Enhance search functionality with new query filters and utility functions

- Added multiple test cases for searching issues with various query filters in `issues_test.go`.
- Introduced utility functions in `search_utils.go` to check for specific filters and extract repository information from queries.
- Created comprehensive tests in `search_utils_test.go` to validate the new filtering logic and ensure accurate query parsing.

Author: gokhanarkan

pkg/github/issues_test.go

@@ -410,6 +410,100 @@ func Test_SearchIssues(t *testing.T) {
 			expectError:    false,
 			expectedResult: mockSearchResult,
 		},
+		{
+			name: "query with existing is:issue filter - no duplication",
+			mockedClient: mock.NewMockedHTTPClient(
+				mock.WithRequestMatchHandler(
+					mock.GetSearchIssues,
+					expectQueryParams(
+						t,
+						map[string]string{
+							"q":        "repo:github/github-mcp-server is:issue is:open (label:critical OR label:urgent)",
+							"page":     "1",
+							"per_page": "30",
+						},
+					).andThen(
+						mockResponse(t, http.StatusOK, mockSearchResult),
+					),
+				),
+			),
+			requestArgs: map[string]interface{}{
+				"query": "repo:github/github-mcp-server is:issue is:open (label:critical OR label:urgent)",
+			},
+			expectError:    false,
+			expectedResult: mockSearchResult,
+		},
+		{
+			name: "query with existing repo: filter and conflicting owner/repo params - uses query filter",
+			mockedClient: mock.NewMockedHTTPClient(
+				mock.WithRequestMatchHandler(
+					mock.GetSearchIssues,
+					expectQueryParams(
+						t,
+						map[string]string{
+							"q":        "is:issue repo:github/github-mcp-server critical",
+							"page":     "1",
+							"per_page": "30",
+						},
+					).andThen(
+						mockResponse(t, http.StatusOK, mockSearchResult),
+					),
+				),
+			),
+			requestArgs: map[string]interface{}{
+				"query": "repo:github/github-mcp-server critical",
+				"owner": "different-owner",
+				"repo":  "different-repo",
+			},
+			expectError:    false,
+			expectedResult: mockSearchResult,
+		},
+		{
+			name: "query with both is: and repo: filters already present",
+			mockedClient: mock.NewMockedHTTPClient(
+				mock.WithRequestMatchHandler(
+					mock.GetSearchIssues,
+					expectQueryParams(
+						t,
+						map[string]string{
+							"q":        "is:issue repo:octocat/Hello-World bug",
+							"page":     "1",
+							"per_page": "30",
+						},
+					).andThen(
+						mockResponse(t, http.StatusOK, mockSearchResult),
+					),
+				),
+			),
+			requestArgs: map[string]interface{}{
+				"query": "is:issue repo:octocat/Hello-World bug",
+			},
+			expectError:    false,
+			expectedResult: mockSearchResult,
+		},
+		{
+			name: "complex query with multiple OR operators and existing filters",
+			mockedClient: mock.NewMockedHTTPClient(
+				mock.WithRequestMatchHandler(
+					mock.GetSearchIssues,
+					expectQueryParams(
+						t,
+						map[string]string{
+							"q":        "repo:github/github-mcp-server is:issue (label:critical OR label:urgent OR label:high-priority OR label:blocker)",
+							"page":     "1",
+							"per_page": "30",
+						},
+					).andThen(
+						mockResponse(t, http.StatusOK, mockSearchResult),
+					),
+				),
+			),
+			requestArgs: map[string]interface{}{
+				"query": "repo:github/github-mcp-server is:issue (label:critical OR label:urgent OR label:high-priority OR label:blocker)",
+			},
+			expectError:    false,
+			expectedResult: mockSearchResult,
+		},
 		{
 			name: "search issues fails",
 			mockedClient: mock.NewMockedHTTPClient(

pkg/github/search_utils.go

@@ -6,11 +6,35 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"regexp"
 
 	"github.com/google/go-github/v73/github"
 	"github.com/mark3labs/mcp-go/mcp"
 )
 
+func hasFilter(query, filterType string) bool {
+	pattern := fmt.Sprintf(`(^|\s)%s:\S+`, regexp.QuoteMeta(filterType))
+	matched, _ := regexp.MatchString(pattern, query)
+	return matched
+}
+
+func hasSpecificFilter(query, filterType, filterValue string) bool {
+	pattern := fmt.Sprintf(`(^|\s)%s:%s($|\s)`, regexp.QuoteMeta(filterType), regexp.QuoteMeta(filterValue))
+	matched, _ := regexp.MatchString(pattern, query)
+	return matched
+}
+
+func extractRepoFilter(query string) (owner, repo string, found bool) {
+	pattern := `(?:^|\s)repo:([^/\s]+)/([^\s]+)`
+	re := regexp.MustCompile(pattern)
+	matches := re.FindStringSubmatch(query)
+
+	if len(matches) >= 3 {
+		return matches[1], matches[2], true
+	}
+	return "", "", false
+}
+
 func searchHandler(
 	ctx context.Context,
 	getClient GetClientFn,
@@ -22,7 +46,10 @@ func searchHandler(
 	if err != nil {
 		return mcp.NewToolResultError(err.Error()), nil
 	}
-	query = fmt.Sprintf("is:%s %s", searchType, query)
+
+	if !hasSpecificFilter(query, "is", searchType) {
+		query = fmt.Sprintf("is:%s %s", searchType, query)
+	}
 
 	owner, err := OptionalParam[string](request, "owner")
 	if err != nil {
@@ -35,7 +62,13 @@ func searchHandler(
 	}
 
 	if owner != "" && repo != "" {
-		query = fmt.Sprintf("repo:%s/%s %s", owner, repo, query)
+		_, _, hasRepoFilter := extractRepoFilter(query)
+
+		// TODO: Existing owner and existing repo?
+		if !hasRepoFilter {
+			query = fmt.Sprintf("repo:%s/%s %s", owner, repo, query)
+		}
+
 	}
 
 	sort, err := OptionalParam[string](request, "sort")