tests: add comprehensive tests for S3 Parquet support

Add test coverage for:
- AWS utilities
- Parquet implementation
- S3 output configuration
- Edge cases handling
- Error handling
- Format conversion
- Multipart uploads
- Queue management
- Recovery mechanisms
- Special features

Signed-off-by: Arbin Cheng <[email protected]>
Signed-off-by: Arbin <[email protected]>

Author: kalavt

tests/include/aws_client_mock.c

@@ -1,4 +1,14 @@
 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*
+ * AWS Client Mock Implementation
+ *
+ * NOTE: This .c file is directly included in test files (not compiled separately).
+ *       Each test is built as a standalone executable, avoiding symbol conflicts.
+ *       DO NOT compile multiple tests using this mock into a single executable
+ *       without refactoring to a test library or using static functions.
+ */
+
 #include "aws_client_mock.h"
 
 #include <fluent-bit/flb_aws_util.h>
@@ -39,14 +49,30 @@ void flb_aws_client_mock_configure_generator(
 /*
  * Clean up generator's memory
  * Cleanup should be called on exiting generator
+ * Note: This is safe to call even if the mock was already freed by S3 plugin cleanup
  */
 void flb_aws_client_mock_destroy_generator()
 {
-    if (flb_aws_client_mock_instance != NULL) {
-        flb_aws_client_mock_destroy(flb_aws_client_mock_instance);
+    struct flb_aws_client_mock *mock = flb_aws_client_mock_instance;
+
+    /* Clear instance first to prevent double-free scenarios */
+    flb_aws_client_mock_instance = NULL;
+
+    if (mock != NULL) {
+        flb_aws_client_mock_destroy(mock);
     }
 }
 
+/*
+ * Clear generator instance without freeing
+ * Use this after flb_destroy() when the S3 plugin has already freed the mock client
+ * This prevents use-after-free when configure_generator is called again
+ */
+void flb_aws_client_mock_clear_generator_instance()
+{
+    flb_aws_client_mock_instance = NULL;
+}
+
 /* Create Mock of flb_aws_client */
 struct flb_aws_client_mock *flb_aws_client_mock_create(
     struct flb_aws_client_mock_request_chain *request_chain)
@@ -203,6 +229,7 @@ static struct flb_http_client *flb_aws_client_mock_vtable_request(
             char *flb_http_methods[] = {
                 "FLB_HTTP_GET",  "FLB_HTTP_POST",    "FLB_HTTP_PUT",
                 "FLB_HTTP_HEAD", "FLB_HTTP_CONNECT", "FLB_HTTP_PATCH",
+                "FLB_HTTP_DELETE",
             };
 
             /*
@@ -236,12 +263,49 @@ static struct flb_http_client *flb_aws_client_mock_vtable_request(
             c = (struct flb_http_client *)val1;
         }
 
+        /*
+         * Special handling for DATA field - must be dynamically allocated
+         * because flb_http_client_destroy() will call flb_free(c->resp.data)
+         */
+        else if (response_config->config_parameter == FLB_AWS_CLIENT_MOCK_SET_DATA) {
+            if (val1 != NULL) {
+                /* Get data size from response config or use strlen */
+                size_t data_len = 0;
+                int j;
+                for (j = 0; j < response->length; ++j) {
+                    if (response->config_parameters[j].config_parameter ==
+                        FLB_AWS_CLIENT_MOCK_SET_DATA_SIZE) {
+                        data_len = (size_t)(uintptr_t)response->config_parameters[j].config_value;
+                        break;
+                    }
+                    if (response->config_parameters[j].config_parameter ==
+                        FLB_AWS_CLIENT_MOCK_SET_DATA_LEN) {
+                        data_len = (size_t)(uintptr_t)response->config_parameters[j].config_value;
+                        break;
+                    }
+                }
+                if (data_len == 0) {
+                    data_len = strlen((char *)val1);
+                }
+                /* Allocate and copy data so flb_http_client_destroy can free it */
+                c->resp.data = flb_malloc(data_len + 1);
+                if (c->resp.data) {
+                    memcpy(c->resp.data, val1, data_len);
+                    c->resp.data[data_len] = '\0';
+                    c->resp.data_len = data_len;
+                    c->resp.data_size = data_len + 1;
+                }
+            }
+        }
+
         /*
         * Response setters
         * Set client fields using XMacro definitions
+        * Note: DATA field is handled specially above
         */
 #define EXPAND_CLIENT_RESPONSE_PARAMETER(lower, UPPER, type)                           \
-        else if (response_config->config_parameter == FLB_AWS_CLIENT_MOCK_SET_##UPPER) \
+        else if (response_config->config_parameter == FLB_AWS_CLIENT_MOCK_SET_##UPPER  \
+                 && response_config->config_parameter != FLB_AWS_CLIENT_MOCK_SET_DATA) \
         {                                                                              \
             c->resp.lower = CONVERT_##type((char *)val1);                              \
         }

tests/include/aws_client_mock.h

@@ -3,9 +3,9 @@
 /*
  * AWS Client Mock
  *
- * Note: AWS Client Mock is not intended to be used with asynchronously
- * running tests. A mock instance is stored and retrieved by
- * the mock generator
+ * Usage: #include both .h and .c files in test files
+ * Limitation: Do not compile multiple tests into one executable (duplicate symbols)
+ * Thread safety: Not safe for concurrent tests (uses static variables)
  */
 
 /*
@@ -189,6 +189,13 @@ void flb_aws_client_mock_configure_generator(
  */
 void flb_aws_client_mock_destroy_generator();
 
+/*
+ * Clear generator instance without freeing
+ * Use this after flb_destroy() when the S3 plugin has already freed the mock client
+ * This prevents use-after-free when configure_generator is called again
+ */
+void flb_aws_client_mock_clear_generator_instance();
+
 /* Create Mock of flb_aws_client */
 struct flb_aws_client_mock *flb_aws_client_mock_create(
     struct flb_aws_client_mock_request_chain *request_chain);