(#12413) nlohmann_json: Add support for Conan V2

* nlohmann_json: Add support for Conan V2

* Fix cross_building call in test package

* Use src directory for source folder in layout

recipes/nlohmann_json/all/conanfile.py

@@ -1,32 +1,37 @@
-from conans import ConanFile, tools
 import os
 
-required_conan_version = ">=1.33.0"
+from conan import ConanFile
+from conan.tools.files import copy, get
+from conan.tools.layout import basic_layout
+
+required_conan_version = ">=1.50.0"
 
 
 class NlohmannJsonConan(ConanFile):
     name = "nlohmann_json"
     homepage = "https://github.com/nlohmann/json"
     description = "JSON for Modern C++ parser and generator."
-    topics = ("conan", "jsonformoderncpp",
-              "nlohmann_json", "json", "header-only")
+    topics = ("jsonformoderncpp", "nlohmann_json", "json", "header-only")
     url = "https://github.com/conan-io/conan-center-index"
-    no_copy_source = True
     license = "MIT"
+    settings = "os", "arch", "compiler", "build_type"
+    no_copy_source = True
 
-    @property
-    def _source_subfolder(self):
-        return "source_subfolder"
+    def layout(self):
+        basic_layout(self, src_folder="src")
 
     def package_id(self):
-        self.info.header_only()
+        self.info.clear()
+
+    def generate(self):
+        pass
 
     def source(self):
-        tools.get(**self.conan_data["sources"][self.version], destination=self._source_subfolder, strip_root=True)
+        get(self, **self.conan_data["sources"][self.version], strip_root=True)
 
     def package(self):
-        self.copy(pattern="LICENSE*", src=self._source_subfolder, dst="licenses")
-        self.copy("*", src=os.path.join(self._source_subfolder, "include"), dst="include")
+        copy(self, "LICENSE*", self.source_folder, os.path.join(self.package_folder, "licenses"))
+        copy(self, "*", os.path.join(self.source_folder, "include"), os.path.join(self.package_folder, "include"))
 
     def package_info(self):
         self.cpp_info.names["cmake_find_package"] = "nlohmann_json"

recipes/nlohmann_json/all/test_package/CMakeLists.txt

@@ -1,9 +1,6 @@
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.15)
 project(test_package)
 
-include(${CMAKE_BINARY_DIR}/conanbuildinfo.cmake)
-conan_basic_setup(TARGETS)
-
 find_package(nlohmann_json REQUIRED CONFIG)
 
 add_executable(${PROJECT_NAME} test_package.cpp)

recipes/nlohmann_json/all/test_package/conanfile.py

@@ -1,10 +1,19 @@
-from conans import ConanFile, CMake, tools
 import os
 
+from conan import ConanFile
+from conan.tools.build import can_run
+from conan.tools.cmake import CMake, cmake_layout
+
 
 class TestPackageConan(ConanFile):
     settings = "os", "compiler", "build_type", "arch"
-    generators = "cmake", "cmake_find_package_multi"
+    generators = "CMakeDeps", "CMakeToolchain", "VirtualRunEnv"
+
+    def requirements(self):
+        self.requires(self.tested_reference_str)
+
+    def layout(self):
+        cmake_layout(self)
 
     def build(self):
         cmake = CMake(self)
@@ -12,6 +21,5 @@ class TestPackageConan(ConanFile):
         cmake.build()
 
     def test(self):
-        if not tools.cross_building(self.settings):
-            bin_path = os.path.join("bin", "test_package")
-            self.run(bin_path, run_environment=True)
+        if can_run(self):
+            self.run(os.path.join(self.cpp.build.bindirs[0], "test_package"), env="conanrun")

recipes/nlohmann_json/all/test_v1_package/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.1.2)
+project(test_package)
+
+include(${CMAKE_BINARY_DIR}/conanbuildinfo.cmake)
+conan_basic_setup(TARGETS)
+
+find_package(nlohmann_json REQUIRED CONFIG)
+
+add_executable(${PROJECT_NAME} ../test_package/test_package.cpp)
+target_link_libraries(${PROJECT_NAME} nlohmann_json::nlohmann_json)
+set_target_properties(${PROJECT_NAME} PROPERTIES CXX_STANDARD 11)

recipes/nlohmann_json/all/test_v1_package/conanfile.py

@@ -0,0 +1,19 @@
+import os
+
+from conan.tools.build import cross_building
+from conans import ConanFile, CMake
+
+
+class TestPackageConan(ConanFile):
+    settings = "os", "compiler", "build_type", "arch"
+    generators = "cmake", "cmake_find_package_multi"
+
+    def build(self):
+        cmake = CMake(self)
+        cmake.configure()
+        cmake.build()
+
+    def test(self):
+        if not cross_building(self):
+            bin_path = os.path.join("bin", "test_package")
+            self.run(bin_path, run_environment=True)