michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: // This file tests the Levenshtein Distance function we've registered.
michael@0: 
michael@0: function createUtf16Database()
michael@0: {
michael@0:   print("Creating the in-memory UTF-16-encoded database.");
michael@0:   let conn = getService().openSpecialDatabase("memory");
michael@0:   conn.executeSimpleSQL("PRAGMA encoding = 'UTF-16'");
michael@0: 
michael@0:   print("Make sure the encoding was set correctly and is now UTF-16.");
michael@0:   let stmt = conn.createStatement("PRAGMA encoding");
michael@0:   do_check_true(stmt.executeStep());
michael@0:   let enc = stmt.getString(0);
michael@0:   stmt.finalize();
michael@0: 
michael@0:   // The value returned will actually be UTF-16le or UTF-16be.
michael@0:   do_check_true(enc === "UTF-16le" || enc === "UTF-16be");
michael@0: 
michael@0:   return conn;
michael@0: }
michael@0: 
michael@0: function check_levenshtein(db, s, t, expectedDistance)
michael@0: {
michael@0:   var stmt = db.createStatement("SELECT levenshteinDistance(:s, :t) AS result");
michael@0:   stmt.params.s = s;
michael@0:   stmt.params.t = t;
michael@0:   try {
michael@0:     do_check_true(stmt.executeStep());
michael@0:     do_check_eq(expectedDistance, stmt.row.result);
michael@0:   } 
michael@0:   finally {
michael@0:     stmt.reset();
michael@0:     stmt.finalize();
michael@0:   }
michael@0: }
michael@0: 
michael@0: function testLevenshtein(db)
michael@0: {
michael@0:   // Basic tests.
michael@0:   check_levenshtein(db, "", "", 0);
michael@0:   check_levenshtein(db, "foo", "", 3);
michael@0:   check_levenshtein(db, "", "bar", 3);
michael@0:   check_levenshtein(db, "yellow", "hello", 2);
michael@0:   check_levenshtein(db, "gumbo", "gambol", 2);
michael@0:   check_levenshtein(db, "kitten", "sitten", 1);
michael@0:   check_levenshtein(db, "sitten", "sittin", 1);
michael@0:   check_levenshtein(db, "sittin", "sitting", 1);
michael@0:   check_levenshtein(db, "kitten", "sitting", 3);
michael@0:   check_levenshtein(db, "Saturday", "Sunday", 3);
michael@0:   check_levenshtein(db, "YHCQPGK", "LAHYQQKPGKA", 6);
michael@0: 
michael@0:   // Test SQL NULL handling.
michael@0:   check_levenshtein(db, "foo", null, null);
michael@0:   check_levenshtein(db, null, "bar", null);
michael@0:   check_levenshtein(db, null, null, null);
michael@0:   
michael@0:   // The levenshteinDistance function allocates temporary memory on the stack
michael@0:   // if it can.  Test some strings long enough to force a heap allocation.
michael@0:   var dots1000 = Array(1001).join(".");
michael@0:   var dashes1000 = Array(1001).join("-");
michael@0:   check_levenshtein(db, dots1000, dashes1000, 1000);
michael@0: }
michael@0: 
michael@0: function run_test()
michael@0: {
michael@0:   testLevenshtein(getOpenedDatabase());
michael@0:   testLevenshtein(createUtf16Database());
michael@0: }
michael@0: 
michael@0: 
michael@0: 
michael@0: