Modify previous commit and add tests

lib/pure/collections/sets.nim

@@ -18,7 +18,7 @@
 ## that ``=`` performs a copy of the set.
 
 import
-  hashes, math
+  hashes, math, algorithm
 
 {.pragma: myShallow.}
 when not defined(nimhygiene):
@@ -123,8 +123,11 @@ iterator items*[A](s: HashSet[A]): A =
 proc hash*[A](s: HashSet[A]): Hash =
   ## hashing of HashSet
   assert s.isValid, "The set needs to be initialized."
+  var hcs: seq[Hash]
   for h in 0..high(s.data):
-    result = result !& s.data[h].hcode
+    hcs.add(s.data[h].hcode)
+  for hc in sorted(hcs, cmp[int]):
+    result = result !& hc
   result = !$result
 
 const

tests/collections/tsets.nim

@@ -1,4 +1,6 @@
 import sets
+import hashes
+import algorithm
 
 block setEquality:
   var
@@ -74,6 +76,52 @@ block orderedSetClearWorked:
 
   doAssert r == "zeat jos"
 
+block hashForHashedSet:
+  let
+    seq1 = "This is the test."
+    seq2 = "the test is This."
+    s1 = seq1.toSet()
+    s2 = seq2.toSet()
+  var hashSeq: seq[Hash] = @[]
+  doAssert s1 == s2
+  doAssert hash(s1) == hash(s2)
+  for c in seq1:
+    if (not (hash(c) in hashSeq)):
+      hashSeq.add(hash(c))
+  doAssert hash(s1) == hash(sorted(hashSeq, cmp[Hash]))
 
+block hashForOrderdSet:
+  let
+    str = "This is the test."
+    rstr = str.reversed
 
+  var
+    s1 = initOrderedSet[char]()
+    s2 = initOrderedSet[char]()
+    r = initOrderedSet[char]()
+    expected: Hash
+    added: seq[char] = @[]
+    reversed: Hash
+    radded: seq[char] = @[]
 
+  expected = 0
+  for c in str:
+    if (not (c in added)):
+      expected = expected !& hash(c)
+      added.add(c)
+    s1.incl(c)
+    s2.incl(c)
+  expected = !$expected
+  doAssert hash(s1) == expected
+  doAssert hash(s1) == hash(s2)
+  doAssert hash(s1) != hash(r)
+
+  reversed = 0
+  for c in rstr:
+    if (not (c in radded)):
+      reversed = reversed !& hash(c)
+      radded.add(c)
+    r.incl(c)
+  reversed = !$reversed
+  doAssert hash(r) == reversed
+  doAssert hash(s1) != reversed