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    "story_id": "mp-2026-08-19-019",
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    "headline": "The Tests Got a Contract Before They Got Code",
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    "dek": "An agent wrote preconditions, postconditions and undefined behavior before generating a test suite.",
    "summary": "An agent wrote preconditions, postconditions and undefined behavior before generating a test suite.",
    "body_text": "On production bugs from Google, spec-driven generation improved bug detection by 9.8 percentage points and branch coverage by 2.5 points over the direct agent baseline. An LLM judge also preferred many generated suites, a result that complements but does not replace executable bug and coverage measurements.",
    "why_it_matters": "An agent wrote preconditions, postconditions and undefined behavior before generating a test suite.",
    "limitations": [
      "An LLM judge also preferred many generated suites, a result that complements but does not replace executable bug and coverage measurements."
    ],
    "importance": 8,
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    "first_published_at": "2026-08-19T09:00:00.000-04:00",
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        "text": "An agent wrote preconditions, postconditions and undefined behavior before generating a test suite.",
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        "qualification": "An LLM judge also preferred many generated suites, a result that complements but does not replace executable bug and coverage measurements."
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    "tags": [
      "test generation",
      "software contracts",
      "coding agents"
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    "image_url": null,
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-08-19-021",
      "title": "arXiv preprint 2608.17177",
      "publisher": "arXiv",
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      "published_at": "2026-08-16T20:00:00.000-04:00",
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  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
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  "cite_this_report": {
    "title": "The Tests Got a Contract Before They Got Code",
    "publisher": "The Machine Press",
    "published_at": "2026-08-19T09:00:00.000-04:00",
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