feat: poll for linked PR after assigning Copilot to issue

Enhances the assign_copilot_to_issue tool to automatically poll for
the PR created by the Copilot coding agent after assignment.

Changes:
- Add findLinkedCopilotPR() to query issue timeline for CrossReferencedEvent
  items from PRs authored by copilot-swe-agent
- Add polling loop (9 attempts, 1s delay) matching remote server latency
- Return structured JSON with PR details when found, or helpful note otherwise
- Add PollConfig for configurable polling (used in tests to disable)
- Add GraphQLFeaturesTransport for feature flag header support

The returned response now includes:
- issue_number, issue_url, owner, repo
- pull_request object (if found during polling)
- Note with instructions to use get_copilot_job_status if PR not yet created

Author: SamMorrowDrums

pkg/github/issues.go

@@ -1609,6 +1609,97 @@ func (d *mvpDescription) String() string {
 	return sb.String()
 }
 
+// linkedPullRequest represents a PR linked to an issue by Copilot.
+type linkedPullRequest struct {
+	Number int
+	URL    string
+	Title  string
+	State  string
+}
+
+// pollConfigKey is a context key for polling configuration.
+type pollConfigKey struct{}
+
+// PollConfig configures the PR polling behavior.
+type PollConfig struct {
+	MaxAttempts int
+	Delay       time.Duration
+}
+
+// ContextWithPollConfig returns a context with polling configuration.
+// Use this in tests to reduce or disable polling.
+func ContextWithPollConfig(ctx context.Context, config PollConfig) context.Context {
+	return context.WithValue(ctx, pollConfigKey{}, config)
+}
+
+// getPollConfig returns the polling configuration from context, or defaults.
+func getPollConfig(ctx context.Context) PollConfig {
+	if config, ok := ctx.Value(pollConfigKey{}).(PollConfig); ok {
+		return config
+	}
+	// Default: 9 attempts with 1s delay = 8s max wait
+	// Based on observed latency in remote server: p50 ~5s, p90 ~7s
+	return PollConfig{MaxAttempts: 9, Delay: 1 * time.Second}
+}
+
+// findLinkedCopilotPR searches for a PR created by the copilot-swe-agent bot that references the given issue.
+// It queries the issue's timeline for CrossReferencedEvent items from PRs authored by copilot-swe-agent.
+func findLinkedCopilotPR(ctx context.Context, client *githubv4.Client, owner, repo string, issueNumber int) (*linkedPullRequest, error) {
+	// Query timeline items looking for CrossReferencedEvent from PRs by copilot-swe-agent
+	var query struct {
+		Repository struct {
+			Issue struct {
+				TimelineItems struct {
+					Nodes []struct {
+						TypeName             string `graphql:"__typename"`
+						CrossReferencedEvent struct {
+							Source struct {
+								PullRequest struct {
+									Number int
+									URL    string
+									Title  string
+									State  string
+									Author struct {
+										Login string
+									}
+								} `graphql:"... on PullRequest"`
+							}
+						} `graphql:"... on CrossReferencedEvent"`
+					}
+				} `graphql:"timelineItems(first: 20, itemTypes: [CROSS_REFERENCED_EVENT])"`
+			} `graphql:"issue(number: $number)"`
+		} `graphql:"repository(owner: $owner, name: $name)"`
+	}
+
+	variables := map[string]any{
+		"owner":  githubv4.String(owner),
+		"name":   githubv4.String(repo),
+		"number": githubv4.Int(issueNumber), //nolint:gosec // Issue numbers are always small positive integers
+	}
+
+	if err := client.Query(ctx, &query, variables); err != nil {
+		return nil, err
+	}
+
+	// Look for a PR from copilot-swe-agent
+	for _, node := range query.Repository.Issue.TimelineItems.Nodes {
+		if node.TypeName != "CrossReferencedEvent" {
+			continue
+		}
+		pr := node.CrossReferencedEvent.Source.PullRequest
+		if pr.Number > 0 && pr.Author.Login == "copilot-swe-agent" {
+			return &linkedPullRequest{
+				Number: pr.Number,
+				URL:    pr.URL,
+				Title:  pr.Title,
+				State:  pr.State,
+			}, nil
+		}
+	}
+
+	return nil, nil
+}
+
 func AssignCopilotToIssue(t translations.TranslationHelperFunc) inventory.ServerTool {
 	description := mvpDescription{
 		summary: "Assign Copilot to a specific issue in a GitHub repository.",
@@ -1815,7 +1906,55 @@ func AssignCopilotToIssue(t translations.TranslationHelperFunc) inventory.Server
 				return nil, nil, fmt.Errorf("failed to update issue with agent assignment: %w", err)
 			}
 
-			return utils.NewToolResultText("successfully assigned copilot to issue"), nil, nil
+			// Poll for a linked PR created by Copilot
+			pollConfig := getPollConfig(ctx)
+
+			var linkedPR *linkedPullRequest
+			for attempt := range pollConfig.MaxAttempts {
+				if attempt > 0 {
+					time.Sleep(pollConfig.Delay)
+				}
+
+				pr, err := findLinkedCopilotPR(ctx, client, params.Owner, params.Repo, int(params.IssueNumber))
+				if err != nil {
+					// Log but don't fail - polling errors are non-fatal
+					continue
+				}
+				if pr != nil {
+					linkedPR = pr
+					break
+				}
+			}
+
+			// Build the result
+			result := map[string]any{
+				"message":      "successfully assigned copilot to issue",
+				"issue_number": updateIssueMutation.UpdateIssue.Issue.Number,
+				"issue_url":    updateIssueMutation.UpdateIssue.Issue.URL,
+				"owner":        params.Owner,
+				"repo":         params.Repo,
+			}
+
+			// Add PR info if found during polling
+			if linkedPR != nil {
+				result["pull_request"] = map[string]any{
+					"number": linkedPR.Number,
+					"url":    linkedPR.URL,
+					"title":  linkedPR.Title,
+					"state":  linkedPR.State,
+				}
+				result["message"] = "successfully assigned copilot to issue - pull request created"
+			} else {
+				result["message"] = "successfully assigned copilot to issue - pull request pending"
+				result["note"] = "The pull request may still be in progress. Use get_copilot_job_status with the pull request number once created, or check the issue timeline for updates."
+			}
+
+			r, err := json.Marshal(result)
+			if err != nil {
+				return utils.NewToolResultError(fmt.Sprintf("failed to marshal response: %s", err)), nil, nil
+			}
+
+			return utils.NewToolResultText(string(r)), result, nil
 		})
 }
 

pkg/github/issues_test.go

@@ -2765,8 +2765,12 @@ func TestAssignCopilotToIssue(t *testing.T) {
 			// Create call request
 			request := createMCPRequest(tc.requestArgs)
 
+			// Disable polling in tests to avoid timeouts
+			ctx := ContextWithPollConfig(context.Background(), PollConfig{MaxAttempts: 0})
+			ctx = ContextWithDeps(ctx, deps)
+
 			// Call handler
-			result, err := handler(ContextWithDeps(context.Background(), deps), &request)
+			result, err := handler(ctx, &request)
 			require.NoError(t, err)
 
 			textContent := getTextResult(t, result)
@@ -2778,7 +2782,16 @@ func TestAssignCopilotToIssue(t *testing.T) {
 			}
 
 			require.False(t, result.IsError, fmt.Sprintf("expected there to be no tool error, text was %s", textContent.Text))
-			require.Equal(t, textContent.Text, "successfully assigned copilot to issue")
+
+			// Verify the JSON response contains expected fields
+			var response map[string]any
+			err = json.Unmarshal([]byte(textContent.Text), &response)
+			require.NoError(t, err, "response should be valid JSON")
+			assert.Equal(t, float64(123), response["issue_number"])
+			assert.Equal(t, "https://github.com/owner/repo/issues/123", response["issue_url"])
+			assert.Equal(t, "owner", response["owner"])
+			assert.Equal(t, "repo", response["repo"])
+			assert.Contains(t, response["message"], "successfully assigned copilot to issue")
 		})
 	}
 }

pkg/github/transport.go

@@ -0,0 +1,43 @@
+package github
+
+import (
+	"net/http"
+	"strings"
+)
+
+// GraphQLFeaturesTransport is an http.RoundTripper that adds GraphQL-Features
+// header to requests based on context values. This is required for using
+// non-GA GraphQL API features like the agent assignment API.
+//
+// Usage:
+//
+//	httpClient := &http.Client{
+//	    Transport: &github.GraphQLFeaturesTransport{
+//	        Transport: http.DefaultTransport,
+//	    },
+//	}
+//	gqlClient := githubv4.NewClient(httpClient)
+//
+// Then use withGraphQLFeatures(ctx, "feature_name") when calling GraphQL operations.
+type GraphQLFeaturesTransport struct {
+	// Transport is the underlying HTTP transport. If nil, http.DefaultTransport is used.
+	Transport http.RoundTripper
+}
+
+// RoundTrip implements http.RoundTripper.
+func (t *GraphQLFeaturesTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	transport := t.Transport
+	if transport == nil {
+		transport = http.DefaultTransport
+	}
+
+	// Clone the request to avoid mutating the original
+	req = req.Clone(req.Context())
+
+	// Check for GraphQL-Features in context and add header if present
+	if features := GetGraphQLFeatures(req.Context()); len(features) > 0 {
+		req.Header.Set("GraphQL-Features", strings.Join(features, ", "))
+	}
+
+	return transport.RoundTrip(req)
+}

pkg/github/transport_test.go

@@ -0,0 +1,151 @@
+package github
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGraphQLFeaturesTransport(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name           string
+		features       []string
+		expectedHeader string
+		hasHeader      bool
+	}{
+		{
+			name:           "no features in context",
+			features:       nil,
+			expectedHeader: "",
+			hasHeader:      false,
+		},
+		{
+			name:           "single feature in context",
+			features:       []string{"issues_copilot_assignment_api_support"},
+			expectedHeader: "issues_copilot_assignment_api_support",
+			hasHeader:      true,
+		},
+		{
+			name:           "multiple features in context",
+			features:       []string{"feature1", "feature2", "feature3"},
+			expectedHeader: "feature1, feature2, feature3",
+			hasHeader:      true,
+		},
+		{
+			name:           "empty features slice",
+			features:       []string{},
+			expectedHeader: "",
+			hasHeader:      false,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			var capturedHeader string
+			var headerExists bool
+
+			// Create a test server that captures the request header
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				capturedHeader = r.Header.Get("GraphQL-Features")
+				headerExists = r.Header.Get("GraphQL-Features") != ""
+				w.WriteHeader(http.StatusOK)
+			}))
+			defer server.Close()
+
+			// Create the transport
+			transport := &GraphQLFeaturesTransport{
+				Transport: http.DefaultTransport,
+			}
+
+			// Create a request
+			ctx := context.Background()
+			if tc.features != nil {
+				ctx = withGraphQLFeatures(ctx, tc.features...)
+			}
+
+			req, err := http.NewRequestWithContext(ctx, http.MethodPost, server.URL, nil)
+			require.NoError(t, err)
+
+			// Execute the request
+			resp, err := transport.RoundTrip(req)
+			require.NoError(t, err)
+			defer resp.Body.Close()
+
+			// Verify the header
+			assert.Equal(t, tc.hasHeader, headerExists)
+			if tc.hasHeader {
+				assert.Equal(t, tc.expectedHeader, capturedHeader)
+			}
+		})
+	}
+}
+
+func TestGraphQLFeaturesTransport_NilTransport(t *testing.T) {
+	t.Parallel()
+
+	var capturedHeader string
+
+	// Create a test server
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		capturedHeader = r.Header.Get("GraphQL-Features")
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer server.Close()
+
+	// Create the transport with nil Transport (should use DefaultTransport)
+	transport := &GraphQLFeaturesTransport{
+		Transport: nil,
+	}
+
+	// Create a request with features
+	ctx := withGraphQLFeatures(context.Background(), "test_feature")
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, server.URL, nil)
+	require.NoError(t, err)
+
+	// Execute the request
+	resp, err := transport.RoundTrip(req)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+
+	// Verify the header was added
+	assert.Equal(t, "test_feature", capturedHeader)
+}
+
+func TestGraphQLFeaturesTransport_DoesNotMutateOriginalRequest(t *testing.T) {
+	t.Parallel()
+
+	// Create a test server
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer server.Close()
+
+	// Create the transport
+	transport := &GraphQLFeaturesTransport{
+		Transport: http.DefaultTransport,
+	}
+
+	// Create a request with features
+	ctx := withGraphQLFeatures(context.Background(), "test_feature")
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, server.URL, nil)
+	require.NoError(t, err)
+
+	// Store the original header value
+	originalHeader := req.Header.Get("GraphQL-Features")
+
+	// Execute the request
+	resp, err := transport.RoundTrip(req)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+
+	// Verify the original request was not mutated
+	assert.Equal(t, originalHeader, req.Header.Get("GraphQL-Features"))
+}