[feature] Add hooks for validate method

conan/internal/conan_app.py

@@ -44,6 +44,7 @@ def __init__(self, conan_api):
         """
         global_conf = conan_api.config.global_conf
         self.global_conf = global_conf
+        self.conan_api = conan_api
         cache_folder = conan_api.home_folder
         self.cache_folder = cache_folder
         self.cache = PkgCache(self.cache_folder, global_conf)

conans/client/graph/compute_pid.py

@@ -6,7 +6,7 @@
 from conan.internal.model.info import ConanInfo, RequirementsInfo, RequirementInfo, PythonRequiresInfo
 
 
-def compute_package_id(node, modes, config_version):
+def compute_package_id(node, modes, config_version, hook_manager):
     """
     Compute the binary package ID of this node
     """
@@ -50,7 +50,7 @@ def compute_package_id(node, modes, config_version):
                                config_version=config_version.copy() if config_version else None)
     conanfile.original_info = conanfile.info.clone()
 
-    run_validate_package_id(conanfile)
+    run_validate_package_id(conanfile, hook_manager)
 
     if conanfile.info.settings_target:
         # settings_target has beed added to conan package via package_id api
@@ -60,7 +60,7 @@ def compute_package_id(node, modes, config_version):
     node.package_id = info.package_id()
 
 
-def run_validate_package_id(conanfile):
+def run_validate_package_id(conanfile, hook_manager=None):
     # IMPORTANT: This validation code must run before calling info.package_id(), to mark "invalid"
     if hasattr(conanfile, "validate_build"):
         with conanfile_exception_formatter(conanfile, "validate_build"):
@@ -73,11 +73,15 @@ def run_validate_package_id(conanfile):
 
     if hasattr(conanfile, "validate"):
         with conanfile_exception_formatter(conanfile, "validate"):
+            if hook_manager:
+                hook_manager.execute("pre_validate", conanfile=conanfile)
             with conanfile_remove_attr(conanfile, ['cpp_info'], "validate"):
                 try:
                     conanfile.validate()
                 except ConanInvalidConfiguration as e:
                     conanfile.info.invalid = str(e)
+            if hook_manager:
+                hook_manager.execute("post_validate", conanfile=conanfile)
 
     # Once we are done, call package_id() to narrow and change possible values
     if hasattr(conanfile, "package_id"):

conans/client/graph/graph_binaries.py

@@ -29,6 +29,7 @@ def __init__(self, conan_app, global_conf):
         self._home_folder = conan_app.cache_folder
         self._global_conf = global_conf
         self._remote_manager = conan_app.remote_manager
+        self._hook_manager = conan_app.conan_api.config.hook_manager
         # These are the nodes with pref (not including PREV) that have been evaluated
         self._evaluated = {}  # {pref: [nodes]}
         compat_folder = HomePaths(conan_app.cache_folder).compatibility_plugin_path
@@ -397,7 +398,7 @@ def _config_version(self):
         return RequirementsInfo(result)
 
     def _evaluate_package_id(self, node, config_version):
-        compute_package_id(node, self._modes, config_version=config_version)
+        compute_package_id(node, self._modes, config_version, self._hook_manager)
 
         # TODO: layout() execution don't need to be evaluated at GraphBuilder time.
         # it could even be delayed until installation time, but if we got enough info here for
@@ -458,7 +459,7 @@ def _evaluate_single(n):
         if node.path is not None:
             if node.path.endswith(".py"):
                 # For .py we keep evaluating the package_id, validate(), etc
-                compute_package_id(node, self._modes, config_version=config_version)
+                compute_package_id(node, self._modes, config_version, self._hook_manager)
             # To support the ``[layout]`` in conanfile.txt
             if hasattr(node.conanfile, "layout"):
                 with conanfile_exception_formatter(node.conanfile, "layout"):

conans/client/hook_manager.py

@@ -4,6 +4,7 @@
 from conan.errors import ConanException
 
 valid_hook_methods = ["pre_export", "post_export",
+                      "pre_validate", "post_validate",
                       "pre_source", "post_source",
                       "pre_generate", "post_generate",
                       "pre_build", "post_build", "post_build_fail",

test/integration/extensions/hooks/hook_test.py

@@ -21,6 +21,12 @@ def post_export(conanfile):
     assert conanfile.export_sources_folder, "export_sources_folder not defined"
     assert conanfile.recipe_folder, "recipe_folder not defined"
 
+def pre_validate(conanfile):
+    conanfile.output.info("Hello")
+
+def post_validate(conanfile):
+    conanfile.output.info("Hello")
+
 def pre_source(conanfile):
     conanfile.output.info("Hello")
     assert conanfile.source_folder, "source_folder not defined"
@@ -176,3 +182,21 @@ def build(self):
         assert "conanfile.py: [HOOK - my_hook/hook_my_hook.py] post_build_fail(): Hello" in c.out
         assert "ERROR: conanfile.py: Error in build() method, line 5" in c.out
 
+    def test_validate_hook(self):
+        """ The validate hooks are executed only if the method is declared in the recipe.
+        """
+        c = TestClient()
+        hook_path = os.path.join(c.paths.hooks_path, "testing", "hook_complete.py")
+        save(hook_path, complete_hook)
+
+        conanfile = textwrap.dedent("""
+            from conan import ConanFile
+            class Pkg(ConanFile):
+                def validate(self):
+                    pass
+            """)
+        c.save({"conanfile.py": conanfile})
+
+        c.run("create . --name=foo --version=0.1.0")
+        assert f"foo/0.1.0: [HOOK - testing/hook_complete.py] pre_validate(): Hello" in c.out
+        assert f"foo/0.1.0: [HOOK - testing/hook_complete.py] post_validate(): Hello" in c.out