check for circular self-dependency

src/poetry/console/commands/add.py

@@ -126,6 +126,7 @@ def handle(self) -> int:
         # dictionary.
         content: dict[str, Any] = self.poetry.file.read()
         poetry_content = content["tool"]["poetry"]
+        project_name = canonicalize_name(poetry_content["name"])
 
         if group == MAIN_GROUP:
             if "dependencies" not in poetry_content:
@@ -223,6 +224,14 @@ def handle(self) -> int:
 
             canonical_constraint_name = canonicalize_name(constraint_name)
 
+            if canonical_constraint_name == project_name:
+                self.line_error(
+                    f"<error>Cannot add dependency on <c1>{constraint_name}</c1> to"
+                    " project with the same name."
+                )
+                self.line_error("\nNo changes were applied.")
+                return 1
+
             for key in section:
                 if canonicalize_name(key) == canonical_constraint_name:
                     section[key] = constraint

src/poetry/factory.py

@@ -9,6 +9,7 @@
 from typing import cast
 
 from cleo.io.null_io import NullIO
+from packaging.utils import canonicalize_name
 from poetry.core.factory import Factory as BaseFactory
 from poetry.core.packages.dependency_group import MAIN_GROUP
 from poetry.core.packages.project_package import ProjectPackage
@@ -319,4 +320,18 @@ def validate(
 
         results["errors"].extend(validate_object(config))
 
+        # A project should not depend on itself.
+        dependencies = set(config.get("dependencies", {}).keys())
+        dependencies.update(config.get("dev-dependencies", {}).keys())
+        groups = config.get("group", {}).values()
+        for group in groups:
+            dependencies.update(group.get("dependencies", {}).keys())
+
+        dependencies = {canonicalize_name(d) for d in dependencies}
+
+        if canonicalize_name(config["name"]) in dependencies:
+            results["errors"].append(
+                f"Project name ({config['name']}) is same as one of its dependencies"
+            )
+
         return results

tests/console/commands/test_add.py

@@ -1073,6 +1073,18 @@ def test_add_should_skip_when_adding_canonicalized_existing_package_with_no_cons
     assert expected in tester.io.fetch_output()
 
 
+def test_add_should_fail_circular_dependency(
+    app: PoetryTestApplication, repo: TestRepository, tester: CommandTester
+) -> None:
+    repo.add_package(get_package("simple-project", "1.1.2"))
+    result = tester.execute("simple-project")
+
+    assert result == 1
+
+    expected = "Cannot add dependency on simple-project to project with the same name."
+    assert expected in tester.io.fetch_error()
+
+
 def test_add_latest_should_not_create_duplicate_keys(
     project_factory: ProjectFactory,
     repo: TestRepository,

tests/console/commands/test_check.py

@@ -43,6 +43,7 @@ def test_check_invalid(
 
     expected = """\
 Error: 'description' is a required property
+Error: Project name (invalid) is same as one of its dependencies
 Error: Unrecognized classifiers: ['Intended Audience :: Clowns'].
 Warning: A wildcard Python dependency is ambiguous.\
  Consider specifying a more explicit one.

tests/fixtures/invalid_pyproject/pyproject.toml

@@ -15,3 +15,4 @@ classifiers = [
 [tool.poetry.dependencies]
 python = "*"
 pendulum = {"version" = "^2.0.5", allows-prereleases = true}
+invalid = "1.0"

tests/fixtures/sample_project/pyproject.toml

@@ -1,5 +1,5 @@
 [tool.poetry]
-name = "my-package"
+name = "sample-project"
 version = "1.2.3"
 description = "Some description."
 authors = [
@@ -51,7 +51,7 @@ pytest = "~3.4"
 
 
 [tool.poetry.scripts]
-my-script = "my_package:main"
+my-script = "sample_project:main"
 
 
 [tool.poetry.plugins."blogtool.parsers"]

tests/fixtures/with_default_source/pyproject.toml

@@ -1,5 +1,5 @@
 [tool.poetry]
-name = "my-package"
+name = "with-default-source"
 version = "1.2.3"
 description = "Some description."
 authors = [
@@ -48,7 +48,7 @@ pytest = "~3.4"
 
 
 [tool.poetry.scripts]
-my-script = "my_package:main"
+my-script = "with_default_source:main"
 
 
 [tool.poetry.plugins."blogtool.parsers"]

tests/fixtures/with_default_source_legacy/pyproject.toml

@@ -1,5 +1,5 @@
 [tool.poetry]
-name = "my-package"
+name = "default-source-legacy"
 version = "1.2.3"
 description = "Some description."
 authors = [
@@ -48,7 +48,7 @@ pytest = "~3.4"
 
 
 [tool.poetry.scripts]
-my-script = "my_package:main"
+my-script = "default_source_legacy:main"
 
 
 [tool.poetry.plugins."blogtool.parsers"]

tests/fixtures/with_explicit_source/pyproject.toml

@@ -1,5 +1,5 @@
 [tool.poetry]
-name = "my-package"
+name = "with-explicit-source"
 version = "1.2.3"
 description = "Some description."
 authors = [

tests/fixtures/with_local_config/pyproject.toml

@@ -1,5 +1,5 @@
 [tool.poetry]
-name = "my-package"
+name = "local-config"
 version = "1.2.3"
 description = "Some description."
 authors = [
@@ -48,7 +48,7 @@ pytest = "~3.4"
 
 
 [tool.poetry.scripts]
-my-script = "my_package:main"
+my-script = "local_config:main"
 
 
 [tool.poetry.plugins."blogtool.parsers"]

tests/fixtures/with_two_default_sources/pyproject.toml

@@ -1,5 +1,5 @@
 [tool.poetry]
-name = "my-package"
+name = "two-default-sources"
 version = "1.2.3"
 description = "Some description."
 authors = [
@@ -48,7 +48,7 @@ pytest = "~3.4"
 
 
 [tool.poetry.scripts]
-my-script = "my_package:main"
+my-script = "two_default_sources:main"
 
 
 [tool.poetry.plugins."blogtool.parsers"]

tests/fixtures/with_two_default_sources_legacy/pyproject.toml

@@ -1,5 +1,5 @@
 [tool.poetry]
-name = "my-package"
+name = "two-default-sources-legacy"
 version = "1.2.3"
 description = "Some description."
 authors = [
@@ -48,7 +48,7 @@ pytest = "~3.4"
 
 
 [tool.poetry.scripts]
-my-script = "my_package:main"
+my-script = "two_default_sources_legacy:main"
 
 
 [tool.poetry.plugins."blogtool.parsers"]

tests/publishing/test_publisher.py

@@ -9,6 +9,7 @@
 
 from cleo.io.buffered_io import BufferedIO
 from cleo.io.null_io import NullIO
+from packaging.utils import canonicalize_name
 
 from poetry.factory import Factory
 from poetry.publishing.publisher import Publisher
@@ -72,7 +73,8 @@ def test_publish_can_publish_to_given_repository(
         ("http://foo.bar",),
         {"cert": True, "client_cert": None, "dry_run": False, "skip_existing": False},
     ] == uploader_upload.call_args
-    assert "Publishing my-package (1.2.3) to foo" in io.fetch_output()
+    project_name = canonicalize_name(fixture_name)
+    assert f"Publishing {project_name} (1.2.3) to foo" in io.fetch_output()
 
 
 def test_publish_raises_error_for_undefined_repository(

tests/test_factory.py

@@ -37,7 +37,7 @@ def test_create_poetry(fixture_dir: FixtureDirGetter) -> None:
 
     package = poetry.package
 
-    assert package.name == "my-package"
+    assert package.name == "sample-project"
     assert package.version.text == "1.2.3"
     assert package.description == "Some description."
     assert package.authors == ["Sébastien Eustace <sebastien@eustace.io>"]
@@ -418,6 +418,7 @@ def test_create_poetry_fails_on_invalid_configuration(
     expected = """\
 The Poetry configuration is invalid:
   - 'description' is a required property
+  - Project name (invalid) is same as one of its dependencies
 """
     assert str(e.value) == expected