Fix solver adding uninstall operations for non-existing packages

CHANGELOG.md

@@ -16,6 +16,7 @@
 
 - Fixed handling of markers with the `in` operator.
 - Fixed `update` not properly adding new packages to the lock file.
+- Fixed solver adding uninstall operations for non-installed packages.
 
 
 ## [0.6.5] - 2018-03-22

poetry/installation/installer.py

@@ -330,6 +330,18 @@ class Installer:
         self._installer.update(source, target)
 
     def _execute_uninstall(self, operation: Uninstall) -> None:
+        if operation.skipped:
+            if self.is_verbose() and (self._execute_operations or self.is_dry_run()):
+                self._io.writeln(
+                    '  - Not removing <info>{}</> (<comment>{}</>) {}'.format(
+                        operation.package.pretty_name,
+                        operation.package.full_pretty_version,
+                        operation.skip_reason
+                    )
+                )
+
+            return
+
         if self._execute_operations or self.is_dry_run():
             self._io.writeln(
                 '  - Removing <info>{}</> (<comment>{}</>)'.format(

poetry/puzzle/solver.py

@@ -105,12 +105,18 @@ class Solver:
                     break
 
             if remove:
-                for locked in self._locked.packages:
-                    if locked.name == pkg.name:
-                        operations.append(Uninstall(pkg))
-
+                skip = True
+                for installed in self._installed.packages:
+                    if installed.name == pkg.name:
+                        skip = False
                         break
 
+                op = Uninstall(pkg)
+                if skip:
+                    op.skip('Not currently installed')
+
+                operations.append(op)
+
         requested_names = [r.name for r in requested]
 
         return sorted(

tests/puzzle/test_solver.py

@@ -88,8 +88,9 @@ def test_solver_install_single(solver, repo):
     ])
 
 
-def test_solver_remove_if_no_longer_locked(solver, locked):
+def test_solver_remove_if_no_longer_locked(solver, locked, installed):
     package_a = get_package('A', '1.0')
+    installed.add_package(package_a)
     locked.add_package(package_a)
 
     ops = solver.solve([])
@@ -99,6 +100,21 @@ def test_solver_remove_if_no_longer_locked(solver, locked):
     ])
 
 
+def test_remove_non_installed(solver, repo, locked):
+    package_a = get_package('A', '1.0')
+    locked.add_package(package_a)
+
+    repo.add_package(package_a)
+
+    request = []
+
+    ops = solver.solve(request)
+
+    check_solver_result(ops, [
+        {'job': 'remove', 'package': package_a, 'skipped': True},
+    ])
+
+
 def test_install_non_existing_package_fail(solver, repo):
     package_a = get_package('A', '1.0')
     repo.add_package(package_a)