fix: handle removal of optional dependencies

src/poetry/console/commands/remove.py

@@ -94,6 +94,11 @@ def handle(self) -> int:
                 if group_name not in groups_content and group_name != MAIN_GROUP
             )
 
+            # Also search optional dependencies sections
+            removed |= self._remove_optional_packages(
+                packages, project_content, poetry_content
+            )
+
             for group_name, standard_section, poetry_section in group_sections:
                 removed |= self._remove_packages(
                     packages=packages,
@@ -212,6 +217,72 @@ def _remove_packages(
 
         return removed
 
+    def _remove_optional_packages(
+        self,
+        packages: list[str],
+        project_content: dict[str, Any],
+        poetry_content: dict[str, Any],
+    ) -> set[str]:
+        """Remove packages from optional dependency sections.
+
+        Handles both [project.optional-dependencies] (PEP 621) and
+        [tool.poetry.extras] (legacy) sections.
+        """
+        removed: set[str] = set()
+
+        # PEP 621: [project.optional-dependencies]
+        optional_deps = project_content.get("optional-dependencies", {})
+        for extra_name, deps_list in list(optional_deps.items()):
+            for package in packages:
+                normalized_name = canonicalize_name(package)
+                for requirement in deps_list.copy():
+                    if not isinstance(requirement, str):
+                        continue
+                    if (
+                        Dependency.create_from_pep_508(requirement).name
+                        == normalized_name
+                    ):
+                        deps_list.remove(requirement)
+                        removed.add(package)
+            if not deps_list:
+                del optional_deps[extra_name]
+        if (
+            "optional-dependencies" in project_content
+            and not project_content["optional-dependencies"]
+        ):
+            del project_content["optional-dependencies"]
+
+        # Legacy: [tool.poetry.extras]
+        extras = poetry_content.get("extras", {})
+        for extra_name, extras_list in list(extras.items()):
+            for package in packages:
+                normalized_name = canonicalize_name(package)
+                for item in extras_list.copy():
+                    if canonicalize_name(item) == normalized_name:
+                        extras_list.remove(item)
+            if not extras_list:
+                del extras[extra_name]
+        if "extras" in poetry_content and not poetry_content["extras"]:
+            del poetry_content["extras"]
+
+        # Also remove from [tool.poetry.dependencies] if marked optional
+        poetry_deps = poetry_content.get("dependencies", {})
+        for package in packages:
+            normalized_name = canonicalize_name(package)
+            for dep_name in list(poetry_deps):
+                if canonicalize_name(dep_name) == normalized_name:
+                    dep_value = poetry_deps[dep_name]
+                    if isinstance(dep_value, dict) and dep_value.get("optional"):
+                        del poetry_deps[dep_name]
+                        removed.add(package)
+
+        if removed:
+            group = self.poetry.package.dependency_group(MAIN_GROUP)
+            for package in removed:
+                group.remove_dependency(package)
+
+        return removed
+
     def _remove_references_to_group(
         self, group_name: str, content: dict[str, Any]
     ) -> None:

tests/console/commands/test_remove.py

@@ -906,3 +906,84 @@ def test_remove_group_cleans_up_include_group_references(
         assert "foobar3" in content.get("group", {})
         assert "include-groups" in content["group"]["foobar3"]
         assert content["group"]["foobar3"]["include-groups"] == ["foobar2"]
+
+
+def test_remove_optional_dependency_from_project(
+    tester: CommandTester,
+    app: PoetryTestApplication,
+    repo: TestRepository,
+    installed: Repository,
+) -> None:
+    """Regression test for #10703: cannot remove optional dependency."""
+    repo.add_package(Package("pylint", "3.0.0"))
+    repo.add_package(Package("bar", "1.0.0"))
+
+    pyproject: dict[str, Any] = app.poetry.file.read()
+
+    optional_deps: dict[str, Any] = tomlkit.parse(
+        """\
+[project.optional-dependencies]
+linting = [
+    "pylint>=3.0",
+]
+"""
+    )
+
+    pyproject["project"]["optional-dependencies"] = optional_deps["project"][
+        "optional-dependencies"
+    ]
+    pyproject = cast("TOMLDocument", pyproject)
+    app.poetry.file.write(pyproject)
+
+    app.poetry.package.add_dependency(Factory.create_dependency("pylint", ">=3.0"))
+
+    tester.execute("pylint")
+
+    pyproject = app.poetry.file.read()
+    pyproject = cast("dict[str, Any]", pyproject)
+    assert "optional-dependencies" not in pyproject.get(
+        "project", {}
+    ) or "pylint" not in str(
+        pyproject["project"].get("optional-dependencies", {})
+    )
+
+
+def test_remove_optional_dependency_from_poetry_extras(
+    tester: CommandTester,
+    app: PoetryTestApplication,
+    repo: TestRepository,
+    installed: Repository,
+) -> None:
+    """Regression test for #10703: cannot remove optional dependency (legacy format)."""
+    repo.add_package(Package("pylint", "3.0.0"))
+
+    pyproject: dict[str, Any] = app.poetry.file.read()
+
+    poetry_deps: dict[str, Any] = tomlkit.parse(
+        """\
+[tool.poetry.dependencies]
+pylint = {version = "^3.0", optional = true}
+
+[tool.poetry.extras]
+linting = ["pylint"]
+"""
+    )
+
+    pyproject["tool"]["poetry"]["dependencies"] = poetry_deps["tool"]["poetry"][
+        "dependencies"
+    ]
+    pyproject["tool"]["poetry"]["extras"] = poetry_deps["tool"]["poetry"]["extras"]
+    pyproject = cast("TOMLDocument", pyproject)
+    app.poetry.file.write(pyproject)
+
+    app.poetry.package.add_dependency(Factory.create_dependency("pylint", "^3.0"))
+
+    tester.execute("pylint")
+
+    pyproject = app.poetry.file.read()
+    pyproject = cast("dict[str, Any]", pyproject)
+    poetry_content = pyproject["tool"]["poetry"]
+    assert "pylint" not in poetry_content.get("dependencies", {})
+    assert "extras" not in poetry_content or "pylint" not in str(
+        poetry_content.get("extras", {})
+    )