fix(invariants): assert runtime relationships, not API shapes

packages/context/time-context/tests/invariant.spec.ts

@@ -0,0 +1,83 @@
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import type { ContentBlock } from '@deepseek-ai/dsh-llm'
+import type { Session, SessionEvent } from '@deepseek-ai/dsh-session'
+import * as TimeInvariant from '@deepseek-ai/dsh-time-context/invariant'
+import InvariantService from '@deepseek-ai/dsh-invariants'
+
+const SECOND = Date.parse('2026-07-14T00:00:00Z')
+
+async function setup(): Promise<Context> {
+  const ctx = new Context()
+  await ctx.plugin(InvariantService)
+  await ctx.plugin(TimeInvariant)
+  return ctx
+}
+
+function event(text: string, time = SECOND + 456, content?: unknown[]): SessionEvent {
+  return {
+    type: 'context/message',
+    seq: 0,
+    time,
+    data: {
+      content: (content ?? [{ type: 'text', text }]) as ContentBlock[],
+      source: { kind: 'plugin', plugin: 'time-context' },
+    },
+  }
+}
+
+function reading(
+  turn = '1',
+  step = '1',
+  baseline = 'model-visible message',
+  timestamp = '2026-07-14T00:00:00+00:00[UTC]',
+): string {
+  return `Time sampled while preparing turn ${turn}, step ${step}: ${timestamp}\n`
+    + `Elapsed since the preceding ${baseline}: unavailable.`
+}
+
+describe('time-context invariants', () => {
+  it('accepts a reading whose turn, step, baseline, and timestamp agree', async () => {
+    const ctx = await setup()
+    const text = 'Time sampled while preparing turn 2, step 3: 2026-07-14T00:00:00+00:00[UTC]\n'
+      + 'Elapsed since the preceding step context: 4m 2s.'
+    expect(() => { ctx.emit('session/event', {} as Session, event(text)) }).not.toThrow()
+  })
+
+  it.each([
+    ['not a reading', SECOND, undefined, /durable reading format/],
+    [reading('0'), SECOND, undefined, /positive safe integers/],
+    [reading('999999999999999999999'), SECOND, undefined, /positive safe integers/],
+    [reading('1', '0', 'step context'), SECOND, undefined, /positive safe integers/],
+    [reading('1', '999999999999999999999', 'step context'), SECOND, undefined, /positive safe integers/],
+    [reading('1', '1', 'step context'), SECOND, undefined, /wrong elapsed-time baseline/],
+    [reading('1', '2', 'model-visible message'), SECOND, undefined, /wrong elapsed-time baseline/],
+    [reading('1', '1', 'model-visible message', '2026-99-99T00:00:00+00:00[UTC]'), SECOND, undefined, /durable event second/],
+    [reading(), Number.NaN, undefined, /durable event second/],
+    [reading(), SECOND - 1, undefined, /durable event second/],
+    [reading(), SECOND + 1_000, undefined, /durable event second/],
+    ['ignored', SECOND, [], /exactly one text block/],
+    ['ignored', SECOND, [{ type: 'image', data: 'x', mimeType: 'image/png' }], /exactly one text block/],
+    ['ignored', SECOND, [{ type: 'text', text: 'one' }, { type: 'text', text: 'two' }], /exactly one text block/],
+  ] as const)('rejects an incoherent durable reading', async (text, time, content, message) => {
+    const ctx = await setup()
+    expect(() => {
+      ctx.emit('session/event', {} as Session, event(text, time, content === undefined ? undefined : [...content]))
+    }).toThrow(message)
+  })
+
+  it('ignores context messages owned by another package', async () => {
+    const ctx = await setup()
+    const other = event('unrelated') as SessionEvent<'context/message'>
+    other.data.source = { kind: 'plugin', plugin: 'other' }
+    expect(() => { ctx.emit('session/event', {} as Session, other) }).not.toThrow()
+    other.data.source = { kind: 'user' }
+    expect(() => { ctx.emit('session/event', {} as Session, other) }).not.toThrow()
+    expect(() => {
+      ctx.emit('session/event', {} as Session, {
+        type: 'turn/start', seq: 0, time: 0, data: { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } },
+      })
+      ctx.emit('tools/change')
+    }).not.toThrow()
+  })
+})