`json`: fix additionalProperties, allow space after enum/const (#7840)

* json: default additionalProperty to true

* json: don't force additional props after normal properties!

* json: allow space after enum/const

* json: update pydantic example to set additionalProperties: false

* json: prevent additional props to redefine a typed prop

* port not_strings to python, add trailing space

* fix not_strings & port to js+py

* Update json-schema-to-grammar.cpp

* fix _not_strings for substring overlaps

* json: fix additionalProperties default, uncomment tests

* json: add integ. test case for additionalProperties

* json: nit: simplify condition

* reformat grammar integ tests w/ R"""()""" strings where there's escapes

* update # tokens in server test: consts can now have trailing space

common/json-schema-to-grammar.cpp

@@ -614,6 +614,75 @@ private:
         return _add_rule(name, "\"\\\"\" " + to_rule(transform()) + " \"\\\"\" space");
     }
 
+    /*
+        Returns a rule that matches a JSON string that is none of the provided strings
+
+        not_strings({"a"})
+            -> ["] ( [a] char+ | [^"a] char* )? ["] space
+        not_strings({"and", "also"})
+            -> ["] ( [a] ([l] ([s] ([o] char+ | [^"o] char*) | [^"s] char*) | [n] ([d] char+ | [^"d] char*) | [^"ln] char*) | [^"a] char* )? ["] space
+    */
+    std::string _not_strings(const std::vector<std::string> & strings) {
+
+        struct TrieNode {
+            std::map<char, TrieNode> children;
+            bool is_end_of_string;
+
+            TrieNode() : is_end_of_string(false) {}
+
+            void insert(const std::string & string) {
+                auto node = this;
+                for (char c : string) {
+                    node = &node->children[c];
+                }
+                node->is_end_of_string = true;
+            }
+        };
+
+        TrieNode trie;
+        for (const auto & s : strings) {
+            trie.insert(s);
+        }
+
+        std::string char_rule = _add_primitive("char", PRIMITIVE_RULES.at("char"));
+        std::ostringstream out;
+        out << "[\"] ( ";
+        std::function<void(const TrieNode &)> visit = [&](const TrieNode & node) {
+            std::ostringstream rejects;
+            auto first = true;
+            for (const auto & kv : node.children) {
+                rejects << kv.first;
+                if (first) {
+                    first = false;
+                } else {
+                    out << " | ";
+                }
+                out << "[" << kv.first << "]";
+                if (!kv.second.children.empty()) {
+                    out << " (";
+                    visit(kv.second);
+                    out << ")";
+                } else if (kv.second.is_end_of_string) {
+                    out << " " << char_rule << "+";
+                }
+            }
+            if (!node.children.empty()) {
+                if (!first) {
+                    out << " | ";
+                }
+                out << "[^\"" << rejects.str() << "] " << char_rule << "*";
+            }
+        };
+        visit(trie);
+
+        out << " )";
+        if (!trie.is_end_of_string) {
+            out << "?";
+        }
+        out << " [\"] space";
+        return out.str();
+    }
+
     std::string _resolve_ref(const std::string & ref) {
         std::string ref_name = ref.substr(ref.find_last_of('/') + 1);
         if (_rules.find(ref_name) == _rules.end() && _refs_being_resolved.find(ref) == _refs_being_resolved.end()) {
@@ -634,6 +703,7 @@ private:
         std::vector<std::string> required_props;
         std::vector<std::string> optional_props;
         std::unordered_map<std::string, std::string> prop_kv_rule_names;
+        std::vector<std::string> prop_names;
         for (const auto & kv : properties) {
             const auto &prop_name = kv.first;
             const auto &prop_schema = kv.second;
@@ -648,11 +718,18 @@ private:
             } else {
                 optional_props.push_back(prop_name);
             }
+            prop_names.push_back(prop_name);
         }
-        if (additional_properties.is_object() || (additional_properties.is_boolean() && additional_properties.get<bool>())) {
+        if (!(additional_properties.is_boolean() && !additional_properties.get<bool>())) {
             std::string sub_name = name + (name.empty() ? "" : "-") + "additional";
-            std::string value_rule = visit(additional_properties.is_object() ? additional_properties : json::object(), sub_name + "-value");
-            std::string kv_rule = _add_rule(sub_name + "-kv", _add_primitive("string", PRIMITIVE_RULES.at("string")) + " \":\" space " + value_rule);
+            std::string value_rule =
+                additional_properties.is_object() ? visit(additional_properties, sub_name + "-value")
+                : _add_primitive("value", PRIMITIVE_RULES.at("value"));
+
+            auto key_rule =
+                prop_names.empty() ? _add_primitive("string", PRIMITIVE_RULES.at("string"))
+                : _add_rule(sub_name + "-k", _not_strings(prop_names));
+            std::string kv_rule = _add_rule(sub_name + "-kv", key_rule + " \":\" space " + value_rule);
             prop_kv_rule_names["*"] = kv_rule;
             optional_props.push_back("*");
         }
@@ -678,15 +755,11 @@ private:
                 }
                 std::string k = ks[0];
                 std::string kv_rule_name = prop_kv_rule_names[k];
-                if (k == "*") {
-                    res = _add_rule(
-                        name + (name.empty() ? "" : "-") + "additional-kvs",
-                        kv_rule_name + " ( \",\" space " + kv_rule_name + " )*"
-                    );
-                } else if (first_is_optional) {
-                    res = "( \",\" space " + kv_rule_name + " )?";
+                std::string comma_ref = "( \",\" space " + kv_rule_name + " )";
+                if (first_is_optional) {
+                    res = comma_ref + (k == "*" ? "*" : "?");
                 } else {
-                    res = kv_rule_name;
+                    res = kv_rule_name + (k == "*" ? " " + comma_ref + "*" : "");
                 }
                 if (ks.size() > 1) {
                     res += " " + _add_rule(
@@ -824,13 +897,13 @@ public:
             }
             return _add_rule(rule_name, _generate_union_rule(name, schema_types));
         } else if (schema.contains("const")) {
-            return _add_rule(rule_name, _generate_constant_rule(schema["const"]));
+            return _add_rule(rule_name, _generate_constant_rule(schema["const"]) + " space");
         } else if (schema.contains("enum")) {
             std::vector<std::string> enum_values;
             for (const auto & v : schema["enum"]) {
                 enum_values.push_back(_generate_constant_rule(v));
             }
-            return _add_rule(rule_name, join(enum_values.begin(), enum_values.end(), " | "));
+            return _add_rule(rule_name, "(" + join(enum_values.begin(), enum_values.end(), " | ") + ") space");
         } else if ((schema_type.is_null() || schema_type == "object")
                 && (schema.contains("properties") ||
                     (schema.contains("additionalProperties") && schema["additionalProperties"] != true))) {

examples/json-schema-pydantic-example.py

@@ -3,7 +3,7 @@
 #! pip install pydantic
 #! python json-schema-pydantic-example.py
 
-from pydantic import BaseModel, TypeAdapter
+from pydantic import BaseModel, Extra, TypeAdapter
 from annotated_types import MinLen
 from typing import Annotated, List, Optional
 import json, requests
@@ -50,12 +50,16 @@ else:
 if __name__ == '__main__':
 
     class QAPair(BaseModel):
+        class Config:
+            extra = 'forbid'  # triggers additionalProperties: false in the JSON schema
         question: str
         concise_answer: str
         justification: str
         stars: Annotated[int, Field(ge=1, le=5)]
 
     class PyramidalSummary(BaseModel):
+        class Config:
+            extra = 'forbid'  # triggers additionalProperties: false in the JSON schema
         title: str
         summary: str
         question_answers: Annotated[List[QAPair], MinLen(2)]

examples/json_schema_to_grammar.py

@@ -4,8 +4,7 @@ import itertools
 import json
 import re
 import sys
-from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
-
+from typing import Any, List, Optional, Set, Tuple, Union
 
 def _build_repetition(item_rule, min_items, max_items, separator_rule=None):
 
@@ -276,6 +275,51 @@ class SchemaConverter:
 
         return ''.join(('(', *recurse(0), ')'))
 
+    def _not_strings(self, strings):
+        class TrieNode:
+            def __init__(self):
+                self.children = {}
+                self.is_end_of_string = False
+
+            def insert(self, string):
+                node = self
+                for c in string:
+                    node = node.children.setdefault(c, TrieNode())
+                node.is_end_of_string = True
+
+        trie = TrieNode()
+        for s in strings:
+            trie.insert(s)
+
+        char_rule = self._add_primitive('char', PRIMITIVE_RULES['char'])
+        out = ['["] ( ']
+
+        def visit(node):
+            rejects = []
+            first = True
+            for c in sorted(node.children.keys()):
+                child = node.children[c]
+                rejects.append(c)
+                if first:
+                    first = False
+                else:
+                    out.append(' | ')
+                out.append(f'[{c}]')
+                if child.children:
+                    out.append(f' (')
+                    visit(child)
+                    out.append(')')
+                elif child.is_end_of_string:
+                    out.append(f' {char_rule}+')
+            if node.children:
+                if not first:
+                    out.append(' | ')
+                out.append(f'[^"{"".join(rejects)}] {char_rule}*')
+        visit(trie)
+
+        out.append(f' ){"" if trie.is_end_of_string else "?"} ["] space')
+        return ''.join(out)
+
     def _add_rule(self, name, rule):
         esc_name = INVALID_RULE_CHARS_RE.sub('-', name)
         if esc_name not in self._rules or self._rules[esc_name] == rule:
@@ -524,10 +568,10 @@ class SchemaConverter:
             return self._add_rule(rule_name, self._generate_union_rule(name, [{'type': t} for t in schema_type]))
 
         elif 'const' in schema:
-            return self._add_rule(rule_name, self._generate_constant_rule(schema['const']))
+            return self._add_rule(rule_name, self._generate_constant_rule(schema['const']) + ' space')
 
         elif 'enum' in schema:
-            rule = ' | '.join((self._generate_constant_rule(v) for v in schema['enum']))
+            rule = '(' + ' | '.join((self._generate_constant_rule(v) for v in schema['enum'])) + ') space'
             return self._add_rule(rule_name, rule)
 
         elif schema_type in (None, 'object') and \
@@ -632,7 +676,7 @@ class SchemaConverter:
                 self._add_primitive(dep, dep_rule)
         return n
 
-    def _build_object_rule(self, properties: List[Tuple[str, Any]], required: Set[str], name: str, additional_properties: Union[bool, Any]):
+    def _build_object_rule(self, properties: List[Tuple[str, Any]], required: Set[str], name: str, additional_properties: Optional[Union[bool, Any]]):
         prop_order = self._prop_order
         # sort by position in prop_order (if specified) then by original order
         sorted_props = [kv[0] for _, kv in sorted(enumerate(properties), key=lambda ikv: (prop_order.get(ikv[1][0], len(prop_order)), ikv[0]))]
@@ -647,12 +691,16 @@ class SchemaConverter:
         required_props = [k for k in sorted_props if k in required]
         optional_props = [k for k in sorted_props if k not in required]
 
-        if additional_properties == True or isinstance(additional_properties, dict):
+        if additional_properties != False:
             sub_name = f'{name}{"-" if name else ""}additional'
-            value_rule = self.visit({} if additional_properties == True else additional_properties, f'{sub_name}-value')
+            value_rule = self.visit(additional_properties, f'{sub_name}-value') if isinstance(additional_properties, dict) else \
+                self._add_primitive('value', PRIMITIVE_RULES['value'])
+            key_rule = self._add_primitive('string', PRIMITIVE_RULES['string']) if not sorted_props \
+                else self._add_rule(f'{sub_name}-k', self._not_strings(sorted_props))
+
             prop_kv_rule_names["*"] = self._add_rule(
                 f'{sub_name}-kv',
-                self._add_primitive('string', PRIMITIVE_RULES['string']) + f' ":" space {value_rule}'
+                f'{key_rule} ":" space {value_rule}'
             )
             optional_props.append("*")
 
@@ -667,15 +715,11 @@ class SchemaConverter:
             def get_recursive_refs(ks, first_is_optional):
                 [k, *rest] = ks
                 kv_rule_name = prop_kv_rule_names[k]
-                if k == '*':
-                    res = self._add_rule(
-                        f'{name}{"-" if name else ""}additional-kvs',
-                        f'{kv_rule_name} ( "," space ' + kv_rule_name + ' )*'
-                    )
-                elif first_is_optional:
-                    res = f'( "," space {kv_rule_name} )?'
+                comma_ref = f'( "," space {kv_rule_name} )'
+                if first_is_optional:
+                    res = comma_ref + ('*' if k == '*' else '?')
                 else:
-                    res = kv_rule_name
+                    res = kv_rule_name + (' ' + comma_ref + "*" if k == '*' else '')
                 if len(rest) > 0:
                     res += ' ' + self._add_rule(
                         f'{name}{"-" if name else ""}{k}-rest',

examples/server/public/json-schema-to-grammar.mjs

@@ -532,6 +532,64 @@ export class SchemaConverter {
     return this._addRule(name, "\"\\\"\" " + toRule(transform()) + " \"\\\"\" space")
   }
 
+  _notStrings(strings) {
+    class TrieNode {
+      constructor() {
+        this.children = {};
+        this.isEndOfString = false;
+      }
+
+      insert(str) {
+        let node = this;
+        for (const c of str) {
+          node = node.children[c] = node.children[c] || new TrieNode();
+        }
+        node.isEndOfString = true;
+      }
+    }
+
+    const trie = new TrieNode();
+    for (const s of strings) {
+      trie.insert(s);
+    }
+
+    const charRuleName = this._addPrimitive('char', PRIMITIVE_RULES['char']);
+    const out = ['["] ( '];
+
+    const visit = (node) => {
+      const rejects = [];
+      let first = true;
+      for (const c of Object.keys(node.children).sort()) {
+        const child = node.children[c];
+        rejects.push(c);
+        if (first) {
+          first = false;
+        } else {
+          out.push(' | ');
+        }
+        out.push(`[${c}]`);
+        if (Object.keys(child.children).length > 0) {
+          out.push(' (');
+          visit(child);
+          out.push(')');
+        } else if (child.isEndOfString) {
+          out.push(` ${charRuleName}+`);
+        }
+      }
+      if (Object.keys(node.children).length > 0) {
+        if (!first) {
+          out.push(' | ');
+        }
+        out.push(`[^"${rejects.join('')}] ${charRuleName}*`);
+      }
+    };
+
+    visit(trie);
+
+    out.push(` )${trie.isEndOfString ? '' : '?'} ["] space`);
+    return out.join('');
+  }
+
   _resolveRef(ref) {
     let refName = ref.split('/').pop();
     if (!(refName in this._rules) && !this._refsBeingResolved.has(ref)) {
@@ -560,9 +618,9 @@ export class SchemaConverter {
     } else if (Array.isArray(schemaType)) {
       return this._addRule(ruleName, this._generateUnionRule(name, schemaType.map(t => ({ type: t }))));
     } else if ('const' in schema) {
-      return this._addRule(ruleName, this._generateConstantRule(schema.const));
+      return this._addRule(ruleName, this._generateConstantRule(schema.const) + ' space');
     } else if ('enum' in schema) {
-      const rule = schema.enum.map(v => this._generateConstantRule(v)).join(' | ');
+      const rule = '(' + schema.enum.map(v => this._generateConstantRule(v)).join(' | ') + ') space';
       return this._addRule(ruleName, rule);
     } else if ((schemaType === undefined || schemaType === 'object') &&
                ('properties' in schema ||
@@ -599,7 +657,7 @@ export class SchemaConverter {
         }
       }
 
-      return this._addRule(ruleName, this._buildObjectRule(properties, required, name, /* additionalProperties= */ false));
+      return this._addRule(ruleName, this._buildObjectRule(properties, required, name, null));
     } else if ((schemaType === undefined || schemaType === 'array') && ('items' in schema || 'prefixItems' in schema)) {
       const items = schema.items ?? schema.prefixItems;
       if (Array.isArray(items)) {
@@ -693,12 +751,19 @@ export class SchemaConverter {
     const requiredProps = sortedProps.filter(k => required.has(k));
     const optionalProps = sortedProps.filter(k => !required.has(k));
 
-    if (typeof additionalProperties === 'object' || additionalProperties === true) {
+    if (additionalProperties !== false) {
       const subName = `${name ?? ''}${name ? '-' : ''}additional`;
-      const valueRule = this.visit(additionalProperties === true ? {} : additionalProperties, `${subName}-value`);
+      const valueRule =
+        additionalProperties != null && typeof additionalProperties === 'object' ? this.visit(additionalProperties, `${subName}-value`)
+        : this._addPrimitive('value', PRIMITIVE_RULES['value']);
+
+      const key_rule =
+        sortedProps.length === 0 ? this._addPrimitive('string', PRIMITIVE_RULES['string'])
+        : this._addRule(`${subName}-k`, this._notStrings(sortedProps));
+
       propKvRuleNames['*'] = this._addRule(
         `${subName}-kv`,
-        `${this._addPrimitive('string', PRIMITIVE_RULES['string'])} ":" space ${valueRule}`);
+        `${key_rule} ":" space ${valueRule}`);
       optionalProps.push('*');
     }
 
@@ -715,15 +780,11 @@ export class SchemaConverter {
         const [k, ...rest] = ks;
         const kvRuleName = propKvRuleNames[k];
         let res;
-        if (k === '*') {
-            res = this._addRule(
-                `${name ?? ''}${name ? '-' : ''}additional-kvs`,
-                `${kvRuleName} ( "," space ` + kvRuleName + ` )*`
-            )
-        } else if (firstIsOptional) {
-          res = `( "," space ${kvRuleName} )?`;
+        const commaRef = `( "," space ${kvRuleName} )`;
+        if (firstIsOptional) {
+          res = commaRef + (k === '*' ? '*' : '?');
         } else {
-          res = kvRuleName;
+          res = kvRuleName + (k === '*' ? ' ' + commaRef + '*' : '');
         }
         if (rest.length > 0) {
           res += ' ' + this._addRule(

examples/server/tests/features/server.feature

@@ -82,7 +82,7 @@ Feature: llama.cpp server
 
     Examples: Prompts
       | response_format                                                     | n_predicted | re_content             |
-      | {"type": "json_object", "schema": {"const": "42"}}                  | 5           | "42"                   |
+      | {"type": "json_object", "schema": {"const": "42"}}                  | 6           | "42"                   |
       | {"type": "json_object", "schema": {"items": [{"type": "integer"}]}} | 10          | \[ -300 \]             |
       | {"type": "json_object"}                                             | 10          | \{ " Jacky.            |
 

tests/test-grammar-integration.cpp

@@ -15,8 +15,6 @@
 
 using json = nlohmann::ordered_json;
 
-//#define INCLUDE_FAILING_TESTS 1
-
 static llama_grammar* build_grammar(const std::string & grammar_str) {
     auto parsed_grammar = grammar_parser::parse(grammar_str.c_str());
 
@@ -754,7 +752,7 @@ static void test_json_schema() {
         )""",
         // Passing strings
         {
-            "{}",
+            R"""({})""",
             R"""({"foo": "bar"})""",
         },
         // Failing strings
@@ -762,7 +760,7 @@ static void test_json_schema() {
             "",
             "[]",
             "null",
-            "\"\"",
+            R"""("")""",
             "true",
         }
     );
@@ -770,16 +768,14 @@ static void test_json_schema() {
     test_schema(
         "exotic formats (list)",
         // Schema
-        R"""(
-            {
+        R"""({
             "items": [
                 { "format": "date" },
                 { "format": "uuid" },
                 { "format": "time" },
                 { "format": "date-time" }
             ]
-            }
-        )""",
+        })""",
         // Passing strings
         {
             // "{}", // NOTE: This string passes for this schema on https://www.jsonschemavalidator.net/ -- should it?
@@ -798,125 +794,113 @@ static void test_json_schema() {
     test_schema(
         "string",
         // Schema
-        R"""(
-            {
-                "type": "string"
-            }
-        )""",
+        R"""({
+            "type": "string"
+        })""",
         // Passing strings
         {
-            "\"foo\"",
-            "\"bar\"",
-            "\"\"",
+            R"""("foo")""",
+            R"""("bar")""",
+            R"""("")""",
         },
         // Failing strings
         {
-            "{}",
-            "\"foo\": \"bar\"",
+            R"""({})""",
+            R"""("foo": "bar")""",
         }
     );
 
     test_schema(
         "string w/ min length 1",
         // Schema
-        R"""(
-            {
-                "type": "string",
-                "minLength": 1
-            }
-        )""",
+        R"""({
+            "type": "string",
+            "minLength": 1
+        })""",
         // Passing strings
         {
-            "\"foo\"",
-            "\"bar\"",
+            R"""("foo")""",
+            R"""("bar")""",
         },
         // Failing strings
         {
-            "\"\"",
-            "{}",
-            "\"foo\": \"bar\"",
+            R"""("")""",
+            R"""({})""",
+            R"""("foo": "bar")""",
         }
     );
 
     test_schema(
         "string w/ min length 3",
         // Schema
-        R"""(
-            {
+        R"""({
                 "type": "string",
                 "minLength": 3
-            }
-        )""",
+        })""",
         // Passing strings
         {
-            "\"foo\"",
-            "\"bar\"",
-            "\"foobar\"",
+            R"""("foo")""",
+            R"""("bar")""",
+            R"""("foobar")""",
         },
         // Failing strings
         {
-            "\"\"",
-            "\"f\"",
-            "\"fo\"",
+            R"""("")""",
+            R"""("f")""",
+            R"""("fo")""",
         }
     );
 
     test_schema(
         "string w/ max length",
         // Schema
-        R"""(
-            {
-                "type": "string",
-                "maxLength": 3
-            }
-        )""",
+        R"""({
+            "type": "string",
+            "maxLength": 3
+        })""",
         // Passing strings
         {
-            "\"foo\"",
-            "\"bar\"",
-            "\"\"",
-            "\"f\"",
-            "\"fo\"",
+            R"""("foo")""",
+            R"""("bar")""",
+            R"""("")""",
+            R"""("f")""",
+            R"""("fo")""",
         },
         // Failing strings
         {
-            "\"foobar\"",
+            R"""("foobar")""",
         }
     );
 
     test_schema(
         "string w/ min & max length",
         // Schema
-        R"""(
-            {
-                "type": "string",
-                "minLength": 1,
-                "maxLength": 4
-            }
-        )""",
+        R"""({
+            "type": "string",
+            "minLength": 1,
+            "maxLength": 4
+        })""",
         // Passing strings
         {
-            "\"foo\"",
-            "\"bar\"",
-            "\"f\"",
-            "\"barf\"",
+            R"""("foo")""",
+            R"""("bar")""",
+            R"""("f")""",
+            R"""("barf")""",
         },
         // Failing strings
         {
-            "\"\"",
-            "\"barfo\"",
-            "\"foobar\"",
+            R"""("")""",
+            R"""("barfo")""",
+            R"""("foobar")""",
         }
     );
 
     test_schema(
         "boolean",
         // Schema
-        R"""(
-            {
-                "type": "boolean"
-            }
-        )""",
+        R"""({
+            "type": "boolean"
+        })""",
         // Passing strings
         {
             "true",
@@ -924,122 +908,112 @@ static void test_json_schema() {
         },
         // Failing strings
         {
-            "\"\"",
-            "\"true\"",
-            "True",
-            "FALSE",
+            R"""("")""",
+            R"""("true")""",
+            R"""(True)""",
+            R"""(FALSE)""",
         }
     );
 
     test_schema(
         "integer",
         // Schema
-        R"""(
-            {
-                "type": "integer"
-            }
-        )""",
+        R"""({
+            "type": "integer"
+        })""",
         // Passing strings
         {
-            "0",
-            "12345",
-            "1234567890123456"
+            R"""(0)""",
+            R"""(12345)""",
+            R"""(1234567890123456)""",
         },
         // Failing strings
         {
-            "",
-            "01",
-            "007",
-            "12345678901234567"
+            R"""()""",
+            R"""(01)""",
+            R"""(007)""",
+            R"""(12345678901234567  )""",
         }
     );
 
     test_schema(
         "string const",
         // Schema
-        R"""(
-            {
-                "const": "foo"
-            }
-        )""",
+        R"""({
+            "const": "foo"
+        })""",
         // Passing strings
         {
-            "\"foo\"",
+            R"""("foo")""",
         },
         // Failing strings
         {
-            "foo",
-            "\"bar\"",
+            R"""(foo)""",
+            R"""("bar")""",
         }
     );
 
     test_schema(
         "non-string const",
         // Schema
-        R"""(
-            {
-                "const": true
-            }
-        )""",
+        R"""({
+            "const": true
+        })""",
         // Passing strings
         {
-            "true",
+            R"""(true)""",
         },
         // Failing strings
         {
-            "",
-            "foo",
-            "\"true\"",
+            R"""()""",
+            R"""(foo)""",
+            R"""("true")""",
         }
     );
 
     test_schema(
         "non-string const",
         // Schema
-        R"""(
-            {
-                "enum": ["red", "amber", "green", null, 42, ["foo"]]
-            }
-        )""",
+        R"""({
+            "enum": ["red", "amber", "green", null, 42, ["foo"]]
+        })""",
         // Passing strings
         {
-            "\"red\"",
-            "null",
-            "42",
-            "[\"foo\"]",
+            R"""("red")""",
+            R"""(null)""",
+            R"""(42)""",
+            R"""(["foo"])""",
         },
         // Failing strings
         {
-            "",
-            "420",
-            "true",
-            "foo",
+            R"""()""",
+            R"""(420)""",
+            R"""(true)""",
+            R"""(foo)""",
         }
     );
 
     test_schema(
         "min+max items",
         // Schema
-        R"""(
-            {
-                "items": {
-                    "type": ["number", "integer"]
-                },
-                "minItems": 3,
-                "maxItems": 5
-            }
-        )""",
+        R"""({
+            "items": {
+                "type": ["number", "integer"]
+            },
+            "minItems": 3,
+            "maxItems": 5
+        })""",
         // Passing strings
         {
-            "[1, 2, 3]",
-            "[1, 2, 3, 4]",
-            "[1, 2, 3, 4, 5]",
+            R"""([1, 2, 3])""",
+            R"""([1, 2, 3, 4])""",
+            R"""([1, 2, 3, 4, 5])""",
         },
         // Failing strings
         {
-            "[1, 2]",
-            "[1, 2, 3, 4, 5, 6]",
-            "1"
+            R"""([1, 2])""",
+            R"""([1, 2, 3, 4, 5, 6])""",
+            R"""(1)""",
         }
     );
 
@@ -1047,16 +1021,14 @@ static void test_json_schema() {
     test_schema(
         "object properties",
         // Schema
-        R"""(
-            {
+        R"""({
             "type": "object",
             "properties": {
                 "number": { "type": "number" },
                 "street_name": { "type": "string" },
                 "street_type": { "enum": ["Street", "Avenue", "Boulevard"] }
             }
-            }
-        )""",
+        })""",
         // Passing strings
         {
             R"""({ "number": 1600, "street_name": "Pennsylvania", "street_type":"Avenue"})""",
@@ -1066,12 +1038,8 @@ static void test_json_schema() {
             // "By extension, even an empty object is valid"
             R"""({})""",
             // "By default, providing additional properties is valid"
-#ifdef INCLUDE_FAILING_TESTS
-            // TODO: The following should pass, but currently FAILS. Additional properties should be permitted by default.
             R"""({ "number": 1600, "street_name": "Pennsylvania", "street_type":"Avenue", "direction":"NW"})""",
-            // TODO: Spaces should be permitted around enum values, but currently they fail to pass.
             R"""({ "number": 1600, "street_name": "Pennsylvania", "street_type": "Avenue" })""",
-#endif
         },
         // Failing strings
         {
@@ -1084,13 +1052,35 @@ static void test_json_schema() {
         }
     );
 
+    test_schema(
+        "additional properties can't override other properties",
+        R"""({
+            "properties": {
+                "a": {"type": "integer"},
+                "b": {"type": "integer"}
+            },
+            "additionalProperties": true
+        })""",
+        // Passing strings
+        {
+            R"""({"a": 42})""",
+            R"""({"c": ""})""",
+            R"""({"a": 42, "c": ""})""",
+            R"""({"a_": ""})""",
+        },
+        // Failing strings
+        {
+            R"""()""",
+            R"""({"a": ""})""",
+            R"""({"a": "", "b": ""})""",
+        }
+    );
 
     // Properties (from: https://json-schema.org/understanding-json-schema/reference/object#properties)
     test_schema(
         "object properties, additionalProperties: true",
         // Schema
-        R"""(
-            {
+        R"""({
             "type": "object",
             "properties": {
                 "number": { "type": "number" },
@@ -1098,26 +1088,18 @@ static void test_json_schema() {
                 "street_type": { "enum": ["Street", "Avenue", "Boulevard"] }
             },
             "additionalProperties": true
-            }
-        )""",
+        })""",
         // Passing strings
         {
             // "By extension, even an empty object is valid"
             R"""({})""",
-#ifdef INCLUDE_FAILING_TESTS
-            // TODO: Following line should pass and doesn't
             R"""({"number":1600,"street_name":"Pennsylvania","street_type":"Avenue"})""",
             // "By default, leaving out properties is valid"
-            // TODO: Following line should pass and doesn't
             R"""({ "street_name": "Pennsylvania" })""",
-            // TODO: Following line should pass and doesn't
             R"""({ "number": 1600, "street_name": "Pennsylvania" })""",
             // "By default, providing additional properties is valid"
-            // TODO: The following should pass, but currently FAILS. Additional properties should be permitted by default.
             R"""({ "number": 1600, "street_name": "Pennsylvania", "street_type":"Avenue", "direction":"NW"})""",
-            // TODO: Spaces should be permitted around enum values, but currently they fail to pass.
             R"""({ "number": 1600, "street_name": "Pennsylvania", "street_type": "Avenue" })""",
-#endif
         },
         // Failing strings
         {
@@ -1132,8 +1114,7 @@ static void test_json_schema() {
     test_schema(
         "required + optional props each in original order",
         // Schema
-        R"""(
-            {
+        R"""({
             "type": "object",
             "properties": {
                 "number": { "type": "number" },
@@ -1141,18 +1122,15 @@ static void test_json_schema() {
                 "street_type": { "enum": ["Street", "Avenue", "Boulevard"] }
             },
             "additionalProperties": false
-            }
-        )""",
+        })""",
         // Passing strings
         {
             R"""({ "street_name": "Pennsylvania" })""",
             R"""({ "number": 1600, "street_type":"Avenue"})""",
             R"""({ "number": 1600, "street_name": "Pennsylvania" })""",
             R"""({ "number": 1600, "street_name": "Pennsylvania", "street_type":"Avenue"})""",
-#ifdef INCLUDE_FAILING_TESTS
-            // TODO: Spaces should be permitted around enum values, but currently they fail to pass.
+            // Spaces are permitted around enum values
             R"""({ "number": 1600, "street_name": "Pennsylvania", "street_type": "Avenue" })""",
-#endif
         },
         // Failing strings
         {
@@ -1166,18 +1144,16 @@ static void test_json_schema() {
     test_schema(
         "required + optional props each in original order",
         // Schema
-        R"""(
-            {
-                "properties": {
-                    "b": {"type": "string"},
-                    "a": {"type": "string"},
-                    "d": {"type": "string"},
-                    "c": {"type": "string"}
-                },
-                "required": ["a", "b"],
-                "additionalProperties": false
-            }
-        )""",
+        R"""({
+            "properties": {
+                "b": {"type": "string"},
+                "a": {"type": "string"},
+                "d": {"type": "string"},
+                "c": {"type": "string"}
+            },
+            "required": ["a", "b"],
+            "additionalProperties": false
+        })""",
         // Passing strings
         {
             R"""({"b": "foo", "a": "bar"})""",
@@ -1197,8 +1173,7 @@ static void test_json_schema() {
     test_schema(
         "required props",
         // Schema
-        R"""(
-            {
+        R"""({
             "$schema": "https://json-schema.org/draft/2020-12/schema",
             "$id": "https://example.com/product.schema.json",
             "title": "Product",
@@ -1244,8 +1219,7 @@ static void test_json_schema() {
                 }
             },
             "required": [ "productId", "productName", "price" ]
-            }
-        )""",
+        })""",
         // Passing strings
         {
             R"""({"productId": 1, "productName": "A green door", "price": 12.50})""",

tests/test-json-schema-to-grammar.cpp

@@ -473,7 +473,7 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
             "const": "foo"
         })""",
         R"""(
-            root ::= "\"foo\""
+            root ::= "\"foo\"" space
             space ::= | " " | "\n" [ \t]{0,20}
         )"""
     });
@@ -485,7 +485,7 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
             "const": 123
         })""",
         R"""(
-            root ::= "123"
+            root ::= "123" space
             space ::= | " " | "\n" [ \t]{0,20}
         )"""
     });
@@ -497,7 +497,7 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
             "enum": ["red", "amber", "green", null, 42, ["foo"]]
         })""",
         R"""(
-            root ::= "\"red\"" | "\"amber\"" | "\"green\"" | "null" | "42" | "[\"foo\"]"
+            root ::= ("\"red\"" | "\"amber\"" | "\"green\"" | "null" | "42" | "[\"foo\"]") space
             space ::= | " " | "\n" [ \t]{0,20}
         )"""
     });
@@ -816,13 +816,12 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
         })""",
         R"""(
             additional-kv ::= string ":" space additional-value
-            additional-kvs ::= additional-kv ( "," space additional-kv )*
             additional-value ::= "[" space (number ("," space number)*)? "]" space
             char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
             decimal-part ::= [0-9]{1,16}
             integral-part ::= [0] | [1-9] [0-9]{0,15}
             number ::= ("-"? integral-part) ("." decimal-part)? ([eE] [-+]? integral-part)? space
-            root ::= "{" space  (additional-kvs )? "}" space
+            root ::= "{" space  (additional-kv ( "," space additional-kv )* )? "}" space
             space ::= | " " | "\n" [ \t]{0,20}
             string ::= "\"" char* "\"" space
         )"""
@@ -899,13 +898,13 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
         })""",
         R"""(
             a-kv ::= "\"a\"" space ":" space number
-            additional-kv ::= string ":" space string
-            additional-kvs ::= additional-kv ( "," space additional-kv )*
+            additional-k ::= ["] ( [a] char+ | [^"a] char* )? ["] space
+            additional-kv ::= additional-k ":" space string
             char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
             decimal-part ::= [0-9]{1,16}
             integral-part ::= [0] | [1-9] [0-9]{0,15}
             number ::= ("-"? integral-part) ("." decimal-part)? ([eE] [-+]? integral-part)? space
-            root ::= "{" space a-kv ( "," space ( additional-kvs ) )? "}" space
+            root ::= "{" space a-kv ( "," space ( additional-kv ( "," space additional-kv )* ) )? "}" space
             space ::= | " " | "\n" [ \t]{0,20}
             string ::= "\"" char* "\"" space
         )"""
@@ -923,16 +922,15 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
         })""",
         R"""(
             a-kv ::= "\"a\"" space ":" space number
-            a-rest ::= additional-kvs
-            additional-kv ::= string ":" space number
-            additional-kvs ::= additional-kv ( "," space additional-kv )*
+            a-rest ::= ( "," space additional-kv )*
+            additional-k ::= ["] ( [a] char+ | [^"a] char* )? ["] space
+            additional-kv ::= additional-k ":" space number
             char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
             decimal-part ::= [0-9]{1,16}
             integral-part ::= [0] | [1-9] [0-9]{0,15}
             number ::= ("-"? integral-part) ("." decimal-part)? ([eE] [-+]? integral-part)? space
-            root ::= "{" space  (a-kv a-rest | additional-kvs )? "}" space
+            root ::= "{" space  (a-kv a-rest | additional-kv ( "," space additional-kv )* )? "}" space
             space ::= | " " | "\n" [ \t]{0,20}
-            string ::= "\"" char* "\"" space
         )"""
     });
 
@@ -942,25 +940,100 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
         R"""({
             "type": "object",
             "properties": {
-                "a": {"type": "number"},
-                "b": {"type": "number"}
+                "and": {"type": "number"},
+                "also": {"type": "number"}
             },
-            "required": ["a"],
+            "required": ["and"],
             "additionalProperties": {"type": "number"}
         })""",
         R"""(
-            a-kv ::= "\"a\"" space ":" space number
-            additional-kv ::= string ":" space number
-            additional-kvs ::= additional-kv ( "," space additional-kv )*
-            b-kv ::= "\"b\"" space ":" space number
-            b-rest ::= additional-kvs
+            additional-k ::= ["] ( [a] ([l] ([s] ([o] char+ | [^"o] char*) | [^"s] char*) | [n] ([d] char+ | [^"d] char*) | [^"ln] char*) | [^"a] char* )? ["] space
+            additional-kv ::= additional-k ":" space number
+            also-kv ::= "\"also\"" space ":" space number
+            also-rest ::= ( "," space additional-kv )*
+            and-kv ::= "\"and\"" space ":" space number
             char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
             decimal-part ::= [0-9]{1,16}
             integral-part ::= [0] | [1-9] [0-9]{0,15}
             number ::= ("-"? integral-part) ("." decimal-part)? ([eE] [-+]? integral-part)? space
-            root ::= "{" space a-kv ( "," space ( b-kv b-rest | additional-kvs ) )? "}" space
+            root ::= "{" space and-kv ( "," space ( also-kv also-rest | additional-kv ( "," space additional-kv )* ) )? "}" space
+            space ::= | " " | "\n" [ \t]{0,20}
+        )"""
+    });
+
+    test({
+        SUCCESS,
+        "optional props with empty name",
+        R"""({
+            "properties": {
+                "": {"type": "integer"},
+                "a": {"type": "integer"}
+            },
+            "additionalProperties": {"type": "integer"}
+        })""",
+        R"""(
+            -kv ::= "\"\"" space ":" space root
+            -rest ::= ( "," space a-kv )? a-rest
+            a-kv ::= "\"a\"" space ":" space integer
+            a-rest ::= ( "," space additional-kv )*
+            additional-k ::= ["] ( [a] char+ | [^"a] char* ) ["] space
+            additional-kv ::= additional-k ":" space integer
+            char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
+            integer ::= ("-"? integral-part) space
+            integral-part ::= [0] | [1-9] [0-9]{0,15}
+            root ::= ("-"? integral-part) space
+            root0 ::= "{" space  (-kv -rest | a-kv a-rest | additional-kv ( "," space additional-kv )* )? "}" space
+            space ::= | " " | "\n" [ \t]{0,20}
+        )"""
+    });
+
+    test({
+        SUCCESS,
+        "optional props with nested names",
+        R"""({
+            "properties": {
+                "a": {"type": "integer"},
+                "aa": {"type": "integer"}
+            },
+            "additionalProperties": {"type": "integer"}
+        })""",
+        R"""(
+            a-kv ::= "\"a\"" space ":" space integer
+            a-rest ::= ( "," space aa-kv )? aa-rest
+            aa-kv ::= "\"aa\"" space ":" space integer
+            aa-rest ::= ( "," space additional-kv )*
+            additional-k ::= ["] ( [a] ([a] char+ | [^"a] char*) | [^"a] char* )? ["] space
+            additional-kv ::= additional-k ":" space integer
+            char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
+            integer ::= ("-"? integral-part) space
+            integral-part ::= [0] | [1-9] [0-9]{0,15}
+            root ::= "{" space  (a-kv a-rest | aa-kv aa-rest | additional-kv ( "," space additional-kv )* )? "}" space
+            space ::= | " " | "\n" [ \t]{0,20}
+        )"""
+    });
+
+    test({
+        SUCCESS,
+        "optional props with common prefix",
+        R"""({
+            "properties": {
+                "ab": {"type": "integer"},
+                "ac": {"type": "integer"}
+            },
+            "additionalProperties": {"type": "integer"}
+        })""",
+        R"""(
+            ab-kv ::= "\"ab\"" space ":" space integer
+            ab-rest ::= ( "," space ac-kv )? ac-rest
+            ac-kv ::= "\"ac\"" space ":" space integer
+            ac-rest ::= ( "," space additional-kv )*
+            additional-k ::= ["] ( [a] ([b] char+ | [c] char+ | [^"bc] char*) | [^"a] char* )? ["] space
+            additional-kv ::= additional-k ":" space integer
+            char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
+            integer ::= ("-"? integral-part) space
+            integral-part ::= [0] | [1-9] [0-9]{0,15}
+            root ::= "{" space  (ab-kv ab-rest | ac-kv ac-rest | additional-kv ( "," space additional-kv )* )? "}" space
             space ::= | " " | "\n" [ \t]{0,20}
-            string ::= "\"" char* "\"" space
         )"""
     });
 
@@ -1015,15 +1088,28 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
         R"""(
             alternative-0 ::= foo
             alternative-1 ::= bar
-            bar ::= "{" space  (bar-b-kv )? "}" space
+            array ::= "[" space ( value ("," space value)* )? "]" space
+            bar ::= "{" space  (bar-b-kv bar-b-rest | bar-additional-kv ( "," space bar-additional-kv )* )? "}" space
+            bar-additional-k ::= ["] ( [b] char+ | [^"b] char* )? ["] space
+            bar-additional-kv ::= bar-additional-k ":" space value
             bar-b-kv ::= "\"b\"" space ":" space number
+            bar-b-rest ::= ( "," space bar-additional-kv )*
+            boolean ::= ("true" | "false") space
+            char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
             decimal-part ::= [0-9]{1,16}
-            foo ::= "{" space  (foo-a-kv )? "}" space
+            foo ::= "{" space  (foo-a-kv foo-a-rest | foo-additional-kv ( "," space foo-additional-kv )* )? "}" space
             foo-a-kv ::= "\"a\"" space ":" space number
+            foo-a-rest ::= ( "," space foo-additional-kv )*
+            foo-additional-k ::= ["] ( [a] char+ | [^"a] char* )? ["] space
+            foo-additional-kv ::= foo-additional-k ":" space value
             integral-part ::= [0] | [1-9] [0-9]{0,15}
+            null ::= "null" space
             number ::= ("-"? integral-part) ("." decimal-part)? ([eE] [-+]? integral-part)? space
+            object ::= "{" space ( string ":" space value ("," space string ":" space value)* )? "}" space
             root ::= alternative-0 | alternative-1
             space ::= | " " | "\n" [ \t]{0,20}
+            string ::= "\"" char* "\"" space
+            value ::= object | array | string | number | boolean | null
         )"""
     });
 
@@ -1059,15 +1145,25 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
         })""",
         R"""(
             a-kv ::= "\"a\"" space ":" space number
+            additional-k ::= ["] ( [a] char+ | [b] char+ | [c] char+ | [d] char+ | [^"abcd] char* )? ["] space
+            additional-kv ::= additional-k ":" space value
+            array ::= "[" space ( value ("," space value)* )? "]" space
             b-kv ::= "\"b\"" space ":" space number
+            boolean ::= ("true" | "false") space
             c-kv ::= "\"c\"" space ":" space number
+            c-rest ::= ( "," space additional-kv )*
+            char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
             d-kv ::= "\"d\"" space ":" space number
-            d-rest ::= ( "," space c-kv )?
+            d-rest ::= ( "," space c-kv )? c-rest
             decimal-part ::= [0-9]{1,16}
             integral-part ::= [0] | [1-9] [0-9]{0,15}
+            null ::= "null" space
             number ::= ("-"? integral-part) ("." decimal-part)? ([eE] [-+]? integral-part)? space
-            root ::= "{" space a-kv "," space b-kv ( "," space ( d-kv d-rest | c-kv ) )? "}" space
+            object ::= "{" space ( string ":" space value ("," space string ":" space value)* )? "}" space
+            root ::= "{" space a-kv "," space b-kv ( "," space ( d-kv d-rest | c-kv c-rest | additional-kv ( "," space additional-kv )* ) )? "}" space
             space ::= | " " | "\n" [ \t]{0,20}
+            string ::= "\"" char* "\"" space
+            value ::= object | array | string | number | boolean | null
         )"""
     });