Nomad changes

docs/snippets/c/plugins/plugin_testing.md

@@ -0,0 +1,84 @@
+```c title="C"
+#include <kreuzberg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Round-trip test: register a no-op validator, confirm it appears in the
+ * registry list, then unregister and confirm it disappears. */
+
+static char *dup_cstr(const char *s) {
+    size_t len = strlen(s);
+    char *out = (char *)malloc(len + 1);
+    if (out) {
+        memcpy(out, s, len + 1);
+    }
+    return out;
+}
+
+static int32_t validate_fn(
+    const void *user_data,
+    const char *result,
+    const char *config,
+    char **out_error
+) {
+    (void)user_data;
+    (void)result;
+    (void)config;
+    (void)out_error;
+    return 0;
+}
+
+static int32_t priority_fn(const void *user_data) {
+    (void)user_data;
+    return 50;
+}
+
+static int contains_name(const char *json, const char *name) {
+    if (!json || !name) {
+        return 0;
+    }
+    return strstr(json, name) != NULL;
+}
+
+int main(void) {
+    const char *plugin_name = "noop-validator";
+
+    KREUZBERGKreuzbergValidatorVTable vtable = {0};
+    vtable.validate = validate_fn;
+    vtable.priority = priority_fn;
+
+    char *err = NULL;
+    if (kreuzberg_register_validator(plugin_name, vtable, NULL, &err) != 0) {
+        fprintf(stderr, "register failed: %s\n", err ? err : "(no detail)");
+        kreuzberg_free_string(err);
+        return 1;
+    }
+
+    char *list_after_register = kreuzberg_list_validators();
+    if (!contains_name(list_after_register, plugin_name)) {
+        fprintf(stderr, "FAIL: validator missing after register\n");
+        kreuzberg_free_string(list_after_register);
+        return 1;
+    }
+    printf("PASS: %s present after register\n", plugin_name);
+    kreuzberg_free_string(list_after_register);
+
+    if (kreuzberg_unregister_validator(plugin_name, &err) != 0) {
+        fprintf(stderr, "unregister failed: %s\n", err ? err : "(no detail)");
+        kreuzberg_free_string(err);
+        return 1;
+    }
+
+    char *list_after_unregister = kreuzberg_list_validators();
+    if (contains_name(list_after_unregister, plugin_name)) {
+        fprintf(stderr, "FAIL: validator still present after unregister\n");
+        kreuzberg_free_string(list_after_unregister);
+        return 1;
+    }
+    printf("PASS: %s absent after unregister\n", plugin_name);
+    kreuzberg_free_string(list_after_unregister);
+
+    return 0;
+}
+```