| 5 | } |
| 6 | |
| 7 | export async function* parseSSE(response: Response): AsyncGenerator<ServerSentEvent> { |
| 8 | const reader = response.body?.getReader(); |
| 9 | if (!reader) return; |
| 10 | |
| 11 | const decoder = new TextDecoder(); |
| 12 | let buffer = ''; |
| 13 | let event: Partial<ServerSentEvent> = {}; |
| 14 | |
| 15 | const processLine = (rawLine: string): ServerSentEvent | undefined => { |
| 16 | const line = rawLine.endsWith('\r') ? rawLine.slice(0, -1) : rawLine; |
| 17 | |
| 18 | if (line === '') { |
| 19 | const completed = event.data !== undefined |
| 20 | ? { data: event.data, event: event.event, id: event.id } |
| 21 | : undefined; |
| 22 | event = {}; |
| 23 | return completed; |
| 24 | } |
| 25 | |
| 26 | if (line.startsWith(':')) return undefined; |
| 27 | |
| 28 | const colonIndex = line.indexOf(':'); |
| 29 | if (colonIndex === -1) return undefined; |
| 30 | |
| 31 | const field = line.slice(0, colonIndex); |
| 32 | const value = line.slice(colonIndex + 1).trimStart(); |
| 33 | |
| 34 | switch (field) { |
| 35 | case 'data': |
| 36 | event.data = event.data !== undefined ? `${event.data}\n${value}` : value; |
| 37 | break; |
| 38 | case 'event': |
| 39 | event.event = value; |
| 40 | break; |
| 41 | case 'id': |
| 42 | event.id = value; |
| 43 | break; |
| 44 | } |
| 45 | |
| 46 | return undefined; |
| 47 | }; |
| 48 | |
| 49 | try { |
| 50 | while (true) { |
| 51 | const { done, value } = await reader.read(); |
| 52 | if (done) break; |
| 53 | |
| 54 | buffer += decoder.decode(value, { stream: true }); |
| 55 | |
| 56 | const lines = buffer.split('\n'); |
| 57 | buffer = lines.pop() || ''; |
| 58 | |
| 59 | for (const line of lines) { |
| 60 | const completed = processLine(line); |
| 61 | if (completed) { |
| 62 | yield completed; |
| 63 | } |
| 64 | } |