validate extras against dependencies and in schema

src/poetry/core/factory.py

@@ -409,6 +409,20 @@ def validate(
                             'Use "allow-prereleases" instead.'
                         )
 
+                if "extras" in config:
+                    for extra_name, requirements in config["extras"].items():
+                        extra_name = canonicalize_name(extra_name)
+
+                        for req in requirements:
+                            for dependency in config["dependencies"].keys():
+                                if req == dependency:
+                                    break
+                            else:
+                                result["warnings"].append(
+                                    f'Cannot find dependency "{req}" for extra '
+                                    f'"{extra_name}" in main dependencies.'
+                                )
+
             # Checking for scripts with extras
             if "scripts" in config:
                 scripts = config["scripts"]

src/poetry/core/json/schemas/poetry-schema.json

@@ -155,7 +155,8 @@
         "^[a-zA-Z-_.0-9]+$": {
           "type": "array",
           "items": {
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z-_.0-9]+$"
           }
         }
       }

tests/fixtures/project_failing_strict_validation/pyproject.toml

@@ -5,6 +5,9 @@ readme = ["README.rst", "README_WITH_ANOTHER_EXTENSION.md"]
 python = "*"
 pathlib2 = { version = "^2.2", python = "3.7", allows-prereleases = true }
 
+[tool.poetry.extras]
+some_extras = ["missing_extra", "another_missing_extra"]
+
 [tool.poetry.scripts]
 a_script_with_unknown_extra = { reference = "a_script_with_unknown_extra.py", type = "file", extras = ["foo"] }
 a_script_without_extras = { reference = "a_script_without_extras.py", type = "file" }

tests/json/test_poetry_schema.py

@@ -57,3 +57,15 @@ def test_multiline_description(base_object: dict[str, Any]) -> None:
     errors = validate_object(base_object, "poetry-schema")
     assert len(errors) == 1
     assert errors[0] == f"[description] {bad_description!r} does not match '^[^\\n]*$'"
+
+
+def test_bad_extra(base_object: dict[str, Any]) -> None:
+    bad_extra = "a{[*+"
+    base_object["extras"] = {}
+    base_object["extras"]["test"] = [bad_extra]
+
+    errors = validate_object(base_object, "poetry-schema")
+    assert len(errors) == 1
+    assert (
+        errors[0] == f"[extras.test.0] {bad_extra!r} does not match '^[a-zA-Z-_.0-9]+$'"
+    )

tests/test_factory.py

@@ -250,6 +250,14 @@ def test_validate_strict_fails_strict_and_non_strict() -> None:
                 'The "pathlib2" dependency specifies the "allows-prereleases" property,'
                 ' which is deprecated. Use "allow-prereleases" instead.'
             ),
+            (
+                'Cannot find dependency "missing_extra" for extra "some-extras" in '
+                "main dependencies."
+            ),
+            (
+                'Cannot find dependency "another_missing_extra" for extra '
+                '"some-extras" in main dependencies.'
+            ),
         ],
     }