test/py: Add tests for the erofs

Add Python scripts to test 'ls' and 'load' commands, as well as
test related filesystem functions.

Signed-off-by: Huang Jianan <jnhuang95@gmail.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 3e7ae7e..f25ca7c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -816,6 +816,7 @@
 F:	cmd/erofs.c
 F:	fs/erofs/
 F:	include/erofs.h
+F:	test/py/tests/test_fs/test_erofs.py
 
 EVENTS
 M:	Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index eaaac6d..41f73f8 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -104,6 +104,7 @@
 CONFIG_CMD_BTRFS=y
 CONFIG_CMD_CBFS=y
 CONFIG_CMD_CRAMFS=y
+CONFIG_CMD_EROFS=y
 CONFIG_CMD_EXT4_WRITE=y
 CONFIG_CMD_SQUASHFS=y
 CONFIG_CMD_MTDPARTS=y
diff --git a/test/py/tests/test_fs/test_erofs.py b/test/py/tests/test_fs/test_erofs.py
new file mode 100644
index 0000000..458a52b
--- /dev/null
+++ b/test/py/tests/test_fs/test_erofs.py
@@ -0,0 +1,211 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (C) 2022 Huang Jianan <jnhuang95@gmail.com>
+# Author: Huang Jianan <jnhuang95@gmail.com>
+
+import os
+import pytest
+import shutil
+import subprocess
+
+EROFS_SRC_DIR = 'erofs_src_dir'
+EROFS_IMAGE_NAME = 'erofs.img'
+
+def generate_file(name, size):
+    """
+    Generates a file filled with 'x'.
+    """
+    content = 'x' * size
+    file = open(name, 'w')
+    file.write(content)
+    file.close()
+
+def make_erofs_image(build_dir):
+    """
+    Makes the EROFS images used for the test.
+
+    The image is generated at build_dir with the following structure:
+    erofs_src_dir/
+    ├── f4096
+    ├── f7812
+    ├── subdir/
+    │   └── subdir-file
+    ├── symdir -> subdir
+    └── symfile -> f5096
+    """
+    root = os.path.join(build_dir, EROFS_SRC_DIR)
+    os.makedirs(root)
+
+    # 4096: uncompressed file
+    generate_file(os.path.join(root, 'f4096'), 4096)
+
+    # 7812: Compressed file
+    generate_file(os.path.join(root, 'f7812'), 7812)
+
+    # sub-directory with a single file inside
+    subdir_path = os.path.join(root, 'subdir')
+    os.makedirs(subdir_path)
+    generate_file(os.path.join(subdir_path, 'subdir-file'), 100)
+
+    # symlink
+    os.symlink('subdir', os.path.join(root, 'symdir'))
+    os.symlink('f7812', os.path.join(root, 'symfile'))
+
+    input_path = os.path.join(build_dir, EROFS_SRC_DIR)
+    output_path = os.path.join(build_dir, EROFS_IMAGE_NAME)
+    args = ' '.join([output_path, input_path])
+    subprocess.run(['mkfs.erofs -zlz4 ' + args], shell=True, check=True,
+                   stdout=subprocess.DEVNULL)
+
+def clean_erofs_image(build_dir):
+    """
+    Deletes the image and src_dir at build_dir.
+    """
+    path = os.path.join(build_dir, EROFS_SRC_DIR)
+    shutil.rmtree(path)
+    image_path = os.path.join(build_dir, EROFS_IMAGE_NAME)
+    os.remove(image_path)
+
+def erofs_ls_at_root(u_boot_console):
+    """
+    Test if all the present files and directories were listed.
+    """
+    no_slash = u_boot_console.run_command('erofsls host 0')
+    slash = u_boot_console.run_command('erofsls host 0 /')
+    assert no_slash == slash
+
+    expected_lines = ['./', '../', '4096   f4096', '7812   f7812', 'subdir/',
+                      '<SYM>   symdir', '<SYM>   symfile', '4 file(s), 3 dir(s)']
+
+    output = u_boot_console.run_command('erofsls host 0')
+    for line in expected_lines:
+        assert line in output
+
+def erofs_ls_at_subdir(u_boot_console):
+    """
+    Test if the path resolution works.
+    """
+    expected_lines = ['./', '../', '100   subdir-file', '1 file(s), 2 dir(s)']
+    output = u_boot_console.run_command('erofsls host 0 subdir')
+    for line in expected_lines:
+        assert line in output
+
+def erofs_ls_at_symlink(u_boot_console):
+    """
+    Test if the symbolic link's target resolution works.
+    """
+    output = u_boot_console.run_command('erofsls host 0 symdir')
+    output_subdir = u_boot_console.run_command('erofsls host 0 subdir')
+    assert output == output_subdir
+
+    expected_lines = ['./', '../', '100   subdir-file', '1 file(s), 2 dir(s)']
+    for line in expected_lines:
+        assert line in output
+
+def erofs_ls_at_non_existent_dir(u_boot_console):
+    """
+    Test if the EROFS support will crash when get a nonexistent directory.
+    """
+    out_non_existent = u_boot_console.run_command('erofsls host 0 fff')
+    out_not_dir = u_boot_console.run_command('erofsls host 0 f1000')
+    assert out_non_existent == out_not_dir
+    assert '' in out_non_existent
+
+def erofs_load_files(u_boot_console, files, sizes, address):
+    """
+    Loads files and asserts their checksums.
+    """
+    build_dir = u_boot_console.config.build_dir
+    for (file, size) in zip(files, sizes):
+        out = u_boot_console.run_command('erofsload host 0 {} {}'.format(address, file))
+
+        # check if the right amount of bytes was read
+        assert size in out
+
+        # calculate u-boot file's checksum
+        out = u_boot_console.run_command('md5sum {} {}'.format(address, hex(int(size))))
+        u_boot_checksum = out.split()[-1]
+
+        # calculate original file's checksum
+        original_file_path = os.path.join(build_dir, EROFS_SRC_DIR + '/' + file)
+        out = subprocess.run(['md5sum ' + original_file_path], shell=True, check=True,
+                             capture_output=True, text=True)
+        original_checksum = out.stdout.split()[0]
+
+        # compare checksum
+        assert u_boot_checksum == original_checksum
+
+def erofs_load_files_at_root(u_boot_console):
+    """
+    Test load file from the root directory.
+    """
+    files = ['f4096', 'f7812']
+    sizes = ['4096', '7812']
+    address = '$kernel_addr_r'
+    erofs_load_files(u_boot_console, files, sizes, address)
+
+def erofs_load_files_at_subdir(u_boot_console):
+    """
+    Test load file from the subdirectory.
+    """
+    files = ['subdir/subdir-file']
+    sizes = ['100']
+    address = '$kernel_addr_r'
+    erofs_load_files(u_boot_console, files, sizes, address)
+
+def erofs_load_files_at_symlink(u_boot_console):
+    """
+    Test load file from the symlink.
+    """
+    files = ['symfile']
+    sizes = ['7812']
+    address = '$kernel_addr_r'
+    erofs_load_files(u_boot_console, files, sizes, address)
+
+def erofs_load_non_existent_file(u_boot_console):
+    """
+    Test if the EROFS support will crash when load a nonexistent file.
+    """
+    address = '$kernel_addr_r'
+    file = 'non-existent'
+    out = u_boot_console.run_command('erofsload host 0 {} {}'.format(address, file))
+    assert 'Failed to load' in out
+
+def erofs_run_all_tests(u_boot_console):
+    """
+    Runs all test cases.
+    """
+    erofs_ls_at_root(u_boot_console)
+    erofs_ls_at_subdir(u_boot_console)
+    erofs_ls_at_symlink(u_boot_console)
+    erofs_ls_at_non_existent_dir(u_boot_console)
+    erofs_load_files_at_root(u_boot_console)
+    erofs_load_files_at_subdir(u_boot_console)
+    erofs_load_files_at_symlink(u_boot_console)
+    erofs_load_non_existent_file(u_boot_console)
+
+@pytest.mark.boardspec('sandbox')
+@pytest.mark.buildconfigspec('cmd_fs_generic')
+@pytest.mark.buildconfigspec('cmd_erofs')
+@pytest.mark.buildconfigspec('fs_erofs')
+@pytest.mark.requiredtool('mkfs.erofs')
+@pytest.mark.requiredtool('md5sum')
+
+def test_erofs(u_boot_console):
+    """
+    Executes the erofs test suite.
+    """
+    build_dir = u_boot_console.config.build_dir
+
+    try:
+        # setup test environment
+        make_erofs_image(build_dir)
+        image_path = os.path.join(build_dir, EROFS_IMAGE_NAME)
+        u_boot_console.run_command('host bind 0 {}'.format(image_path))
+        # run all tests
+        erofs_run_all_tests(u_boot_console)
+    except:
+        clean_erofs_image(build_dir)
+        raise AssertionError
+
+    # clean test environment
+    clean_erofs_image(build_dir)
diff --git a/tools/docker/Dockerfile b/tools/docker/Dockerfile
index f1d597a..c51e343 100644
--- a/tools/docker/Dockerfile
+++ b/tools/docker/Dockerfile
@@ -48,6 +48,7 @@
 	dosfstools \
 	e2fsprogs \
 	efitools \
+	erofs-utils \
 	expect \
 	fakeroot \
 	flex \