Add specifying state change reason to update_issue tool

README.md

@@ -591,12 +591,14 @@ The following sets of tools are available (all are on by default):
 - **update_issue** - Edit issue
   - `assignees`: New assignees (string[], optional)
   - `body`: New description (string, optional)
+  - `duplicate_of`: Issue number that this issue is a duplicate of. Only used when state_reason is 'duplicate'. (number, optional)
   - `issue_number`: Issue number to update (number, required)
   - `labels`: New labels (string[], optional)
   - `milestone`: New milestone number (number, optional)
   - `owner`: Repository owner (string, required)
   - `repo`: Repository name (string, required)
   - `state`: New state (string, optional)
+  - `state_reason`: Reason for the state change. Ignored unless state is changed. (string, optional)
   - `title`: New title (string, optional)
   - `type`: New issue type (string, optional)
 

pkg/github/__toolsnaps__/update_issue.snap

@@ -17,6 +17,10 @@
         "description": "New description",
         "type": "string"
       },
+      "duplicate_of": {
+        "description": "Issue number that this issue is a duplicate of. Only used when state_reason is 'duplicate'.",
+        "type": "number"
+      },
       "issue_number": {
         "description": "Issue number to update",
         "type": "number"
@@ -48,6 +52,16 @@
         ],
         "type": "string"
       },
+      "state_reason": {
+        "description": "Reason for the state change. Ignored unless state is changed.",
+        "enum": [
+          "completed",
+          "not_planned",
+          "duplicate",
+          "reopened"
+        ],
+        "type": "string"
+      },
       "title": {
         "description": "New title",
         "type": "string"

pkg/github/issues.go

@@ -18,6 +18,25 @@ import (
 	"github.com/shurcooL/githubv4"
 )
 
+// CloseIssueInput represents the input for closing an issue via the GraphQL API.
+// Used to extend the functionality of the githubv4 library to support closing issues as duplicates.
+type CloseIssueInput struct {
+	IssueID          githubv4.ID             `json:"issueId"`
+	ClientMutationID *githubv4.String        `json:"clientMutationId,omitempty"`
+	StateReason      *IssueClosedStateReason `json:"stateReason,omitempty"`
+	DuplicateIssueID *githubv4.ID            `json:"duplicateIssueId,omitempty"`
+}
+
+// IssueClosedStateReason represents the reason an issue was closed.
+// Used to extend the functionality of the githubv4 library to support closing issues as duplicates.
+type IssueClosedStateReason string
+
+const (
+	IssueClosedStateReasonCompleted  IssueClosedStateReason = "COMPLETED"
+	IssueClosedStateReasonDuplicate  IssueClosedStateReason = "DUPLICATE"
+	IssueClosedStateReasonNotPlanned IssueClosedStateReason = "NOT_PLANNED"
+)
+
 // IssueFragment represents a fragment of an issue node in the GraphQL API.
 type IssueFragment struct {
 	Number     githubv4.Int
@@ -1099,7 +1118,7 @@ func ListIssues(getGQLClient GetGQLClientFn, t translations.TranslationHelperFun
 }
 
 // UpdateIssue creates a tool to update an existing issue in a GitHub repository.
-func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (tool mcp.Tool, handler server.ToolHandlerFunc) {
+func UpdateIssue(getClient GetClientFn, getGQLClient GetGQLClientFn, t translations.TranslationHelperFunc) (tool mcp.Tool, handler server.ToolHandlerFunc) {
 	return mcp.NewTool("update_issue",
 			mcp.WithDescription(t("TOOL_UPDATE_ISSUE_DESCRIPTION", "Update an existing issue in a GitHub repository.")),
 			mcp.WithToolAnnotation(mcp.ToolAnnotation{
@@ -1128,6 +1147,13 @@ func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (t
 				mcp.Description("New state"),
 				mcp.Enum("open", "closed"),
 			),
+			mcp.WithString("state_reason",
+				mcp.Description("Reason for the state change. Ignored unless state is changed."),
+				mcp.Enum("completed", "not_planned", "duplicate", "reopened"),
+			),
+			mcp.WithNumber("duplicate_of",
+				mcp.Description("Issue number that this issue is a duplicate of. Only used when state_reason is 'duplicate'."),
+			),
 			mcp.WithArray("labels",
 				mcp.Description("New labels"),
 				mcp.Items(
@@ -1167,6 +1193,8 @@ func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (t
 
 			// Create the issue request with only provided fields
 			issueRequest := &github.IssueRequest{}
+			restUpdateNeeded := false
+			gqlUpdateNeeded := false
 
 			// Set optional parameters if provided
 			title, err := OptionalParam[string](request, "title")
@@ -1175,6 +1203,7 @@ func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (t
 			}
 			if title != "" {
 				issueRequest.Title = github.Ptr(title)
+				restUpdateNeeded = true
 			}
 
 			body, err := OptionalParam[string](request, "body")
@@ -1183,14 +1212,45 @@ func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (t
 			}
 			if body != "" {
 				issueRequest.Body = github.Ptr(body)
+				restUpdateNeeded = true
 			}
 
+			// Handle state and state_reason parameters
 			state, err := OptionalParam[string](request, "state")
 			if err != nil {
 				return mcp.NewToolResultError(err.Error()), nil
 			}
-			if state != "" {
+
+			stateReason, err := OptionalParam[string](request, "state_reason")
+			if err != nil {
+				return mcp.NewToolResultError(err.Error()), nil
+			}
+
+			// Validate state_reason usage
+			if stateReason != "" && state == "" {
+				return mcp.NewToolResultError("state_reason can only be used when state is also provided"), nil
+			}
+			if state == "open" && stateReason != "" && stateReason != "reopened" {
+				return mcp.NewToolResultError("when state is 'open', state_reason can only be 'reopened'"), nil
+			}
+			if state == "closed" && stateReason != "" && stateReason != "completed" && stateReason != "not_planned" && stateReason != "duplicate" {
+				return mcp.NewToolResultError("when state is 'closed', state_reason can only be 'completed', 'not_planned', or 'duplicate'"), nil
+			}
+
+			// Use GraphQL for duplicate closure, REST for everything else
+			if state == "closed" && stateReason == "duplicate" {
+				gqlUpdateNeeded = true
+			} else if state != "" {
 				issueRequest.State = github.Ptr(state)
+				if stateReason != "" {
+					issueRequest.StateReason = github.Ptr(stateReason)
+				}
+				restUpdateNeeded = true
+			}
+
+			duplicateOf, err := OptionalIntParam(request, "duplicate_of")
+			if err != nil {
+				return mcp.NewToolResultError(err.Error()), nil
 			}
 
 			// Get labels
@@ -1200,6 +1260,7 @@ func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (t
 			}
 			if len(labels) > 0 {
 				issueRequest.Labels = &labels
+				restUpdateNeeded = true
 			}
 
 			// Get assignees
@@ -1209,6 +1270,7 @@ func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (t
 			}
 			if len(assignees) > 0 {
 				issueRequest.Assignees = &assignees
+				restUpdateNeeded = true
 			}
 
 			milestone, err := OptionalIntParam(request, "milestone")
@@ -1218,6 +1280,7 @@ func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (t
 			if milestone != 0 {
 				milestoneNum := milestone
 				issueRequest.Milestone = &milestoneNum
+				restUpdateNeeded = true
 			}
 
 			// Get issue type
@@ -1227,34 +1290,117 @@ func UpdateIssue(getClient GetClientFn, t translations.TranslationHelperFunc) (t
 			}
 			if issueType != "" {
 				issueRequest.Type = github.Ptr(issueType)
+				restUpdateNeeded = true
 			}
 
-			client, err := getClient(ctx)
-			if err != nil {
-				return nil, fmt.Errorf("failed to get GitHub client: %w", err)
+			if !restUpdateNeeded && !gqlUpdateNeeded {
+				return mcp.NewToolResultError("No update parameters provided."), nil
 			}
-			updatedIssue, resp, err := client.Issues.Edit(ctx, owner, repo, issueNumber, issueRequest)
-			if err != nil {
-				return nil, fmt.Errorf("failed to update issue: %w", err)
+
+			// Handle REST API updates (title, body, state, labels, assignees, milestone, type, state_reason except "duplicate")
+			if restUpdateNeeded {
+				client, err := getClient(ctx)
+				if err != nil {
+					return nil, fmt.Errorf("failed to get GitHub client: %w", err)
+				}
+
+				_, resp, err := client.Issues.Edit(ctx, owner, repo, issueNumber, issueRequest)
+				if err != nil {
+					return ghErrors.NewGitHubAPIErrorResponse(ctx,
+						"failed to update issue",
+						resp,
+						err,
+					), nil
+				}
+				defer func() { _ = resp.Body.Close() }()
+
+				if resp.StatusCode != http.StatusOK {
+					body, err := io.ReadAll(resp.Body)
+					if err != nil {
+						return nil, fmt.Errorf("failed to read response body: %w", err)
+					}
+					return mcp.NewToolResultError(fmt.Sprintf("failed to update issue: %s", string(body))), nil
+				}
 			}
-			defer func() { _ = resp.Body.Close() }()
 
-			if resp.StatusCode != http.StatusOK {
-				body, err := io.ReadAll(resp.Body)
+			// Handle GraphQL API updates (state_reason = "duplicate")
+			if gqlUpdateNeeded {
+				if duplicateOf == 0 {
+					return mcp.NewToolResultError("duplicate_of must be provided when state_reason is 'duplicate'"), nil
+				}
+
+				gqlClient, err := getGQLClient(ctx)
 				if err != nil {
-					return nil, fmt.Errorf("failed to read response body: %w", err)
+					return nil, fmt.Errorf("failed to get GraphQL client: %w", err)
+				}
+
+				var issueQuery struct {
+					Repository struct {
+						Issue struct {
+							ID githubv4.ID
+						} `graphql:"issue(number: $issueNumber)"`
+						DuplicateIssue struct {
+							ID githubv4.ID
+						} `graphql:"duplicateIssue: issue(number: $duplicateNumber)"`
+					} `graphql:"repository(owner: $owner, name: $repo)"`
+				}
+
+				err = gqlClient.Query(ctx, &issueQuery, map[string]interface{}{
+					"owner":           githubv4.String(owner),
+					"repo":            githubv4.String(repo),
+					"issueNumber":     githubv4.Int(issueNumber), // #nosec G115 - issue numbers are always small positive integers
+					"duplicateNumber": githubv4.Int(duplicateOf), // #nosec G115 - issue numbers are always small positive integers
+				})
+				if err != nil {
+					return ghErrors.NewGitHubGraphQLErrorResponse(ctx, "Failed to find issues", err), nil
+				}
+
+				var mutation struct {
+					CloseIssue struct {
+						Issue struct {
+							ID     githubv4.ID
+							Number githubv4.Int
+							URL    githubv4.String
+							State  githubv4.String
+						}
+					} `graphql:"closeIssue(input: $input)"`
+				}
+
+				duplicateStateReason := IssueClosedStateReasonDuplicate
+				err = gqlClient.Mutate(ctx, &mutation, CloseIssueInput{
+					IssueID:          issueQuery.Repository.Issue.ID,
+					StateReason:      &duplicateStateReason,
+					DuplicateIssueID: &issueQuery.Repository.DuplicateIssue.ID,
+				}, nil)
+				if err != nil {
+					return ghErrors.NewGitHubGraphQLErrorResponse(ctx, "Failed to close issue as duplicate", err), nil
 				}
-				return mcp.NewToolResultError(fmt.Sprintf("failed to update issue: %s", string(body))), nil
 			}
 
+			// Get the final state of the issue to return
+			client, err := getClient(ctx)
+			if err != nil {
+				return nil, err
+			}
+
+			finalIssue, resp, err := client.Issues.Get(ctx, owner, repo, issueNumber)
+			if err != nil {
+				return ghErrors.NewGitHubAPIErrorResponse(ctx, "Failed to get issue", resp, err), nil
+			}
+			defer func() {
+				if resp != nil && resp.Body != nil {
+					_ = resp.Body.Close()
+				}
+			}()
+
 			// Return minimal response with just essential information
 			minimalResponse := MinimalResponse{
-				URL: updatedIssue.GetHTMLURL(),
+				URL: finalIssue.GetHTMLURL(),
 			}
 
 			r, err := json.Marshal(minimalResponse)
 			if err != nil {
-				return nil, fmt.Errorf("failed to marshal response: %w", err)
+				return mcp.NewToolResultError(fmt.Sprintf("Failed to marshal response: %v", err)), nil
 			}
 
 			return mcp.NewToolResultText(string(r)), nil