Refactor examples

Signed-off-by: Cristian Le <cristian.le@mpsd.mpg.de>

CMakeLists.txt

@@ -5,6 +5,11 @@ if (POLICY CMP0140)
     # Enables: return(PROPAGATE)
     cmake_policy(SET CMP0140 NEW)
 endif ()
+# TODO: Remove when bumping cmake >= 3.22
+if (POLICY CMP0127)
+    # Enables: cmake_dependent_option: Full Condition Syntax
+    cmake_policy(SET CMP0127 NEW)
+endif ()
 
 #[==============================================================================================[
 #                                    Basic project definition                                   #
@@ -38,7 +43,12 @@ include(CMakeDependentOption)
 
 option(JSON_VALIDATOR_INSTALL "JsonValidator: Install targets" ${PROJECT_IS_TOP_LEVEL})
 option(JSON_VALIDATOR_BUILD_TESTS "JsonValidator: Build tests" ${PROJECT_IS_TOP_LEVEL})
+if (CMAKE_VERSION VERSION_GREATER_EQUAL 3.22)
+    # Only enable BUILD_EXAMPLES if we are building tests or installing the targets
+    cmake_dependent_option(JSON_VALIDATOR_BUILD_EXAMPLES "JsonValidator: Build examples" ${PROJECT_IS_TOP_LEVEL} "JSON_VALIDATOR_BUILD_TESTS OR JSON_VALIDATOR_INSTALL" OFF)
+else ()
     option(JSON_VALIDATOR_BUILD_EXAMPLES "JsonValidator: Build examples" ${PROJECT_IS_TOP_LEVEL})
+endif ()
 option(JSON_VALIDATOR_SHARED_LIBS "JsonValidator: Build as shared library" ${PROJECT_IS_TOP_LEVEL})
 cmake_dependent_option(JSON_VALIDATOR_TEST_COVERAGE "JsonValidator: Build with test coverage" OFF "JSON_VALIDATOR_BUILD_TESTS" OFF)
 mark_as_advanced(JSON_VALIDATOR_TEST_COVERAGE)

example/CMakeLists.txt

@@ -1,14 +1,87 @@
-# simple nlohmann_json_schema_validator-executable
+# TODO: This definition should be moved to /test, together with the for loop
-add_executable(json-schema-validate json-schema-validate.cpp)
+function(schema_validator_add_test name)
-target_link_libraries(json-schema-validate nlohmann_json_schema_validator)
+    #[===[.md
+    # schema_validator_add_test
 
-add_executable(readme-json-schema readme.cpp)
+    Internal helper for adding example/functional tests specific for the current template project
-target_link_libraries(readme-json-schema nlohmann_json_schema_validator)
 
-add_executable(format-json-schema format.cpp)
+    ## Synopsis
-target_link_libraries(format-json-schema nlohmann_json_schema_validator)
+    ```cmake
+    schema_validator_add_test(<name>
+            [TEST_NAME <test_name>]
+            [TARGET <target>]
+            [LABELS <label1> <label2>])
+    ```
 
-if (JSON_VALIDATOR_INSTALL)
+    ## Options
-    install(TARGETS json-schema-validate readme-json-schema format-json-schema
+
-            DESTINATION ${CMAKE_INSTALL_BINDIR})
+    `<name>`
+      Path to the CMake project to be executed relative to `${CMAKE_CURRENT_SOURCE_DIR}`
+
+    `TEST_NAME` [Default: `<name>`]
+      Name for the test to be used as the ctest name
+
+    `LABELS`
+      Additional labels to be added
+
+    ]===]
+
+    list(APPEND CMAKE_MESSAGE_CONTEXT "schema_validator_add_test")
+
+    set(ARGS_Options)
+    set(ARGS_OneValue
+            TEST_NAME
+    )
+    set(ARGS_MultiValue
+            LABELS
+    )
+    cmake_parse_arguments(PARSE_ARGV 1 ARGS "${ARGS_Options}" "${ARGS_OneValue}" "${ARGS_MultiValue}")
+    # Check required/optional arguments
+    if (ARGC LESS 1)
+        message(FATAL_ERROR "Missing test name")
     endif ()
+    if (NOT DEFINED ARGS_TEST_NAME)
+        set(ARGS_TEST_NAME test-${name})
+    endif ()
+    set(extra_args)
+    if (nlohmann_json_schema_validator_IS_TOP_LEVEL)
+        list(APPEND extra_args
+                -DFETCHCONTENT_TRY_FIND_PACKAGE_MODE=ALWAYS
+                # Generated Config file point to binary targets until it is installed
+                -Dnlohmann_json_schema_validator_ROOT=${Template_BINARY_DIR}
+                -DFETCHCONTENT_SOURCE_DIR_TEMPLATE=${Template_SOURCE_DIR}
+        )
+    endif ()
+
+    add_test(NAME ${ARGS_TEST_NAME}
+            COMMAND ${CMAKE_CTEST_COMMAND} --build-and-test ${CMAKE_CURRENT_SOURCE_DIR}/${test}
+            ${CMAKE_CURRENT_BINARY_DIR}/${test}
+            # Use the same build environment as the current runner
+            --build-generator "${CMAKE_GENERATOR}"
+            --build-options -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
+            ${extra_args}
+            --test-command ${CMAKE_CTEST_COMMAND} --test-dir ${CMAKE_CURRENT_BINARY_DIR}/${test}
+            --output-on-failure --no-tests=ignore
+    )
+    set_tests_properties(${ARGS_TEST_NAME} PROPERTIES
+            LABELS "${ARGS_LABELS}"
+    )
+endfunction()
+
+foreach (example IN ITEMS
+        format
+        readme
+        validate
+)
+    if (JSON_VALIDATOR_INSTALL)
+        # The projects need to be added only if they are to be installed
+        add_subdirectory(${example})
+    elseif (JSON_VALIDATOR_BUILD_TESTS)
+        schema_validator_add_test(${example})
+    else ()
+        # Can be simplified after CMake >= 3.22
+        message(WARNING
+                "Nothing specified to do with the examples. Enable this together with INSTALL or BUILD_TESTS"
+        )
+    endif ()
+endforeach ()

example/format/CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.24)
+
+project(example_format LANGUAGES CXX)
+
+include(FetchContent)
+
+# The target check is not generally needed. It is used here because these projects are reused by the top-level project
+if (NOT TARGET nlohmann_json_schema_validator::validator)
+    # Note: The 3.24 cmake requirement only appears due to `FetchContent_Declare(FIND_PACKAGE_ARGS)`
+    # To support earlier versions, you can replace this with `find_package` or remove `FIND_PACKAGE_ARGS`
+    FetchContent_Declare(nlohmann_json_schema_validator
+            GIT_REPOSITORY https://github.com/pboettch/json-schema-validator
+            GIT_TAG main
+            FIND_PACKAGE_ARGS CONFIG
+    )
+    FetchContent_MakeAvailable(nlohmann_json_schema_validator)
+endif ()
+
+add_executable(format-json-schema format.cpp)
+target_link_libraries(format-json-schema PRIVATE nlohmann_json_schema_validator::validator)
+
+# Reusing the top-level install in order to bundle these executables
+if (JSON_VALIDATOR_INSTALL)
+    install(TARGETS format-json-schema
+            DESTINATION ${CMAKE_INSTALL_BINDIR})
+endif ()

example/readme/CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.24)
+
+project(example_readme LANGUAGES CXX)
+
+include(FetchContent)
+
+# The target check is not generally needed. It is used here because these projects are reused by the top-level project
+if (NOT TARGET nlohmann_json_schema_validator::validator)
+    # Note: The 3.24 cmake requirement only appears due to `FetchContent_Declare(FIND_PACKAGE_ARGS)`
+    # To support earlier versions, you can replace this with `find_package` or remove `FIND_PACKAGE_ARGS`
+    FetchContent_Declare(nlohmann_json_schema_validator
+            GIT_REPOSITORY https://github.com/pboettch/json-schema-validator
+            GIT_TAG main
+            FIND_PACKAGE_ARGS CONFIG
+    )
+    FetchContent_MakeAvailable(nlohmann_json_schema_validator)
+endif ()
+
+add_executable(readme-json-schema readme.cpp)
+target_link_libraries(readme-json-schema PRIVATE nlohmann_json_schema_validator::validator)
+
+# Reusing the top-level install in order to bundle these executables
+if (JSON_VALIDATOR_INSTALL)
+    install(TARGETS readme-json-schema
+            DESTINATION ${CMAKE_INSTALL_BINDIR})
+endif ()

example/validate/CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.24)
+
+project(example_validate LANGUAGES CXX)
+
+include(FetchContent)
+
+# The target check is not generally needed. It is used here because these projects are reused by the top-level project
+if (NOT TARGET nlohmann_json_schema_validator::validator)
+    # Note: The 3.24 cmake requirement only appears due to `FetchContent_Declare(FIND_PACKAGE_ARGS)`
+    # To support earlier versions, you can replace this with `find_package` or remove `FIND_PACKAGE_ARGS`
+    FetchContent_Declare(nlohmann_json_schema_validator
+            GIT_REPOSITORY https://github.com/pboettch/json-schema-validator
+            GIT_TAG main
+            FIND_PACKAGE_ARGS CONFIG
+    )
+    FetchContent_MakeAvailable(nlohmann_json_schema_validator)
+endif ()
+
+add_executable(json-schema-validate json-schema-validate.cpp)
+target_link_libraries(json-schema-validate PRIVATE nlohmann_json_schema_validator::validator)
+
+# Reusing the top-level install in order to bundle these executables
+if (JSON_VALIDATOR_INSTALL)
+    install(TARGETS json-schema-validate
+            DESTINATION ${CMAKE_INSTALL_BINDIR})
+endif ()