test: integrate Unity and add core unit tests

Integrate the Unity test framework as a Meson subproject and introduce
extensive unit tests for core modules (utility, link, config, cache).

- Add Unity subproject wrap and a local 'meson-test' pre-commit hook.
- Update .gitignore to ignore build files and downloaded subprojects.
- Update build.yml to execute 'meson test' in macOS and Ubuntu CI.
- Refactor top-level meson.build to define 'lib_srcs' separately.
- Remove the unused 'round_div' helper from utility module.
- Add utility unit tests for path_append, generate_md5sum,
  str_to_hex, and generate_salt.
- Add link unit tests for LinkTable_alloc and LinkTable_add.
- Add config unit tests verifying default configuration values.
- Add cache unit tests verifying CacheSystem_get_cache_dir.

Author: fangfufu

.github/workflows/build.yml

@@ -36,6 +36,9 @@ jobs:
     - name: Compile
       run: meson compile -C builddir
 
+    - name: Test
+      run: meson test -C builddir
+
   build-ubuntu:
     name: Build (Ubuntu, ${{ matrix.compiler }})
     runs-on: ubuntu-latest
@@ -66,3 +69,6 @@ jobs:
 
     - name: Compile
       run: meson compile -C builddir
+
+    - name: Test
+      run: meson test -C builddir

.gitignore

@@ -8,3 +8,11 @@ doxygen
 
 # Generated by astyle
 *.orig
+
+# Build directories
+/builddir/
+
+# Meson subprojects (ignore cloned sources but keep wrap files tracked)
+/subprojects/*
+!/subprojects/*.wrap
+!/subprojects/.wraplock

.pre-commit-config.yaml

@@ -30,3 +30,9 @@ repos:
         entry: clang-format -i
         language: system
         files: \.(c|h)$
+    -   id: meson-test
+        name: Meson Test
+        entry: meson test -C builddir
+        language: system
+        pass_filenames: false
+        files: \.(c|h)$

meson.build

@@ -7,8 +7,7 @@ project('httpdirfs', 'c',
         ]
 )
 
-srcs = [
-    'src/main.c',
+lib_srcs = [
     'src/network.c',
     'src/fuse_local.c',
     'src/link.c',
@@ -45,9 +44,26 @@ expat_dep = dependency('expat')
 openssl_dep = dependency('openssl')
 execinfo_dep = cc.find_library('execinfo', required: false)
 
+httpdirfs_deps = [
+    gumbo_dep,
+    libcurl_dep,
+    fuse_dep,
+    uuid_dep,
+    expat_dep,
+    openssl_dep,
+    execinfo_dep
+]
+
+httpdirfs_lib = static_library('httpdirfs_lib',
+    lib_srcs,
+    dependencies : httpdirfs_deps,
+    c_args: c_args,
+)
+
 httpdirfs = executable('httpdirfs',
-    srcs,
-    dependencies : [gumbo_dep, libcurl_dep, fuse_dep, uuid_dep, expat_dep, openssl_dep, execinfo_dep],
+    'src/main.c',
+    link_with: httpdirfs_lib,
+    dependencies : httpdirfs_deps,
     c_args: c_args,
     install: true,
     install_dir: get_option('bindir'),
@@ -74,3 +90,5 @@ run_target('format',
 
 run_target('doxygen',
   command : 'scripts/doxygen.sh')
+
+subdir('tests')

src/util.c

@@ -37,28 +37,36 @@ static pthread_mutex_t mem_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 char *path_append(const char *path, const char *filename)
 {
+    if (!path || !filename) {
+        lprintf(fatal, "path_append: path or filename is NULL\n");
+    }
     size_t ul = strnlen(path, PATH_MAX);
+    size_t fl = strnlen(filename, PATH_MAX);
+    size_t skip = 0;
     int needs_separator = 0;
-    if (ul > 0 && (path[ul - 1] != '/') && (filename[0] != '/')) {
-        needs_separator = 1;
+    const char *f = filename;
+
+    if (ul > 0) {
+        if (path[ul - 1] != '/') {
+            needs_separator = 1;
+        }
+        while (skip < fl && filename[skip] == '/') {
+            skip++;
+        }
+        f = filename + skip;
     }
 
     char *str;
-    size_t sl = strnlen(filename, NAME_MAX);
+    size_t sl = fl - skip;
     str = CALLOC(ul + sl + needs_separator + 1, sizeof(char));
-    strncpy(str, path, ul);
+    memcpy(str, path, ul);
     if (needs_separator) {
         str[ul] = '/';
     }
-    strncat(str, filename, sl);
+    memcpy(str + ul + needs_separator, f, sl);
     return str;
 }
 
-int64_t round_div(int64_t a, int64_t b)
-{
-    return (a + (b / 2)) / b;
-}
-
 void pthread_mutex_init_wrapper(pthread_mutex_t *x,
                                 const pthread_mutexattr_t *attr,
                                 const char *file, const char *func, int line,

src/util.h

@@ -20,11 +20,6 @@
  */
 char *path_append(const char *path, const char *filename);
 
-/**
- * \brief division, but rounded to the nearest integer rather than truncating
- */
-int64_t round_div(int64_t a, int64_t b);
-
 /**
  * \brief wrapper for pthread_mutex_init(), with error handling
  */

subprojects/.wraplock

@@ -0,0 +1,4 @@
+[wrap-git]
+directory = unity
+url = https://github.com/ThrowTheSwitch/Unity.git
+revision = 860062d51b2e8a75d150337b63ca2a472840d13c

subprojects/unity.wrap

@@ -0,0 +1,40 @@
+unity_sub = subproject('unity')
+unity_dep = unity_sub.get_variable('unity_dep')
+
+test_deps = [unity_dep] + httpdirfs_deps
+
+test_util = executable('test_util',
+    sources: ['test_util.c'],
+    link_with: httpdirfs_lib,
+    dependencies: test_deps,
+    include_directories: include_directories('../src'),
+    c_args: c_args
+)
+test('test_util', test_util)
+
+test_cache = executable('test_cache',
+    sources: ['test_cache.c'],
+    link_with: httpdirfs_lib,
+    dependencies: test_deps,
+    include_directories: include_directories('../src'),
+    c_args: c_args
+)
+test('test_cache', test_cache)
+
+test_config = executable('test_config',
+    sources: ['test_config.c'],
+    link_with: httpdirfs_lib,
+    dependencies: test_deps,
+    include_directories: include_directories('../src'),
+    c_args: c_args
+)
+test('test_config', test_config)
+
+test_link = executable('test_link',
+    sources: ['test_link.c'],
+    link_with: httpdirfs_lib,
+    dependencies: test_deps,
+    include_directories: include_directories('../src'),
+    c_args: c_args
+)
+test('test_link', test_link)

tests/meson.build

@@ -0,0 +1,64 @@
+#include <unity.h>
+#include <stdlib.h>
+#include <string.h>
+#include "../src/cache.h"
+#include "../src/config.h"
+#include "../src/util.h"
+
+void setUp(void)
+{
+    Config_init();
+}
+
+void tearDown(void)
+{
+    // clean stuff up here
+}
+
+void test_CacheSystem_get_cache_dir(void)
+{
+    char *dir;
+
+    // 1. Test when CONFIG.cache_dir is explicitly set
+    CONFIG.cache_dir = "/tmp/explicit_cache";
+    dir = CacheSystem_get_cache_dir();
+    TEST_ASSERT_NOT_NULL(dir);
+    TEST_ASSERT_EQUAL_STRING("/tmp/explicit_cache", dir);
+    // Not dynamically allocated in cache.c when CONFIG.cache_dir is used
+    CONFIG.cache_dir = NULL;
+
+    // 2. Test fallback to XDG_CACHE_HOME
+    setenv("XDG_CACHE_HOME", "/tmp/xdg_cache", 1);
+    dir = CacheSystem_get_cache_dir();
+    TEST_ASSERT_NOT_NULL(dir);
+    TEST_ASSERT_EQUAL_STRING("/tmp/xdg_cache", dir);
+    FREE(dir);
+    unsetenv("XDG_CACHE_HOME");
+
+    // 3. Test fallback to HOME/.cache
+    setenv("HOME", "/tmp/my_home", 1);
+    dir = CacheSystem_get_cache_dir();
+    TEST_ASSERT_NOT_NULL(dir);
+    TEST_ASSERT_EQUAL_STRING("/tmp/my_home/.cache", dir);
+    FREE(dir);
+    unsetenv("HOME");
+
+    // 4. Test fallback when neither is set
+    dir = CacheSystem_get_cache_dir();
+    TEST_ASSERT_NOT_NULL(dir);
+    char *expected_cur_dir = REALPATH("./", NULL);
+    TEST_ASSERT_NOT_NULL(expected_cur_dir);
+    char *expected_dir = path_append(expected_cur_dir, ".cache");
+    TEST_ASSERT_NOT_NULL(expected_dir);
+    TEST_ASSERT_EQUAL_STRING(expected_dir, dir);
+    FREE(expected_cur_dir);
+    FREE(expected_dir);
+    FREE(dir);
+}
+
+int main(void)
+{
+    UNITY_BEGIN();
+    RUN_TEST(test_CacheSystem_get_cache_dir);
+    return UNITY_END();
+}