trunner was not actually being tested in non-CTFFI mode; minor testament cleanups (#14377)

* use check
* trunner now works with cpp
* cleanup: move compiler/unittest_light => stdtest/unittest_light
* fix tests/readme.md
* remove deadcode references to rodfiles
* fix for windows

testament/categories.nim

@@ -32,7 +32,6 @@ const
     "nimble-packages-1",
     "nimble-packages-2",
     "niminaction",
-    "rodfiles",
     "threads",
     "untestable",
     "stdlib",
@@ -671,10 +670,6 @@ proc processCategory(r: var TResults, cat: Category,
                      options, testsDir: string,
                      runJoinableTests: bool) =
   case cat.string.normalize
-  of "rodfiles":
-    when false:
-      compileRodFiles(r, cat, options)
-      runRodFiles(r, cat, options)
   of "ic":
     when false:
       icTests(r, testsDir, cat, options)

testament/lib/stdtest/unittest_light.nim

@@ -0,0 +1,38 @@
+# note: consider merging tests/assert/testhelper.nim here.
+
+proc mismatch*[T](lhs: T, rhs: T): string =
+  ## Simplified version of `unittest.require` that satisfies a common use case,
+  ## while avoiding pulling too many dependencies. On failure, diagnostic
+  ## information is provided that in particular makes it easy to spot
+  ## whitespace mismatches and where the mismatch is.
+  proc replaceInvisible(s: string): string =
+    for a in s:
+      case a
+      of '\n': result.add "\\n\n"
+      else: result.add a
+
+  proc quoted(s: string): string = result.addQuoted s
+
+  result.add "\n"
+  result.add "lhs:{" & replaceInvisible(
+      $lhs) & "}\nrhs:{" & replaceInvisible($rhs) & "}\n"
+  when compiles(lhs.len):
+    if lhs.len != rhs.len:
+      result.add "lhs.len: " & $lhs.len & " rhs.len: " & $rhs.len & "\n"
+    when compiles(lhs[0]):
+      var i = 0
+      while i < lhs.len and i < rhs.len:
+        if lhs[i] != rhs[i]: break
+        i.inc
+      result.add "first mismatch index: " & $i & "\n"
+      if i < lhs.len and i < rhs.len:
+        result.add "lhs[i]: {" & quoted($lhs[i]) & "}\nrhs[i]: {" & quoted(
+            $rhs[i]) & "}\n"
+      result.add "lhs[0..<i]:{" & replaceInvisible($lhs[
+          0..<i]) & "}"
+
+proc assertEquals*[T](lhs: T, rhs: T) =
+  when false: # can be useful for debugging to see all that's fed to this.
+    echo "----" & $lhs
+  if lhs!=rhs:
+    doAssert false, mismatch(lhs, rhs)