4 files changed, 102 insertions, 0 deletions
diff --git a/tests/lexer_test.c b/tests/lexer_test.c
new file mode 100644
index 0000000..c5c9f14
--- /dev/null
+++ b/tests/lexer_test.c
@@ -0,0 +1,63 @@
+#include <string.h>
+#include <stdbool.h>
+
+#include "lexer/lexer.h"
+#include "tests.h"
+
+static bool token_matches(struct Token token, enum TokenType type, const char* text)
+{
+	size_t length = strlen(text);
+	return token.type == type
+		&& token.length == length
+		&& memcmp(token.start, text, length) == 0;
+}
+
+static void test_identifiers_and_integers(struct TestContext* context)
+{
+	struct Lexer lexer = create_lexer("rax 42");
+	check(context, token_matches(scan_token(&lexer), TOKEN_IDENTIFIER, "rax"));
+	check(context, token_matches(scan_token(&lexer), TOKEN_INTEGER, "42"));
+	check(context, scan_token(&lexer).type == TOKEN_EOF);
+}
+
+static void test_operators(struct TestContext* context)
+{
+	struct Lexer lexer = create_lexer("= == += != /");
+	check(context, scan_token(&lexer).type == TOKEN_EQUAL);
+	check(context, scan_token(&lexer).type == TOKEN_EQUAL_EQUAL);
+	check(context, scan_token(&lexer).type == TOKEN_PLUS_EQUAL);
+	check(context, scan_token(&lexer).type == TOKEN_BANG_EQUAL);
+	check(context, scan_token(&lexer).type == TOKEN_SLASH);
+}
+
+static void test_literals(struct TestContext* context)
+{
+	struct Lexer lexer = create_lexer("\"hi\\n\" '0'");
+	check(context, token_matches(scan_token(&lexer), TOKEN_STRING, "\"hi\\n\""));
+	check(context, token_matches(scan_token(&lexer), TOKEN_CHAR, "'0'"));
+}
+
+static void test_keywords(struct TestContext* context)
+{
+	struct Lexer lexer = create_lexer("const proc mainly");
+	check(context, scan_token(&lexer).type == TOKEN_CONST);
+	check(context, scan_token(&lexer).type == TOKEN_PROC);
+	check(context, scan_token(&lexer).type == TOKEN_IDENTIFIER);
+}
+
+static void test_line_counting(struct TestContext* context)
+{
+	struct Lexer lexer = create_lexer("a\nb\nc");
+	check(context, scan_token(&lexer).line == 1);
+	check(context, scan_token(&lexer).line == 2);
+	check(context, scan_token(&lexer).line == 3);
+}
+
+void run_lexer_tests(struct TestContext* context)
+{
+	test_identifiers_and_integers(context);
+	test_operators(context);
+	test_literals(context);
+	test_keywords(context);
+	test_line_counting(context);
+}
diff --git a/tests/main.c b/tests/main.c
new file mode 100644
index 0000000..49ac448
--- /dev/null
+++ b/tests/main.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+#include "tests.h"
+
+int main(void)
+{
+	struct TestContext context = { 0, 0 };
+
+	run_lexer_tests(&context);
+
+	printf("\n%d checks, %d failure(s)\n", context.checks, context.failures);
+	return context.failures == 0 ? 0 : 1;
+}
diff --git a/tests/test.h b/tests/test.h
new file mode 100644
index 0000000..c5e2e73
--- /dev/null
+++ b/tests/test.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <stdio.h>
+
+struct TestContext
+{
+	int checks;
+	int failures;
+};
+
+#define check(context, condition) \
+	do \
+	{ \
+		(context)->checks += 1; \
+		if (!(condition)) \
+		{ \
+			(context)->failures += 1; \
+			printf("  FAIL %s:%d: %s\n", __FILE__, __LINE__, #condition); \
+		} \
+	} \
+	while (0)
diff --git a/tests/tests.h b/tests/tests.h
new file mode 100644
index 0000000..4ed1348
--- /dev/null
+++ b/tests/tests.h
@@ -0,0 +1,5 @@
+#pragma once
+
+#include "test.h"
+
+void run_lexer_tests(struct TestContext* context);