chore: import upstream snapshot with attribution

pkg/http/headers/headers.go

@@ -0,0 +1,56 @@
+package headers
+
+const (
+	// AuthorizationHeader is a standard HTTP Header.
+	AuthorizationHeader = "Authorization"
+	// ContentTypeHeader is a standard HTTP Header.
+	ContentTypeHeader = "Content-Type"
+	// AcceptHeader is a standard HTTP Header.
+	AcceptHeader = "Accept"
+	// UserAgentHeader is a standard HTTP Header.
+	UserAgentHeader = "User-Agent"
+
+	// ContentTypeJSON is the standard MIME type for JSON.
+	ContentTypeJSON = "application/json"
+	// ContentTypeEventStream is the standard MIME type for Event Streams.
+	ContentTypeEventStream = "text/event-stream"
+
+	// ForwardedForHeader is a standard HTTP Header used to forward the originating IP address of a client.
+	ForwardedForHeader = "X-Forwarded-For"
+
+	// RealIPHeader is a standard HTTP Header used to indicate the real IP address of the client.
+	RealIPHeader = "X-Real-IP"
+
+	// ForwardedHostHeader is a standard HTTP Header for preserving the original Host header when proxying.
+	ForwardedHostHeader = "X-Forwarded-Host"
+	// ForwardedProtoHeader is a standard HTTP Header for preserving the original protocol when proxying.
+	ForwardedProtoHeader = "X-Forwarded-Proto"
+
+	// RequestHmacHeader is used to authenticate requests to the Raw API.
+	RequestHmacHeader = "Request-Hmac"
+
+	// MCP-specific headers.
+
+	// MCPReadOnlyHeader indicates whether the MCP is in read-only mode.
+	MCPReadOnlyHeader = "X-MCP-Readonly"
+	// MCPToolsetsHeader is a comma-separated list of MCP toolsets that the request is for.
+	MCPToolsetsHeader = "X-MCP-Toolsets"
+	// MCPToolsHeader is a comma-separated list of MCP tools that the request is for.
+	MCPToolsHeader = "X-MCP-Tools"
+	// MCPLockdownHeader indicates whether lockdown mode is enabled.
+	MCPLockdownHeader = "X-MCP-Lockdown"
+	// MCPInsidersHeader indicates whether insiders mode is enabled for early access features.
+	MCPInsidersHeader = "X-MCP-Insiders"
+	// MCPExcludeToolsHeader is a comma-separated list of MCP tools that should be
+	// disabled regardless of other settings or header values.
+	MCPExcludeToolsHeader = "X-MCP-Exclude-Tools"
+	// MCPFeaturesHeader is a comma-separated list of feature flags to enable.
+	MCPFeaturesHeader = "X-MCP-Features"
+
+	// GitHub-specific headers.
+
+	// GraphQLFeaturesHeader is a comma-separated list of GraphQL feature flags to enable for GraphQL requests.
+	GraphQLFeaturesHeader = "GraphQL-Features"
+	// GitHubAPIVersionHeader is the header used to specify the GitHub API version.
+	GitHubAPIVersionHeader = "X-GitHub-Api-Version"
+)

pkg/http/headers/parse.go

@@ -0,0 +1,21 @@
+package headers
+
+import "strings"
+
+// ParseCommaSeparated splits a header value by comma, trims whitespace,
+// and filters out empty values
+func ParseCommaSeparated(value string) []string {
+	if value == "" {
+		return []string{}
+	}
+
+	parts := strings.Split(value, ",")
+	result := make([]string, 0, len(parts))
+	for _, p := range parts {
+		trimmed := strings.TrimSpace(p)
+		if trimmed != "" {
+			result = append(result, trimmed)
+		}
+	}
+	return result
+}

pkg/http/headers/parse_test.go

@@ -0,0 +1,58 @@
+package headers
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseCommaSeparated(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected []string
+	}{
+		{
+			name:     "empty string",
+			input:    "",
+			expected: []string{},
+		},
+		{
+			name:     "single value",
+			input:    "foo",
+			expected: []string{"foo"},
+		},
+		{
+			name:     "multiple values",
+			input:    "foo,bar,baz",
+			expected: []string{"foo", "bar", "baz"},
+		},
+		{
+			name:     "whitespace trimmed",
+			input:    " foo , bar , baz ",
+			expected: []string{"foo", "bar", "baz"},
+		},
+		{
+			name:     "empty values filtered",
+			input:    "foo,,bar,",
+			expected: []string{"foo", "bar"},
+		},
+		{
+			name:     "only commas",
+			input:    ",,,",
+			expected: []string{},
+		},
+		{
+			name:     "whitespace only values filtered",
+			input:    "foo,   ,bar",
+			expected: []string{"foo", "bar"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := ParseCommaSeparated(tt.input)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}