feat(issues): add batch_update_issue_labels granular tool

pkg/github/__toolsnaps__/batch_update_issue_labels.snap

@@ -0,0 +1,64 @@
+{
+  "annotations": {
+    "destructiveHint": false,
+    "idempotentHint": false,
+    "openWorldHint": true,
+    "readOnlyHint": false,
+    "title": "Batch Update Issue Labels"
+  },
+  "description": "Apply label changes to multiple issues in one call. Each entry in operations targets one issue and can add labels, remove labels, or both. Labels not named in the operation are left untouched. Invalid input fails the whole call before any change is applied; per-issue API errors are reported individually.",
+  "inputSchema": {
+    "properties": {
+      "operations": {
+        "description": "One entry per issue, in any order. Each entry requires issue_number plus at least one non-empty of add or remove (arrays of label names). Duplicate issue numbers are rejected.",
+        "items": {
+          "additionalProperties": false,
+          "properties": {
+            "add": {
+              "description": "Label names to add to this issue (GitHub creates missing labels implicitly)",
+              "items": {
+                "minLength": 1,
+                "type": "string"
+              },
+              "type": "array"
+            },
+            "issue_number": {
+              "description": "The issue number to update",
+              "minimum": 1,
+              "type": "number"
+            },
+            "remove": {
+              "description": "Label names to remove from this issue",
+              "items": {
+                "minLength": 1,
+                "type": "string"
+              },
+              "type": "array"
+            }
+          },
+          "required": [
+            "issue_number"
+          ],
+          "type": "object"
+        },
+        "minItems": 1,
+        "type": "array"
+      },
+      "owner": {
+        "description": "Repository owner (username or organization)",
+        "type": "string"
+      },
+      "repo": {
+        "description": "Repository name",
+        "type": "string"
+      }
+    },
+    "required": [
+      "owner",
+      "repo",
+      "operations"
+    ],
+    "type": "object"
+  },
+  "name": "batch_update_issue_labels"
+}

pkg/github/batch_labels_granular_test.go

@@ -0,0 +1,156 @@
+package github
+
+import (
+	"context"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/github/github-mcp-server/pkg/translations"
+	gogithub "github.com/google/go-github/v89/github"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGranularBatchUpdateIssueLabels(t *testing.T) {
+	tests := []struct {
+		name           string
+		mockedClient   *http.Client
+		requestArgs    map[string]any
+		expectToolErr  bool
+		expectedErrMsg string
+	}{
+		{
+			name: "add and remove across multiple issues",
+			mockedClient: MockHTTPClientWithHandlers(map[string]http.HandlerFunc{
+				PostReposIssuesByOwnerByRepoByIssueNumberLabels: expectRequestBody(t, []any{"bug", "priority/high"}).
+					andThen(mockResponse(t, http.StatusOK, []*gogithub.Label{
+						{Name: "bug"},
+						{Name: "priority/high"},
+					})),
+				DeleteReposIssuesByOwnerByRepoByIssueNumberLabel: mockResponse(t, http.StatusNoContent, nil),
+			}),
+			requestArgs: map[string]any{
+				"owner": "owner",
+				"repo":  "repo",
+				"operations": []any{
+					map[string]any{
+						"issue_number": float64(1),
+						"add":          []any{"bug", "priority/high"},
+					},
+					map[string]any{
+						"issue_number": float64(2),
+						"remove":       []any{"wontfix"},
+					},
+				},
+			},
+			expectToolErr: false,
+		},
+		{
+			name:         "empty operations array rejected",
+			mockedClient: MockHTTPClientWithHandlers(nil),
+			requestArgs: map[string]any{
+				"owner":      "owner",
+				"repo":       "repo",
+				"operations": []any{},
+			},
+			expectToolErr:  true,
+			expectedErrMsg: "operations must contain at least one entry",
+		},
+		{
+			name:         "missing operations parameter rejected",
+			mockedClient: MockHTTPClientWithHandlers(nil),
+			requestArgs: map[string]any{
+				"owner": "owner",
+				"repo":  "repo",
+			},
+			expectToolErr:  true,
+			expectedErrMsg: "missing required parameter: operations",
+		},
+		{
+			name:         "operation without add or remove rejected",
+			mockedClient: MockHTTPClientWithHandlers(nil),
+			requestArgs: map[string]any{
+				"owner": "owner",
+				"repo":  "repo",
+				"operations": []any{
+					map[string]any{"issue_number": float64(1)},
+				},
+			},
+			expectToolErr:  true,
+			expectedErrMsg: "at least one non-empty of add or remove is required",
+		},
+		{
+			name:         "duplicate issue numbers rejected",
+			mockedClient: MockHTTPClientWithHandlers(nil),
+			requestArgs: map[string]any{
+				"owner": "owner",
+				"repo":  "repo",
+				"operations": []any{
+					map[string]any{"issue_number": float64(1), "add": []any{"bug"}},
+					map[string]any{"issue_number": float64(1), "remove": []any{"wontfix"}},
+				},
+			},
+			expectToolErr:  true,
+			expectedErrMsg: "duplicate issue_number 1",
+		},
+		{
+			name:         "empty label name in add rejected",
+			mockedClient: MockHTTPClientWithHandlers(nil),
+			requestArgs: map[string]any{
+				"owner": "owner",
+				"repo":  "repo",
+				"operations": []any{
+					map[string]any{"issue_number": float64(1), "add": []any{""}},
+				},
+			},
+			expectToolErr:  true,
+			expectedErrMsg: "add contains an empty label name",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			deps := BaseDeps{Client: mustNewGHClient(t, tc.mockedClient)}
+			serverTool := GranularBatchUpdateIssueLabels(translations.NullTranslationHelper)
+			handler := serverTool.Handler(deps)
+
+			request := createMCPRequest(tc.requestArgs)
+			result, err := handler(ContextWithDeps(context.Background(), deps), &request)
+			require.NoError(t, err)
+			if tc.expectToolErr {
+				errorContent := getErrorResult(t, result)
+				assert.Contains(t, errorContent.Text, tc.expectedErrMsg)
+				return
+			}
+			assert.False(t, result.IsError)
+			textContent := getTextResult(t, result)
+			assert.Contains(t, textContent.Text, `"issue_number":1`)
+			assert.Contains(t, textContent.Text, `"applied":true`)
+		})
+	}
+}
+
+func TestGranularBatchUpdateIssueLabelsPartialFailure(t *testing.T) {
+	client := mustNewGHClient(t, MockHTTPClientWithHandlers(map[string]http.HandlerFunc{
+		PostReposIssuesByOwnerByRepoByIssueNumberLabels: func(_ http.ResponseWriter, _ *http.Request) {},
+	}))
+	deps := BaseDeps{Client: client}
+	serverTool := GranularBatchUpdateIssueLabels(translations.NullTranslationHelper)
+	handler := serverTool.Handler(deps)
+
+	request := createMCPRequest(map[string]any{
+		"owner": "owner",
+		"repo":  "repo",
+		"operations": []any{
+			map[string]any{"issue_number": float64(1), "add": []any{"bug"}},
+		},
+	})
+	result, err := handler(ContextWithDeps(context.Background(), deps), &request)
+	require.NoError(t, err)
+	// A per-issue API failure must surface as a tool error with a JSON body
+	// identifying the failing issue.
+	assert.True(t, result.IsError, "expected IsError on API failure")
+	textContent := getTextResult(t, result)
+	assert.True(t, strings.Contains(textContent.Text, "add failed"))
+}

pkg/github/granular_tools_test.go

@@ -38,6 +38,7 @@ func TestGranularToolSnaps(t *testing.T) {
 		GranularUpdateIssueBody,
 		GranularUpdateIssueAssignees,
 		GranularUpdateIssueLabels,
+		GranularBatchUpdateIssueLabels,
 		GranularUpdateIssueMilestone,
 		GranularUpdateIssueType,
 		GranularUpdateIssueState,
@@ -84,6 +85,7 @@ func TestIssuesGranularToolset(t *testing.T) {
 			"update_issue_body",
 			"update_issue_assignees",
 			"update_issue_labels",
+			"batch_update_issue_labels",
 			"update_issue_milestone",
 			"update_issue_type",
 			"update_issue_state",

pkg/github/helper_test.go

@@ -64,6 +64,8 @@ const (
 	GetReposIssuesCommentsByOwnerByRepoByIssueNumber            = "GET /repos/{owner}/{repo}/issues/{issue_number}/comments"
 	PostReposIssuesByOwnerByRepo                                = "POST /repos/{owner}/{repo}/issues"
 	PostReposIssuesCommentsByOwnerByRepoByIssueNumber           = "POST /repos/{owner}/{repo}/issues/{issue_number}/comments"
+	PostReposIssuesByOwnerByRepoByIssueNumberLabels             = "POST /repos/{owner}/{repo}/issues/{issue_number}/labels"
+	DeleteReposIssuesByOwnerByRepoByIssueNumberLabel            = "DELETE /repos/{owner}/{repo}/issues/{issue_number}/labels/{name}"
 	PostReposIssuesReactionsByOwnerByRepoByIssueNumber          = "POST /repos/{owner}/{repo}/issues/{issue_number}/reactions"
 	PatchReposIssuesByOwnerByRepoByIssueNumber                  = "PATCH /repos/{owner}/{repo}/issues/{issue_number}"
 	GetReposIssuesSubIssuesByOwnerByRepoByIssueNumber           = "GET /repos/{owner}/{repo}/issues/{issue_number}/sub_issues"