[njs] Fixed String.prototype.replace() when function returns non-string.

[Dmitry Volyntsev]

details:   https://hg.nginx.org/njs/rev/3a650363913a
branches:  
changeset: 1373:3a650363913a
user:      Dmitry Volyntsev <xeioex at nginx.com>
date:      Tue Apr 14 12:43:09 2020 +0000
description:
Fixed String.prototype.replace() when function returns non-string.

This closes #303 issue on Github.

diffstat:

 src/njs_string.c         |  47 ++++++++++++++++++++++++-----------------------
 src/test/njs_unit_test.c |   6 ++++++
 2 files changed, 30 insertions(+), 23 deletions(-)

diffs (78 lines):

diff -r c6f1ae6d8fac -r 3a650363913a src/njs_string.c
--- a/src/njs_string.c	Tue Apr 14 12:42:05 2020 +0000
+++ b/src/njs_string.c	Tue Apr 14 12:43:09 2020 +0000
@@ -3718,34 +3718,35 @@ njs_string_replace_regexp_function(njs_v
     r->part[0].size = captures[0];
 
     ret = njs_function_apply(vm, r->function, arguments, n + 3, &r->retval);
-
     if (njs_slow_path(ret != NJS_OK)) {
-        return ret;
-    }
-
-    (void) njs_string_prop(&string, this);
-
-    if (njs_is_string(&r->retval)) {
-        njs_string_replacement_copy(&r->part[r->empty ? 0 : 1], &r->retval);
-
-        if (njs_regexp_pattern(regex)->global) {
-            r->part += 2;
-
-            if (r->part[0].start > (string.start + string.size)) {
-                return njs_string_replace_regexp_join(vm, r);
-            }
-
-            return njs_string_replace_regexp(vm, this, regex, r);
+        goto exception;
+    }
+
+    if (njs_slow_path(!njs_is_string(&r->retval))) {
+        ret = njs_value_to_string(vm, &r->retval, &r->retval);
+        if (njs_slow_path(ret != NJS_OK)) {
+            goto exception;
         }
-
-        return njs_string_replace_regexp_join(vm, r);
-    }
+    }
+
+    njs_string_replacement_copy(&r->part[r->empty ? 0 : 1], &r->retval);
+
+    if (njs_regexp_pattern(regex)->global) {
+        r->part += 2;
+
+        if (r->part[0].start > (string.start + string.size)) {
+            return njs_string_replace_regexp_join(vm, r);
+        }
+
+        return njs_string_replace_regexp(vm, this, regex, r);
+    }
+
+    return njs_string_replace_regexp_join(vm, r);
+
+exception:
 
     njs_regex_match_data_free(r->match_data, vm->regex_context);
 
-    njs_internal_error(vm, "unexpected retval type:%s",
-                       njs_type_string(r->retval.type));
-
     return NJS_ERROR;
 }
 
diff -r c6f1ae6d8fac -r 3a650363913a src/test/njs_unit_test.c
--- a/src/test/njs_unit_test.c	Tue Apr 14 12:42:05 2020 +0000
+++ b/src/test/njs_unit_test.c	Tue Apr 14 12:43:09 2020 +0000
@@ -7231,6 +7231,12 @@ static njs_unit_test_t  njs_test[] =
                        "{ return '|'+s+'|'+o+'|'+m+'|'+p+'|' })"),
       njs_str("abc|abcdefghdijklm|3|d|d|efghdijklm") },
 
+    { njs_str("'abc'.replace(/b/, ()=>1)"),
+      njs_str("a1c") },
+
+    { njs_str("var n = 0; 'abbbc'.replace(/b/g, function() {return ++n;})"),
+      njs_str("a123c") },
+
     { njs_str("'abcdefghdijklm'.replace(/x/, 'X')"),
       njs_str("abcdefghdijklm") },