Add rustls_result test

Author: lucic71

tests/unit/rustls_result.c

@@ -0,0 +1,68 @@
+// no-compile: refcount
+#include <stdio.h>
+
+#include "../../rules/rustls/rustls.h"
+
+static int to_code(rustls_result r) {
+  switch (r) {
+  case RUSTLS_RESULT_OK:
+    return 0;
+  case RUSTLS_RESULT_NULL_PARAMETER:
+    return 1;
+  default:
+    return 2;
+  }
+}
+
+static int classify(rustls_result r) {
+  if (r == RUSTLS_RESULT_PLAINTEXT_EMPTY) {
+    return 10;
+  } else if (r == RUSTLS_RESULT_UNEXPECTED_EOF) {
+    return 20;
+  } else if (r != RUSTLS_RESULT_OK) {
+    return 30;
+  }
+  return 0;
+}
+
+static void describe(rustls_result r, char *buf, size_t len, size_t *out_n) {
+  size_t n = 0;
+  if (r != RUSTLS_RESULT_OK && len > 0) {
+    buf[n++] = '!';
+  }
+  *out_n = n;
+}
+
+static rustls_result init_zero(void) {
+  rustls_result r = 0;
+  return r;
+}
+
+static rustls_result reset(rustls_result r) {
+  r = 0;
+  return r;
+}
+
+static int is_unset(rustls_result r) { return r == 0; }
+
+int main(void) {
+  rustls_result r = RUSTLS_RESULT_OK;
+  char buf[16];
+  size_t n = 0;
+
+  printf("%d\n", to_code(r));
+  printf("%d\n", to_code(RUSTLS_RESULT_NULL_PARAMETER));
+  printf("%d\n", classify(RUSTLS_RESULT_PLAINTEXT_EMPTY));
+  printf("%d\n", classify(RUSTLS_RESULT_UNEXPECTED_EOF));
+  printf("%d\n", classify(RUSTLS_RESULT_OK));
+
+  describe(RUSTLS_RESULT_NULL_PARAMETER, buf, sizeof(buf), &n);
+  printf("%d\n", (int)n);
+  describe(RUSTLS_RESULT_OK, buf, sizeof(buf), &n);
+  printf("%d\n", (int)n);
+
+  printf("%d\n", is_unset(init_zero()));
+  printf("%d\n", to_code(init_zero()));
+  printf("%d\n", is_unset(reset(RUSTLS_RESULT_OK)));
+  return 0;
+}