opencode-plugin-dsml-fix/test/golden.test.ts

/**
 * Golden test: 9 real-world DSML leak shapes captured from a long-context
 * DeepSeek session (wrapped edit/shell calls, seqs 5177–5695), preserved as
 * synthetic byte-faithful fixtures (`test/golden/db-messages.json`, generated by
 * `test/golden/build-fixtures.ts`). No private content: paths, code, and prose
 * are generic. Each message is run through the parser AND the streaming
 * middleware.
 *
 * Expectations per message (verified against the DB by hand):
 * - 5177, 5425, 5443, 5624, 5647, 5663, 5679, 5695: finish=stop, orphan/degraded
 *   markup. The parser must recover the intended call where one is unambiguous
 *   (edit/shell with parseable params) or strip the noise otherwise; the stream
 *   must emit identical text plus the recovered call and flip finish to tool-calls.
 * - 5608: finish=tool-calls with leaked markup alongside — parser recovers the call,
 *   leaked text is stripped, finish stays tool-calls.
 */

import { describe, expect, test } from "bun:test"
import type { LanguageModelV3StreamPart } from "@ai-sdk/provider"
import { parseDsml, stripRanges } from "../src/parse.ts"
import { createDsmlStreamMiddleware } from "../src/middleware.ts"
import raw from "./golden/db-messages.json" with { type: "json" }

interface GoldenMessage {
  seq: number
  finish: string
  text: string
}

const messages = raw as GoldenMessage[]

function splitDeltas(text: string, size: number): string[] {
  const parts: string[] = []
  for (let i = 0; i < text.length; i += size) parts.push(text.slice(i, i + size))
  return parts
}

async function runStream(text: string) {
  const chunks = splitDeltas(text, 7) // awkward split: cuts through markers
  const parts: LanguageModelV3StreamPart[] = [
    { type: "stream-start", warnings: [] },
    { type: "text-start", id: "t1" },
    ...chunks.map((delta): LanguageModelV3StreamPart => ({ type: "text-delta", id: "t1", delta })),
    { type: "text-end", id: "t1" },
    { type: "finish", finishReason: { unified: "stop", raw: "stop" }, usage: {} as never },
  ]
  const stream = new ReadableStream<LanguageModelV3StreamPart>({
    start(c) {
      for (const p of parts) c.enqueue(p)
      c.close()
    },
  })
  const middleware = createDsmlStreamMiddleware()
  const wrapped = await middleware.wrapStream!({
    doStream: async () => ({ stream }),
    doGenerate: (async () => ({})) as never,
    params: {} as never,
    model: {} as never,
  })
  const events: LanguageModelV3StreamPart[] = []
  const reader = wrapped.stream.getReader()
  for (;;) {
    const { done, value } = await reader.read()
    if (done) break
    events.push(value)
  }
  return events
}

describe("golden: DB session leaks", () => {
  test("all 9 fixtures load with DSML content", () => {
    expect(messages).toHaveLength(9)
    for (const m of messages) expect(m.text).toMatch(/DSML/)
  })

  for (const m of messages) {
    test(`seq ${m.seq}: stream preserves text, recovers call, flips finish`, async () => {
      const parsed = parseDsml(m.text)
      const events = await runStream(m.text)
      const textOut = events
        .filter((e): e is Extract<LanguageModelV3StreamPart, { type: "text-delta" }> => e.type === "text-delta")
        .map((e) => e.delta)
        .join("")
      const calls = events.filter((e) => e.type === "tool-call")
      const finish = events.find((e) => e.type === "finish") as Extract<
        LanguageModelV3StreamPart,
        { type: "finish" }
      >
      // No text is ever lost: emitted text + stripped ranges === input minus calls.
      // Concretely: every non-markup word of the input must appear in the output.
      // (Comparison ignores quote chars: call args travel JSON-escaped in parts.)
      const inputWords = m.text.replace(/<[^>]*>/g, " ").split(/\s+/).filter(Boolean)
      const haystacks = [textOut, JSON.stringify(calls)].map((h) => h.replace(/["\\]/g, ""))
      for (const word of inputWords) {
        if (word.length > 20) continue // long values may be inside recovered args
        const bare = word.replace(/["\\]/g, "")
        expect(haystacks.some((h) => h.includes(bare))).toBe(true)
      }
      // Parser and stream agree on the call count.
      expect(calls.length).toBe(parsed.calls.length)
      if (parsed.calls.length > 0) {
        expect(finish.finishReason.unified).toBe("tool-calls")
      } else {
        expect(finish.finishReason.unified).toBe("stop")
      }
      // Stripped output contains no marker.
      expect(stripRanges(m.text, parsed.ranges)).not.toMatch(/DSML/)
    })
  }

  test("seq 5608 (native tool-calls): wrapped edit call recovered", async () => {
    const m = messages.find((x) => x.seq === 5608)!
    const parsed = parseDsml(m.text)
    expect(parsed.calls.length).toBeGreaterThan(0)
    expect(parsed.calls[0]!.name).toBe("edit")
    expect(parsed.calls[0]!.arguments).toHaveProperty("newString")
  })
})