Add a --lock option to poetry update (#389)

README.md

@@ -364,6 +364,8 @@ poetry update requests toml
 #### Options
 
 * `--dry-run` : Outputs the operations but will not execute anything (implicitly enables --verbose).
+* `--no-dev` : Do not install dev dependencies.
+* `--lock` : Do not perform install (only update the lockfile).
 
 ### add
 

docs/docs/cli.md

@@ -149,6 +149,8 @@ poetry update requests toml
 ### Options
 
 * `--dry-run` : Outputs the operations but will not execute anything (implicitly enables --verbose).
+* `--no-dev` : Do not install dev dependencies.
+* `--lock` : Do not perform install (only update the lockfile).
 
 ## add
 

poetry/console/commands/update.py

@@ -10,6 +10,7 @@ class UpdateCommand(EnvCommand):
         { --no-dev : Do not install dev dependencies. }
         { --dry-run : Outputs the operations but will not execute anything
                       (implicitly enables --verbose). }
+        { --lock : Do not perform install (only update the lockfile). }
     """
 
     _loggers = ["poetry.repositories.pypi_repository"]
@@ -32,6 +33,7 @@ class UpdateCommand(EnvCommand):
 
         installer.dev_mode(not self.option("no-dev"))
         installer.dry_run(self.option("dry-run"))
+        installer.execute_operations(not self.option("lock"))
 
         # Force update
         installer.update(True)