57 lines
1.9 KiB
TypeScript
57 lines
1.9 KiB
TypeScript
import { describe, it, expect } from 'vitest';
|
|
import { createFramePusher } from '../src/webui/debug-stream';
|
|
|
|
function harness(sizes: number[]) {
|
|
// desiredSize() returns the next scripted value each call.
|
|
let i = 0;
|
|
const frames: string[] = [];
|
|
const push = createFramePusher({
|
|
desiredSize: () => (i < sizes.length ? sizes[i++] : (sizes[sizes.length - 1] ?? 1)),
|
|
enqueue: (chunk) => {
|
|
frames.push(Buffer.from(chunk).toString());
|
|
},
|
|
encode: (s) => Buffer.from(s),
|
|
});
|
|
return { push, frames };
|
|
}
|
|
|
|
describe('createFramePusher', () => {
|
|
it('enqueues an SSE data frame when there is headroom', () => {
|
|
const { push, frames } = harness([1]);
|
|
push({ kind: 'event', x: 1 });
|
|
expect(frames).toEqual([`data: ${JSON.stringify({ kind: 'event', x: 1 })}\n\n`]);
|
|
});
|
|
|
|
it('drops under backpressure (desiredSize <= 0) without enqueuing', () => {
|
|
const { push, frames } = harness([0, -3]);
|
|
push({ a: 1 });
|
|
push({ a: 2 });
|
|
expect(frames).toEqual([]);
|
|
});
|
|
|
|
it('emits a coalesced dropped marker before the next delivered frame', () => {
|
|
const { push, frames } = harness([0, 0, 5]); // drop, drop, then headroom
|
|
push({ a: 1 });
|
|
push({ a: 2 });
|
|
push({ a: 3 });
|
|
expect(frames).toEqual([
|
|
`data: ${JSON.stringify({ kind: 'dropped', count: 2 })}\n\n`,
|
|
`data: ${JSON.stringify({ a: 3 })}\n\n`,
|
|
]);
|
|
});
|
|
|
|
it('treats null desiredSize as always-deliver (no backpressure signal)', () => {
|
|
let i = 0;
|
|
const frames: string[] = [];
|
|
const push = createFramePusher({
|
|
desiredSize: () => (i++ === 0 ? null : 1),
|
|
enqueue: (chunk) => {
|
|
frames.push(Buffer.from(chunk).toString());
|
|
},
|
|
encode: (s) => Buffer.from(s),
|
|
});
|
|
push({ a: 1 });
|
|
expect(frames).toHaveLength(1);
|
|
});
|
|
});
|