From 74abfa517bd6d8b199094a98f36269d90f5ef3ee Mon Sep 17 00:00:00 2001
From: Maxim Zhukov <maxim.zhukov.dev@gmail.com>
Date: Wed, 21 Apr 2021 02:09:52 -0500
Subject: [PATCH] Replace the like query where clause with the RegExp

---
 like.ts      |  7 ++++
 like_test.ts | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 mod_test.ts  |  2 +-
 3 files changed, 99 insertions(+), 1 deletion(-)
 create mode 100644 like.ts
 create mode 100644 like_test.ts

diff --git a/like.ts b/like.ts
new file mode 100644
index 0000000..119d6d3
--- /dev/null
+++ b/like.ts
@@ -0,0 +1,7 @@
+export function getLikeRegExp(input: string): RegExp {
+  const pattern = input
+    .replaceAll(".", "\\.")
+    .replaceAll("%", ".*?");
+
+  return new RegExp("^" + pattern + "$");
+}
diff --git a/like_test.ts b/like_test.ts
new file mode 100644
index 0000000..4a5d956
--- /dev/null
+++ b/like_test.ts
@@ -0,0 +1,91 @@
+import { assert, assertEquals } from "./deps.ts";
+import { getLikeRegExp } from "./like.ts";
+
+Deno.test("where name like 'abc.txt'", () => {
+  const regexp = getLikeRegExp("abc.txt");
+
+  /* Match */
+  assert("abc.txt".match(regexp));
+
+  /* Does not match */
+  assertEquals("a.txt".match(regexp), null);
+  assertEquals("abc_d.txt".match(regexp), null);
+  assertEquals("abc.tx".match(regexp), null);
+});
+
+Deno.test("where name like '%.txt'", () => {
+  const regexp = getLikeRegExp("%.txt");
+
+  /* Match */
+  assert("abc.txt".match(regexp));
+  assert("c.txt".match(regexp));
+  assert("ab_c.txt".match(regexp));
+  assert("ab_-\/*+ddc.txt".match(regexp));
+
+  /* Does not match */
+  assertEquals("abc.bin".match(regexp), null);
+  assertEquals(".txn".match(regexp), null);
+  assertEquals("abc_txt".match(regexp), null);
+  assertEquals("abc.!txt".match(regexp), null);
+  assertEquals("abc.txt_bin".match(regexp), null);
+});
+
+Deno.test("where name like '%.txt%'", () => {
+  const regexp = getLikeRegExp("%.txt%");
+
+  /* Match */
+  assert("abc.txt".match(regexp));
+  assert("c.txt".match(regexp));
+  assert("ab_c.txt".match(regexp));
+  assert("ab_-\/*+ddc.txt".match(regexp));
+
+  /* Does not match */
+  assertEquals("abc.bin".match(regexp), null);
+  assertEquals(".txn".match(regexp), null);
+  assertEquals("abc_txt".match(regexp), null);
+});
+
+Deno.test("where name like 'ab%txt'", () => {
+  const regexp = getLikeRegExp("ab%txt");
+
+  /* Match */
+  assert("abc.txt".match(regexp));
+  assert("abdef_.txt".match(regexp));
+  assert("ab_c.txt".match(regexp));
+  assert("ab_-\/*+ddc.txt".match(regexp));
+
+  /* Does not match */
+  assertEquals("abc.bin".match(regexp), null);
+  assertEquals("abc".match(regexp), null);
+  assertEquals("d_abc.txt".match(regexp), null);
+  assertEquals("abc.txt.".match(regexp), null);
+  assertEquals("abc.txt!".match(regexp), null);
+});
+
+Deno.test("where name like 'abc.%'", () => {
+  const regexp = getLikeRegExp("abc.%");
+
+  /* Match */
+  assert("abc.txt".match(regexp));
+  assert("abc.bin".match(regexp));
+  assert("abc.".match(regexp));
+
+  /* Does not match */
+  assertEquals("abc".match(regexp), null);
+  assertEquals("d".match(regexp), null);
+  assertEquals("abc?.".match(regexp), null);
+});
+
+Deno.test("where name like '%.%'", () => {
+  const regexp = getLikeRegExp("%.%");
+
+  /* Match */
+  assert("abc.txt".match(regexp));
+  assert("abc.bin".match(regexp));
+  assert("abc.".match(regexp));
+  assert(".".match(regexp));
+  assert(".txt".match(regexp));
+
+  /* Does not match */
+  assertEquals("abc".match(regexp), null);
+});
diff --git a/mod_test.ts b/mod_test.ts
index be424c9..9214a3b 100644
--- a/mod_test.ts
+++ b/mod_test.ts
@@ -4,7 +4,7 @@ import { fsselect } from "./mod.ts";
 
 Deno.test("if 'select * from .' works", async () => {
   const result = await fsselect("select * from .");
-  assert(result.length === 18);
+  assert(result.length === 20);
 });
 
 Deno.test("if 'select * from root' works", async () => {