A bunch more tests covering NFG casing issues.

Hopefully correct, and covering various edge cases; there's no doubt
some further ones.

S15-nfg/case-change.t

@@ -1,6 +1,6 @@
 use Test;
 
-plan 20;
+plan 52;
 
 # LATIN CAPITAL LETTER D, COMBINING DOT BELOW, COMBINING DOT ABOVE
 {
@@ -18,6 +18,11 @@ plan 20;
     is $x.tc.chars, 1, 'tc still gives us one char';
     is $x.tc, $x, 'tc gives identity';
     is $x.tc.NFD.list, (0x0044, 0x0323, 0x0307), 'tc gives correct NFD';
+
+    #?rakudo.moar 3 skip 'NYI'
+    is $x.fc.chars, 1, 'fc still gives us one char';
+    isnt $x.fc, $x, 'fc does not give identity';
+    is $x.fc.NFD.list, (0x0064, 0x0323, 0x0307), 'fc gives correct NFD';
 }
 
 # LATIN SMALL LETTER D, COMBINING DOT BELOW, COMBINING DOT ABOVE
@@ -36,4 +41,62 @@ plan 20;
     is $x.tc.chars, 1, 'tc still gives us one char';
     isnt $x.tc, $x, 'tc does not give identity';
     is $x.tc.NFD.list, (0x0044, 0x0323, 0x0307), 'tc gives correct NFD';
+
+    #?rakudo.moar 3 skip 'NYI'
+    is $x.fc.chars, 1, 'fc still gives us one char';
+    is $x.fc, $x, 'fc gives identity';
+    is $x.fc.NFD.list, (0x0064, 0x0323, 0x0307), 'fc gives correct NFD';
+}
+
+# LATIN SMALL LETTER J WITH CARON, COMBINING DOT BELOW
+# Interesting because on .uc, .tc there is no precomposed uppercase char, so
+# we will have to form a new synthetic. And with .fc, the CaseFolder table
+# has us take it to pieces, but we'll still need to re-compose it for NFG.
+#?rakudo.moar skip 'NYI'
+{
+    my $x = Uni.new(0x01F0, 0x0323).Str;
+    is $x.chars, 1, 'Sanity: 0x01F0, 0x0323 = 1 grapheme';
+
+    is $x.uc.chars, 1, 'uc still gives us one char';
+    isnt $x.uc, $x, 'uc does not give identity';
+    is $x.uc.NFD.list, (0x004A, 0x0323, 0x030C), 'uc gives correct NFD';
+
+    is $x.lc.chars, 1, 'lc still gives us one char';
+    is $x.lc, $x, 'lc gives identity';
+    is $x.lc.NFD.list, (0x01F0, 0x0323), 'lc gives correct NFD';
+
+    is $x.tc.chars, 1, 'tc still gives us one char';
+    isnt $x.tc, $x, 'tc does not give identity';
+    is $x.tc.NFD.list, (0x004A, 0x0323, 0x030C), 'tc gives correct NFD';
+
+    is $x.fc.chars, 1, 'fc still gives us one char';
+    is $x.fc, $x, 'fc gives identity';
+    is $x.fc.NFD.list, (0x01F0, 0x0323), 'fc gives correct NFD';
+}
+
+# LATIN SMALL LIGATURE FF, COMBINING DOT BELOW
+# This is trickier than the previous one. Which it can casefold to two
+# codepoints, the second is a combiner. But this expands to two base
+# chars, meaning that we need to make sure to sneak the combiner in
+# between the two.
+#?rakudo.moar skip 'NYI'
+{
+    my $x = Uni.new(0xFB00, 0x0323).Str;
+    is $x.chars, 1, 'Sanity: 0xFB00, 0x0323 = 1 grapheme';
+
+    is $x.uc.chars, 2, 'uc gives us 2 chars';
+    isnt $x.uc, $x, 'uc does not give identity';
+    is $x.uc.NFD.list, (0x0046, 0x0323, 0x0046), 'uc gives correct NFD';
+
+    is $x.lc.chars, 1, 'lc still gives us one char';
+    is $x.lc, $x, 'lc gives identity';
+    is $x.lc.NFD.list, (0xFB00, 0x0323), 'lc gives correct NFD';
+
+    is $x.tc.chars, 2, 'tc gives us two chars';
+    isnt $x.tc, $x, 'tc does not give identity';
+    is $x.tc.NFD.list, (0x0046, 0x0323, 0x0066), 'tc gives correct NFD';
+
+    is $x.fc.chars, 2, 'fc gives us two chars';
+    isnt $x.fc, $x, 'fc gives identity';
+    is $x.fc.NFD.list, (0x0066, 0x0323, 0x0066), 'fc gives correct NFD';
 }