Helpers::getSuggestion() better balance. Replacement is more expensive than insertion/deletion.

tests/dibi/Helpers.getSuggestion().phpt

@@ -0,0 +1,36 @@
+<?php
+
+use Dibi\Helpers;
+use Tester\Assert;
+
+require __DIR__ . '/bootstrap.php';
+
+
+Assert::same(NULL, Helpers::getSuggestion([], ''));
+Assert::same(NULL, Helpers::getSuggestion([], 'a'));
+Assert::same(NULL, Helpers::getSuggestion(['a'], 'a'));
+Assert::same('a', Helpers::getSuggestion(['a', 'b'], ''));
+Assert::same('b', Helpers::getSuggestion(['a', 'b'], 'a')); // ignore 100% match
+Assert::same('a1', Helpers::getSuggestion(['a1', 'a2'], 'a')); // take first
+Assert::same(NULL, Helpers::getSuggestion(['aaa', 'bbb'], 'a'));
+Assert::same(NULL, Helpers::getSuggestion(['aaa', 'bbb'], 'ab'));
+Assert::same(NULL, Helpers::getSuggestion(['aaa', 'bbb'], 'abc'));
+Assert::same('bar', Helpers::getSuggestion(['foo', 'bar', 'baz'], 'baz'));
+Assert::same('abcd', Helpers::getSuggestion(['abcd'], 'acbd'));
+Assert::same('abcd', Helpers::getSuggestion(['abcd'], 'axbd'));
+Assert::same(NULL, Helpers::getSuggestion(['abcd'], 'axyd'));
+
+
+/*
+length  allowed ins/del  replacements
+-------------------------------------
+0       1                0
+1       1                1
+2       1                1
+3       1                1
+4       2                1
+5       2                2
+6       2                2
+7       2                2
+8       3                2
+*/