API.md

cpp-oasvalidator v1.1.1: API Reference

cpp-oasvalidator offers a comprehensive API for validating HTTP requests in accordance with OpenAPI specifications. It encompasses various validation categories including Path, Body, Parameters, and Response.

The API functions return a ValidationError type and accept a reference to a std::string for populating error messages in case of validation failure. A successful validation returns ValidationError::NONE. Otherwise, an error code is returned and the error message is populated. The error message follows this JSON schema:

{
  "errorCode": "INVALID_BODY",
  "details": {
    "specRef": "#/paths/%2Fpet/put/requestBody/content/application%2Fjson/schema",
    "code": "type",
    "description": "The property type 'string' is not on the approved list: 'array'.",
    "instance": "#/photoUrls",
    "schema": "#/properties/photoUrls"
  }
}

cpp-oasvalidator defines the following ValidationError enum to categorize various types of validation errors:

enum class validationError
{
    NONE                 = 0,
    INVALID_METHOD       = -1,
    INVALID_ROUTE        = -2,
    INVALID_PATH_PARAM   = -3,
    INVALID_QUERY_PARAM  = -4,
    INVALID_HEADER_PARAM = -5,
    INVALID_BODY         = -6,
    INVALID_RSP          = -7
};

• errorCode: Corresponds to the ValidationError enum value.
• details: Provides a specRef pointing to the exact location in the OpenAPI spec where the request failed. This is URI-encoded to handle special characters.
  • Additional fields in details offer context-specific insights such as the type of error and relevant references.

Designed with performance and optimization as priorities, cpp-oasvalidator performs lazy deserialization and parsing of request components (path, query, header parameters, and body) only when all preceding validations pass.

Four overloaded methods are available to validate different combinations of request components (e.g., with/without body or headers) to accommodate various HTTP methods and use-cases.

The following API reference outlines each function and its sequence of validation checks.

Table of Contents

1. Constructor
2. Validate Route
3. Validate Body
4. Validate Path Parameters
5. Validate Query Parameters
6. Validate Header Parameters
7. Validate Request
8. Validate Request (Overloaded)
9. Validate Request (Overloaded)
10. Validate Request (Overloaded)

1. Constructor 🏗️

Initializes an OASValidator object with the OpenAPI specification from the provided file path.

Synopsis

explicit OASValidator(const std::string& oas_specs);

Arguments

• oas_specs: The file path to the OpenAPI specification or a JSON string containing the OpenAPI specification.

Example

OASValidator oas_validator("/path/to/openapi/spec.json");

Throws

This constructor will throw an ValidatorInitExc if it fails to initialize with the provided OpenAPI specification.

Note

Ensure that the OpenAPI specification file exists at the provided path and is in a valid JSON format.

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2. Validate Route 🗺️

Validates the HTTP method and path/route against the OpenAPI specification, and populates error_msg with details if validation fails.

Validation sequence

1. HTTP method
2. Route

Synopsis

ValidationError ValidateRoute(
    const std::string& method,
    const std::string& http_path,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "GET", "POST") as a std::string.
• http_path: The HTTP path (e.g., "/api/v1/resource") as a std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, whereas other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE

Example

std::string error_msg;
ValidationError result = oas_validator.ValidateRoute("GET", "/api/v1/resource", error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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3. Validate Body 📦

Validates the JSON body of the HTTP request against JSON schema the OpenAPI specification for the specific route, and sets error_msg with a descriptive error message if validation fails.

Validation sequence

1. HTTP method
2. Route
3. Body schema

Synopsis

ValidationError ValidateBody(
    const std::string& method,
    const std::string& http_path,
    const std::string& json_body,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "POST", "PUT") as a std::string.
• http_path: The HTTP path (e.g., "/api/v1/resource") as a std::string.
• json_body: The JSON body of the HTTP request as a std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, while other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE
  • ValidationError::INVALID_BODY

Example

std::string error_msg;
ValidationError result = oas_validator.ValidateBody("POST", "/api/v1/resource", "{\"key\": \"value\"}", error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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4. Validate Path Parameters 📂

Validates the path parameters of the HTTP request against the OpenAPI specification, and populates error_msg with a descriptive message if validation fails.

Validation sequence

1. HTTP method
2. Route
3. Path parameters (in the sequence of provided in OpenAPI spec)

Synopsis

ValidationError ValidatePathParam(
    const std::string& method,
    const std::string& http_path,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "GET", "DELETE") as a std::string.
• http_path: The HTTP path with parameters (e.g., "/api/v1/resource/{id}") as a std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, whereas other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE
  • ValidationError::INVALID_PATH_PARAM

Example

std::string error_msg;
ValidationError result = oas_validator.ValidatePathParam("GET", "/api/v1/resource/123", error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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5. Validate Query Parameters ❓

Validates the query parameters of the HTTP request against the OpenAPI specification, and sets error_msg with a descriptive error message if validation fails.

Validation sequence

1. HTTP method
2. Route
3. Query parameters (in the sequence of provided in OpenAPI spec)

Synopsis

ValidationError ValidateQueryParam(
    const std::string& method,
    const std::string& http_path,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "GET", "DELETE") as a std::string.
• http_path: The HTTP path including query parameters (e.g., "/api/v1/resource?name=value") as a std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, while other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE
  • ValidationError::INVALID_QUERY_PARAM

Example

std::string error_msg;
ValidationError result = oas_validator.ValidateQueryParam("GET", "/api/v1/resource?name=value", error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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6. Validate Header Parameters 📋

Validates the HTTP headers against the OpenAPI specification, and populates error_msg with a descriptive message if validation fails.

Validation sequence

1. HTTP method
2. Route
3. Header parameters

Synopsis

ValidationError ValidateHeaders(
    const std::string& method,
    const std::string& http_path,
    const std::unordered_map<std::string, std::string>& headers,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "GET", "POST") as a std::string.
• http_path: The HTTP path (e.g., "/api/v1/resource") as a std::string.
• headers: The HTTP headers as an std::unordered_map of std::string to std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, while other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE
  • ValidationError::INVALID_HEADER_PARAM

Example

std::unordered_map<std::string, std::string> headers = {{"Authorization", "Bearer token"}};
std::string error_msg;
ValidationError result = oas_validator.ValidateHeaders("GET", "/api/v1/resource", headers, error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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7. Validate Request ✔️

Validates the entire HTTP request including method, route, path params, and/or query params against the OpenAPI specification, and sets error_msg with a descriptive error message if validation fails.

Validation sequence

1. HTTP method
2. Route
3. Path parameters (if specified in specs, in the sequence of provided in OpenAPI spec)
4. Query parameters (if specified in specs, in the sequence of provided in OpenAPI spec)

Synopsis

ValidationError ValidateRequest(
    const std::string& method,
    const std::string& http_path,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "POST", "PUT") as a std::string.
• http_path: The HTTP path (e.g., "/api/v1/resource") as a std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, while other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE
  • ValidationError::INVALID_PATH_PARAM
  • ValidationError::INVALID_QUERY_PARAM

Example

std::string error_msg;
ValidationError result = oas_validator.ValidateRequest("POST", "/api/v1/resource", error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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8. Validate Request (Overloaded) ✔️🔠

Validates the entire HTTP request including method, route, JSON body, path/query params (if specified) against the OpenAPI specification, and sets error_msg with a descriptive error message if validation fails.

Validation sequence

1. HTTP method
2. Route
3. Body schema
4. Path parameters (if specified in specs, in the sequence of provided in OpenAPI spec)
5. Query parameters (if specified in specs, in the sequence of provided in OpenAPI spec)

Synopsis

ValidationError ValidateRequest(
    const std::string& method,
    const std::string& http_path,
    const std::string& json_body,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "POST", "PUT") as a std::string.
• http_path: The HTTP path (e.g., "/api/v1/resource") as a std::string.
• json_body: The JSON body of the HTTP request as a std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, while other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE
  • ValidationError::INVALID_BODY
  • ValidationError::INVALID_PATH_PARAM
  • ValidationError::INVALID_QUERY_PARAM

Example

std::string error_msg;
ValidationError result = oas_validator.ValidateRequest("POST", "/api/v1/resource", "{\"key\": \"value\"}", error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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9. Validate Request (Overloaded) ✔️🔢

Validates the entire HTTP request including method, route, path/query params (if specified) and headers against the OpenAPI specification, and sets error_msg with a descriptive error message if validation fails.

Validation sequence

1. HTTP method
2. Route
3. Path parameters (if specified in specs, in the sequence of provided in OpenAPI spec)
4. Query parameters (if specified in specs, in the sequence of provided in OpenAPI spec)
5. Header parameters

Synopsis

ValidationError ValidateRequest(
    const std::string& method,
    const std::string& http_path,
    const std::unordered_map<std::string, std::string>& headers,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "GET", "DELETE") as a std::string.
• http_path: The HTTP path (e.g., "/api/v1/resource") as a std::string.
• headers: The HTTP headers as an std::unordered_map of std::string to std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, while other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE
  • ValidationError::INVALID_PATH_PARAM
  • ValidationError::INVALID_QUERY_PARAM
  • ValidationError::INVALID_HEADER_PARAM

Example

std::unordered_map<std::string, std::string> headers = {{"Authorization", "Bearer token"}};
std::string error_msg;
ValidationError result = oas_validator.ValidateRequest("GET", "/api/v1/resource", headers, error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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10. Validate Request (Overloaded) ✔️🔣

Validates the entire HTTP request including method, route, JSON body, path/query params (if specified) and headers against the OpenAPI specification, and sets error_msg with a descriptive error message if validation fails.

Validation sequence

1. HTTP method
2. Route
3. Body schema
4. Path parameters (if specified in specs, in the sequence of provided in OpenAPI spec)
5. Query parameters (if specified in specs, in the sequence of provided in OpenAPI spec)
6. Header parameters

Synopsis

ValidationError ValidateRequest(
    const std::string& method,
    const std::string& http_path,
    const std::string& json_body,
    const std::unordered_map<std::string, std::string>& headers,
    std::string& error_msg
);

Arguments

• method: The HTTP method (e.g., "POST", "PUT") as a std::string.
• http_path: The HTTP path (e.g., "/api/v1/resource") as a std::string.
• json_body: The JSON body of the HTTP request as a std::string.
• headers: The HTTP headers as an std::unordered_map of std::string to std::string.
• error_msg: Reference to a std::string where the error message will be stored in case of a validation error.

Returns

• ValidationError: An enum indicating the result of the validation. A return value of ValidationError::NONE signifies successful validation, while other values indicate specific types of validation failures.
• Possible values:
  • ValidationError::NONE
  • ValidationError::INVALID_METHOD
  • ValidationError::INVALID_ROUTE
  • ValidationError::INVALID_BODY
  • ValidationError::INVALID_PATH_PARAM
  • ValidationError::INVALID_QUERY_PARAM
  • ValidationError::INVALID_HEADER_PARAM

Example

std::unordered_map<std::string, std::string> headers = {{"Authorization", "Bearer token"}};
std::string error_msg;
ValidationError result = oas_validator.ValidateRequest("POST", "/api/v1/resource", "{\"key\": \"value\"}", headers, error_msg);

if (result != ValidationError::NONE) {
    std::cerr << "Validation failed: " << error_msg << std::endl;
}

Notes

• The error_msg argument will be populated with a JSON string in case of a validation error.

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