Makes it possible for header only libs to be buidl tested.

This adds the concept of "testable header only" recipes. Those are
recipes for header only libraries that also include a "test_package"
that should be built across configurations to check for correct
functioning of header libs that have platform and/or system
requirements. This resolves issue
bincrafters/community#1391

bincrafters/autodetect.py

@@ -1,8 +1,6 @@
 import os
 from bincrafters.build_shared import get_recipe_path, inspect_value_from_recipe
 
-_recipe_path = os.path.dirname(get_recipe_path())
-
 
 def _file_contains(file, word):
     """ Read file and search for word
@@ -40,13 +38,21 @@ def recipe_has_setting(setting_name):
 
 
 def is_custom_build_py_existing() -> (bool, str):
-    custom_build_path = os.path.join(_recipe_path, "build.py")
+    custom_build_path = os.path.join(os.path.dirname(get_recipe_path()), "build.py")
     if os.path.isfile(custom_build_path):
         return True, custom_build_path
 
     return False, None
 
 
+def has_test_package():
+    test_package_path = os.path.join(os.path.dirname(get_recipe_path()), "test_package")
+    if os.path.isdir(test_package_path):
+        return True
+
+    return False
+
+
 def is_pure_c():
     if recipe_contains("del self.settings.compiler.libcxx") and recipe_contains("del self.settings.compiler.cppstd"):
         return True
@@ -65,6 +71,13 @@ def is_unconditional_header_only():
     return False
 
 
+def is_testable_header_only():
+    if is_unconditional_header_only() and has_test_package():
+        return True
+
+    return False
+
+
 def is_installer():
     if not is_unconditional_header_only() and not is_conditional_header_only():
         if (recipe_contains("self.env_info.PATH.append") or recipe_contains("self.env_info.PATH.extend")) \
@@ -78,7 +91,9 @@ def autodetect() -> str:
     if is_installer():
         return "installer"
     else:
-        if is_unconditional_header_only():
+        if is_testable_header_only():
+            return "testable_header_only"
+        elif is_unconditional_header_only():
             return "unconditional_header_only"
         else:
             if is_conditional_header_only():

bincrafters/build_autodetect.py

@@ -65,6 +65,9 @@ def run_autodetect():
     ###
     # Output collected recipe information in the builds logs
     ###
+    recipe_conanfile = get_recipe_path()
+    printer.print_message("Recipe path: {}".format(str(recipe_conanfile)))
+
     recipe_is_installer = is_installer()
     printer.print_message("Is the package an installer for executable(s)? {}"
                           .format(str(recipe_is_installer)))
@@ -74,6 +77,10 @@ def run_autodetect():
         printer.print_message("Is the package header only? {}"
                               .format(str(recipe_is_unconditional_header_only)))
 
+        recipe_is_testable_header_only = is_testable_header_only()
+        printer.print_message("Is the package testable header only? {}"
+                              .format(str(recipe_is_testable_header_only)))
+
         if not recipe_is_unconditional_header_only:
             recipe_is_conditional_header_only = is_conditional_header_only()
             printer.print_message("Is the package conditionally header only ('header_only' option)? {}"
@@ -98,6 +105,9 @@ def run_autodetect():
         builder = build_template_installer.get_builder(**kwargs)
         builder.add({"os": get_os(), "arch_build": arch, "arch": arch}, {}, {}, {})
         builder.run()
+    elif is_testable_header_only():
+        builder = build_template_header_only.get_builder(**kwargs)
+        builder.run()
     elif recipe_is_unconditional_header_only:
         builder = build_template_header_only.get_builder(**kwargs)
         builder.run()