[graphql] workspaceLocationEntryOrError root resolver (#21523)

adds a way to load workspace location entries individually by name 

## How I Tested These Changes

added test

python_modules/dagster-graphql/dagster_graphql/implementation/external.py

@@ -18,6 +18,7 @@
         GrapheneRepository,
         GrapheneRepositoryConnection,
         GrapheneWorkspace,
+        GrapheneWorkspaceLocationEntry,
         GrapheneWorkspaceLocationStatusEntries,
     )
     from dagster_graphql.schema.util import ResolveInfo
@@ -188,3 +189,15 @@ def fetch_location_statuses(
             for status_entry in workspace_request_context.get_code_location_statuses()
         ]
     )
+
+
+def fetch_location_entry(
+    request_context: WorkspaceRequestContext, name: str
+) -> Optional["GrapheneWorkspaceLocationEntry"]:
+    from ..schema.external import GrapheneWorkspaceLocationEntry
+
+    location_entry = request_context.get_location_entry(name)
+    if location_entry is None:
+        return None
+
+    return GrapheneWorkspaceLocationEntry(location_entry)

python_modules/dagster-graphql/dagster_graphql/implementation/utils.py

@@ -133,7 +133,7 @@ def default_on_exception(
     ) -> "GraphenePythonError":
         from dagster_graphql.schema.errors import GraphenePythonError
 
-        # Transform exception in to PythonErron to present to user
+        # Transform exception in to PythonError to present to user
         return GraphenePythonError(serializable_error_info_from_exc_info(exc_info))
 
     # global behavior for how to handle unexpected exceptions

python_modules/dagster-graphql/dagster_graphql/schema/external.py

@@ -497,6 +497,12 @@ class Meta:
         name = "RepositoryOrError"
 
 
+class GrapheneWorkspaceLocationEntryOrError(graphene.Union):
+    class Meta:
+        types = (GrapheneWorkspaceLocationEntry, GraphenePythonError)
+        name = "WorkspaceLocationEntryOrError"
+
+
 types = [
     GrapheneLocationStateChangeEvent,
     GrapheneLocationStateChangeEventType,
@@ -506,4 +512,5 @@ class Meta:
     GrapheneRepositoryConnection,
     GrapheneRepositoryLocation,
     GrapheneRepositoryOrError,
+    GrapheneWorkspaceLocationEntryOrError,
 ]

python_modules/dagster-graphql/dagster_graphql/schema/roots/query.py

@@ -46,6 +46,7 @@
 from dagster_graphql.schema.env_vars import GrapheneEnvVarWithConsumersListOrError
 
 from ...implementation.external import (
+    fetch_location_entry,
     fetch_location_statuses,
     fetch_repositories,
     fetch_repository,
@@ -119,6 +120,7 @@
     GrapheneRepositoriesOrError,
     GrapheneRepositoryConnection,
     GrapheneRepositoryOrError,
+    GrapheneWorkspaceLocationEntryOrError,
     GrapheneWorkspaceLocationStatusEntriesOrError,
     GrapheneWorkspaceOrError,
 )
@@ -207,7 +209,13 @@ class Meta:
 
     locationStatusesOrError = graphene.Field(
         graphene.NonNull(GrapheneWorkspaceLocationStatusEntriesOrError),
-        description="Retrieve location status for workspace locations",
+        description="Retrieve location status for workspace locations.",
+    )
+
+    workspaceLocationEntryOrError = graphene.Field(
+        GrapheneWorkspaceLocationEntryOrError,
+        name=graphene.Argument(graphene.NonNull(graphene.String)),
+        description="Retrieve a workspace entry by name.",
     )
 
     pipelineOrError = graphene.Field(
@@ -591,6 +599,10 @@ def resolve_repositoryOrError(
     def resolve_workspaceOrError(self, graphene_info: ResolveInfo):
         return fetch_workspace(graphene_info.context)
 
+    @capture_error
+    def resolve_workspaceLocationEntryOrError(self, graphene_info: ResolveInfo, name: str):
+        return fetch_location_entry(graphene_info.context, name)
+
     @capture_error
     def resolve_locationStatusesOrError(self, graphene_info: ResolveInfo):
         return fetch_location_statuses(graphene_info.context)

python_modules/dagster-graphql/dagster_graphql_tests/graphql/test_workspace.py

@@ -18,65 +18,74 @@
 
 from .graphql_context_test_suite import GraphQLContextVariant, make_graphql_context_test_suite
 
-WORKSPACE_QUERY = """
-query {
-   workspaceOrError {
-      __typename
-      ... on Workspace {
-        locationEntries {
-          __typename
-          id
-          name
-          locationOrLoadError {
-            __typename
-            ... on RepositoryLocation {
-                id
-                name
-                repositories {
-                    name
-                }
-                isReloadSupported
-                dagsterLibraryVersions {
-                  name
-                  version
-                }
-            }
-            ... on PythonError {
-              message
-              stack
-              errorChain {
-                error {
-                  message
-                  stack
-                }
-              }
-            }
-          }
-          loadStatus
-          displayMetadata {
-            key
-            value
-          }
-          updatedTimestamp
-          featureFlags {
-            name
-            enabled
-          }
+LOCATION_ENTRY_FRAGMENT = """
+fragment locationEntryFragment on WorkspaceLocationEntry {
+  __typename
+  id
+  name
+  locationOrLoadError {
+    __typename
+    ... on RepositoryLocation {
+      id
+      name
+      repositories {
+        name
+      }
+      isReloadSupported
+      dagsterLibraryVersions {
+        name
+        version
+      }
+    }
+    ... on PythonError {
+      message
+      stack
+      errorChain {
+        error {
+          message
+          stack
         }
       }
-      ... on PythonError {
+    }
+  }
+  loadStatus
+  displayMetadata {
+    key
+    value
+  }
+  updatedTimestamp
+  featureFlags {
+    name
+    enabled
+  }
+}
+"""
+
+WORKSPACE_QUERY = (
+    """
+query {
+  workspaceOrError {
+    __typename
+    ... on Workspace {
+      locationEntries {
+        ...locationEntryFragment
+      }
+    }
+    ... on PythonError {
+      message
+      stack
+      errorChain {
+        error {
           message
           stack
-          errorChain {
-            error {
-                message
-                stack
-            }
-          }
+        }
       }
     }
+  }
 }
 """
+    + LOCATION_ENTRY_FRAGMENT
+)
 
 LOCATION_STATUS_QUERY = """
 query {
@@ -98,6 +107,22 @@
 }
 """
 
+LOCATION_ENTRY_QUERY = (
+    """
+query ($name: String!) {
+  workspaceLocationEntryOrError(name: $name) {
+    __typename
+    ...locationEntryFragment
+    ... on PythonError {
+        message
+        stack
+    }
+  }
+}
+"""
+    + LOCATION_ENTRY_FRAGMENT
+)
+
 
 @pytest.fixture(scope="function")
 def enable_masking_user_code_errors() -> Any:
@@ -301,3 +326,34 @@ def test_load_workspace_masked(self, graphql_context, enable_masking_user_code_e
                 "Search in logs for this error ID for more details"
                 in failure_node["locationOrLoadError"]["message"]
             )
+
+    def test_workspace_entry_by_name(self, graphql_context) -> None:
+        result = execute_dagster_graphql(graphql_context, LOCATION_ENTRY_QUERY, {"name": "test"})
+        assert result
+        assert result.data["workspaceLocationEntryOrError"]
+        assert (
+            result.data["workspaceLocationEntryOrError"]["__typename"] == "WorkspaceLocationEntry"
+        )
+        assert (
+            result.data["workspaceLocationEntryOrError"]["locationOrLoadError"]["__typename"]
+            == "RepositoryLocation"
+        )
+
+        result = execute_dagster_graphql(
+            graphql_context, LOCATION_ENTRY_QUERY, {"name": "does_not_exist"}
+        )
+        assert result
+        assert result.data["workspaceLocationEntryOrError"] is None
+
+        with mock.patch(
+            "dagster_graphql.schema.roots.query.fetch_location_entry",
+        ) as mock_fetch:
+            mock_fetch.side_effect = Exception("boom")
+
+            result = execute_dagster_graphql(
+                graphql_context, LOCATION_ENTRY_QUERY, {"name": "test"}
+            )
+            assert result
+            assert result.data["workspaceLocationEntryOrError"]
+            assert result.data["workspaceLocationEntryOrError"]["__typename"] == "PythonError"
+            assert "boom" in result.data["workspaceLocationEntryOrError"]["message"]