Add comprehensive test coverage for Relations and ucumUnit

c/include/json_structure/error_codes.h

@@ -30,6 +30,8 @@ typedef enum {
     JS_SCHEMA_ROOT_MISSING_NAME,
     JS_SCHEMA_ROOT_MISSING_SCHEMA,
     JS_SCHEMA_ROOT_MISSING_TYPE,
+    JS_SCHEMA_KEYWORD_EMPTY,
+    JS_SCHEMA_NAME_INVALID,
 
     /* Type errors */
     JS_SCHEMA_TYPE_INVALID,
@@ -104,6 +106,7 @@ typedef enum {
     JS_SCHEMA_MINITEMS_NEGATIVE,
     JS_SCHEMA_MULTIPLEOF_INVALID,
     JS_SCHEMA_KEYWORD_INVALID_TYPE,
+    JS_SCHEMA_CONSTRAINT_VALUE_INVALID,
 
     /* Import errors */
     JS_SCHEMA_IMPORT_NOT_ALLOWED,

c/src/error_codes.c

@@ -18,6 +18,8 @@ static const char* g_schema_error_messages[] = {
     [JS_SCHEMA_ROOT_MISSING_NAME] = "Root schema missing 'name' property",
     [JS_SCHEMA_ROOT_MISSING_SCHEMA] = "Root schema missing '$schema' property",
     [JS_SCHEMA_ROOT_MISSING_TYPE] = "Root schema missing 'type' property",
+    [JS_SCHEMA_KEYWORD_EMPTY] = "Keyword value cannot be empty",
+    [JS_SCHEMA_NAME_INVALID] = "Name must be a valid identifier",
 
     [JS_SCHEMA_TYPE_INVALID] = "Invalid type value",
     [JS_SCHEMA_TYPE_NOT_STRING] = "Type must be a string",
@@ -81,6 +83,7 @@ static const char* g_schema_error_messages[] = {
     [JS_SCHEMA_MINITEMS_NEGATIVE] = "minItems cannot be negative",
     [JS_SCHEMA_MULTIPLEOF_INVALID] = "multipleOf must be positive",
     [JS_SCHEMA_KEYWORD_INVALID_TYPE] = "Keyword has invalid type",
+    [JS_SCHEMA_CONSTRAINT_VALUE_INVALID] = "Constraint value is invalid",
 
     [JS_SCHEMA_IMPORT_NOT_ALLOWED] = "$import not allowed",
     [JS_SCHEMA_IMPORT_FAILED] = "Failed to import schema",