add support for PEP 621: poetry add - change "--optional" to require …

…an extra the optional dependency is added to (python-poetry#9135)

docs/cli.md

@@ -456,7 +456,7 @@ about dependency groups.
 * `--dev (-D)`: Add package as development dependency. (**Deprecated**, use `-G dev` instead)
 * `--editable (-e)`: Add vcs/path dependencies as editable.
 * `--extras (-E)`: Extras to activate for the dependency. (multiple values allowed)
-* `--optional`: Add as an optional dependency.
+* `--optional`: Add as an optional dependency to an extra.
 * `--python`: Python version for which the dependency must be installed.
 * `--platform`: Platforms for which the dependency must be installed.
 * `--source`: Name of the source to use to install the package.

src/poetry/console/commands/add.py

@@ -54,7 +54,12 @@ class AddCommand(InstallerCommand, InitCommand):
             flag=False,
             multiple=True,
         ),
-        option("optional", None, "Add as an optional dependency."),
+        option(
+            "optional",
+            None,
+            "Add as an optional dependency to an extra.",
+            flag=False,
+        ),
         option(
             "python",
             None,
@@ -137,6 +142,10 @@ def handle(self) -> int:
                 "You can only specify one package when using the --extras option"
             )
 
+        optional = self.option("optional")
+        if optional and group != MAIN_GROUP:
+            raise ValueError("You can only add optional dependencies to the main group")
+
         # tomlkit types are awkward to work with, treat content as a mostly untyped
         # dictionary.
         content: dict[str, Any] = self.poetry.file.read()
@@ -156,13 +165,19 @@ def handle(self) -> int:
                 or "optional-dependencies" in project_content
             ):
                 use_project_section = True
+                if optional:
+                    project_section = project_content.get(
+                        "optional-dependencies", {}
+                    ).get(optional, array())
+                else:
+                    project_section = project_content.get("dependencies", array())
                 project_dependency_names = [
-                    Dependency.create_from_pep_508(dep).name
-                    for dep in project_content.get("dependencies", {})
+                    Dependency.create_from_pep_508(dep).name for dep in project_section
                 ]
+            else:
+                project_section = array()
 
             poetry_section = poetry_content.get("dependencies", table())
-            project_section = project_content.get("dependencies", array())
         else:
             if "group" not in poetry_content:
                 poetry_content["group"] = table(is_super_table=True)
@@ -194,6 +209,13 @@ def handle(self) -> int:
             self.line("Nothing to add.")
             return 0
 
+        if optional and not use_project_section:
+            self.line_error(
+                "<warning>Optional dependencies will not be added to extras"
+                " in legacy mode. Consider converting your project to use the [project]"
+                " section.</warning>"
+            )
+
         requirements = self._determine_requirements(
             packages,
             allow_prereleases=self.option("allow-prereleases"),
@@ -214,7 +236,7 @@ def handle(self) -> int:
 
                 constraint[key] = value
 
-            if self.option("optional"):
+            if optional:
                 constraint["optional"] = True
 
             if self.option("allow-prereleases"):
@@ -290,7 +312,7 @@ def handle(self) -> int:
                 # that cannot be stored in the project section
                 poetry_constraint: dict[str, Any] = inline_table()
                 if not isinstance(constraint, str):
-                    for key in ["optional", "allow-prereleases", "develop", "source"]:
+                    for key in ["allow-prereleases", "develop", "source"]:
                         if value := constraint.get(key):
                             poetry_constraint[key] = value
                     if poetry_constraint:
@@ -310,9 +332,15 @@ def handle(self) -> int:
                     poetry_section[constraint_name] = poetry_constraint
 
         # Refresh the locker
-        if project_section and "dependencies" not in project_content:
+        if project_section:
             assert group == MAIN_GROUP
-            project_content["dependencies"] = project_section
+            if optional:
+                if "optional-dependencies" not in project_content:
+                    project_content["optional-dependencies"] = table()
+                if optional not in project_content["optional-dependencies"]:
+                    project_content["optional-dependencies"][optional] = project_section
+            elif "dependencies" not in project_content:
+                project_content["dependencies"] = project_section
         if poetry_section:
             if "tool" not in content:
                 content["tool"] = table()

tests/console/commands/test_add.py

@@ -795,10 +795,40 @@ def test_add_url_constraint_wheel_with_extras(
     }
 
 
+@pytest.mark.parametrize("project_dependencies", [True, False])
+@pytest.mark.parametrize(
+    ("existing_extras", "expected_extras"),
+    [
+        (None, {"my-extra": ["cachy (==0.2.0)"]}),
+        (
+            {"other": ["foo>2"]},
+            {"other": ["foo>2"], "my-extra": ["cachy (==0.2.0)"]},
+        ),
+        ({"my-extra": ["foo>2"]}, {"my-extra": ["foo>2", "cachy (==0.2.0)"]}),
+        (
+            {"my-extra": ["foo>2", "cachy (==0.1.0)", "bar>1"]},
+            {"my-extra": ["foo>2", "cachy (==0.2.0)", "bar>1"]},
+        ),
+    ],
+)
 def test_add_constraint_with_optional(
-    app: PoetryTestApplication, tester: CommandTester
+    app: PoetryTestApplication,
+    tester: CommandTester,
+    project_dependencies: bool,
+    existing_extras: dict[str, list[str]] | None,
+    expected_extras: dict[str, list[str]],
 ) -> None:
-    tester.execute("cachy=0.2.0 --optional")
+    pyproject: dict[str, Any] = app.poetry.file.read()
+    if project_dependencies:
+        pyproject["project"]["dependencies"] = ["foo>1"]
+        if existing_extras:
+            pyproject["project"]["optional-dependencies"] = existing_extras
+    else:
+        pyproject["tool"]["poetry"]["dependencies"]["foo"] = "^1.0"
+    pyproject = cast("TOMLDocument", pyproject)
+    app.poetry.file.write(pyproject)
+
+    tester.execute("cachy=0.2.0 --optional my-extra")
     expected = """\
 
 Updating dependencies
@@ -813,14 +843,37 @@ def test_add_constraint_with_optional(
     assert isinstance(tester.command, InstallerCommand)
     assert tester.command.installer.executor.installations_count == 0
 
-    pyproject: dict[str, Any] = app.poetry.file.read()
-    content = pyproject["tool"]["poetry"]
+    pyproject2: dict[str, Any] = app.poetry.file.read()
+    project_content = pyproject2["project"]
+    poetry_content = pyproject2["tool"]["poetry"]
 
-    assert "cachy" in content["dependencies"]
-    assert content["dependencies"]["cachy"] == {
-        "version": "0.2.0",
-        "optional": True,
-    }
+    if project_dependencies:
+        assert "cachy" not in poetry_content["dependencies"]
+        assert "cachy" not in project_content["dependencies"]
+        assert "my-extra" in project_content["optional-dependencies"]
+        assert project_content["optional-dependencies"] == expected_extras
+        assert not tester.io.fetch_error()
+    else:
+        assert "dependencies" not in project_content
+        assert "optional-dependencies" not in project_content
+        assert "cachy" in poetry_content["dependencies"]
+        assert poetry_content["dependencies"]["cachy"] == {
+            "version": "0.2.0",
+            "optional": True,
+        }
+        assert (
+            "Optional dependencies will not be added to extras in legacy mode."
+            in tester.io.fetch_error()
+        )
+
+
+def test_add_constraint_with_optional_not_main_group(
+    app: PoetryTestApplication, tester: CommandTester
+) -> None:
+    with pytest.raises(ValueError) as e:
+        tester.execute("cachy=0.2.0 --group dev --optional my-extra")
+
+    assert str(e.value) == "You can only add optional dependencies to the main group"
 
 
 def test_add_constraint_with_python(