enable experimental:strictDefs (#24225)

testament/lib/stdtest/specialpaths.nim

@@ -38,6 +38,7 @@ proc splitTestFile*(file: string): tuple[cat: string, path: string] =
   ## At least one directory is required in the path, to use as a category name
   runnableExamples:
     doAssert splitTestFile("tests/fakedir/tfakename.nim") == ("fakedir", "tests/fakedir/tfakename.nim".unixToNativePath)
+  result = ("", "")
   for p in file.parentDirs(inclusive = false):
     let parent = p.parentDir
     if parent.lastPathPart == testsFname:

testament/lib/stdtest/unittest_light.nim

@@ -6,13 +6,18 @@ proc mismatch*[T](lhs: T, rhs: T): string =
   ## 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.
+  result = ""
+
   proc replaceInvisible(s: string): string =
+    result = ""
     for a in s:
       case a
       of '\n': result.add "\\n\n"
       else: result.add a
 
-  proc quoted(s: string): string = result.addQuoted s
+  proc quoted(s: string): string =
+    result = ""
+    result.addQuoted s
 
   result.add '\n'
   result.add "lhs:{" & replaceInvisible(