check for circular self-dependency

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_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

@@ -11,6 +11,7 @@
 from cleo.io.null_io import NullIO
 
 from poetry.factory import Factory
+from packaging.utils import canonicalize_name
 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