Merge pull request #217 from smoser/bump-constraints-empty-updates

Allow empty constraints file as a placeholder.

Author: aborrero

pipelines/py/tw/bump-constraints.yaml

@@ -5,7 +5,9 @@ inputs:
     description: Path to the constraints file to update
     default: constraints.txt
   packages:
-    description: List of package==version pairs to update (newline separated, with optional comments)
+    description: |
+      List of package==version pairs to update (newline separated, with optional comments)
+      Use the string '# future-updates' as a placeholder.
     required: true
   only-replace:
     description: Only update packages already in the constraints file (set to false to allow adding new packages)

tw/pkg/commands/bumpconstraints/bumpconstraints.go

@@ -104,7 +104,13 @@ func (c *cfg) Run(cmd *cobra.Command) error {
 
 	// Check that we have updates to process
 	if len(c.Packages) == 0 {
-		return fmt.Errorf("no package updates specified (provide as arguments or use -u/--updates-file)")
+		contents, err := os.ReadFile(c.UpdatesFile)
+		placeholder := "# future-updates"
+		if err == nil && strings.TrimSpace(string(contents)) == placeholder {
+			log.InfoContextf(ctx, "Constraints file is intentionally empty")
+		} else {
+			return fmt.Errorf("no package updates specified (provide as arguments or use -u/--updates-file). Use string '%s' as placeholder", placeholder)
+		}
 	}
 
 	// Parse package updates from arguments