Patch release candidate.

CMakeLists.txt

@@ -9,8 +9,8 @@ project(simdjson
 
 set(PROJECT_VERSION_MAJOR 0)
 set(PROJECT_VERSION_MINOR 9)
-set(PROJECT_VERSION_PATCH 1)
+set(PROJECT_VERSION_PATCH 4)
-set(SIMDJSON_SEMANTIC_VERSION "0.9.1" CACHE STRING "simdjson semantic version")
+set(SIMDJSON_SEMANTIC_VERSION "0.9.4" CACHE STRING "simdjson semantic version")
 set(SIMDJSON_LIB_VERSION "8.0.0" CACHE STRING "simdjson library version")
 set(SIMDJSON_LIB_SOVERSION "8" CACHE STRING "simdjson library soversion")
 set(SIMDJSON_GITHUB_REPOSITORY https://github.com/simdjson/simdjson)

Doxyfile

@@ -38,7 +38,7 @@ PROJECT_NAME           = simdjson
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = "0.9.1"
+PROJECT_NUMBER         = "0.9.4"
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

benchmark/CMakeLists.txt

@@ -37,4 +37,5 @@ if (TARGET benchmark::benchmark)
   endif()
 endif()
 
-include(checkperf.cmake)
+# deliberately disabling.
+# include(checkperf.cmake)

include/simdjson/common_defs.h

@@ -251,4 +251,23 @@ namespace std {
 #endif
 #endif
 
+
+
+#if SIMDJSON_CPLUSPLUS17
+// if we have C++, then fallthrough is a default attribute
+# define simdjson_fallthrough [[fallthrough]]
+// check if we have __attribute__ support
+#elif defined(__has_attribute)
+// check if we have the __fallthrough__ attribute
+#if __has_attribute(__fallthrough__)
+// we are good to go:
+# define simdjson_fallthrough                    __attribute__((__fallthrough__))
+#endif
+#endif
+// on some systems, we simply do not have support for fallthrough, so use a default:
+#ifndef simdjson_fallthrough
+# define simdjson_fallthrough do {} while (0)  /* fallthrough */
+#endif
+
+
 #endif // SIMDJSON_COMMON_DEFS_H

include/simdjson/generic/ondemand/value_iterator-inl.h

@@ -139,21 +139,35 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
   return false;
 }
 
+
 simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator::find_field_unordered_raw(const std::string_view key) noexcept {
+  /**
+   * When find_field_unordered_raw is called, we can either be pointing at the
+   * first key, pointing outside (at the closing brace) or if a key was matched
+   * we can be either pointing right afterthe ':' right before the value (that we need skip),
+   * or we may have consumed the value and we might be at a comma or at the
+   * final brace (ready for a call to has_next_field()).
+   */
   error_code error;
   bool has_value;
-  //
+
+  // First, we scan from that point to the end.
+  // If we don't find a match, we may loop back around, and scan from the beginning to that point.
+  token_position search_start = _json_iter->position();
+
+  // We want to know whether we need to go back to the beginning.
+  bool at_first = at_first_field();
+  ///////////////
   // Initially, the object can be in one of a few different places:
   //
-  // 1. The start of the object, at the first field:
+  // 1. At the first key:
   //
   //    ```
   //    { "a": [ 1, 2 ], "b": [ 3, 4 ] }
   //      ^ (depth 2, index 1)
   //    ```
   //
-  if (at_first_field()) {
+  if (at_first) {
-    // If we're at the beginning of the object, we definitely have a field
     has_value = true;
 
   // 2. When a previous search did not yield a value or the object is empty:
@@ -166,14 +180,16 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
   //    ```
   //
   } else if (!is_open()) {
+
 #ifdef SIMDJSON_DEVELOPMENT_CHECKS
     // If we're past the end of the object, we're being iterated out of order.
     // Note: this isn't perfect detection. It's possible the user is inside some other object; if so,
     // this object iterator will blithely scan that object for fields.
     if (_json_iter->depth() < depth() - 1) { return OUT_OF_ORDER_ITERATION; }
 #endif
-    has_value = false;
+    _json_iter->reenter_child(_start_position + 1, _depth);
-
+    at_first = true;
+    has_value = started_object();
   // 3. When a previous search found a field or an iterator yielded a value:
   //
   //    ```
@@ -189,8 +205,13 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
   //    ```
   //
   } else {
-    // Finish the previous value and see if , or } is next
+    // If someone queried a key but they did access the value, then we are left pointing
+    // at the ':' and we need to move forward through the value... If the value was
+    // processed then skip_child() does not move the iterator (but may adjust the depth).
     if ((error = skip_child() )) { abandon(); return error; }
+    // The has_next_field() advances the pointer and check that either ',' or '}' is found.
+    // It returns true if ',' is found, false otherwise. If anything other than ',' or '}' is found,
+    // then we are in error and we abort.
     if ((error = has_next_field().get(has_value) )) { abandon(); return error; }
 #ifdef SIMDJSON_DEVELOPMENT_CHECKS
     if (_json_iter->start_position(_depth) != _start_position) { return OUT_OF_ORDER_ITERATION; }
@@ -211,10 +232,6 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
   // ```
   //
 
-  // First, we scan from that point to the end.
-  // If we don't find a match, we loop back around, and scan from the beginning to that point.
-  token_position search_start = _json_iter->position();
-
   // Next, we find a match starting from the current position.
   while (has_value) {
     SIMDJSON_ASSUME( _json_iter->_depth == _depth ); // We must be at the start of a field
@@ -222,8 +239,11 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
     // Get the key and colon, stopping at the value.
     raw_json_string actual_key;
     // size_t max_key_length = _json_iter->peek_length() - 2; // -2 for the two quotes
-
+    // field_key() advances the pointer and checks that '"' is found (corresponding to a key).
+    // The depth is left unchanged by field_key().
     if ((error = field_key().get(actual_key) )) { abandon(); return error; };
+    // field_value() will advance and check that we find a ':' separating the
+    // key and the value. It will also increment the depth by one.
     if ((error = field_value() )) { abandon(); return error; }
 
     // If it matches, stop and return
@@ -236,31 +256,44 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
     // input).
     if (actual_key.unsafe_is_equal(key)) {
       logger::log_event(*this, "match", key, -2);
+      // If we return here, then we return while pointing at the ':' that we just checked.
       return true;
     }
 
     // No match: skip the value and see if , or } is next
     logger::log_event(*this, "no match", key, -2);
+    // The call to skip_child is meant to skip over the value corresponding to the key.
+    // After skip_child(), we are right before the next comma (',') or the final brace ('}').
     SIMDJSON_TRY( skip_child() );
+    // The has_next_field() advances the pointer and check that either ',' or '}' is found.
+    // It returns true if ',' is found, false otherwise. If anything other than ',' or '}' is found,
+    // then we are in error and we abort.
     if ((error = has_next_field().get(has_value) )) { abandon(); return error; }
   }
+  // Performance note: it maybe wasteful to rewind to the beginning when there might be
+  // no other query following. Indeed, it would require reskipping the whole object.
+  // Instead, you can just stay where you are. If there is a new query, there is always time
+  // to rewind.
+  if(at_first) { return false; }
 
   // If we reach the end without finding a match, search the rest of the fields starting at the
   // beginning of the object.
   // (We have already run through the object before, so we've already validated its structure. We
   // don't check errors in this bit.)
   _json_iter->reenter_child(_start_position + 1, _depth);
-
   has_value = started_object();
-  while (_json_iter->position() < search_start) {
+  while (true) {
     SIMDJSON_ASSUME(has_value); // we should reach search_start before ever reaching the end of the object
     SIMDJSON_ASSUME( _json_iter->_depth == _depth ); // We must be at the start of a field
 
     // Get the key and colon, stopping at the value.
     raw_json_string actual_key;
     // size_t max_key_length = _json_iter->peek_length() - 2; // -2 for the two quotes
-
+    // field_key() advances the pointer and checks that '"' is found (corresponding to a key).
+    // The depth is left unchanged by field_key().
     error = field_key().get(actual_key); SIMDJSON_ASSUME(!error);
+    // field_value() will advance and check that we find a ':' separating the
+    // key and the value.  It will also increment the depth by one.
     error = field_value(); SIMDJSON_ASSUME(!error);
 
     // If it matches, stop and return
@@ -273,16 +306,28 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
     // input).
     if (actual_key.unsafe_is_equal(key)) {
       logger::log_event(*this, "match", key, -2);
+      // If we return here, then we return while pointing at the ':' that we just checked.
       return true;
     }
 
     // No match: skip the value and see if , or } is next
     logger::log_event(*this, "no match", key, -2);
+    // The call to skip_child is meant to skip over the value corresponding to the key.
+    // After skip_child(), we are right before the next comma (',') or the final brace ('}').
     SIMDJSON_TRY( skip_child() );
+    // If we reached the end of the key-value pair we started from, then we know
+    // that the key is not there so we return false. We are either right before
+    // the next comma or the final brace.
+    if(_json_iter->position() == search_start) { return false; }
+    // The has_next_field() advances the pointer and check that either ',' or '}' is found.
+    // It returns true if ',' is found, false otherwise. If anything other than ',' or '}' is found,
+    // then we are in error and we abort.
     error = has_next_field().get(has_value); SIMDJSON_ASSUME(!error);
+    // If we make the mistake of exiting here, then we could be left pointing at a key
+    // in the middle of an object. That's not an allowable state.
   }
-
+  // If the loop ended, we're out of fields to look at. The program should
-  // If the loop ended, we're out of fields to look at.
+  // never reach this point.
   return false;
 }
 

include/simdjson/simdjson_version.h

@@ -4,7 +4,7 @@
 #define SIMDJSON_SIMDJSON_VERSION_H
 
 /** The version of simdjson being used (major.minor.revision) */
-#define SIMDJSON_VERSION 0.9.1
+#define SIMDJSON_VERSION 0.9.4
 
 namespace simdjson {
 enum {
@@ -19,7 +19,7 @@ enum {
   /**
    * The revision (major.minor.REVISION) of simdjson being used.
    */
-  SIMDJSON_VERSION_REVISION = 1
+  SIMDJSON_VERSION_REVISION = 4
 };
 } // namespace simdjson
 

singleheader/simdjson.cpp

@@ -1,4 +1,4 @@
-/* auto-generated on 2021-03-18 11:30:40 -0400. Do not edit! */
+/* auto-generated on 2021-05-14 09:22:48 -0400. Do not edit! */
 /* begin file src/simdjson.cpp */
 #include "simdjson.h"
 

singleheader/simdjson.h

@@ -1,4 +1,4 @@
-/* auto-generated on 2021-03-18 11:30:40 -0400. Do not edit! */
+/* auto-generated on 2021-05-14 09:22:48 -0400. Do not edit! */
 /* begin file include/simdjson.h */
 #ifndef SIMDJSON_H
 #define SIMDJSON_H
@@ -2045,6 +2045,25 @@ namespace std {
 #endif
 #endif
 
+
+
+#if SIMDJSON_CPLUSPLUS17
+// if we have C++, then fallthrough is a default attribute
+# define simdjson_fallthrough [[fallthrough]]
+// check if we have __attribute__ support
+#elif defined(__has_attribute)
+// check if we have the __fallthrough__ attribute
+#if __has_attribute(__fallthrough__)
+// we are good to go:
+# define simdjson_fallthrough                    __attribute__((__fallthrough__))
+#endif
+#endif
+// on some systems, we simply do not have support for fallthrough, so use a default:
+#ifndef simdjson_fallthrough
+# define simdjson_fallthrough do {} while (0)  /* fallthrough */
+#endif
+
+
 #endif // SIMDJSON_COMMON_DEFS_H
 /* end file include/simdjson/common_defs.h */
 
@@ -2059,7 +2078,7 @@ SIMDJSON_DISABLE_UNDESIRED_WARNINGS
 #define SIMDJSON_SIMDJSON_VERSION_H
 
 /** The version of simdjson being used (major.minor.revision) */
-#define SIMDJSON_VERSION 0.9.1
+#define SIMDJSON_VERSION 0.9.4
 
 namespace simdjson {
 enum {
@@ -2074,7 +2093,7 @@ enum {
   /**
    * The revision (major.minor.REVISION) of simdjson being used.
    */
-  SIMDJSON_VERSION_REVISION = 1
+  SIMDJSON_VERSION_REVISION = 4
 };
 } // namespace simdjson
 
@@ -22088,21 +22107,35 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
   return false;
 }
 
+
 simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator::find_field_unordered_raw(const std::string_view key) noexcept {
+  /**
+   * When find_field_unordered_raw is called, we can either be pointing at the
+   * first key, pointing outside (at the closing brace) or if a key was matched
+   * we can be either pointing right afterthe ':' right before the value (that we need skip),
+   * or we may have consumed the value and we might be at a comma or at the
+   * final brace (ready for a call to has_next_field()).
+   */
   error_code error;
   bool has_value;
-  //
+
+  // First, we scan from that point to the end.
+  // If we don't find a match, we may loop back around, and scan from the beginning to that point.
+  token_position search_start = _json_iter->position();
+
+  // We want to know whether we need to go back to the beginning.
+  bool at_first = at_first_field();
+  ///////////////
   // Initially, the object can be in one of a few different places:
   //
-  // 1. The start of the object, at the first field:
+  // 1. At the first key:
   //
   //    ```
   //    { "a": [ 1, 2 ], "b": [ 3, 4 ] }
   //      ^ (depth 2, index 1)
   //    ```
   //
-  if (at_first_field()) {
+  if (at_first) {
-    // If we're at the beginning of the object, we definitely have a field
     has_value = true;
 
   // 2. When a previous search did not yield a value or the object is empty:
@@ -22115,14 +22148,16 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
   //    ```
   //
   } else if (!is_open()) {
+
 #ifdef SIMDJSON_DEVELOPMENT_CHECKS
     // If we're past the end of the object, we're being iterated out of order.
     // Note: this isn't perfect detection. It's possible the user is inside some other object; if so,
     // this object iterator will blithely scan that object for fields.
     if (_json_iter->depth() < depth() - 1) { return OUT_OF_ORDER_ITERATION; }
 #endif
-    has_value = false;
+    _json_iter->reenter_child(_start_position + 1, _depth);
-
+    at_first = true;
+    has_value = started_object();
   // 3. When a previous search found a field or an iterator yielded a value:
   //
   //    ```
@@ -22138,8 +22173,13 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
   //    ```
   //
   } else {
-    // Finish the previous value and see if , or } is next
+    // If someone queried a key but they did access the value, then we are left pointing
+    // at the ':' and we need to move forward through the value... If the value was
+    // processed then skip_child() does not move the iterator (but may adjust the depth).
     if ((error = skip_child() )) { abandon(); return error; }
+    // The has_next_field() advances the pointer and check that either ',' or '}' is found.
+    // It returns true if ',' is found, false otherwise. If anything other than ',' or '}' is found,
+    // then we are in error and we abort.
     if ((error = has_next_field().get(has_value) )) { abandon(); return error; }
 #ifdef SIMDJSON_DEVELOPMENT_CHECKS
     if (_json_iter->start_position(_depth) != _start_position) { return OUT_OF_ORDER_ITERATION; }
@@ -22160,10 +22200,6 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
   // ```
   //
 
-  // First, we scan from that point to the end.
-  // If we don't find a match, we loop back around, and scan from the beginning to that point.
-  token_position search_start = _json_iter->position();
-
   // Next, we find a match starting from the current position.
   while (has_value) {
     SIMDJSON_ASSUME( _json_iter->_depth == _depth ); // We must be at the start of a field
@@ -22171,8 +22207,11 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
     // Get the key and colon, stopping at the value.
     raw_json_string actual_key;
     // size_t max_key_length = _json_iter->peek_length() - 2; // -2 for the two quotes
-
+    // field_key() advances the pointer and checks that '"' is found (corresponding to a key).
+    // The depth is left unchanged by field_key().
     if ((error = field_key().get(actual_key) )) { abandon(); return error; };
+    // field_value() will advance and check that we find a ':' separating the
+    // key and the value. It will also increment the depth by one.
     if ((error = field_value() )) { abandon(); return error; }
 
     // If it matches, stop and return
@@ -22185,31 +22224,44 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
     // input).
     if (actual_key.unsafe_is_equal(key)) {
       logger::log_event(*this, "match", key, -2);
+      // If we return here, then we return while pointing at the ':' that we just checked.
       return true;
     }
 
     // No match: skip the value and see if , or } is next
     logger::log_event(*this, "no match", key, -2);
+    // The call to skip_child is meant to skip over the value corresponding to the key.
+    // After skip_child(), we are right before the next comma (',') or the final brace ('}').
     SIMDJSON_TRY( skip_child() );
+    // The has_next_field() advances the pointer and check that either ',' or '}' is found.
+    // It returns true if ',' is found, false otherwise. If anything other than ',' or '}' is found,
+    // then we are in error and we abort.
     if ((error = has_next_field().get(has_value) )) { abandon(); return error; }
   }
+  // Performance note: it maybe wasteful to rewind to the beginning when there might be
+  // no other query following. Indeed, it would require reskipping the whole object.
+  // Instead, you can just stay where you are. If there is a new query, there is always time
+  // to rewind.
+  if(at_first) { return false; }
 
   // If we reach the end without finding a match, search the rest of the fields starting at the
   // beginning of the object.
   // (We have already run through the object before, so we've already validated its structure. We
   // don't check errors in this bit.)
   _json_iter->reenter_child(_start_position + 1, _depth);
-
   has_value = started_object();
-  while (_json_iter->position() < search_start) {
+  while (true) {
     SIMDJSON_ASSUME(has_value); // we should reach search_start before ever reaching the end of the object
     SIMDJSON_ASSUME( _json_iter->_depth == _depth ); // We must be at the start of a field
 
     // Get the key and colon, stopping at the value.
     raw_json_string actual_key;
     // size_t max_key_length = _json_iter->peek_length() - 2; // -2 for the two quotes
-
+    // field_key() advances the pointer and checks that '"' is found (corresponding to a key).
+    // The depth is left unchanged by field_key().
     error = field_key().get(actual_key); SIMDJSON_ASSUME(!error);
+    // field_value() will advance and check that we find a ':' separating the
+    // key and the value.  It will also increment the depth by one.
     error = field_value(); SIMDJSON_ASSUME(!error);
 
     // If it matches, stop and return
@@ -22222,16 +22274,28 @@ simdjson_warn_unused simdjson_really_inline simdjson_result<bool> value_iterator
     // input).
     if (actual_key.unsafe_is_equal(key)) {
       logger::log_event(*this, "match", key, -2);
+      // If we return here, then we return while pointing at the ':' that we just checked.
       return true;
     }
 
     // No match: skip the value and see if , or } is next
     logger::log_event(*this, "no match", key, -2);
+    // The call to skip_child is meant to skip over the value corresponding to the key.
+    // After skip_child(), we are right before the next comma (',') or the final brace ('}').
     SIMDJSON_TRY( skip_child() );
+    // If we reached the end of the key-value pair we started from, then we know
+    // that the key is not there so we return false. We are either right before
+    // the next comma or the final brace.
+    if(_json_iter->position() == search_start) { return false; }
+    // The has_next_field() advances the pointer and check that either ',' or '}' is found.
+    // It returns true if ',' is found, false otherwise. If anything other than ',' or '}' is found,
+    // then we are in error and we abort.
     error = has_next_field().get(has_value); SIMDJSON_ASSUME(!error);
+    // If we make the mistake of exiting here, then we could be left pointing at a key
+    // in the middle of an object. That's not an allowable state.
   }
-
+  // If the loop ended, we're out of fields to look at. The program should
-  // If the loop ended, we're out of fields to look at.
+  // never reach this point.
   return false;
 }
 

tests/ondemand/ondemand_object_tests.cpp

@@ -7,6 +7,178 @@ namespace object_tests {
   using namespace std;
   using simdjson::ondemand::json_type;
 
+  // In this test, no non-trivial object in an array have a missing key
+  bool no_missing_keys() {
+    TEST_START();
+    simdjson::ondemand::parser parser;
+    simdjson::padded_string docdata =  R"([{"a":"a"},{}])"_padded;
+    simdjson::ondemand::document doc;
+    auto error = parser.iterate(docdata).get(doc);
+    if(error != simdjson::SUCCESS) { return false; }
+    simdjson::ondemand::array a;
+    error = doc.get_array().get(a);
+    if(error != simdjson::SUCCESS) { return false; }
+    size_t counter{0};
+    for(auto elem : a) {
+      error = elem.find_field_unordered("a").error();
+      if(counter == 0) {
+        ASSERT_EQUAL( error, simdjson::SUCCESS);
+      } else {
+        ASSERT_EQUAL( error, simdjson::NO_SUCH_FIELD);
+      }
+      counter++;
+    }
+    return true;
+  }
+
+  bool missing_key_continue() {
+    TEST_START();
+    simdjson::ondemand::parser parser;
+    simdjson::padded_string docdata =  R"({"a":0, "b":1, "c":2})"_padded;
+    simdjson::ondemand::document doc;
+    ASSERT_SUCCESS(parser.iterate(docdata).get(doc));
+    int64_t num;
+    ASSERT_SUCCESS(doc["a"].get(num));
+    ASSERT_EQUAL(num, 0);
+    ASSERT_SUCCESS(doc["b"].get(num));
+    ASSERT_EQUAL(num, 1);
+    ASSERT_SUCCESS(doc["c"].get(num));
+    ASSERT_EQUAL(num, 2);
+    // Start again, but omit a key
+    ASSERT_SUCCESS(parser.iterate(docdata).get(doc));
+    ASSERT_SUCCESS(doc["a"].get(num));
+    ASSERT_EQUAL(num, 0);
+    ASSERT_SUCCESS(doc["c"].get(num));
+    ASSERT_EQUAL(num, 2);
+    // Start again, but request a missing key
+    ASSERT_SUCCESS(parser.iterate(docdata).get(doc));
+    simdjson::ondemand::object obj;
+    ASSERT_SUCCESS(doc.get_object().get(obj));
+    ASSERT_SUCCESS(obj["a"].get(num));
+    ASSERT_EQUAL(num, 0);
+    assert_error(obj["d"].get(num), NO_SUCH_FIELD);
+    ASSERT_SUCCESS(obj["c"].get(num));
+    ASSERT_EQUAL(num, 2);
+    // Start again, but request a missing key first
+    ASSERT_SUCCESS(parser.iterate(docdata).get(doc));
+    ASSERT_SUCCESS(doc.get_object().get(obj));
+    assert_error(obj["d"].get(num), NO_SUCH_FIELD);
+    ASSERT_SUCCESS(obj["a"].get(num));
+    ASSERT_EQUAL(num, 0);
+    // Start again, but request a missing key twice
+    ASSERT_SUCCESS(parser.iterate(docdata).get(doc));
+    ASSERT_SUCCESS(doc.get_object().get(obj));
+    ASSERT_SUCCESS(obj["a"].get(num));
+    ASSERT_EQUAL(num, 0);
+    assert_error(obj["d"].get(num), NO_SUCH_FIELD);
+    assert_error(obj["z"].get(num), NO_SUCH_FIELD);
+    // Because we do a full circle, you can query the same
+    // key twice!!!
+    ASSERT_SUCCESS(obj["a"].get(num));
+    ASSERT_EQUAL(num, 0);
+    ASSERT_SUCCESS(obj["b"].get(num));
+    ASSERT_EQUAL(num, 1);
+    ASSERT_SUCCESS(obj["b"].get(num));
+    ASSERT_EQUAL(num, 1);
+    ASSERT_SUCCESS(obj["a"].get(num));
+    ASSERT_EQUAL(num, 0);
+    assert_error(obj["d"].get(num), NO_SUCH_FIELD);
+    ASSERT_SUCCESS(obj["a"].get(num));
+    ASSERT_EQUAL(num, 0);
+    TEST_SUCCEED();
+  }
+
+  bool missing_keys() {
+    TEST_START();
+    simdjson::ondemand::parser parser;
+    simdjson::padded_string docdata =  R"([{"a":"a"},{}])"_padded;
+    simdjson::ondemand::document doc;
+    auto error = parser.iterate(docdata).get(doc);
+    if(error != simdjson::SUCCESS) { return false; }
+    simdjson::ondemand::array a;
+    error = doc.get_array().get(a);
+    if(error != simdjson::SUCCESS) { return false; }
+    for(auto elem : a) {
+      error = elem.find_field_unordered("keynotfound").error();
+      if(error != simdjson::NO_SUCH_FIELD) {
+        std::cout << error << std::endl;
+        return false;
+      }
+    }
+    return true;
+  }
+
+#if SIMDJSON_EXCEPTIONS
+  // used in issue_1521
+  // difficult to use as a lambda because it is recursive.
+  void broken_descend(ondemand::object node) {
+    if(auto type = node.find_field_unordered("type"); type.error() == SUCCESS && type == "child") {
+      auto n = node.find_field_unordered("name");
+      if(n.error() == simdjson::SUCCESS) {
+          std::cout << std::string_view(n) << std::endl;
+      }
+    } else {
+     for (ondemand::object child_node : node["nodes"]) { broken_descend(child_node); }
+    }
+  }
+
+  bool broken_issue_1521() {
+    TEST_START();
+    ondemand::parser parser;
+    padded_string json = R"({"type":"root","nodes":[{"type":"child","nodes":[]},{"type":"child","name":"child-name","nodes":[]}]})"_padded;
+    ondemand::document file_tree = parser.iterate(json);
+    try {
+      broken_descend(file_tree);
+    } catch(simdjson::simdjson_error& e) {
+      std::cout << "The document is valid JSON: " << json << std::endl;
+      TEST_FAIL(e.error());
+    }
+    TEST_SUCCEED();
+  }
+
+  bool fixed_broken_issue_1521() {
+    TEST_START();
+    ondemand::parser parser;
+    // We omit the ',"nodes":[]'
+    padded_string json = R"({"type":"root","nodes":[{"type":"child"},{"type":"child","name":"child-name","nodes":[]}]})"_padded;
+    ondemand::document file_tree = parser.iterate(json);
+    try {
+      broken_descend(file_tree);
+    } catch(simdjson::simdjson_error& e) {
+      std::cout << "The document is valid JSON: " << json << std::endl;
+      TEST_FAIL(e.error());
+    }
+    TEST_SUCCEED();
+  }
+
+  // used in issue_1521
+  // difficult to use as a lambda because it is recursive.
+  void descend(ondemand::object node) {
+    auto n = node.find_field_unordered("name");
+    if(auto type = node.find_field_unordered("type"); type.error() == SUCCESS && type == "child") {
+      if(n.error() == simdjson::SUCCESS) {
+          std::cout << std::string_view(n) << std::endl;
+      }
+    } else {
+     for (ondemand::object child_node : node["nodes"]) { descend(child_node); }
+    }
+  }
+
+  bool issue_1521() {
+    TEST_START();
+    ondemand::parser parser;
+    padded_string json = R"({"type":"root","nodes":[{"type":"child","nodes":[]},{"type":"child","name":"child-name","nodes":[]}]})"_padded;
+    ondemand::document file_tree = parser.iterate(json);
+    try {
+      descend(file_tree);
+    } catch(simdjson::simdjson_error& e) {
+      std::cout << "The document is valid JSON: " << json << std::endl;
+      TEST_FAIL(e.error());
+    }
+    TEST_SUCCEED();
+  }
+#endif
+
   bool iterate_object() {
     TEST_START();
     auto json = R"({ "a": 1, "b": 2, "c": 3 })"_padded;
@@ -893,6 +1065,14 @@ namespace object_tests {
 
   bool run() {
     return
+           no_missing_keys() &&
+           missing_key_continue() &&
+           missing_keys() &&
+#if SIMDJSON_EXCEPTIONS
+           fixed_broken_issue_1521() &&
+           issue_1521() &&
+           broken_issue_1521() &&
+#endif
            iterate_object() &&
            iterate_empty_object() &&
            object_index() &&