App.find_dir(): Allow return value None

Allow find_dir() to return None in case it couldn't find a directory, that's a legal outcome. Add a boolean parameter "throw" to support throwing an exception if the existence needs to be asserted.
It would probably be nicer for the type checkers to split this up into a throwing and non-throwing function. Postponed.
Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/App.py

@@ -456,24 +456,27 @@ class App(Base):
         search_subdirs: list[str] = [],
         search_absdirs: list[str] = [],
         pretty: bool = True,
-    ) -> str:
+        throw: bool = False,
+    ) -> str | None:
         ret = self.__find_dir(name, search_subdirs, search_absdirs, pretty)
-        if ret is None:
+        if ret is not None:
-            msg = f'Failed to find directory for "{name}"'
+            return ret
+        if not throw:
+            return None
+        msg = f'Failed to find directory for "{name}":'
         log(ERR, msg)
         for search_name, search in [
             ('subdirs', search_subdirs),
             ('absdirs', search_absdirs),
         ]:
             if search:
-                    log(ERR, f'  Searched {search_name} in:')
+                log(ERR, f'Searched {search_name}:')
                 for d in search:
                     log(ERR, f' - {d}')
         raise FileNotFoundError(msg)
-        return ret
 
     # TODO: add support for customizing this in project.conf
-    def htdocs_dir(self, project: str) -> str:
+    def htdocs_dir(self, project: str) -> str | None:
         return self.find_dir(
             project,
             ['/src/html/htdocs', '/tools/html/htdocs', '/htdocs'],
@@ -481,7 +484,7 @@ class App(Base):
         )
 
     # TODO: add support for customizing this in project.conf
-    def tmpl_dir(self, name: str) -> str:
+    def tmpl_dir(self, name: str) -> str | None:
         return self.find_dir(name, ['/tmpl'], ['/opt/' + name + '/share/tmpl'])
 
     def strip_module_from_spec(self, mod):

src/python/jw/pkg/cmds/projects/CmdGetAuthInfo.py

@@ -57,9 +57,12 @@ class CmdGetAuthInfo(Cmd):  # export
 
         # --- Milk jw-pkg repo
         jw_pkg_dir = self.app.find_dir('jw-pkg', pretty = False)
+        if jw_pkg_dir is None:
+            log(DEBUG, 'Can\'t find jw-pkg directory')
+            return None
         if not os.path.isdir(jw_pkg_dir + '/.git'):
             log(DEBUG, f'jw-pkg directory is not a Git repo: {jw_pkg_dir}')
-            return
+            return None
         git_result = await self.app.exec_context.run(
             ['git', '-C', jw_pkg_dir, 'remote', '-v']
         )

src/python/jw/pkg/cmds/projects/CmdTmplDir.py

@@ -22,5 +22,8 @@ class CmdTmplDir(Cmd):  # export
     async def _run(self, args: Namespace) -> None:
         r = []
         for m in args.module:
-            r.append(self.app.tmpl_dir(m))
+            d = self.app.tmpl_dir(m)
+            if d is None:
+                continue
+            r.append(d)
         print(' '.join(r))