restructure project

internal/lexer/lexer_test.go

@@ -0,0 +1,212 @@
+package lexer
+
+import (
+	"monkey/internal/token"
+	"testing"
+)
+
+func TestNextToken(t *testing.T) {
+	input := `#!./monkey-lang
+				five := 5;
+				ten := 10;
+				
+				add := fn(x, y) {
+				  x + y;
+				};
+				
+				# this is a comment
+				result := add(five, ten);
+				!-/*5;
+				5 < 10 > 5;
+				
+				if (5 < 10) {
+					return true;
+				} else {
+					return false;
+				}
+				
+				// this is another comment
+				10 == 10;
+				10 != 9;
+				"foobar"
+				"foo bar"
+				[1, 2];
+				{"foo": "bar"}
+				d.foo
+				&|^~
+				!&&||
+				<<>>
+			`
+
+	tests := []struct {
+		expectedType    token.TokenType
+		expectedLiteral string
+	}{
+		{token.COMMENT, "!./monkey-lang"},
+		{token.IDENT, "five"},
+		{token.BIND, ":="},
+		{token.INT, "5"},
+		{token.SEMICOLON, ";"},
+		{token.IDENT, "ten"},
+		{token.BIND, ":="},
+		{token.INT, "10"},
+		{token.SEMICOLON, ";"},
+		{token.IDENT, "add"},
+		{token.BIND, ":="},
+		{token.FUNCTION, "fn"},
+		{token.LPAREN, "("},
+		{token.IDENT, "x"},
+		{token.COMMA, ","},
+		{token.IDENT, "y"},
+		{token.RPAREN, ")"},
+		{token.LBRACE, "{"},
+		{token.IDENT, "x"},
+		{token.PLUS, "+"},
+		{token.IDENT, "y"},
+		{token.SEMICOLON, ";"},
+		{token.RBRACE, "}"},
+		{token.SEMICOLON, ";"},
+		{token.COMMENT, " this is a comment"},
+		{token.IDENT, "result"},
+		{token.BIND, ":="},
+		{token.IDENT, "add"},
+		{token.LPAREN, "("},
+		{token.IDENT, "five"},
+		{token.COMMA, ","},
+		{token.IDENT, "ten"},
+		{token.RPAREN, ")"},
+		{token.SEMICOLON, ";"},
+
+		{token.NOT, "!"},
+		{token.MINUS, "-"},
+		{token.DIVIDE, "/"},
+		{token.MULTIPLY, "*"},
+		{token.INT, "5"},
+		{token.SEMICOLON, ";"},
+		{token.INT, "5"},
+		{token.LT, "<"},
+		{token.INT, "10"},
+		{token.GT, ">"},
+		{token.INT, "5"},
+		{token.SEMICOLON, ";"},
+
+		{token.IF, "if"},
+		{token.LPAREN, "("},
+		{token.INT, "5"},
+		{token.LT, "<"},
+		{token.INT, "10"},
+		{token.RPAREN, ")"},
+		{token.LBRACE, "{"},
+
+		{token.RETURN, "return"},
+		{token.TRUE, "true"},
+		{token.SEMICOLON, ";"},
+
+		{token.RBRACE, "}"},
+		{token.ELSE, "else"},
+		{token.LBRACE, "{"},
+
+		{token.RETURN, "return"},
+		{token.FALSE, "false"},
+		{token.SEMICOLON, ";"},
+
+		{token.RBRACE, "}"},
+		{token.COMMENT, " this is another comment"},
+		{token.INT, "10"},
+		{token.EQ, "=="},
+		{token.INT, "10"},
+		{token.SEMICOLON, ";"},
+
+		{token.INT, "10"},
+		{token.NOT_EQ, "!="},
+		{token.INT, "9"},
+		{token.SEMICOLON, ";"},
+
+		{token.STRING, "foobar"},
+		{token.STRING, "foo bar"},
+
+		{token.LBRACKET, "["},
+		{token.INT, "1"},
+		{token.COMMA, ","},
+		{token.INT, "2"},
+		{token.RBRACKET, "]"},
+		{token.SEMICOLON, ";"},
+
+		{token.LBRACE, "{"},
+		{token.STRING, "foo"},
+		{token.COLON, ":"},
+		{token.STRING, "bar"},
+		{token.RBRACE, "}"},
+		{token.IDENT, "d"},
+		{token.DOT, "."},
+		{token.IDENT, "foo"},
+		{token.BITWISE_AND, "&"},
+		{token.BITWISE_OR, "|"},
+		{token.BITWISE_XOR, "^"},
+		{token.BITWISE_NOT, "~"},
+		{token.NOT, "!"},
+		{token.AND, "&&"},
+		{token.OR, "||"},
+		{token.LEFT_SHIFT, "<<"},
+		{token.RIGHT_SHIFT, ">>"},
+		{token.EOF, ""},
+	}
+
+	l := New(input)
+
+	for i, tt := range tests {
+		tok := l.NextToken()
+
+		if tok.Type != tt.expectedType {
+			t.Fatalf("tests[%d] - tokentype wrong. expected=%q, got=%q",
+				i, tt.expectedType, tok.Type)
+		}
+
+		if tok.Literal != tt.expectedLiteral {
+			t.Fatalf("tests[%d] - literal wrong. expected=%q, got=%q",
+				i, tt.expectedLiteral, tok.Literal)
+		}
+	}
+}
+
+func TestStringEscapes(t *testing.T) {
+	input := `#!./monkey-lang
+a := "\"foo\""
+b := "\x00\x0a\x7f"
+c := "\r\n\t"
+`
+
+	tests := []struct {
+		expectedType    token.TokenType
+		expectedLiteral string
+	}{
+		{token.COMMENT, "!./monkey-lang"},
+		{token.IDENT, "a"},
+		{token.BIND, ":="},
+		{token.STRING, "\"foo\""},
+		{token.IDENT, "b"},
+		{token.BIND, ":="},
+		{token.STRING, "\x00\n\u007f"},
+		{token.IDENT, "c"},
+		{token.BIND, ":="},
+		{token.STRING, "\r\n\t"},
+		{token.EOF, ""},
+	}
+
+	lexer := New(input)
+
+	for i, test := range tests {
+		token := lexer.NextToken()
+
+		if token.Type != test.expectedType {
+			t.Fatalf("tests[%d] - token type wrong. expected=%q, got=%q",
+				i, test.expectedType, token.Type)
+		}
+
+		if token.Literal != test.expectedLiteral {
+			t.Fatalf("tests[%d] - literal wrong. expected=%q, got=%q",
+				i, test.expectedLiteral, token.Literal)
+		}
+	}
+
+}