Resolve project fields and items to GraphQL node IDs

Extend ResolvedField with the GraphQL node ID alongside the existing
numeric databaseId, and extend the #2914 paginated issue-item resolver
to also return the item's node ID (resolveProjectItemByIssueNumber),
keeping resolveProjectItemIDByIssueNumber as a numeric-only wrapper for
existing callers. These node IDs are what the upcoming aliased
GraphQL mutations need as ItemID/FieldID inputs, in place of the
numeric IDs the REST API takes.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: d7dc302d-e6f2-41e9-a2c8-ed598de47067

Author: zwick

pkg/github/projects_resolver.go

@@ -20,10 +20,13 @@ type ResolvedFieldOption struct {
 	Name string
 }
 
-// ResolvedField is a project field resolved by name; Options is only set when
-// DataType == "SINGLE_SELECT".
+// ResolvedField is a project field resolved by name or numeric ID; Options is
+// only set when DataType == "SINGLE_SELECT". ID is the field's numeric
+// databaseId; NodeID is the GraphQL node ID required by aliased
+// updateProjectV2ItemFieldValue / clearProjectV2ItemFieldValue mutations.
 type ResolvedField struct {
 	ID       string
+	NodeID   string
 	Name     string
 	DataType string
 	Options  []ResolvedFieldOption
@@ -117,19 +120,22 @@ func listAllProjectFields(ctx context.Context, gqlClient *githubv4.Client, owner
 				}
 				all = append(all, ResolvedField{
 					ID:       fmt.Sprintf("%d", n.ProjectV2SingleSelectField.DatabaseID),
+					NodeID:   fmt.Sprintf("%v", n.ProjectV2SingleSelectField.ID),
 					Name:     string(n.ProjectV2SingleSelectField.Name),
 					DataType: string(n.ProjectV2SingleSelectField.DataType),
 					Options:  opts,
 				})
 			case n.ProjectV2IterationField.ID != nil:
 				all = append(all, ResolvedField{
 					ID:       fmt.Sprintf("%d", n.ProjectV2IterationField.DatabaseID),
+					NodeID:   fmt.Sprintf("%v", n.ProjectV2IterationField.ID),
 					Name:     string(n.ProjectV2IterationField.Name),
 					DataType: string(n.ProjectV2IterationField.DataType),
 				})
 			case n.ProjectV2Field.ID != nil:
 				all = append(all, ResolvedField{
 					ID:       fmt.Sprintf("%d", n.ProjectV2Field.DatabaseID),
+					NodeID:   fmt.Sprintf("%v", n.ProjectV2Field.ID),
 					Name:     string(n.ProjectV2Field.Name),
 					DataType: string(n.ProjectV2Field.DataType),
 				})
@@ -266,13 +272,23 @@ func resolveSingleSelectOptionByName(field *ResolvedField, optionName string) (s
 // project item's full database ID in one GraphQL hop. Returns a structured
 // error if the issue is not an item on the project.
 func resolveProjectItemIDByIssueNumber(ctx context.Context, gqlClient *githubv4.Client, owner, ownerType string, projectNumber int, issueOwner, issueRepo string, issueNumber int) (int64, error) {
+	_, itemID, err := resolveProjectItemByIssueNumber(ctx, gqlClient, owner, ownerType, projectNumber, issueOwner, issueRepo, issueNumber)
+	return itemID, err
+}
+
+// resolveProjectItemByIssueNumber resolves a (project, issue) pair to the
+// project item's GraphQL node ID and full database ID in one paginated
+// GraphQL traversal. Returns a structured error if the issue is not an item
+// on the project.
+func resolveProjectItemByIssueNumber(ctx context.Context, gqlClient *githubv4.Client, owner, ownerType string, projectNumber int, issueOwner, issueRepo string, issueNumber int) (nodeID string, itemID int64, err error) {
 	projectID, err := resolveProjectNodeID(ctx, gqlClient, owner, ownerType, projectNumber)
 	if err != nil {
-		return 0, err
+		return "", 0, err
 	}
 
 	type projectItemsConnection struct {
 		Nodes []struct {
+			ID             githubv4.ID
 			FullDatabaseID githubv4.String `graphql:"fullDatabaseId"`
 			Project        struct {
 				ID githubv4.ID
@@ -296,18 +312,18 @@ func resolveProjectItemIDByIssueNumber(ctx context.Context, gqlClient *githubv4.
 	}
 
 	if err := gqlClient.Query(ctx, &firstPageQuery, vars); err != nil {
-		return 0, fmt.Errorf("failed to resolve project item for %s/%s#%d: %w", issueOwner, issueRepo, issueNumber, err)
+		return "", 0, fmt.Errorf("failed to resolve project item for %s/%s#%d: %w", issueOwner, issueRepo, issueNumber, err)
 	}
 
 	projectItems := firstPageQuery.Repository.Issue.ProjectItems
 	for {
 		for _, item := range projectItems.Nodes {
 			if item.Project.ID == projectID {
-				itemID, parseErr := parseInt64(string(item.FullDatabaseID))
+				parsedItemID, parseErr := parseInt64(string(item.FullDatabaseID))
 				if parseErr != nil {
-					return 0, fmt.Errorf("project item ID %q is not an integer: %w", string(item.FullDatabaseID), parseErr)
+					return "", 0, fmt.Errorf("project item ID %q is not an integer: %w", string(item.FullDatabaseID), parseErr)
 				}
-				return itemID, nil
+				return fmt.Sprintf("%v", item.ID), parsedItemID, nil
 			}
 		}
 
@@ -324,12 +340,12 @@ func resolveProjectItemIDByIssueNumber(ctx context.Context, gqlClient *githubv4.
 		}
 		vars["after"] = projectItems.PageInfo.EndCursor
 		if err := gqlClient.Query(ctx, &nextPageQuery, vars); err != nil {
-			return 0, fmt.Errorf("failed to resolve project item for %s/%s#%d: %w", issueOwner, issueRepo, issueNumber, err)
+			return "", 0, fmt.Errorf("failed to resolve project item for %s/%s#%d: %w", issueOwner, issueRepo, issueNumber, err)
 		}
 		projectItems = nextPageQuery.Repository.Issue.ProjectItems
 	}
 
-	return 0, ghErrors.NewStructuredResolutionError(
+	return "", 0, ghErrors.NewStructuredResolutionError(
 		"item_not_in_project",
 		fmt.Sprintf("%s/%s#%d", issueOwner, issueRepo, issueNumber),
 		"the issue exists but is not an item on the named project; add it first via add_project_item",

pkg/github/projects_resolver_test.go

@@ -204,6 +204,7 @@ type resolveItemByIssueQuery struct {
 		Issue struct {
 			ProjectItems struct {
 				Nodes []struct {
+					ID             githubv4.ID
 					FullDatabaseID githubv4.String `graphql:"fullDatabaseId"`
 					Project        struct {
 						ID githubv4.ID
@@ -220,6 +221,7 @@ type resolveItemByIssuePageQuery struct {
 		Issue struct {
 			ProjectItems struct {
 				Nodes []struct {
+					ID             githubv4.ID
 					FullDatabaseID githubv4.String `graphql:"fullDatabaseId"`
 					Project        struct {
 						ID githubv4.ID