diff --git a/compiler/erg_parser/tests/parse_test.rs b/compiler/erg_parser/tests/parse_test.rs
index 04aba987..c22ebc47 100644
--- a/compiler/erg_parser/tests/parse_test.rs
+++ b/compiler/erg_parser/tests/parse_test.rs
@@ -8,37 +8,37 @@ use erg_parser::ParserRunner;
 
 #[test]
 fn parse_dependent() -> Result<(), ParserRunnerErrors> {
-    parse_test_from_code("tests/dependent.er")
+    expect_success("tests/dependent.er")
 }
 
 #[test]
 fn parse_fib() -> Result<(), ParserRunnerErrors> {
-    parse_test_from_code("tests/fib.er")
+    expect_success("tests/fib.er")
 }
 
 #[test]
 fn parse_hello_world() -> Result<(), ParserRunnerErrors> {
-    parse_test_from_code("tests/hello_world.er")
+    expect_success("tests/hello_world.er")
 }
 
 #[test]
 fn parse_simple_if() -> Result<(), ParserRunnerErrors> {
-    parse_test_from_code("tests/simple_if.er")
+    expect_success("tests/simple_if.er")
 }
 
 #[test]
 fn parse_stack() -> Result<(), ParserRunnerErrors> {
-    parse_test_from_code("tests/stack.er")
+    expect_failure("tests/stack.er")
 }
 
 #[test]
 fn parse_test1_basic_syntax() -> Result<(), ParserRunnerErrors> {
-    parse_test_from_code("tests/test1_basic_syntax.er")
+    expect_success("tests/test1_basic_syntax.er")
 }
 
 #[test]
 fn parse_test2_advanced_syntax() -> Result<(), ParserRunnerErrors> {
-    parse_test_from_code("tests/test2_advanced_syntax.er")
+    expect_success("tests/test2_advanced_syntax.er")
 }
 
 fn parse_test_from_code(file_path: &'static str) -> Result<(), ParserRunnerErrors> {
@@ -71,3 +71,20 @@ fn parse_test_from_code(file_path: &'static str) -> Result<(), ParserRunnerError
         }
     }
 }
+
+fn expect_success(file_path: &'static str) -> Result<(), ParserRunnerErrors> {
+    match parse_test_from_code(file_path) {
+        Ok(_) => Ok(()),
+        Err(e) => {
+            e.fmt_all_stderr();
+            Err(e)
+        }
+    }
+}
+
+fn expect_failure(file_path: &'static str) -> Result<(), ParserRunnerErrors> {
+    match parse_test_from_code(file_path) {
+        Ok(_) => Err(ParserRunnerErrors::empty()),
+        Err(_) => Ok(()),
+    }
+}
diff --git a/compiler/erg_parser/tests/simple_if.er b/compiler/erg_parser/tests/simple_if.er
index 3a4c28c9..007bffce 100644
--- a/compiler/erg_parser/tests/simple_if.er
+++ b/compiler/erg_parser/tests/simple_if.er
@@ -17,4 +17,12 @@ print! if False:
 
 print!(if(True, () -> "a", () -> "b"))
 
-# TODO: do/do!
+if! True:
+    do! print! "hello"
+    do! print! "world"
+
+if! False:
+    do!:
+        print! "a"
+    do!:
+        print! "b"
diff --git a/compiler/erg_parser/tests/test.rs b/compiler/erg_parser/tests/test.rs
deleted file mode 100644
index 5e0d1320..00000000
--- a/compiler/erg_parser/tests/test.rs
+++ /dev/null
@@ -1,118 +0,0 @@
-use std::iter::Iterator;
-
-use erg_common::config::Input;
-
-// use erg_compiler::parser;
-
-use erg_parser::error::ParseResult;
-use erg_parser::lex::Lexer;
-use erg_parser::token::*;
-use TokenKind::*;
-
-const FILE1: &str = "tests/test1_basic_syntax.er";
-
-#[test]
-fn test_lexer() -> ParseResult<()> {
-    let mut lexer = Lexer::new(Input::File(FILE1.into()));
-    let newline = "\n";
-    let /*mut*/ token_array = vec![
-            (Symbol, "_a"),
-            (Equal, "="),
-            (IntLit, "1234"),
-            (Plus, "+"),
-            (RatioLit, "1113.0"),
-            (Plus, "+"),
-            (RatioLit, "0.30102"),
-            // (Symbol, "a"),
-            (Newline, newline),
-            (Symbol, "a"),
-            (Comma, ","),
-            (UBar, "_"),
-            (Comma, ","),
-            (Spread, "..."),
-            (Symbol, "b"),
-            (Equal, "="),
-            (Symbol, "five_elem_tuple"),
-            (Newline, newline),
-            (Symbol, "if!"),
-            (Symbol, "True"),
-            (Comma, ","),
-            (Symbol, "do!"),
-            (Newline, newline),
-            (Indent, "    "),
-            (Symbol, "print!"),
-            // (LParen, "("),
-            (StrLit, "\\\\hello, world\\\""),
-            // (RParen, ")"),
-            (Newline, newline),
-            (IntLit, "10"),
-            (Dot, "."),
-            (Symbol, "times!"),
-            // (LParen, "("),
-            // (RParen, ")"),
-            (Symbol, "do!"),
-            (Newline, newline),
-            (Indent, "    "),
-            (Symbol, "if!"),
-            (Symbol, "True"),
-            (Comma, ","),
-            (Symbol, "do!"),
-            (Newline, newline),
-            (Indent, "    "),
-            (Symbol, "print!"),
-            (StrLit, ""),
-            (Newline, newline),
-            // (Comment, " illegal indent"),
-            // (Illegal, "DEDENT"),
-            // (Symbol, "do_nothing"),
-            (Dedent, ""),
-            (Newline, newline),
-            (Newline, newline),
-            (Symbol, "Hello"),
-            (Equal, "="),
-            (Symbol, "S2c"),
-            // (LParen, "("),
-            (StrLit, "hello"),
-            // (RParen, ")"),
-            (Newline, newline),
-            (Dedent, ""),
-            (Dedent, ""),
-            (Symbol, "aあ아"),
-            (Equal, "="),
-            (Newline, newline),
-            (Indent, "    "),
-            (Newline, newline),
-            (StrLit, "aaa"),
-            (Newline, newline),
-            (Dedent, ""),
-            (Symbol, "x"),
-            (Semi, ";"),
-            (Symbol, "x"),
-            (Semi, ";"),
-            (Semi, ";"),
-            (Symbol, "x"),
-            (Semi, ";"),
-            (Newline, newline),
-            (IntLit, "10"),
-            (Closed, ".."),
-            (Symbol, "twelve"),
-            (Semi, ";"),
-            (Newline, newline),
-            (EOF, "EOF"),
-        ];
-
-    let mut tok: Token;
-    for i in token_array.into_iter() {
-        tok = lexer.next().unwrap().unwrap();
-        assert_eq!(tok, Token::from_str(i.0, i.1));
-        println!("{tok}");
-    }
-    Ok(())
-}
-
-#[test]
-fn tesop_te_prec() {
-    assert_eq!(Mod.precedence(), Some(160));
-    assert_eq!(LParen.precedence(), Some(0));
-    assert_eq!(Illegal.precedence(), None);
-}
diff --git a/compiler/erg_parser/tests/test1_basic_syntax.er b/compiler/erg_parser/tests/test1_basic_syntax.er
index a5032eb9..ffd77c3f 100644
--- a/compiler/erg_parser/tests/test1_basic_syntax.er
+++ b/compiler/erg_parser/tests/test1_basic_syntax.er
@@ -5,10 +5,10 @@ _a = 1_234 + 1113.* 3_000.2e-4 ** 0003 * .4
 a, _, ...b = five_elem_tuple
 f x, y =
     x + y
-if! True, do!
+if! True, do!:
     print! "\\hello, world\""
-    10.times! do!
-        if! x.y.z, do!
+    10.times! do!:
+        if! x.y.z, do!:
             print! ""
         # illegal indent
         # do_nothing!
diff --git a/compiler/erg_parser/tests/test2_advanced_syntax.er b/compiler/erg_parser/tests/test2_advanced_syntax.er
index 271bd621..d434abda 100644
--- a/compiler/erg_parser/tests/test2_advanced_syntax.er
+++ b/compiler/erg_parser/tests/test2_advanced_syntax.er
@@ -1,28 +1,18 @@
 # Check that a parser can pass the advanced syntax
 # 高度な文法をチェックする
 
-# overloading (多重定義)
-f x = 1 + x + 2
-f x, y =
-    1 + x + y
-f x, y, z =
-    1 + x + y + z
-assert 4 == f 1
-assert 4 == f 1, 1
-assert 3 == f 1, 1, 1
-
-# pattern overloading
+# mutliple patterns definition
 fib 0 = 0
 fib 1 = 1
 fib(n: Nat) -> Nat = fib(n-1) + fib(n-2)
 
-# keyword arguments (キーワード引数)
+# keyword arguments
 t = if True:
-    then: 1
-    else: 2
+    then := 1
+    else := 2
 assert t == 1
 
 # import
 math = import "math"
 # {*} = "math" # use all
-{pi} = import "math"
+{pi, ...} = import "math"
diff --git a/compiler/erg_parser/tests/test3_literal_syntax.er b/compiler/erg_parser/tests/test3_literal_syntax.er
new file mode 100644
index 00000000..2bbae620
--- /dev/null
+++ b/compiler/erg_parser/tests/test3_literal_syntax.er
@@ -0,0 +1,30 @@
+## Basic Literals ##
+# Nat Literal
+0, 1, 2, 100_000
+
+# Int Literal: Positive numbers cannot be determined during tokenization
+-1, -10, -100_000
+
+# Ratio Literal
+0.00, -0.0, .1, 400.
+
+# Str Literal
+"", "a", "こんにちは", "\" \\ "
+
+# Boolean Litteral
+True, False
+
+# None Literal
+None
+
+# Ellipsis Literal
+...
+
+# Infinite Literal
+Inf, -Inf
+
+# Not Implemeted Literal
+NotImplemented
+
+# Exponetial Literal
+# 1e-34, 0.4e-10, 2.455+e5
diff --git a/compiler/erg_parser/tests/tokenize_test.rs b/compiler/erg_parser/tests/tokenize_test.rs
new file mode 100644
index 00000000..47744926
--- /dev/null
+++ b/compiler/erg_parser/tests/tokenize_test.rs
@@ -0,0 +1,314 @@
+use std::iter::Iterator;
+
+use erg_common::config::Input;
+
+// use erg_compiler::parser;
+
+use erg_parser::error::ParseResult;
+use erg_parser::lex::Lexer;
+use erg_parser::token::*;
+use TokenKind::*;
+
+const FILE1: &str = "tests/test1_basic_syntax.er";
+const FILE2: &str = "tests/test2_advanced_syntax.er";
+const FILE3: &str = "tests/test3_literal_syntax.er";
+
+#[test]
+fn test_lexer_for_basic() -> ParseResult<()> {
+    let mut lexer = Lexer::new(Input::File(FILE1.into()));
+    let newline = "\n";
+    let /*mut*/ token_array = vec![
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (Symbol, "_a"),
+        (Equal, "="),
+        (NatLit, "1_234"),
+        (Plus, "+"),
+        (RatioLit, "1113."),
+        (Star, "*"),
+        (RatioLit, "3_000.2e-4"),
+        (Pow, "**"),
+        (NatLit, "0003"),
+        (Star, "*"),
+        (RatioLit, ".4"),
+        (Newline, newline),
+        (Symbol, "a"),
+        (Comma, ","),
+        (UBar, "_"),
+        (Comma, ","),
+        (Spread, "..."), // EllipsisLit
+        (Symbol, "b"),
+        (Equal, "="),
+        (Symbol, "five_elem_tuple"),
+        (Newline, newline),
+        (Symbol, "f"),
+        (Symbol, "x"),
+        (Comma, ","),
+        (Symbol, "y"),
+        (Equal, "="),
+        (Newline, newline),
+        (Indent, "    "),
+        (Symbol, "x"),
+        (Plus, "+"),
+        (Symbol, "y"),
+        (Newline, newline),
+        (Dedent, ""),
+        (Symbol, "if!"),
+        (BoolLit, "True"),
+        (Comma, ","),
+        (Symbol, "do!"),
+        (Colon, ":"),
+        (Newline, newline),
+        (Indent, "    "),
+        (Symbol, "print!"),
+        (StrLit, "\"\\\\hello, world\\\"\""),
+        (Newline, newline),
+        (NatLit, "10"),
+        (Dot, "."),
+        (Symbol, "times!"),
+        (Symbol, "do!"),
+        (Colon, ":"),
+        (Newline, newline),
+        (Indent, "    "),
+        (Symbol, "if!"),
+        (Symbol, "x"),
+        (Dot, "."),
+        (Symbol, "y"),
+        (Dot, "."),
+        (Symbol, "z"),
+        (Comma, ","),
+        (Symbol, "do!"),
+        (Colon, ":"),
+        (Newline, newline),
+        (Indent, "    "),
+        (Symbol, "print!"),
+        (StrLit, "\"\""),
+        (Newline, newline),
+        (Dedent, ""),
+        (Newline, newline),
+        (Newline, newline),
+        (Symbol, "Hello"),
+        (Equal, "="),
+        (Symbol, "S2c"),
+        (StrLit, "\"hello\""),
+        (Newline, newline),
+        (Dedent, ""),
+        (Dedent, ""),
+        (Symbol, "aあ아"),
+        (Equal, "="),
+        (Newline, newline),
+        (Indent, "    "),
+        (Newline, newline),
+        (StrLit, "\"aaa\""),
+        (Newline, newline),
+        (Dedent, ""),
+        (Symbol, "x"),
+        (Semi, ";"),
+        (Symbol, "x"),
+        (Semi, ";"),
+        (Semi, ";"),
+        (Symbol, "x"),
+        (Semi, ";"),
+        (Newline, newline),
+        (NatLit, "10"),
+        (Closed, ".."),
+        (Symbol, "twelve"),
+        (Semi, ";"),
+        (Newline, newline),
+        (EOF, ""),
+    ];
+    let mut tok: Token;
+    for (id, i) in token_array.into_iter().enumerate() {
+        tok = lexer.next().unwrap().unwrap();
+        assert_eq!(tok, Token::from_str(i.0, i.1));
+        print!("{id:>03}: ");
+        println!("{tok}");
+    }
+    Ok(())
+}
+
+#[test]
+fn test_lexer_for_advanced() -> ParseResult<()> {
+    let mut lexer = Lexer::new(Input::File(FILE2.into()));
+    let newline = "\n";
+    let /*mut*/ token_array = vec![
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (Symbol, "fib"),
+        (NatLit, "0"),
+        (Equal, "="),
+        (NatLit, "0"),
+        (Newline, newline),
+        (Symbol, "fib"),
+        (NatLit, "1"),
+        (Equal, "="),
+        (NatLit, "1"),
+        (Newline, newline),
+        (Symbol, "fib"),
+        (LParen, "("),
+        (Symbol, "n"),
+        (Colon, ":"),
+        (Symbol, "Nat"),
+        (RParen, ")"),
+        (FuncArrow, "->"),
+        (Symbol, "Nat"),
+        (Equal, "="),
+        (Symbol, "fib"),
+        (LParen, "("),
+        (Symbol, "n"),
+        (Minus, "-"),
+        (NatLit, "1"),
+        (RParen, ")"),
+        (Plus, "+"),
+        (Symbol, "fib"),
+        (LParen, "("),
+        (Symbol, "n"),
+        (Minus, "-"),
+        (NatLit, "2"),
+        (RParen, ")"),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (Symbol, "t"),
+        (Equal, "="),
+        (Symbol, "if"),
+        (BoolLit, "True"),
+        (Colon, ":"),
+        (Newline, newline),
+        (Indent, "    "),
+        (Symbol, "then"),
+        (Walrus, ":="),
+        (NatLit, "1"),
+        (Newline, newline),
+        (Symbol, "else"),
+        (Walrus, ":="),
+        (NatLit, "2"),
+        (Newline, newline),
+        (Dedent, ""),
+        (Symbol, "assert"),
+        (Symbol, "t"),
+        (DblEq, "=="),
+        (NatLit, "1"),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (Symbol, "math"),
+        (Equal, "="),
+        (Symbol, "import"),
+        (StrLit, "\"math\""),
+        (Newline, newline),
+        (Newline, newline),
+        (LBrace, "{"),
+        (Symbol, "pi"),
+        (Comma, ","),
+        (EllipsisLit, "..."),
+        (RBrace, "}"),
+        (Equal, "="),
+        (Symbol, "import"),
+        (StrLit, "\"math\""),
+        (Newline, newline),
+        (EOF, ""),
+    ];
+
+    let mut tok: Token;
+    for (id, i) in token_array.into_iter().enumerate() {
+        print!("{id:>03}: ");
+        tok = lexer.next().unwrap().unwrap();
+        assert_eq!(tok, Token::from_str(i.0, i.1));
+        println!("{tok}");
+    }
+    Ok(())
+}
+
+#[test]
+fn test_lexer_for_literals() -> ParseResult<()> {
+    let mut lexer = Lexer::new(Input::File(FILE3.into()));
+    let newline = "\n";
+    let /*mut*/ token_array = vec![
+        (Newline, newline),
+        (Newline, newline),
+        (NatLit, "0"),
+        (Comma, ","),
+        (NatLit, "1"),
+        (Comma, ","),
+        (NatLit, "2"),
+        (Comma, ","),
+        (NatLit, "100_000"),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (IntLit, "-1"),
+        (Comma, ","),
+        (IntLit, "-10"),
+        (Comma, ","),
+        (IntLit, "-100_000"),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (RatioLit, "0.00"),
+        (Comma, ","),
+        (RatioLit, "-0.0"),
+        (Comma, ","),
+        (RatioLit, ".1"),
+        (Comma, ","),
+        (RatioLit, "400."),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (StrLit, "\"\""),
+        (Comma, ","),
+        (StrLit, "\"a\""),
+        (Comma, ","),
+        (StrLit, "\"こんにちは\""),
+        (Comma, ","),
+        (StrLit, "\"\\\" \\\\ \""),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (BoolLit, "True"),
+        (Comma, ","),
+        (BoolLit, "False"),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (NoneLit, "None"),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (EllipsisLit, "..."),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (InfLit, "Inf"),
+        (Comma, ","),
+        (PreMinus, "-"),
+        (InfLit, "Inf"),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        (NoImplLit, "NotImplemented"),
+        (Newline, newline),
+        (Newline, newline),
+        (Newline, newline),
+        // (EOF, ""),
+    ];
+
+    let mut tok: Token;
+    for (id, i) in token_array.into_iter().enumerate() {
+        print!("{id:>03}: ");
+        tok = lexer.next().unwrap().unwrap();
+        assert_eq!(tok, Token::from_str(i.0, i.1));
+        println!("{tok}");
+    }
+    Ok(())
+}
+
+#[test]
+fn tesop_te_prec() {
+    assert_eq!(Mod.precedence(), Some(170));
+    assert_eq!(LParen.precedence(), Some(0));
+    assert_eq!(Illegal.precedence(), None);
+}