refactor: Do not assume there is only one workspace target in app.py

While working with workspaces in _frontend/app.py, we currently assume
that there is only workspace in the pippeline. This limits our ability
to support multiple workspaces in a given command.

Remove this assumption from _frontend/app.py which will allow for the
possibility of supporting multiple workspaces from _frontend/cli.py in
future. This commit does not change the behavior of these commands
though as the target is instead passed as an argument.

2 files changed, 11 insertions, 9 deletions

diff --git a/buildstream/_frontend/app.py b/buildstream/_frontend/app.py
index fe2c460c5..db9c97b84 100644
--- a/buildstream/_frontend/app.py
+++ b/buildstream/_frontend/app.py
@@ -432,15 +432,14 @@ class App():
     # Open a project workspace - this requires full initialization
     #
     # Args:
+    #    target (Element): The element to open the workspace for
     #    directory (str): The directory to stage the source in
     #    no_checkout (bool): Whether to skip checking out the source
     #    track_first (bool): Whether to track and fetch first
     #    force (bool): Whether to ignore contents in an existing directory
     #
-    def open_workspace(self, directory, no_checkout, track_first, force):
+    def open_workspace(self, target, directory, no_checkout, track_first, force):
 
-        # When working on workspaces we only have one target
-        target = self.pipeline.targets[0]
         workdir = os.path.abspath(directory)
 
         if not list(target.sources()):
@@ -521,11 +520,10 @@ class App():
     # changes.
     #
     # Args:
+    #    target (Element): The element to reset the workspace for
     #    track (bool): Whether to also track the source
     #
-    def reset_workspace(self, track):
-        # When working on workspaces we only have one target
-        target = self.pipeline.targets[0]
+    def reset_workspace(self, target, track):
         workspace = self.project.workspaces.get_workspace(target.name)
 
         if workspace is None:
@@ -533,7 +531,7 @@ class App():
                            .format(target.name))
 
         self.close_workspace(target.name, True)
-        self.open_workspace(workspace.path, False, track, False)
+        self.open_workspace(target, workspace.path, False, track, False)
 
     ############################################################
     #                      Local Functions                     #
diff --git a/buildstream/_frontend/cli.py b/buildstream/_frontend/cli.py
index 9720bc44e..628a6cc85 100644
--- a/buildstream/_frontend/cli.py
+++ b/buildstream/_frontend/cli.py
@@ -624,7 +624,9 @@ def workspace_open(app, no_checkout, force, track_, element, directory):
             sys.exit(-1)
 
     with app.initialized((element,), rewritable=track_, track_elements=[element] if track_ else None):
-        app.open_workspace(directory, no_checkout, track_, force)
+        # This command supports only one target
+        target = app.pipeline.targets[0]
+        app.open_workspace(target, directory, no_checkout, track_, force)
 
 
 ##################################################################
@@ -669,7 +671,9 @@ def workspace_reset(app, track_, element):
             sys.exit(-1)
 
     with app.initialized((element,)):
-        app.reset_workspace(track_)
+        # This command supports only one target
+        target = app.pipeline.targets[0]
+        app.reset_workspace(target, track_)
 
 
 ##################################################################