Add more package validation (#9986)

* validate packages are not empty strings

* add test

* changelog

* Update core/dbt/contracts/project.py

* fix test message

.changes/unreleased/Fixes-20240422-152244.yaml

@@ -0,0 +1,6 @@
+kind: Fixes
+body: Validate against empty strings in package definitions
+time: 2024-04-22T15:22:44.575999-05:00
+custom:
+  Author: emmyoop
+  Issue: "9985"

core/dbt/contracts/project.py

@@ -101,13 +101,26 @@ class PackageConfig(dbtClassMixin):
     @classmethod
     def validate(cls, data):
         for package in data.get("packages", data):
+            # This can happen when the target is a variable that is not filled and results in hangs
+            if isinstance(package, dict):
+                if package.get("package") == "":
+                    raise ValidationError(
+                        "A hub package is missing the value. It is a required property."
+                    )
+                if package.get("local") == "":
+                    raise ValidationError(
+                        "A local package is missing the value. It is a required property."
+                    )
+                if package.get("git") == "":
+                    raise ValidationError(
+                        "A git package is missing the value. It is a required property."
+                    )
             if isinstance(package, dict) and package.get("package"):
                 if not package["version"]:
                     raise ValidationError(
                         f"{package['package']} is missing the version. When installing from the Hub "
                         "package index, version is a required property"
                     )
-
                 if "/" not in package["package"]:
                     raise ValidationError(
                         f"{package['package']} was not found in the package index. Packages on the index "

tests/functional/dependencies/test_simple_dependency.py

@@ -434,3 +434,44 @@ def test_malformed_tarball_package_causes_exception(self, project):
         ) as e:
             run_dbt(["deps"])
             assert e is not None
+
+
+class TestEmptyDependency:
+    def test_empty_package(self, project):
+        # We have to specify the bad formatted package here because if we do it
+        # in a `packages` fixture, the test will blow up in the setup phase, meaning
+        # we can't appropriately catch it with a `pytest.raises`
+        empty_hub_package = {
+            "packages": [
+                {
+                    "package": "",
+                    "version": "1.0.0",
+                }
+            ]
+        }
+        write_config_file(empty_hub_package, "packages.yml")
+        with pytest.raises(DbtProjectError, match="A hub package is missing the value"):
+            run_dbt(["deps"])
+
+        empty_git_package = {
+            "packages": [
+                {
+                    "git": "",
+                    "revision": "1.0.0",
+                }
+            ]
+        }
+        write_config_file(empty_git_package, "packages.yml")
+        with pytest.raises(DbtProjectError, match="A git package is missing the value"):
+            run_dbt(["deps"])
+
+        empty_local_package = {
+            "packages": [
+                {
+                    "local": "",
+                }
+            ]
+        }
+        write_config_file(empty_local_package, "packages.yml")
+        with pytest.raises(DbtProjectError, match="A local package is missing the value"):
+            run_dbt(["deps"])