feat(storage/vfs): add nullfs test cases for vfs

components/esp_system/test_apps/console/main/test_app_main.c

@@ -54,11 +54,11 @@ void app_main(void)
     printf("Hello World\n");
 
     int fd = open("/dev/null", O_RDWR);
-    assert(fd >= 0); // Standard check
+    assert(fd >= 0 && "Could not open file"); // Standard check
 
     // Check if correct file descriptor is returned
     // In this case it should be neither of 0, 1, 2 (== stdin, stdout, stderr)
-    assert(fd > 2);
+    assert(fd > 2 && "Incorrect file descriptor returned, stdin, stdout, stderr were not correctly assigned");
 
     close(fd);
 

components/vfs/test_apps/main/CMakeLists.txt

@@ -2,7 +2,7 @@ set(src "test_app_main.c" "test_vfs_access.c"
         "test_vfs_append.c" "test_vfs_eventfd.c"
         "test_vfs_fd.c" "test_vfs_lwip.c"
         "test_vfs_open.c" "test_vfs_paths.c"
-        "test_vfs_select.c"
+        "test_vfs_select.c" "test_vfs_nullfs.c"
         )
 
 idf_component_register(SRCS ${src}

components/vfs/test_apps/main/test_vfs_nullfs.c

@@ -0,0 +1,138 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include "unity.h"
+#include "esp_vfs.h"
+
+#include "esp_vfs_null.h"
+#include "unity_test_runner.h"
+
+TEST_CASE("Can open and close /dev/null", "[vfs_nullfs]")
+{
+    int fd = open("/dev/null", O_RDWR);
+    TEST_ASSERT(fd >= 0);
+    close(fd);
+}
+
+TEST_CASE("Can write to /dev/null", "[vfs_nullfs]")
+{
+    int fd = open("/dev/null", O_RDWR);
+    TEST_ASSERT(fd >= 0);
+
+    // Can write to /dev/null
+    ssize_t ret = write(fd, "hello", 5);
+    TEST_ASSERT_EQUAL(5, ret);
+
+    // Write does not change the file offset
+    off_t offset = lseek(fd, 0, SEEK_CUR);
+    TEST_ASSERT_EQUAL(0, offset);
+
+    close(fd);
+}
+
+TEST_CASE("Can read from /dev/null", "[vfs_nullfs]")
+{
+    int fd = open("/dev/null", O_RDWR);
+    TEST_ASSERT(fd >= 0);
+
+    // Can read from /dev/null
+    char buf[5] = {0};
+    ssize_t ret = read(fd, buf, 5);
+
+    // Read always returns 0 bytes -> EOF
+    TEST_ASSERT_EQUAL(0, ret);
+
+    // Read does not modify the buffer
+    for (int i = 0; i < 5; i++) {
+        TEST_ASSERT_EQUAL(0, buf[i]);
+    }
+
+    // Read does not change the file offset
+    off_t offset = lseek(fd, 0, SEEK_CUR);
+    TEST_ASSERT_EQUAL(0, offset);
+
+
+    close(fd);
+}
+
+TEST_CASE("Can lseek /dev/null", "[vfs_nullfs]")
+{
+    int fd = open("/dev/null", O_RDWR);
+    TEST_ASSERT(fd >= 0);
+
+    off_t offset = lseek(fd, 0, SEEK_SET);
+    TEST_ASSERT_EQUAL(0, offset);
+
+    offset = lseek(fd, 0, SEEK_CUR);
+    TEST_ASSERT_EQUAL(0, offset);
+
+    offset = lseek(fd, 0, SEEK_END);
+    TEST_ASSERT_EQUAL(0, offset);
+
+    close(fd);
+}
+
+TEST_CASE("Can fstat /dev/null", "[vfs_nullfs]")
+{
+    int fd = open("/dev/null", O_RDWR);
+    TEST_ASSERT(fd >= 0);
+
+    struct stat st;
+    int ret = fstat(fd, &st);
+    TEST_ASSERT_EQUAL(0, ret);
+
+    TEST_ASSERT_EQUAL(0, st.st_size);
+    TEST_ASSERT_EQUAL(S_IFCHR, st.st_mode & S_IFMT);
+
+    close(fd);
+}
+
+TEST_CASE("Can fsync /dev/null", "[vfs_nullfs]")
+{
+    int fd = open("/dev/null", O_RDWR);
+    TEST_ASSERT(fd >= 0);
+
+    int ret = fsync(fd);
+    TEST_ASSERT_EQUAL(0, ret);
+
+    close(fd);
+}
+
+TEST_CASE("Can pread /dev/null", "[vfs_nullfs]")
+{
+    int fd = open("/dev/null", O_RDWR);
+    TEST_ASSERT(fd >= 0);
+
+    char buf[5] = {0};
+    ssize_t ret = pread(fd, buf, 5, 0);
+    TEST_ASSERT_EQUAL(0, ret);
+
+    close(fd);
+}
+
+TEST_CASE("Can pwrite /dev/null", "[vfs_nullfs]")
+{
+    int fd = open("/dev/null", O_RDWR);
+    TEST_ASSERT(fd >= 0);
+
+    ssize_t ret = pwrite(fd, "hello", 5, 0);
+    TEST_ASSERT_EQUAL(5, ret);
+
+    close(fd);
+}
+
+TEST_CASE("Can stat /dev/null", "[vfs_nullfs]")
+{
+    struct stat st;
+    int ret = stat("/dev/null", &st);
+    TEST_ASSERT_EQUAL(0, ret);
+
+    TEST_ASSERT_EQUAL(0, st.st_size);
+    TEST_ASSERT_EQUAL(S_IFCHR, st.st_mode & S_IFMT);
+}