hermes-agent/ui-tui/src/__tests__/streamingMarkdown.test.ts
Austin Pickett e4120d1e6d Merge remote-tracking branch 'origin/main' into fix/markdown
Made-with: Cursor

# Conflicts:
#	ui-tui/src/components/markdown.tsx
2026-04-28 22:01:02 -04:00

121 lines
4.6 KiB
TypeScript

import { describe, expect, it } from 'vitest'
import { findStableBoundary } from '../components/streamingMarkdown.js'
// We test the pure boundary logic by rendering the component's ref
// behaviour through repeated calls. Since React isn't being rendered here,
// we reach into the module to test findStableBoundary via its exported
// behaviour — but the pure helper isn't exported. So test the component's
// observable output: pass sequential text values and verify the stable
// prefix never retreats.
//
// Strategy: mount StreamingMd in isolation and observe which <Md>
// instances it renders (by text prop). Without a DOM renderer that's
// heavy, so we validate the helper behaviour by directly invoking the
// fence/boundary logic via a re-exported surface.
import { DEFAULT_THEME } from '../theme.js'
describe('findStableBoundary', () => {
it('returns -1 when no blank line exists yet', () => {
expect(findStableBoundary('partial line with no newline yet')).toBe(-1)
})
it('returns -1 when only single newlines exist', () => {
expect(findStableBoundary('line one\nline two\nline three')).toBe(-1)
})
it('splits after the last blank line separator', () => {
// 'first\n\nsecond\n\nthird' → last blank = before 'third'
const text = 'first paragraph\n\nsecond paragraph\n\nthird'
const idx = findStableBoundary(text)
expect(text.slice(0, idx)).toBe('first paragraph\n\nsecond paragraph\n\n')
expect(text.slice(idx)).toBe('third')
})
it('refuses to split inside an open fenced block', () => {
// Fence opens, contains a blank line inside the code, no close yet.
const text = '```ts\nfn();\n\nmore code here'
expect(findStableBoundary(text)).toBe(-1)
})
it('splits before an open fenced block but not inside', () => {
const text = 'intro paragraph\n\n```ts\nfn();\n\nmore code'
const idx = findStableBoundary(text)
expect(text.slice(0, idx)).toBe('intro paragraph\n\n')
expect(text.slice(idx).startsWith('```ts')).toBe(true)
})
it('allows splitting after a fenced block closes', () => {
const text = '```ts\nfn();\n```\n\nnarration continues'
const idx = findStableBoundary(text)
expect(text.slice(0, idx)).toBe('```ts\nfn();\n```\n\n')
expect(text.slice(idx)).toBe('narration continues')
})
it('walks backwards through nested fence boundaries safely', () => {
// Two closed fences + narration + one new open fence. The only legal
// split is before the open fence, not between the closed ones.
const text = '```js\na\n```\n\nmid text\n\n```python\nstill open'
const idx = findStableBoundary(text)
expect(text.slice(0, idx)).toBe('```js\na\n```\n\nmid text\n\n')
})
it('handles empty input', () => {
expect(findStableBoundary('')).toBe(-1)
})
it('refuses to split inside an open $$ math block', () => {
// Display math has been opened but not closed; the only blank line
// sits inside the open block, so there's no safe boundary yet.
const text = '$$\nx + y\n\nmore math'
expect(findStableBoundary(text)).toBe(-1)
})
it('allows splitting after a $$ math block closes', () => {
const text = '$$\nx + y = z\n$$\n\nnarration continues'
const idx = findStableBoundary(text)
expect(text.slice(0, idx)).toBe('$$\nx + y = z\n$$\n\n')
expect(text.slice(idx)).toBe('narration continues')
})
it('splits before an open $$ block but not inside', () => {
// Mirror of the existing fenced-code test: prose, then an unclosed
// math block. The only safe boundary is the blank line BEFORE `$$`.
const text = 'intro paragraph\n\n$$\nx + y\n\nmore'
const idx = findStableBoundary(text)
expect(text.slice(0, idx)).toBe('intro paragraph\n\n')
expect(text.slice(idx).startsWith('$$')).toBe(true)
})
it('treats single-line $$x$$ as zero net toggle', () => {
// `$$x = y$$` opens AND closes on one line, so the stable boundary
// after it is allowed.
const text = 'intro\n\n$$x = y$$\n\nnarration'
const idx = findStableBoundary(text)
expect(text.slice(0, idx)).toBe('intro\n\n$$x = y$$\n\n')
expect(text.slice(idx)).toBe('narration')
})
it('refuses to split inside an open \\[ math block', () => {
const text = '\\[\nx + y\n\nmore'
expect(findStableBoundary(text)).toBe(-1)
})
})
describe('streaming theme assumption', () => {
it('theme is exportable (component import sanity check)', () => {
// Sanity that the theme we pass doesn't change shape. Component import
// already happens above — this is a smoke test that the module graph
// for streamingMarkdown wires up without cycles.
expect(DEFAULT_THEME.color.accent).toBeTruthy()
})
})