More refactoring of tests and packages

Squashed commit of the following:

commit c4659d8be4d664ba7fd4b59d613536f2368cff0e
Author: riton <riton@riton.home>
Date:   Mon Jul 14 21:44:48 2025 +0300

    fix package name typo

commit ec802339b838d059f4bc9e4da7cc370ab4d91a46
Author: riton <riton@riton.home>
Date:   Mon Jul 14 21:43:42 2025 +0300

    seperate deftest from test instances

commit 92d20e0b8405a4a51f01ff65f8bd81f4d25c1e21
Author: riton <riton@riton.home>
Date:   Mon Jul 14 21:29:47 2025 +0300

    make a test system definition

commit 125e5fe1e8c07230f32e762273c5c0dd259209e6
Author: riton <riton@riton.home>
Date:   Mon Jul 14 00:39:09 2025 +0300

    compiler macro of as-token

commit 0e39c32097783aa39e3fed479bb85b412065f597
Author: riton <riton@riton.home>
Date:   Mon Jul 14 00:21:46 2025 +0300

    define new packages

1 files changed, 53 insertions, 0 deletions

diff --git a/test/lexer-test.lisp b/test/lexer-test.lisp
new file mode 100644
index 0000000..bb7a1bd
--- /dev/null
+++ b/test/lexer-test.lisp
@@ -0,0 +1,53 @@
+(in-package :monkey/test)
+
+(deftest (:lexer test-1)
+  "=+(){},;"
+  (:t/= :t/+ :t/lparen :t/rparen
+   :t/lbrace :t/rbrace :t/comma :t/semicolon :t/eof))
+
+(deftest (:lexer test-2)
+  "let five = 5;
+let ten = 10;
+
+let add = fn(x, y) {
+  x + y;
+};
+
+let result = add(five, ten);
+!-/*;
+5 < 10 > 5;
+
+if (5 < 10) {
+    return true;
+} else {
+    return false;
+}
+10 == 10;
+10 != 9;
+"
+  (:t/let "five" :t/= 5 #\;
+          :t/let "ten" :t/= 10 #\;
+          :t/let "add" :t/= :t/function #\( "x" :t/comma "y" #\) #\{
+          "x" :t/+ "y" #\;
+          #\} #\;
+          :t/let "result" :t/= "add" #\( "five" :t/comma "ten" #\) #\;
+          :t/! :t/- :t// :t/* #\;
+          5 :t/< 10 :t/> 5 #\;
+          :t/if #\( 5 :t/< 10 #\) #\{
+          :t/return :t/true #\;
+          #\} :t/else #\{
+          :t/return :t/false #\;
+          #\}
+          10 :t/== 10 #\;
+          10 :t/!= 9 #\;
+          :t/eof))
+
+(eval-when ()
+  (deftest (:lexer test-fail)
+    "abc gf 5 fn =+(){},;"
+    (:t/= :t/+ :t/lparen :t/rparen
+     :t/lbrace :t/rbrace :t/comma :t/semicolon :t/eof))
+
+  (deftest (:lexer test-fail-2)
+    "let abc x + 5;"
+    (:t/let "abc" :t/= "x" :t/+ 5 :t/eof)))