diff --git a/tests/test-lib.c b/tests/test-lib.c
new file mode 100644
index 00000000..cff7a5d1
--- /dev/null
+++ b/tests/test-lib.c
@@ -0,0 +1,359 @@
+#include <string.h>
+#include <setjmp.h>
+#include <stdarg.h>
+#include <cmocka.h>
+#include <libudev.h>
+#include <sys/sysmacros.h>
+#include "debug.h"
+#include "util.h"
+#include "vector.h"
+#include "structs.h"
+#include "structs_vec.h"
+#include "config.h"
+#include "discovery.h"
+#include "propsel.h"
+#include "test-lib.h"
+
+const int default_mask = (DI_SYSFS|DI_BLACKLIST|DI_WWID|DI_CHECKER|DI_PRIO);
+const char default_devnode[] = "sdTEST";
+const char default_wwid[] = "TEST-WWID";
+/* default_wwid should be a substring of default_wwid_1! */
+const char default_wwid_1[] = "TEST-WWID-1";
+
+/*
+ * Helper wrappers for mock_path().
+ *
+ * We need to make pathinfo() think it has detected a device with
+ * certain vendor/product/rev. This requires faking lots of udev
+ * and sysfs function responses.
+ *
+ * This requires hwtable-test_OBJDEPS = ../libmultipath/discovery.o
+ * in the Makefile in order to wrap calls from discovery.o.
+ *
+ * Note that functions that are called and defined in discovery.o can't
+ * be wrapped this way (e.g. sysfs_get_vendor), because symbols are
+ * resolved by the assembler before the linking stage.
+ */
+
+int __real_open(const char *path, int flags, int mode);
+
+static const char _mocked_filename[] = "mocked_path";
+int __wrap_open(const char *path, int flags, int mode)
+{
+	condlog(4, "%s: %s", __func__, path);
+
+	if (!strcmp(path, _mocked_filename))
+		return 111;
+	return __real_open(path, flags, mode);
+}
+
+int __wrap_execute_program(char *path, char *value, int len)
+{
+	char *val = mock_ptr_type(char *);
+
+	condlog(5, "%s: %s", __func__, val);
+	strlcpy(value, val, len);
+	return 0;
+}
+
+bool __wrap_is_claimed_by_foreign(struct udev_device *ud)
+{
+	condlog(5, "%s: %p", __func__, ud);
+	return false;
+}
+
+struct udev_list_entry
+*__wrap_udev_device_get_properties_list_entry(struct udev_device *ud)
+{
+	void *p = (void*)0x12345678;
+	condlog(5, "%s: %p", __func__, p);
+
+	return p;
+}
+
+struct udev_list_entry
+*__wrap_udev_list_entry_get_next(struct udev_list_entry *udle)
+{
+	void *p  = NULL;
+	condlog(5, "%s: %p", __func__, p);
+
+	return p;
+}
+
+const char *__wrap_udev_list_entry_get_name(struct udev_list_entry *udle)
+{
+	char *val = mock_ptr_type(char *);
+
+	condlog(5, "%s: %s", __func__, val);
+	return val;
+}
+
+struct udev_device *__wrap_udev_device_ref(struct udev_device *ud)
+{
+	return ud;
+}
+
+struct udev_device *__wrap_udev_device_unref(struct udev_device *ud)
+{
+	return ud;
+}
+
+char *__wrap_udev_device_get_subsystem(struct udev_device *ud)
+{
+	char *val = mock_ptr_type(char *);
+
+	condlog(5, "%s: %s", __func__, val);
+	return val;
+}
+
+char *__wrap_udev_device_get_sysname(struct udev_device *ud)
+{
+	char *val  = mock_ptr_type(char *);
+
+	condlog(5, "%s: %s", __func__, val);
+	return val;
+}
+
+char *__wrap_udev_device_get_devnode(struct udev_device *ud)
+{
+	char *val  = mock_ptr_type(char *);
+
+	condlog(5, "%s: %s", __func__, val);
+	return val;
+}
+
+dev_t __wrap_udev_device_get_devnum(struct udev_device *ud)
+{
+	condlog(5, "%s: %p", __func__, ud);
+	return makedev(17, 17);
+}
+
+char *__wrap_udev_device_get_sysattr_value(struct udev_device *ud,
+					     const char *attr)
+{
+	char *val  = mock_ptr_type(char *);
+
+	condlog(5, "%s: %s->%s", __func__, attr, val);
+	return val;
+}
+
+char *__wrap_udev_device_get_property_value(struct udev_device *ud,
+					    const char *attr)
+{
+	char *val  = mock_ptr_type(char *);
+
+	condlog(5, "%s: %s->%s", __func__, attr, val);
+	return val;
+}
+
+int __wrap_sysfs_get_size(struct path *pp, unsigned long long *sz)
+{
+	*sz = 12345678UL;
+	return 0;
+}
+
+void *__wrap_udev_device_get_parent_with_subsystem_devtype(
+	struct udev_device *ud, const char *subsys, char *type)
+{
+	/* return non-NULL for sysfs_get_tgt_nodename */
+	return type;
+}
+
+void *__wrap_udev_device_get_parent(struct udev_device *ud)
+{
+	char *val  = mock_ptr_type(void *);
+
+	condlog(5, "%s: %p", __func__, val);
+	return val;
+}
+
+ssize_t __wrap_sysfs_attr_get_value(struct udev_device *dev,
+				    const char *attr_name,
+				    char *value, size_t sz)
+{
+	char *val  = mock_ptr_type(char *);
+
+	condlog(5, "%s: %s", __func__, val);
+	strlcpy(value, val, sz);
+	return strlen(value);
+}
+
+int __wrap_checker_check(struct checker *c, int st)
+{
+	condlog(5, "%s: %d", __func__, st);
+	return st;
+}
+
+int __wrap_prio_getprio(struct prio *p, struct path *pp, unsigned int tmo)
+{
+	int pr = 5;
+
+	condlog(5, "%s: %d", __func__, pr);
+	return pr;
+}
+
+struct mocked_path *fill_mocked_path(struct mocked_path *mp,
+				     const char *vendor, const char *product,
+				     const char *rev, const char *wwid,
+				     const char *devnode, unsigned int flags)
+{
+	mp->vendor = (vendor ? vendor : "noname");
+	mp->product = (product ? product : "noprod");
+	mp->rev = (rev ? rev : "0");
+	mp->wwid = (wwid ? wwid : default_wwid);
+	mp->devnode = (devnode ? devnode : default_devnode);
+	mp->flags = flags|NEED_SELECT_PRIO|NEED_FD;
+	return mp;
+}
+
+struct mocked_path *mocked_path_from_path(struct mocked_path *mp,
+					  const struct path *pp)
+{
+	mp->vendor = pp->vendor_id;
+	mp->product = pp->product_id;
+	mp->rev = pp->rev;
+	mp->wwid = pp->wwid;
+	mp->devnode = pp->dev;
+	mp->flags = (prio_selected(&pp->prio) ? 0 : NEED_SELECT_PRIO) |
+		(pp->fd < 0 ? NEED_FD : 0) |
+		(pp->getuid ? USE_GETUID : 0);
+	return mp;
+}
+
+static void mock_sysfs_pathinfo(const struct mocked_path *mp)
+{
+	static const char hbtl[] = "4:0:3:1";
+
+	will_return(__wrap_udev_device_get_subsystem, "scsi");
+	will_return(__wrap_udev_device_get_sysname, hbtl);
+	will_return(__wrap_udev_device_get_sysname, hbtl);
+	will_return(__wrap_udev_device_get_sysattr_value, mp->vendor);
+	will_return(__wrap_udev_device_get_sysname, hbtl);
+	will_return(__wrap_udev_device_get_sysattr_value, mp->product);
+	will_return(__wrap_udev_device_get_sysname, hbtl);
+	will_return(__wrap_udev_device_get_sysattr_value, mp->rev);
+
+	/* sysfs_get_tgt_nodename */
+	will_return(__wrap_udev_device_get_sysattr_value, NULL);
+	will_return(__wrap_udev_device_get_parent, NULL);
+	will_return(__wrap_udev_device_get_parent, NULL);
+	will_return(__wrap_udev_device_get_sysname, "nofibre");
+	will_return(__wrap_udev_device_get_sysname, "noiscsi");
+	will_return(__wrap_udev_device_get_parent, NULL);
+	will_return(__wrap_udev_device_get_sysname, "ata25");
+}
+
+/*
+ * Pretend we detected a SCSI device with given vendor/prod/rev
+ */
+void mock_pathinfo(int mask, const struct mocked_path *mp)
+{
+	/* filter_property */
+	will_return(__wrap_udev_device_get_sysname, mp->devnode);
+	if (mp->flags & BL_BY_PROPERTY) {
+		will_return(__wrap_udev_list_entry_get_name, "BAZ");
+		return;
+	} else
+		will_return(__wrap_udev_list_entry_get_name,
+			    "SCSI_IDENT_LUN_NAA_EXT");
+	if (mask & DI_SYSFS)
+		mock_sysfs_pathinfo(mp);
+
+	if (mp->flags & BL_BY_DEVICE &&
+	    (mask & DI_BLACKLIST && mask & DI_SYSFS))
+		return;
+
+	/* path_offline */
+	will_return(__wrap_udev_device_get_subsystem, "scsi");
+	will_return(__wrap_sysfs_attr_get_value, "running");
+
+	if (mask & DI_NOIO)
+		return;
+
+	/* fake open() in pathinfo() */
+	if (mp->flags & NEED_FD)
+		will_return(__wrap_udev_device_get_devnode, _mocked_filename);
+	/* DI_SERIAL is unsupported */
+	assert_false(mask & DI_SERIAL);
+
+	if (mask & DI_WWID) {
+		if (mp->flags & USE_GETUID)
+			will_return(__wrap_execute_program, mp->wwid);
+		else
+			/* get_udev_uid() */
+			will_return(__wrap_udev_device_get_property_value,
+				    mp->wwid);
+	}
+
+	if (mask & DI_CHECKER) {
+		/* get_state -> sysfs_get_timeout  */
+		will_return(__wrap_udev_device_get_subsystem, "scsi");
+		will_return(__wrap_udev_device_get_sysattr_value, "180");
+	}
+
+	if (mask & DI_PRIO && mp->flags & NEED_SELECT_PRIO) {
+
+		/* sysfs_get_timeout, again (!?) */
+		will_return(__wrap_udev_device_get_subsystem, "scsi");
+		will_return(__wrap_udev_device_get_sysattr_value, "180");
+
+	}
+}
+
+void mock_store_pathinfo(int mask,  const struct mocked_path *mp)
+{
+	will_return(__wrap_udev_device_get_sysname, mp->devnode);
+	mock_pathinfo(mask, mp);
+}
+
+struct path *__mock_path(vector pathvec,
+			 const char *vnd, const char *prd,
+			 const char *rev, const char *wwid,
+			 const char *dev,
+			 unsigned int flags, int mask)
+{
+	struct mocked_path mop;
+	struct path *pp;
+	struct config *conf;
+	int r;
+
+	fill_mocked_path(&mop, vnd, prd, rev, wwid, dev, flags);
+	mock_store_pathinfo(mask, &mop);
+
+	conf = get_multipath_config();
+	r = store_pathinfo(pathvec, conf, (void *)&mop, mask, &pp);
+	put_multipath_config(conf);
+
+	if (flags & BL_MASK) {
+		assert_int_equal(r, PATHINFO_SKIPPED);
+		return NULL;
+	}
+	assert_int_equal(r, PATHINFO_OK);
+	assert_non_null(pp);
+	return pp;
+}
+
+
+struct multipath *__mock_multipath(struct vectors *vecs, struct path *pp)
+{
+	struct multipath *mp;
+	struct config *conf;
+	struct mocked_path mop;
+
+	mocked_path_from_path(&mop, pp);
+	/* pathinfo() call in adopt_paths */
+	mock_pathinfo(DI_CHECKER|DI_PRIO, &mop);
+
+	mp = add_map_with_path(vecs, pp, 1);
+	assert_ptr_not_equal(mp, NULL);
+
+	/* TBD: mock setup_map() ... */
+	conf = get_multipath_config();
+	select_pgpolicy(conf, mp);
+	select_no_path_retry(conf, mp);
+	select_retain_hwhandler(conf, mp);
+	select_minio(conf, mp);
+	put_multipath_config(conf);
+
+	return mp;
+}
diff --git a/tests/test-lib.h b/tests/test-lib.h
new file mode 100644
index 00000000..d2745979
--- /dev/null
+++ b/tests/test-lib.h
@@ -0,0 +1,67 @@
+#ifndef __LIB_H
+#define __LIB_H
+
+extern const int default_mask;
+extern const char default_devnode[];
+extern const char default_wwid[];
+extern const char default_wwid_1[];
+
+enum {
+	BL_BY_DEVNODE	= (1 << 0),
+	BL_BY_DEVICE	= (1 << 1),
+	BL_BY_WWID	= (1 << 2),
+	BL_BY_PROPERTY	= (1 << 3),
+	BL_MASK = BL_BY_DEVNODE|BL_BY_DEVICE|BL_BY_WWID|BL_BY_PROPERTY,
+	NEED_SELECT_PRIO = (1 << 8),
+	NEED_FD		= (1 << 9),
+	USE_GETUID	= (1 << 10)
+};
+
+struct mocked_path {
+	const char *vendor;
+	const char *product;
+	const char *rev;
+	const char *wwid;
+	const char *devnode;
+	unsigned int flags;
+};
+
+struct mocked_path *fill_mocked_path(struct mocked_path *mp,
+				     const char *vendor,
+				     const char *product,
+				     const char *rev,
+				     const char *wwid,
+				     const char *devnode,
+				     unsigned int flags);
+
+struct mocked_path *mocked_path_from_path(struct mocked_path *mp,
+					  const struct path *pp);
+
+void mock_pathinfo(int mask, const struct mocked_path *mp);
+void mock_store_pathinfo(int mask, const struct mocked_path *mp);
+struct path *__mock_path(vector pathvec,
+			 const char *vnd, const char *prd,
+			 const char *rev, const char *wwid,
+			 const char *dev,
+			 unsigned int flags, int mask);
+
+#define mock_path(v, p) \
+	__mock_path(hwt->vecs->pathvec,	(v), (p), "0", NULL, NULL,	\
+		    0, default_mask)
+#define mock_path_flags(v, p, f) \
+	__mock_path(hwt->vecs->pathvec,	(v), (p), "0", NULL, NULL, \
+		    (f), default_mask)
+#define mock_path_blacklisted(v, p) \
+	__mock_path(hwt->vecs->pathvec,	(v), (p), "0", NULL, NULL, \
+		    BL_BY_DEVICE, default_mask)
+#define mock_path_wwid(v, p, w) \
+	__mock_path(hwt->vecs->pathvec,	(v), (p), "0", (w), NULL,	\
+		    0, default_mask)
+#define mock_path_wwid_flags(v, p, w, f) \
+	__mock_path(hwt->vecs->pathvec,	(v), (p), "0", (w),		\
+		    NULL, (f), default_mask)
+
+struct multipath *__mock_multipath(struct vectors *vecs, struct path *pp);
+#define mock_multipath(pp) __mock_multipath(hwt->vecs, (pp))
+
+#endif
