tests: runtime: filter_nest: add test case for add_prefix (#8372)

Signed-off-by: Takahiro Yamashita <nokute78@gmail.com>

tests/runtime/filter_nest.c

@@ -14,11 +14,13 @@ int  num_output = 0;
 void flb_test_filter_nest_single(void);
 void flb_test_filter_nest_multi_nest(void);
 void flb_test_filter_nest_multi_lift(void);
+void flb_test_filter_nest_add_prefix(void);
 /* Test list */
 TEST_LIST = {
     {"single", flb_test_filter_nest_single },
     {"multiple events are not dropped(nest)", flb_test_filter_nest_multi_nest},
     {"multiple events are not dropped(lift)", flb_test_filter_nest_multi_lift},
+    {"add_prefix", flb_test_filter_nest_add_prefix},
     {NULL, NULL}
 };
 
@@ -300,3 +302,73 @@ void flb_test_filter_nest_single(void)
     flb_stop(ctx);
     flb_destroy(ctx);
 }
+
+void flb_test_filter_nest_add_prefix(void)
+{
+    int ret;
+    int bytes;
+    char *p, *output, *expected;
+    flb_ctx_t *ctx;
+    int in_ffd;
+    int out_ffd;
+    int filter_ffd;
+    struct flb_lib_out_cb cb_data;
+
+    ctx = flb_create();
+    flb_service_set(ctx,
+                    "Flush", "1",
+                    "Grace", "1",
+                    "Log_Level", "debug",
+                    NULL);
+
+    /* Input */
+    in_ffd = flb_input(ctx, (char *) "lib", NULL);
+    TEST_CHECK(in_ffd >= 0);
+    flb_input_set(ctx, in_ffd, "tag", "test", NULL);
+
+    /* Prepare output callback context*/
+    cb_data.cb = callback_test;
+    cb_data.data = NULL;
+
+    /* Filter */
+    filter_ffd = flb_filter(ctx, (char *) "nest", NULL);
+    TEST_CHECK(filter_ffd >= 0);
+
+    ret = flb_filter_set(ctx, filter_ffd,
+                         "Match", "*",
+                         "Operation", "lift",
+                         "Nest_under", "nested_key",
+                         "Add_prefix", "_nested_key.",
+                         NULL);
+
+    TEST_CHECK(ret == 0);
+
+
+    /* Output */
+    out_ffd = flb_output(ctx, (char *) "lib", (void *) &cb_data);
+    TEST_CHECK(out_ffd >= 0);
+    flb_output_set(ctx, out_ffd,
+                   "match", "test",
+                   "format", "json",
+                   NULL);
+
+    ret = flb_start(ctx);
+    TEST_CHECK(ret == 0);
+
+    p = "[1448403340, {\"nested_key\":{\"key\":\"value\"}}]";
+    bytes = flb_lib_push(ctx, in_ffd, p, strlen(p));
+    TEST_CHECK(bytes == strlen(p));
+
+    flb_time_msleep(1500); /* waiting flush */
+    output = get_output();
+
+    TEST_CHECK_(output != NULL, "Expected output to not be NULL");
+
+    if (output != NULL) {
+        expected = "\"_nested_key.key\":\"value\"}]";
+        TEST_CHECK_(strstr(output, expected) != NULL, "Expected output to contain '%s', got '%s'", expected, output);
+        free(output);
+    }
+    flb_stop(ctx);
+    flb_destroy(ctx);
+}