: string, expected: T, p: (proc(): T)) =
   countTested += 1
   write(stdout, format("[$num/$total] $name: ",
         "num", countTested, "total", totalTests, "name", testName))
   var val = p()
   if val == expected:
     write(stdout, "passed\n")
     countPassed += 1
   else:
     write(stdout, "failed\n")
     countFailed += 1

macro assertEquals*[T](testName: string, expected: T, p: (proc(): T)): stmt =
  totalTestsCT += 1
  quote do:
    assertEqualsImpl(`testName`, `expected`, `p`)

when isMainModule:
  beginTests()
  assertEquals("test #A", 12, proc(): int = 14-2)
  assertEquals("test #B", 12, proc(): int = 12-2)
  endTests()

另一种实现方式是将测试嵌入到自定义块语句中，例如

testSuite:
  assertEquals("test #A", 12, proc(): int = 14-2)
  assertEquals("test #B", 12, proc(): int = 12-2)

testSuite 宏然后会计算嵌入式代码中的断言并相应地初始化变量。

另一种解决方案是不直接执行测试，而是将它们存储在列表中，只在最后执行。

Answer 2

这是 Reimer 的第三个建议的实现，它最适合我。

import macros, strutils

type 
  TestSuiteObj = object
    countTested: int
    countFailed: int
    countPassed: int
    totalTests: int
    tests: seq[(proc (self: TestSuite))]
  TestSuite* = ref TestSuiteObj


proc newTestSuite*(): TestSuite =
  new(result)
  result.countTested = 0
  result.countFailed = 0
  result.countPassed = 0
  result.totalTests = 0
  result.tests = @[]

proc assertEquals*[T](self: TestSuite, testName: string, expected: T, p: (proc(): T)) =
  self.totalTests += 1

  var testProc = proc(self: TestSuite) =
    self.countTested += 1
    write(stdout, format("[$num/$total] $name: ", "num", self.countTested, "total", self.totalTests, "name", testName))
    var val = p()
    if val == expected:
      write(stdout, "passed\n")
      self.countPassed += 1
    else:
      write(stdout, "failed\n")
      self.countFailed += 1

  self.tests.add(testProc)


proc run*(self: TestSuite) =
  self.totalTests = self.tests.len
  for p in self.tests:
    p(self)

  var verdict = case (self.countTested == self.countPassed)
  of true: "PASSED"
  of false: "FAILED"
  echo format("$verdict. Passed [$passed/$total] tests.", "verdict", verdict, "passed", self.countPassed, "total", self.countTested)

  # Sanity
  assert(self.countTested == (self.countFailed+self.countPassed))
  assert(self.countTested == self.totalTests)


when isMainModule:
  var suite = newTestSuite() 
  suite.assertEquals("test #A", 12, proc(): int = 14-2)
  suite.assertEquals("test #B", 12, proc(): int = 12-2)
  suite.run()

Nim 中的编译时调用计数

Compile-time Call Count in Nim

nim-lang