test: fix running 'small' lib tests for OOS build

The 'small' lib test suite was not run for out-of-source builds since
the wrong symlink was created for test binaries and test-run couldn't
find them. Now it is fixed.

When test-run loads tests, first, it searches the suite.ini file and if
it exists test-run consider the dir as a test suite. So there was sense
to create a permanent link for 'small' lib tests.

Closes tarantool#4485

NO_DOC=testing stuff
NO_TEST=testing stuff
NO_CHANGELOG=testing stuff

.gitignore

@@ -98,7 +98,7 @@ test/enterprise-unit
 test/lib/
 test/unit/*.test
 test/unit/fiob
-test/small
+test/small/*.test
 test/var
 test/luajit-tap
 test/unit/popen-child

test/CMakeLists.txt

@@ -35,13 +35,18 @@ if(POLICY CMP0037)
     endif()
 endif(POLICY CMP0037)
 
+# The symlink is needed for out-of-source builds. In the case of in-source
+# builds ${CMAKE_CURRENT_BINARY_DIR} == ${PROJECT_SOURCE_DIR}/test and the
+# symlink already exists. It creates the symlink if the destination doesn't
+# exist.
 add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/small
     COMMAND ${CMAKE_COMMAND} -E create_symlink
-        ${PROJECT_SOURCE_DIR}/src/lib/small/test/
+        ${CMAKE_CURRENT_BINARY_DIR}/../src/lib/small/test/
         ${CMAKE_CURRENT_BINARY_DIR}/small
-        COMMENT Create a symlink for libsmall to fix out-of-source tests)
-add_custom_target(symlink_small_tests ALL
-   DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/small)
+        COMMENT Create the symlink for libsmall test binaries)
+
+add_custom_target(symlink_libsmall_test_binaries ALL
+    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/small)
 
 add_custom_target(test
     DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/small

test/small

@@ -0,0 +1 @@
+../src/lib/small/test/