Add database and statement readonly checks to sqlite in redbean (#914)

test/tool/net/sqlite_test.lua

@@ -0,0 +1,31 @@
+-- Copyright 2023 Justine Alexandra Roberts Tunney
+--
+-- Permission to use, copy, modify, and/or distribute this software for
+-- any purpose with or without fee is hereby granted, provided that the
+-- above copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+-- WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+-- WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+-- AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+-- DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+-- PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+-- TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+-- PERFORMANCE OF THIS SOFTWARE.
+
+local sqlite3 = require "lsqlite3"
+local db = assert(sqlite3.open("file:/memdb1?vfs=memdb&mode=ro",
+  sqlite3.OPEN_URI + sqlite3.OPEN_READWRITE + sqlite3.OPEN_CREATE))
+assert(db:readonly() == true)
+db = sqlite3.open("file:/memdb1?vfs=memdb",
+  sqlite3.OPEN_URI + sqlite3.OPEN_READWRITE + sqlite3.OPEN_CREATE)
+assert(db:readonly() == false)
+assert(db:readonly("main") == false)
+assert(db:readonly("foo") == nil)
+
+assert(db:exec("create table foo(a)") == 0)
+
+local st = assert(db:prepare("select * from foo"))
+assert(st:readonly() == true)
+st = assert(db:prepare("insert into foo (a) values (1)"))
+assert(st:readonly() == false)