Merge ~pelpsi/lpci:backward-compatibility into lpci:main

[Simone Pelosi]

Forced classic to True if snaps are configured as string

If snaps are configured as string the classic confinement is forced
to improve backward compatibility

[Colin Watson (cjwatson)]

LGTM. Please remember to fix the resulting deprecation warning in Launchpad's own `.launchpad.yaml` after this is on stable. :-)

review: Approve

[Jürgen Gmach (jugmac00)]

Looks good!

- please add a news entry for this fix
- I would suggest to add a sentence to the documentation that the default value for classic is True when defining snaps as a list of strings, but also mention that this way is deprecated and the new way should be used
- typo in the commit message: confinment -> confinement

review: Approve

[Jürgen Gmach (jugmac00)]

Sorry for the late note.

diff --git a/NEWS.rst b/NEWS.rst
index 67eb3af..7ce8031 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -2,6 +2,12 @@
 Version history
 ===============
 
+0.0.52 (Unreleased)
+===================
+- Fix regression from adding support to snap keys
+  passed as strings. For these keys confinement classic
+  must be True by default to ensure backward compatibility.
+
 0.0.51 (2023-04-05)
 ===================
 - Add support for snap's channel and confinement level.
diff --git a/docs/configuration.rst b/docs/configuration.rst
index 4a3b255..5875b36 100644
--- a/docs/configuration.rst
+++ b/docs/configuration.rst
@@ -191,6 +191,13 @@ Snap properties
     <https://snapcraft.io/docs/snap-confinement>`_.
     Default value: False.
 
+.. note::
+
+    To ensure backward compatibility default value for
+    classic is True when defining snaps as a list of strings.
+    (i.e. [chromium, firefox]).
+    Please note that this format for defining snaps is deprecated.
+
 .. _package-repositories:
 
 Package-repositories properties
diff --git a/lpcraft/commands/tests/test_run.py b/lpcraft/commands/tests/test_run.py
index 361661c..b1fc6c2 100644
--- a/lpcraft/commands/tests/test_run.py
+++ b/lpcraft/commands/tests/test_run.py
@@ -2103,6 +2103,7 @@ class TestRun(RunBaseTestCase):
                         "chromium",
                         "--channel",
                         "latest/stable",
+                        "--classic",
                     ],
                     check=True,
                     capture_output=True,
@@ -2125,6 +2126,7 @@ class TestRun(RunBaseTestCase):
                         "firefox",
                         "--channel",
                         "latest/stable",
+                        "--classic",
                     ],
                     check=True,
                     capture_output=True,
@@ -2259,6 +2261,7 @@ class TestRun(RunBaseTestCase):
                         "firefox",
                         "--channel",
                         "latest/stable",
+                        "--classic",
                     ],
                     check=True,
                     capture_output=True,
diff --git a/lpcraft/config.py b/lpcraft/config.py
index 0fdb9b4..0d3db3d 100644
--- a/lpcraft/config.py
+++ b/lpcraft/config.py
@@ -8,6 +8,7 @@ from pathlib import Path
 from typing import Any, Dict, Iterator, List, Optional, Tuple, Type, Union
 
 import pydantic
+from craft_cli import emit
 from pydantic import AnyHttpUrl, StrictStr, root_validator, validator
 
 from lpcraft.errors import ConfigurationError
@@ -304,7 +305,17 @@ class Job(ModelConfigDefaults):
         for value in v:
             # Backward compatibility, i.e. [chromium, firefox]
             if type(value) is str:
-                clean_values.append({"name": value})
+                emit.message(
+                    f"Warning: You configured snap `{value}` but "
+                    + "you used a deprecated format. "
+                    + "\nPlease use "
+                    + f"\n...\n-name: {value}\n"
+                    + " classic: True\n...\n"
+                    + "instead.\n"
+                    + "Please refer to the documentation for an "
+                    + "overview of supported formats.",
+                )
+                clean_values.append({"name": value, "classic": True})
             elif type(value) is dict:
                 if "name" not in value or value["name"] is None:
                     raise ValueError(