Adding some more unit tests for various components.

unittests/array_test.c

@@ -3,6 +3,7 @@
 
 int main() {
     int64_t i;
+    dst_init();
     DstArray *array = dst_array(10);
     assert(array->capacity == 10);
     assert(array->count == 0);

unittests/buffer_test.c

@@ -0,0 +1,19 @@
+#include "unit.h"
+#include <dst/dst.h>
+
+int main() {
+    dst_init();
+    DstBuffer *buffer = dst_buffer(100);
+    assert(buffer->count == 0);
+    assert(buffer->capacity == 100);
+    dst_buffer_push_u8(buffer, 'h');
+    dst_buffer_push_u8(buffer, 'e');
+    dst_buffer_push_u8(buffer, 'l');
+    dst_buffer_push_u8(buffer, 'l');
+    dst_buffer_push_u8(buffer, 'o');
+    assert(dst_equals(
+        dst_wrap_string(dst_cstring("hello")),
+        dst_wrap_string(dst_string(buffer->data, buffer->count))
+    ));
+    return 0;
+}

unittests/table_test.c

@@ -0,0 +1,15 @@
+#include "unit.h"
+#include <dst/dst.h>
+
+int main() {
+    dst_init();
+    DstTable *table = dst_table(10);
+    assert(table->count == 0);
+    dst_table_put(table, dst_cstringv("a"), dst_cstringv("b"));
+    dst_table_put(table, dst_cstringv("b"), dst_cstringv("a"));
+    dst_table_put(table, dst_cstringv("a"), dst_cstringv("c"));
+    assert(table->count == 2);
+    dst_table_remove(table, dst_cstringv("a"));
+    assert(table->count == 1);
+    return 0;
+}