Improve example with tests and 3rd party dependencies

- Fake install dependencies into $HOME/.cache (cached)
- Move test files into own folder
- Exclude test files and 3rd party files from coverage

Author: Flamefire

.travis.yml

@@ -2,24 +2,34 @@ language: cpp
 os: linux
 compiler: gcc
 
+cache:
+- directories:
+  - $HOME/.cache
+
 addons:
   apt:
     packages: lcov
 
 before_script:
 - mkdir -p build && cd build
 
+install:
+# (fake) install dependencies
+- mkdir -p $HOME/.cache
+- touch $HOME/.cache/mydepency.cpp
+
 script:
 - cmake -DCODE_COVERAGE=ON ..
 - cmake --build . --config Debug -- -j $(nproc)
 - ctest -j $(nproc) --output-on-failure
 
 after_success:
 # Create lcov report
-- lcov --capture --directory . --output-file coverage.info
-- lcov --remove coverage.info '/usr/*' --output-file coverage.info # filter system-files
+- lcov --directory . --capture --output-file coverage.info # capture coverage info
+- lcov --remove coverage.info '/usr/*' '*/tests/*' "${HOME}"'/.cache/*' --output-file coverage.info # filter out system
 - lcov --list coverage.info
 # Uploading to CodeCov
+# '-f' specifies file(s) to use and disables manual coverage gathering and file search which has already been done above
 - bash <(curl -s https://codecov.io/bash) -f coverage.info || echo "Codecov did not collect coverage reports"
 
 notifications:

CMakeLists.txt

@@ -1,21 +1,18 @@
-cmake_minimum_required (VERSION 3.0)
+cmake_minimum_required (VERSION 3.1)
 project(Example LANGUAGES CXX)
 
-option(CODE_COVERAGE "Enable coverage reporting" OFF)
-
-# Common configuration and force C++ standard
-add_compile_options(-Wall -pedantic)
-if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.1)
-  set(CMAKE_CXX_STANDARD 11)
-else()
-  add_compile_options(-std=c++11)
-endif()
-
+# Use C++11
+set(CMAKE_CXX_STANDARD 11)
+# Require (at least) it
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+# Don't use e.g. GNU extension (like -std=gnu++11) for portability
+set(CMAKE_CXX_EXTENSIONS OFF)
 
 # Code Coverage Configuration
 add_library(coverage_config INTERFACE)
 
-if(CODE_COVERAGE)
+option(CODE_COVERAGE "Enable coverage reporting" OFF)
+if(CODE_COVERAGE AND CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
   # Add required flags (GCC & LLVM/Clang)
   target_compile_options(coverage_config INTERFACE
     -O0        # no optimization
@@ -30,5 +27,13 @@ if(CODE_COVERAGE)
 endif(CODE_COVERAGE)
 
 
-enable_testing() # CTest
 add_subdirectory(src)
+
+option (BUILD_TESTING "Build the testing tree." ON)
+# Only build tests if we are the top-level project
+# Allows this to be used by super projects with `add_subdirectory`
+if (BUILD_TESTING AND (PROJECT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR))
+  enable_testing()
+  add_subdirectory(tests)
+endif()
+

src/CMakeLists.txt

@@ -1,13 +1,7 @@
-cmake_minimum_required(VERSION 3.0)
-
-# The library
 add_library(example complex.cpp)
 target_include_directories(example PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
+# Setting this to the library only avoids errors in 3rd party dependencies which are compile with e.g. -Werror
+target_compile_options(example PUBLIC -Wall -pedantic)
 # Include code-coverage settings:
 target_link_libraries(example PUBLIC coverage_config)
 
-
-# Tests for the library
-add_executable(tests complex_main.cpp)
-target_link_libraries(tests PRIVATE example) # inherits coverage_config
-add_test(NAME example_test COMMAND tests)

tests/CMakeLists.txt

@@ -0,0 +1,6 @@
+add_executable(tests complex_main.cpp)
+# Linking up all libraries (includes the coverage settings set by 'example' library)
+target_link_libraries(tests PRIVATE example)
+
+add_test(NAME example_test COMMAND tests)
+