Basic unit testing facilities (suites, fixtures, cases)

Added: PNimrodNode.lineinfo for better error messages from macros
Added: seq.splice

For easier use from templates and macros, except stament now supports
the list of exception types to be supplied in nkBraket node (array literal).

lib/pure/unittest.nim

@@ -0,0 +1,157 @@
+#
+#
+#            Nimrod's Runtime Library
+#        (c) Copyright 2011 Nimrod Contributors
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## This module implements the standard unit testing facilities such as
+## suites, fixtures and test cases as well as facilities for combinatorial 
+## and randomzied test case generation (not yet available) 
+## and object mocking (not yet available)
+##
+## It is loosely based on C++'s boost.test and Haskell's QuickTest
+##
+## Maintainer: Zahary Karadjov (zah@github)
+##
+
+import
+  macros
+
+type
+  TestStatus* = enum OK, FAILED
+  # ETestFailed* = object of ESynch
+
+var 
+  # XXX: These better be thread-local
+  AbortOnError* = false
+  checkpoints: seq[string] = @[]
+
+template TestSetupIMPL*: stmt = nil
+template TestTeardownIMPL*: stmt = nil
+
+proc shouldRun(testName: string): bool =
+  result = true
+
+template suite*(name: expr, body: stmt): stmt =
+  block:
+    template setup(setupBody: stmt): stmt =
+      template TestSetupIMPL: stmt = setupBody
+
+    template teardown(teardownBody: stmt): stmt =
+      template TestTeardownIMPL: stmt = teardownBody
+
+    body
+
+template test*(name: expr, body: stmt): stmt =
+  if bind shouldRun(name):
+    bind checkpoints = @[]
+    var TestStatusIMPL = OK
+    
+    try:
+      TestSetupIMPL()
+      body
+
+    finally:
+      TestTeardownIMPL()
+      echo "[" & $TestStatusIMPL & "] " & name
+
+proc checkpoint*(msg: string) =
+  checkpoints.add(msg)
+  # TODO: add support for something like SCOPED_TRACE from Google Test
+
+template fail* =
+  for msg in items(bind checkpoints):
+    echo msg
+
+  if AbortOnError: quit(1)
+  
+  TestStatusIMPL = FAILED
+  checkpoints = @[]
+
+macro check*(conditions: stmt): stmt =
+  proc standardRewrite(e: expr): stmt =
+    template rewrite(Exp, lineInfoLit: expr, expLit: string): stmt =
+      if not Exp:
+        checkpoint(lineInfoLit & ": Check failed: " & expLit)
+        fail()
+
+    # XXX: If we don't create a string literal node below, the compiler
+    # will SEGFAULT in a rather strange fashion:
+    #
+    # rewrite(e, e.toStrLit, e.toStrLit) is ok, but
+    #
+    # rewrite(e, e.lineinfo, e.toStrLit) or
+    # rewrite(e, "anything", e.toStrLit) are not
+    #
+    # It may have something to do with the dummyContext hack in 
+    # evals.nim/evalTemplate
+    #
+    result = getAst(rewrite(e, newStrLitNode(e.lineinfo), e.toStrLit))
+  
+  case conditions.kind
+  of nnkCall, nnkCommand, nnkMacroStmt:
+    case conditions[1].kind
+    of nnkInfix:
+      proc rewriteBinaryOp(op: expr): stmt =
+        template rewrite(op, left, right, lineInfoLit: expr, opLit, leftLit, rightLit: string): stmt =
+          block:
+            var 
+              lhs = left
+              rhs = right
+
+            if not `op`(lhs, rhs):
+              checkpoint(lineInfoLit & ": Check failed: " & opLit)
+              checkpoint("  " & leftLit & " was " & $lhs)
+              checkpoint("  " & rightLit & " was " & $rhs)
+              fail()
+
+        result = getAst(rewrite(
+          op[0], op[1], op[2],
+          newStrLitNode(op.lineinfo),
+          op.toStrLit,
+          op[1].toStrLit,
+          op[2].toStrLit))
+        
+      result = rewriteBinaryOp(conditions[1])
+  
+    of nnkCall, nnkCommand:
+      # TODO: We can print out the call arguments in case of failure
+      result = standardRewrite(conditions[1])
+
+    of nnkStmtList:
+      result = newNimNode(nnkStmtList)
+      for i in countup(0, conditions[1].len - 1):
+        result.add(newCall(!"check", conditions[1][i]))
+
+    else:
+      result = standardRewrite(conditions[1])
+
+  else:
+    error conditions.lineinfo & ": Malformed check statement"
+
+template require*(conditions: stmt): stmt =
+  block:
+    const AbortOnError = true    
+    check conditions
+
+macro expect*(exp: stmt): stmt =
+  template expectBody(errorTypes, lineInfoLit: expr, body: stmt): stmt =
+    try:
+      body
+      checkpoint(lineInfoLit & ": Expect Failed, no exception was thrown.")
+      fail()
+    except errorTypes:
+      nil
+
+  var expectCall = exp[0]
+  var body = exp[1]
+  
+  var errorTypes = newNimNode(nnkBracket)
+  for i in countup(1, expectCall.len - 1):
+    errorTypes.add(expectCall[i])
+
+  result = getAst(expectBody(errorTypes, newStrLitNode(exp.lineinfo), body))
+