# Collect errors with ErrorBuilder, log them with ERROR() and keep an audit trail with AUDIT()

> Answer with several errors at once using ErrorBuilder, the SUCCESS() answer, how ERROR() records failures, and how AUDIT() appends who did what to a log file.

Framework: total5
Product: Total.js 5 (total5@0.0.19)
Language: en
Content-SHA256: ccd28753dcc2801ab0c0c92f984123b5941dfcfca8fdb41cbdcbf591eba8a958
Snapshot: c0700e321579725c5cf4f5ace1ad7d2866d1b4f93c24a63c0b41b6b7998e976c
Sources: total5-installed@total5@0.0.19
Review: not-recorded

- **`ErrorBuilder`** collects errors. `push(message, [path], [index])` adds one (`path` is the field it belongs to), `push(404)` adds the text of a status code and sets the status of the answer, `length` counts them, `output()` returns them as an array of `{ error, path, index }` and `toString()` joins the messages. `$.invalid(builder)` answers with that array and the status of the builder (400 unless a status code was pushed).
- **`SUCCESS(value)`** returns the object for a successful operation: `{ success: true, value: value }`.
- **`ERROR(name)`** returns a callback for `function(err)` APIs: when it receives an error it records it under `name`, and it does nothing when the error is empty. `ERROR()` is the same callback without a name. A recorded error is printed to the console, counted in `F.stats.error`, and the last ten are kept in `F.errors` as `{ error, name, date }`.
- **`AUDIT($, message, type)`** appends one JSON line to `logs/audit.log` with who and where (`ip`, `ua`, `url`, and the user when there is one), the `message`, the `type`, the `params`, `query` and `model` of the request in `data`, the name of the application in `app` and the time in `dtcreated`. `AUDIT('name', $, message, type)` writes to `logs/name.log` instead.

```js controllers/reports.js
exports.install = function() {
	ROUTE('GET /builder/', builder);
	ROUTE('GET /builder404/', builder404);
	ROUTE('GET /success/', success);
	ROUTE('GET /error/', error);
	ROUTE('GET /audit/', audit);
	ROUTE('GET /audit-read/{name}/', auditread);
};

function builder($) {
	const errors = new ErrorBuilder();
	errors.push('Name is required', 'name');
	errors.push('Age is too low', 'age', 2);
	$.invalid(errors);
}

function builder404($) {
	const errors = new ErrorBuilder();
	errors.push(404);
	$.invalid(errors);
}

function success($) {
	$.json(SUCCESS('saved'));
}

function error($) {
	const before = F.stats.error;
	ERROR('mypart')('Something broke');
	ERROR('mypart')(null);
	ERROR()('Without a name');
	$.json({ counted: F.stats.error - before, last: F.errors.slice(-2).map(n => ({ error: n.error, name: n.name || null, date: n.date instanceof Date || typeof n.date === 'string' })) });
}

function audit($) {
	AUDIT($, 'Opened the report', 'info');
	AUDIT('security', $, 'Checked the access');
	$.json({ ok: true });
}

function auditread($) {
	setTimeout(function() {
		const lines = require('fs').readFileSync(PATH.logs($.params.name + '.log'), 'utf8').trim().split('\n');
		$.json(lines.map(n => JSON.parse(n)));
	}, 300);
}
```