File size: 4,151 Bytes
9ada4bc
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
"use strict";
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
    var desc = Object.getOwnPropertyDescriptor(m, k);
    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
      desc = { enumerable: true, get: function() { return m[k]; } };
    }
    Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
    o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
    Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
    o["default"] = v;
});
var __importStar = (this && this.__importStar) || function (mod) {
    if (mod && mod.__esModule) return mod;
    var result = {};
    if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
    __setModuleDefault(result, mod);
    return result;
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.stream = exports.events = void 0;
const utils = __importStar(require("./utils.js"));
/**
 * Convert a `Response` body containing Server Sent Events (SSE) into an Async Iterator that yields {@linkcode ServerSentEventMessage} objects.
 *
 * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events}
 *
 * @example
 * ```js
 * // Optional
 * let abort = new AbortController;
 *
 * // Manually fetch a Response
 * let res = await fetch('https://...', {
 *   method: 'POST',
 *   signal: abort.signal,
 *   headers: {
 *     'api-key': 'token <value>',
 *     'content-type': 'application/json',
 *   },
 *   body: JSON.stringify({
 *     stream: true, // <- hypothetical
 *     // ...
 *   })
 * });
 *
 * if (res.ok) {
 *   let stream = events(res, abort.signal);
 *   for await (let event of stream) {
 *     console.log('<<', event.data);
 *   }
 * }
 * ```
 */
async function* events(res, signal) {
    // TODO: throw error?
    if (!res.body)
        return;
    let iter = utils.stream(res.body);
    let line, reader = iter.getReader();
    let event;
    for (;;) {
        if (signal && signal.aborted) {
            return reader.cancel();
        }
        line = await reader.read();
        if (line.done)
            return;
        if (!line.value) {
            if (event)
                yield event;
            event = undefined;
            continue;
        }
        let [field, value] = utils.split(line.value) || [];
        if (!field)
            continue; // comment or invalid
        if (field === 'data') {
            event ||= {};
            event[field] = event[field] ? (event[field] + '\n' + value) : value;
        }
        else if (field === 'event') {
            event ||= {};
            event[field] = value;
        }
        else if (field === 'id') {
            event ||= {};
            event[field] = +value || value;
        }
        else if (field === 'retry') {
            event ||= {};
            event[field] = +value || undefined;
        }
    }
}
exports.events = events;
/**
 * Convenience function that will `fetch` with the given arguments and, if ok, will return the {@linkcode events} async iterator.
 *
 * If the response is not ok (status 200-299), the `Response` is thrown.
 *
 * @example
 * ```js
 * // NOTE: throws `Response` if not 2xx status
 * let events = await stream('https://api.openai.com/...', {
 *   method: 'POST',
 *   headers: {
 *     'Authorization': 'Bearer <token>',
 *     'Content-Type': 'application/json',
 *   },
 *   body: JSON.stringify({
 *     stream: true,
 *     // ...
 *   })
 * });
 *
 * for await (let event of events) {
 *   console.log('<<', JSON.parse(event.data));
 * }
 * ```
 */
async function stream(input, init) {
    let req = new Request(input, init);
    utils.fallback(req.headers, 'Accept', 'text/event-stream');
    utils.fallback(req.headers, 'Content-Type', 'application/json');
    let r = await fetch(req);
    if (!r.ok)
        throw r;
    return events(r, req.signal);
}
exports.stream = stream;