Merge pull request #18 from dsLeks/test-unhandled-character

Add test for unhandled characters
dsLeks · Dec 9, 2023 · 36fbb0f · 36fbb0f
2 parents 065289a + 9742521
commit 36fbb0f
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Showing 3 changed files with 21 additions and 8 deletions.
diff --git a/lexer.cpp b/lexer.cpp
@@ -74,9 +74,8 @@ Result<Token> Lexer::getNextToken() {
   }
 
   std::string identifier;
-  if (((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) && ch != EOF) {
-    while (((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) &&
-           ch != EOF) {
+  if (isalpha(ch)) {
+    while (isalpha(ch)) {
       identifier += ch;
       ch = getNextChar();
     }
@@ -85,12 +84,14 @@ Result<Token> Lexer::getNextToken() {
     lookahead_ = ch;
     has_lookahead_ = true;
 
-    if (identifier == "out") {
-      return Token(Token::out, row, col);
-    }
+    if (identifier == "out") return Token(Token::out, row, col);
+
+    return Token(Token::identifier, row, col, identifier);
   }
 
-  return Token(Token::identifier, row, col, identifier);
+  std::stringstream ss;
+  ss << "Unhandled character '" << ch << "'";
+  return Result<Token>::Error(ss.str());
 }
 
 }  // namespace xos
diff --git a/test.cpp b/test.cpp
@@ -38,4 +38,13 @@ TEST(Lexer, UnfinishedArrowToken) {
   ASSERT_EQ(result.getErr(), "Expected '=>' at row 1, col 1");
 }
 
+TEST(Lexer, UnhandledCharacter) {
+  std::stringstream ss("%");
+  xos::Lexer lexer(ss);
+
+  auto result = lexer.getNextToken();
+  ASSERT_TRUE(result.hasError());
+  ASSERT_EQ(result.getErr(), "Unhandled character '%'");
+}
+
 }  // namespace
diff --git a/xos.h b/xos.h
@@ -63,7 +63,10 @@ class Result {
     assert(!hasError() && "Getting from an invalid result");
     return result_;
   }
-  const auto &getErr() const { return err_; }
+  const auto &getErr() const {
+    assert(hasError() && "Expected an error");
+    return err_;
+  }
 
  private:
   Result() = default;