Fix parsing of string literals with a leading combining character.

Closes #25.

Author: moritz

lib/JSON/Tiny/Actions.pm

@@ -24,9 +24,21 @@ method arraylist($/) {
 }
 
 method string($/) {
-    make +@$<str> == 1
+    my $str =  +@$<str> == 1
         ?? $<str>[0].made
         !! $<str>>>.made.join;
+
+    # see https://github.com/moritz/json/issues/25
+    # when a combining character comes after an opening quote,
+    # it doesn't become part of the quoted string, because
+    # it's stuffed into the same grapheme as the quote.
+    # so we need to extract those combining character(s)
+    # from the match of the opening quote, and stuff it into the string.
+    if $0.Str ne '"' {
+        my @chars := $0.Str.NFC;
+        $str = @chars[1..*].chrs ~ $str;
+    }
+    make $str
 }
 method value:sym<number>($/) { make +$/.Str }
 method value:sym<string>($/) { make $<string>.made }

lib/JSON/Tiny/Grammar.pm

@@ -23,7 +23,8 @@ token value:sym<array>   { <array>  };
 token value:sym<string>  { <string> }
 
 token string {
-    \" ~ \" [ <str> | \\ <str=.str_escape> ]*
+    # see https://github.com/moritz/json/issues/25
+    (:ignoremark '"') ~ \" [ <str> | \\ <str=.str_escape> ]*
 }
 
 token str {

t/01-parse.t

@@ -16,6 +16,8 @@ my @t =
     ' [ ] ',
     # https://github.com/moritz/json/issues/24
     qq/["\x[85]"]/,
+    # https://github.com/moritz/json/issues/25
+    qq/["̥̞ͫͩ̉̎͊ỏ̟͙̞̻̻̹̹r̵̨͇̫̦̺̮̼ͭ,̷̧̬̲͈̤̤̅̉͛ͫ͠ ̣͕̝̳̗̲̩̣͗̋͘e̼ͩ̔̿̾̋̾͘a̸̙͙͔̜͙̳̻͊ͯͪͤͬ͊͆͠c̦̃̓̈̾͗́͝͝ḩ͉͓̦̯̞̆ ̵͇͍ͪ̀́w̷ͩ͗̃͒͏̲̼̯̕i̞̫̜̮̣̰͎̅̂͋̀ͅń̢̨̪̭̠̼͕͎̐́͆̅ͅd̰̤̝͎̹͕ͩ̃̏̃̍͊̔ȏ̶̼̺̪̾ͨ̈̄ͤ̄̚̕w̙̻̱̙̺͎͚̙ͧͪ̊̒̕͝ ̴̼̰̱͈̠ͤ̋̏̇͛&̠̺̟̞͎̳̻̙̽̓́̔̇ͩ͛ͧ̚ ̡̡̫̻͐̌̐̌ͬͦ̂͞"]/,
     # stolen from JSON::XS, 18_json_checker.t, and adapted a bit
     Q<<[
     "JSON Test Pattern pass1",

t/03-unicode.t

@@ -1,17 +1,18 @@
 use v6;
-use JSON::Tiny::Grammar;
-use JSON::Tiny::Actions;
+use JSON::Tiny;
 use Test;
 
-
 my @t =
     '{ "a" : "b\u00E5" }' => { 'a' => 'bå' },
-    '[ "\u2685" ]' => [ '⚅' ];
+    '[ "\u2685" ]' => [ '⚅' ],
+    # issue #25
+    qq{"x\c[ZERO WIDTH JOINER]a"} => "x\c[ZERO WIDTH JOINER]a",
+    qq{"\c[ZERO WIDTH JOINER]"} => "\c[ZERO WIDTH JOINER]",
+    ;
 
 plan (+@t);
 for @t -> $p {
-    my $a = JSON::Tiny::Actions.new();
-    my $o = JSON::Tiny::Grammar.parse($p.key, :actions($a));
-    is-deeply $o.made, $p.value, "Correct data structure for «{$p.key}»"
-        or say "# Got: {$o.made.perl}\n# Expected: {$p.value.perl}";
+    my $got = from-json($p.key);
+    is-deeply $got, $p.value, "Correct data structure for «{$p.key}»"
+        or say "# Got: $got.perl()\n# Expected: {$p.value.perl}";
 }