test: initial external unit test suite for ‘config.c’

This patch adds a separate (external) test binary with unit tests for
config.c

This is achieved by having the test’s source file include
config.c (yes, the C file, not the header file).

This allows us to call e.g. parse_section_*() directly, without having
to go through config_load() (which requires having a readable file at
“path”).

meson.build

@@ -272,6 +272,7 @@ endif
 
 subdir('completions')
 subdir('icons')
+subdir('tests')
 
 summary(
   {

tests/meson.build

@@ -0,0 +1,8 @@
+config_test = executable(
+  'test-config',
+  'test-config.c', '../tokenize.c',
+  wl_proto_headers,
+  link_with: [common],
+  dependencies: [pixman, xkb, fcft])
+
+test('config', config_test)

tests/test-config.c

@@ -0,0 +1,93 @@
+#if !defined(_DEBUG)
+ #define _DEBUG
+#endif
+#undef NDEBUG
+
+#include "../log.h"
+
+#include "../config.c"
+
+#define ALEN(v) (sizeof(v) / sizeof((v)[0]))
+
+/*
+ * Stubs
+ */
+
+void
+user_notification_add_fmt(user_notifications_t *notifications,
+                          enum user_notification_kind kind,
+                          const char *fmt, ...)
+{
+}
+
+static void
+test_boolean(struct context *ctx, bool (*parse_fun)(struct context *ctx),
+             const char *key, bool *conf_ptr)
+{
+    ctx->key = key;
+
+    static const struct {
+        const char *option_string;
+        bool value;
+        bool invalid;
+    } input[] = {
+        {"1", true}, {"0", false},
+        {"on", true}, {"off", false},
+        {"true", true}, {"false", false},
+        {"unittest-invalid-boolean-value", false, true},
+    };
+
+    for (size_t i = 0; i < ALEN(input); i++) {
+        ctx->value = input[i].option_string;
+
+        if (input[i].invalid) {
+            if (parse_fun(ctx)) {
+                BUG("[%s].%s=%s: did not fail to parse as expected",
+                    ctx->section, ctx->key, ctx->value);
+            }
+        } else {
+            if (!parse_fun(ctx)) {
+                BUG("[%s].%s=%s: failed to parse",
+                    ctx->section, ctx->key, ctx->value);
+            }
+            if (*conf_ptr != input[i].value)
+                BUG("[%s].%s=%s: set value (%s) not the expected one (%s)",
+                    ctx->section, ctx->key, ctx->value,
+                    *conf_ptr ? "true" : "false",
+                    input[i].value ? "true" : "false");
+        }
+    }
+}
+
+static void
+test_section_main(void)
+{
+#define CTX(_key, _value)                                               \
+    (struct context){                                                   \
+        .conf = &conf, .section = "main", .key = _key, .value = _value, .path = "unittest"}
+
+    struct config conf = {0};
+    struct context ctx;
+
+    ctx = CTX("shell", "/bin/bash");
+    xassert(parse_section_main(&ctx));
+    xassert(strcmp(conf.shell, "/bin/bash") == 0);
+
+    ctx = CTX("term", "foot-unittest");
+    xassert(parse_section_main(&ctx));
+    xassert(strcmp(conf.term, "foot-unittest") == 0);
+
+    test_boolean(&ctx, &parse_section_main, "login-shell", &conf.login_shell);
+
+    config_free(conf);
+#undef CTX
+}
+
+int
+main(int argc, const char *const *argv)
+{
+    log_init(LOG_COLORIZE_AUTO, false, 0, LOG_CLASS_ERROR);
+    test_section_main();
+    log_deinit();
+    return 0;
+}