APIError.js
const httpStatus = require('http-status');
/**
* @extends Error
*/
class ExtendableError extends Error {
constructor(message, status, isPublic) {
super(message);
this.name = this.constructor.name;
this.message = message;
this.status = status;
this.isPublic = isPublic;
this.isOperational = true; // This is required since bluebird 4 doesn't append it anymore.
Error.captureStackTrace(this, this.constructor.name);
}
}
/**
* Class representing an API error.
* @extends ExtendableError
*/
class APIError extends ExtendableError {
/**
* Creates an API error.
* @param {string} message - Error message.
* @param {number} status - HTTP status code of error.
* @param {boolean} isPublic - Whether the message should be visible to user or not.
*/
constructor(message, status = httpStatus.INTERNAL_SERVER_ERROR, isPublic = false) {
super(message, status, isPublic);
}
}
module.exports = APIError;
express.js
const httpStatus = require('http-status');
// if error is not an instanceOf APIError, convert it.
app.use((err, req, res, next) => {
if (err instanceof expressValidation.ValidationError) {
// validation error contains errors which is an array of error each containing message[]
const unifiedErrorMessage = err.errors.map(error => error.messages.join('. ')).join(' and ');
const error = new APIError(unifiedErrorMessage, err.status, true);
return next(error);
} else if (!(err instanceof APIError)) {
const apiError = new APIError(err.message, err.status, err.isPublic);
return next(apiError);
}
return next(err);
});
// catch 404 and forward to error handler
app.use((req, res, next) => {
const err = new APIError('API not found', httpStatus.NOT_FOUND);
return next(err);
});
// error handler, send stacktrace only during development
app.use((err, req, res, next) => // eslint-disable-line no-unused-vars
res.status(err.status).json({
status: 0,
errmsg: err.isPublic ? err.message : httpStatus[err.status],
stack: config.env === 'development' ? err.stack : {}
})
);
Model层、Service层直接throw APIError
model之间交叉调用时，控制器方法内调用多个model时，需要使用service