1 files changed, 104 insertions, 0 deletions
diff --git a/users/fcuny/exp/monkey/pkg/lexer/lexer_test.go b/users/fcuny/exp/monkey/pkg/lexer/lexer_test.go
new file mode 100644
index 0000000..73b27fb
--- /dev/null
+++ b/users/fcuny/exp/monkey/pkg/lexer/lexer_test.go
@@ -0,0 +1,104 @@
+package lexer
+
+import (
+	"monkey/pkg/token"
+	"testing"
+)
+
+func TestNextTokenBasic(t *testing.T) {
+	input := `=+(){},;`
+
+	tests := []struct {
+		expectedType    token.TokenType
+		expectedLiteral string
+	}{
+		{token.ASSIGN, "="},
+		{token.PLUS, "+"},
+		{token.LPAREN, "("},
+		{token.RPAREN, ")"},
+		{token.LBRACE, "{"},
+		{token.RBRACE, "}"},
+		{token.COMMA, ","},
+		{token.SEMICOLON, ";"},
+	}
+
+	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] - tokenliteral wrong. expected=%q, got=%q", i, tt.expectedLiteral, tok.Literal)
+		}
+	}
+}
+
+func TestNextTokenMonkey(t *testing.T) {
+	input := `let five = 5;
+let ten = 10;
+
+let add = fn(x, y) {
+  x + y
+};
+
+let result = add(five, ten);`
+
+	tests := []struct {
+		expectedType    token.TokenType
+		expectedLiteral string
+	}{
+		{token.LET, "let"},
+		{token.IDENT, "five"},
+		{token.ASSIGN, "="},
+		{token.INT, "5"},
+		{token.SEMICOLON, ";"},
+
+		{token.LET, "let"},
+		{token.IDENT, "ten"},
+		{token.ASSIGN, "="},
+		{token.INT, "10"},
+		{token.SEMICOLON, ";"},
+
+		{token.LET, "let"},
+		{token.IDENT, "add"},
+		{token.ASSIGN, "="},
+		{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.RBRACE, "}"},
+		{token.SEMICOLON, ";"},
+
+		{token.LET, "let"},
+		{token.IDENT, "result"},
+		{token.ASSIGN, "="},
+		{token.IDENT, "add"},
+		{token.LPAREN, "("},
+		{token.IDENT, "five"},
+		{token.COMMA, ","},
+		{token.IDENT, "ten"},
+		{token.RPAREN, ")"},
+		{token.SEMICOLON, ";"},
+	}
+
+	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] - tokenliteral wrong. expected=%q, got=%q", i, tt.expectedLiteral, tok.Literal)
+		}
+	}
+}