Add tests

src/utils/str.nim

@@ -0,0 +1,27 @@
+import std/strutils
+import std/math
+
+proc safeDelete*(str: string, slice: Slice[int]): string =
+  ## Deletes the items `str[slice]`, ignoring elements out of range.
+  if slice.a > str.len - 1:
+    str
+  else:
+    let fromIndex = clamp(slice.a, 0..str.len)
+    let toIndex = clamp(slice.b, 0..str.len - 1)
+
+    var strDup = str
+    strDup.delete(fromIndex..toIndex)
+    strDup
+
+func findAndDelete*(str: string, chars: set[char], start = 0, last = str.len - 1): string =
+  ## Find the next instance of `chars` from `start`.
+  ## When found delete characters until `last`.
+  let startChar = str.find(chars, start, last)
+  if startChar == -1:
+    str
+  else:
+    str.safeDelete(startChar..last)
+
+func deleteAfterNewline*(str: string, start = 0): string =
+  ## Delete string after next Newline from `start`.
+  findAndDelete(str, Newlines, start)