Add support for sqlite3_set_authorizer

docs/api.md

@@ -11,6 +11,7 @@
 - [Database#pragma()](#pragmastring-options---results)
 - [Database#backup()](#backupdestination-options---promise)
 - [Database#function()](#functionname-options-function---this)
+- [Database#setAuthorizer()](#setauthorizerfn---this)
 - [Database#aggregate()](#aggregatename-options---this)
 - [Database#loadExtension()](#loadextensionpath-entrypoint---this)
 - [Database#exec()](#execstring---this)
@@ -176,6 +177,27 @@ db.prepare("SELECT void()").pluck().get(); // => null
 db.prepare("SELECT void(?, ?)").pluck().get(55, 19); // => null
 ```
 
+### .setAuthorizer(fn) -> *this*
+
+Register a [compile-time authorization callback](https://sqlite.org/c3ref/set_authorizer.html) function. 
+
+```js
+db.setAuthorizer(function(op, a0, a1, database, trigger){
+  // do something with the arg
+  // and return the decision as either SQLITE_OK, SQLITE_DENY or SQLITE_IGNORE
+  // not returning any value or throwing an error will cause the driver to return SQLITE_ERROR
+  return SQLITE_DENY;  // for fun :)
+});
+
+db.prepare("SELECT * FROM users")  // this will throw SqliteError: authorization error
+```
+
+The authorizer callback is invoked as SQL statements are being compiled by `sqlite3_prepare()` or its variants. The callback function receives as argument the [action code](https://sqlite.org/c3ref/c_alter_table.html)and the related parameters, along with the current _database_ and _trigger_ name.
+
+The callback function _must_ accept exactly 5 arguments. Any given database can only have a single authorizer function attached to it at any given point in time.
+
+To unset a previously registered authorizer invoke `setAuthorizer` with a `null` argument.
+
 ### .aggregate(*name*, *options*) -> *this*
 
 Registers a user-defined [aggregate function](https://sqlite.org/lang_aggfunc.html).

lib/authorizer.js

@@ -0,0 +1,17 @@
+'use strict';
+
+module.exports = (setAuthorizer) => {
+    return function defineAuthorizer(fn) {
+        if(fn !== null) { // must be a valid function if not null
+            if (typeof fn !== 'function') {
+                throw new TypeError('Expected argument to be a function');
+            }
+
+            if(fn.length != 5) {
+                throw new RangeError('Authorizer function must accept exactly 5 arguments')
+            }
+        }
+
+        return setAuthorizer.call(this, fn)
+    }
+}

lib/codes.js

@@ -0,0 +1,2 @@
+// Codes.js - export sqlite codes / constants https://sqlite.org/c3ref/constlist.html
+module.exports = require('bindings')('better_sqlite3.node').Codes

lib/database.js

@@ -37,6 +37,7 @@ function Database(filenameGiven, options) {
 setErrorConstructor(require('./sqlite-error'));
 util.wrap(CPPDatabase, 'pragma', require('./pragma'));
 util.wrap(CPPDatabase, 'function', require('./function'));
+util.wrap(CPPDatabase, 'setAuthorizer', require('./authorizer'));
 util.wrap(CPPDatabase, 'aggregate', require('./aggregate'));
 util.wrap(CPPDatabase, 'backup', require('./backup'));
 CPPDatabase.prototype.transaction = require('./transaction');

package.json

@@ -16,6 +16,7 @@
   },
   "devDependencies": {
     "chai": "^4.2.0",
+    "chai-spies": "^1.0.0",
     "cli-color": "^2.0.0",
     "fs-extra": "^8.1.0",
     "mocha": "^7.0.1",