text reader passes tests

src/spider/compiler/Compiler.cpp

@@ -3,12 +3,140 @@
 #include <spider/compiler/common.hpp>
 #include <spider/compiler/text/utf8.hpp>
 
-namespace spider {
+#include <spider/compiler/text/TextReader.hpp>
 
+using namespace spider;
 
+class TestRunner {
+private:
+    int totalTests = 0;
+    int passedTests = 0;
 
+public:
+    void assertCondition(bool condition, const std::string& testName) {
+        totalTests++;
+        if (condition) {
+            std::cout << "  [PASS] " << testName << "\n";
+            passedTests++;
+        } else {
+            std::cout << "  [FAIL] " << testName << "\n";
+        }
+    }
+
+    void printSummary() const {
+        std::cout << "\n========================================\n";
+        std::cout << "Test Results: " << passedTests << "/" << totalTests << " passed.\n";
+        std::cout << "========================================\n";
+    }
+};
+
+// ============================================================================
+// TEST SUITES FOR StringTextReader
+// ============================================================================
+
+void test_basic_reading(TestRunner& runner) {
+    std::cout << "\n--- Running: Basic Reading Tests ---\n";
+    std::cout.flush();
+
+    StringTextReader reader("hello");
+
+    runner.assertCondition(reader.current().has_value() && reader.current().value() == 'h', "Initial current character is 'h'");
+    runner.assertCondition(reader.peekChar(1).has_value() && reader.peekChar(1).value() == 'e', "Peek +1 char is 'e'");
+
+    auto next = reader.nextChar(1);
+    runner.assertCondition(next.has_value() && next.value() == 'e', "Advance to next char gives 'e'");
+    runner.assertCondition(reader.current().has_value() && reader.current().value() == 'e', "Current character is now 'e'");
 }
 
+void test_eat_operations(TestRunner& runner) {
+    std::cout << "\n--- Running: Eat Operations Tests ---\n";
+    std::cout.flush();
+
+    StringTextReader reader("constexpr int x = 42;");
+
+    runner.assertCondition(reader.eat("constexpr"), "Eat exact string match 'constexpr'");
+    runner.assertCondition(reader.eat(' '), "Eat single space character");
+    runner.assertCondition(reader.eat("int"), "Eat second string match 'int'");
+
+    runner.assertCondition(!reader.eat("float"), "Eat fails on mismatched string 'float'");
+    runner.assertCondition(reader.eat(' '), "Eat single space after failure");
+    runner.assertCondition(reader.eat('x'), "Eat character 'x'");
+}
+
+void test_push_pop_rollback(TestRunner& runner) {
+    std::cout << "\n--- Running: Push/Pop Rollback Tests ---\n";
+    std::cout.flush();
+
+    StringTextReader reader("function_name()");
+
+    auto savedPos = reader.push();
+    runner.assertCondition(reader.eat("function_"), "Incomplete parse attempt");
+
+    // Rollback
+    reader.pop(savedPos);
+    runner.assertCondition(reader.current().has_value() && reader.current().value() == 'f', "Rollback restores cursor to 'f'");
+    runner.assertCondition(reader.eat("function_name"), "Subsequent match succeeds after rollback");
+}
+
+void test_commit(TestRunner& runner) {
+    std::cout << "\n--- Running: Buffer Commit Tests ---\n";
+    std::cout.flush();
+
+    StringTextReader reader("line1\nline2");
+
+    reader.eat("line1\n");
+    reader.commit(); // Discard historical rollback buffer
+
+    runner.assertCondition(reader.current().has_value() && reader.current().value() == 'l', "Current char after commit is 'l'");
+    runner.assertCondition(reader.eat("line2"), "Reading continues normally after commit");
+}
+
+void test_string_mutations(TestRunner& runner) {
+    std::cout << "\n--- Running: String Mutation Tests (set/append) ---\n";
+    std::cout.flush();
+
+    StringTextReader reader("foo");
+    runner.assertCondition(reader.eat("foo"), "Read initial text 'foo'");
+
+    reader.set("reset_text");
+    runner.assertCondition(reader.eat("reset_text"), "Read completely new text after set()");
+}
+
+void test_eof_handling(TestRunner& runner) {
+    std::cout << "\n--- Running: EOF & Error State Tests ---\n";
+    std::cout.flush();
+
+    StringTextReader reader("a");
+
+    runner.assertCondition(static_cast<bool>(reader), "Reader is valid initially");
+    runner.assertCondition(!reader.isEOF(), "isEOF is false initially");
+
+    reader.eat('a');
+    std::cout << "Index: " << reader.push().index << std::endl;
+    std::cout << "Value: " << reader.current().value_or(0) << std::endl;
+    runner.assertCondition(!reader.current().has_value(), "current() returns empty optional at EOF");
+    runner.assertCondition(reader.isEOF(), "isEOF is true after consuming all input");
+    runner.assertCondition(!reader.hasError(), "hasError remains false on normal EOF");
+}
+
+// ============================================================================
+// MAIN DRIVER
+// ============================================================================
+
 int main() {
+    std::cout << "========================================\n";
+    std::cout << "   StringTextReader Unit Test Suite     \n";
+    std::cout << "========================================\n";
+
+    TestRunner runner;
+    test_basic_reading(runner);
+    test_eat_operations(runner);
+    test_push_pop_rollback(runner);
+    test_commit(runner);
+    test_string_mutations(runner);
+    test_eof_handling(runner);
+    runner.printSummary();
+
     return 0;
 }
+