06F | Ledger: team timeout and handoff contract drift, post-hoc check

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        "text": "New implementation exercise; stubs deliberately incomplete. Implement codec.py encode(fields) and decode(line), reducer.py summarize(lines). fields is a list of strings, length >=1. Encode joins fields with | and escapes backslash as \\\\ and pipe as \\|. decode reverses this, preserves empty and Unicode fields, and raises ValueError for a trailing backslash or an escape other than backslash or pipe. Empty line decodes to ['']. summarize consumes iterable encoded records [event_id, account, signed_integer_cents]. Each record has exactly 3 fields, cents matches optional minus sign followed by one or more ASCII digits (leading zeros allowed, + disallowed). Account and ID may be empty or contain escaped delimiters. Exact retransmissions (same decoded ID/account/integer cents) count once. Conflicting duplicate IDs raise ValueError. Malformed encoding, field count or cents raises ValueError. Return dict account -> summed integer cents, retaining zero totals; empty input -> {}. Use codec.decode in reducer. Do not mutate input. Only codec.py, reducer.py, test_ledger.py may change. No dependency installs.\n=== codec.py ===\ndef encode(fields):\n raise NotImplementedError\ndef decode(line):\n raise NotImplementedError\n=== reducer.py ===\nfrom codec import decode\ndef summarize(lines):\n raise NotImplementedError\n=== test_ledger.py ===\nimport unittest\nclass Smoke(unittest.TestCase):\n def test_import(self):\n  import codec,reducer"
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Malformed encoding, field count or cents raises ValueError. Return dict account -> summed integer cents, retaining zero totals; empty input -> {}. Use codec.decode in reducer. Do not mutate input.\"\n\nThe team interface for codec (agreed, from README — codec.py may still be a stub on disk while you work; DO NOT rely on its on-disk state):\n- codec.decode(line: str) -> list[str]: inverse of encode; splits on unescaped '|'; preserves empty and Unicode fields; raises ValueError on trailing backslash or escape other than '\\\\' or '|'; decode(\"\") == [\"\"].\nBehavior requirements for summarize(lines):\n- lines is any iterable of encoded record strings (list, generator, or file-like). Handle a trailing single newline per line: if a line ends with '\\n', drop it; then if it ends with '\\r', drop it (so \"a|b|c\\n\" and \"a|b|c\" are equivalent). Do NOT mutate or consume the input iterable beyond iterating it.\n- Decode each line with codec.decode; propagate any ValueError from decode unchanged.\n- After decoding there must be exactly 3 fields: [event_id, account, cents_field]; otherwise raise ValueError.\n- cents_field must fully match `-?[0-9]+` (ASCII digit regex, not \\d): optional ASCII minus then one or more ASCII digits. Leading zeros allowed, '+' disallowed, anything else (empty, spaces, '.', unicode digits, letters) -> ValueError. Convert cents_field to Python int.\n- event_id and account may be empty and may contain escaped delimiters (they come back already unescaped from decode). Preserve them exactly as the decoded values.\n- Exact retransmission = same decoded event_id AND same account AND same integer cents; count once (do not add twice).\n- Conflicting duplicate ID: same decoded event_id appearing with a different account OR a different integer cents (including e.g. \"10\" vs \"-10\", \"10\" vs \"7\") -> raise ValueError. Note \"5\" and \"05\" both equal integer 5, so same id + same account + \"5\" then \"05\" is an exact retransmission, NOT a conflict.\n- Result: dict mapping account -> summed integer cents across all unique records. Accounts that appear must remain in the dict even when their total is 0 (\"retaining zero totals\"). Empty input -> {}.\n- Do not change any input structure/list; strings are immutable so just don't write to whatever you're given.\n\nIMPORTANT verification approach (you cannot rely on codec.py being implemented): verify your reducer with in-memory probes by injecting a reference `codec` module into sys.modules inside the python heredoc, e.g.:\n\n```\nimport sys, types\nref = types.ModuleType(\"codec\")\ndef _enc(f): ...\ndef decode(line): ...  # reference implementation matching the agreed interface above\nref.decode = decode\nsys.modules[\"codec\"] = ref\nimport reducer\n```\n\nDo NOT write this reference into any file and do NOT alter the on-disk codec.py. (If by the time you run, codec.py on disk already implements the interface, you may additionally run an integration probe against the real codec at the end for confidence, but your correctness must stand with the injected module.)\n\nCover at minimum these probes against summarize:\n1. summarize([]) == {}\n2. single record, e.g. [\"e1|acct|10\"] -> {\"acct\": 10}\n3. multiple records summing: [\"a1|x|5\",\"a2|x|3\",\"a3|x|-8\"] -> {\"x\": 0} (zero retained)\n4. empty account: [\"e0||5\",\"e1||7\"] -> {\"\": 12}; empty id: [\"|x|9\"] -> {\"x\": 9}\n5. escaped delimiters: id \"a\\b\", account \"North|South\", cents \"-100\" encoded via the reference encoder -> decoded account key \"North|South\" with -100\n6. leading zeros: [\"e|x|0007\"] -> {\"x\": 7}; unicode cents \"١٢\" (Arabic digits) -> ValueError\n7. cents validation: \"5\" ok, \"-5\" ok, \"\" ValueError, \"+5\" ValueError, \"5.0\" ValueError, \"x\" ValueError, \"5 \" ValueError\n8. field count: \"a|b\" and \"a|b|c|d\" -> ValueError; malformed encoding line like \"a\\\\x|b|c\" -> ValueError (from decode)\n9. exact retransmission: [\"e|x|10\",\"e|x|10\",\"e|x|010\"] -> {\"x\": 10}\n10. conflicts: [\"e|x|10\",\"e|y|10\"] -> ValueError; [\"e|x|10\",\"e|x|-10\"] -> ValueError; [\"e|x|5\",\"e|x|05\"] -> OK {\"x\":5}\n11. input immutability: pass a list, confirm after the call the list is unchanged.\n12. iterable input: a generator expression works; trailing-newline variant \"e|x|10\\n\" and \"e|x|10\\r\\n\" equal \"e|x|10\".\n\nReport back concisely:\n- The exact summary of your summarize implementation (structure, not full code).\n- Each probe (input -> expected -> observed) and pass/fail, including the ValueError cases.\n- Your assumptions (especially newline-stripping and the \"5\"/\"05\" decision).\nKeep the report under ~700 words. Do not describe changes to any file other than reducer.py.",
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    "arguments": "{\"subagent_type\": \"reducer-specialist\", \"description\": \"Implement only reducer.py per README\", \"prompt\": \"Workspace: /private/tmp/odsc-workshop6-v2/ledger-team-t1\\n\\nREADME.md there is the complete acceptance contract. Your job: implement ONLY the file reducer.py (function `summarize(lines)`). It must use `codec.decode` from codec.py (the import is already at the top of the stub). Do NOT edit codec.py or test_ledger.py, and do NOT create any new files. Use `PYTHONDONTWRITEBYTECODE=1` in all shell commands. Do not run git commands, do not install anything, no network.\\n\\nContract (verbatim README clauses relevant to you):\\n\\\"summarize consumes iterable encoded records [event_id, account, signed_integer_cents]. Each record has exactly 3 fields, cents matches optional minus sign followed by one or more ASCII digits (leading zeros allowed, + disallowed). Account and ID may be empty or contain escaped delimiters. Exact retransmissions (same decoded ID/account/integer cents) count once. Conflicting duplicate IDs raise ValueError. Malformed encoding, field count or cents raises ValueError. Return dict account -> summed integer cents, retaining zero totals; empty input -> {}. Use codec.decode in reducer. Do not mutate input.\\\"\\n\\nThe team interface for codec (agreed, from README \\u2014 codec.py may still be a stub on disk while you work; DO NOT rely on its on-disk state):\\n- codec.decode(line: str) -> list[str]: inverse of encode; splits on unescaped '|'; preserves empty and Unicode fields; raises ValueError on trailing backslash or escape other than '\\\\\\\\' or '|'; decode(\\\"\\\") == [\\\"\\\"].\\nBehavior requirements for summarize(lines):\\n- lines is any iterable of encoded record strings (list, generator, or file-like). Handle a trailing single newline per line: if a line ends with '\\\\n', drop it; then if it ends with '\\\\r', drop it (so \\\"a|b|c\\\\n\\\" and \\\"a|b|c\\\" are equivalent). Do NOT mutate or consume the input iterable beyond iterating it.\\n- Decode each line with codec.decode; propagate any ValueError from decode unchanged.\\n- After decoding there must be exactly 3 fields: [event_id, account, cents_field]; otherwise raise ValueError.\\n- cents_field must fully match `-?[0-9]+` (ASCII digit regex, not \\\\d): optional ASCII minus then one or more ASCII digits. Leading zeros allowed, '+' disallowed, anything else (empty, spaces, '.', unicode digits, letters) -> ValueError. Convert cents_field to Python int.\\n- event_id and account may be empty and may contain escaped delimiters (they come back already unescaped from decode). Preserve them exactly as the decoded values.\\n- Exact retransmission = same decoded event_id AND same account AND same integer cents; count once (do not add twice).\\n- Conflicting duplicate ID: same decoded event_id appearing with a different account OR a different integer cents (including e.g. \\\"10\\\" vs \\\"-10\\\", \\\"10\\\" vs \\\"7\\\") -> raise ValueError. Note \\\"5\\\" and \\\"05\\\" both equal integer 5, so same id + same account + \\\"5\\\" then \\\"05\\\" is an exact retransmission, NOT a conflict.\\n- Result: dict mapping account -> summed integer cents across all unique records. Accounts that appear must remain in the dict even when their total is 0 (\\\"retaining zero totals\\\"). Empty input -> {}.\\n- Do not change any input structure/list; strings are immutable so just don't write to whatever you're given.\\n\\nIMPORTANT verification approach (you cannot rely on codec.py being implemented): verify your reducer with in-memory probes by injecting a reference `codec` module into sys.modules inside the python heredoc, e.g.:\\n\\n```\\nimport sys, types\\nref = types.ModuleType(\\\"codec\\\")\\ndef _enc(f): ...\\ndef decode(line): ...  # reference implementation matching the agreed interface above\\nref.decode = decode\\nsys.modules[\\\"codec\\\"] = ref\\nimport reducer\\n```\\n\\nDo NOT write this reference into any file and do NOT alter the on-disk codec.py. (If by the time you run, codec.py on disk already implements the interface, you may additionally run an integration probe against the real codec at the end for confidence, but your correctness must stand with the injected module.)\\n\\nCover at minimum these probes against summarize:\\n1. summarize([]) == {}\\n2. single record, e.g. [\\\"e1|acct|10\\\"] -> {\\\"acct\\\": 10}\\n3. multiple records summing: [\\\"a1|x|5\\\",\\\"a2|x|3\\\",\\\"a3|x|-8\\\"] -> {\\\"x\\\": 0} (zero retained)\\n4. empty account: [\\\"e0||5\\\",\\\"e1||7\\\"] -> {\\\"\\\": 12}; empty id: [\\\"|x|9\\\"] -> {\\\"x\\\": 9}\\n5. escaped delimiters: id \\\"a\\\\b\\\", account \\\"North|South\\\", cents \\\"-100\\\" encoded via the reference encoder -> decoded account key \\\"North|South\\\" with -100\\n6. leading zeros: [\\\"e|x|0007\\\"] -> {\\\"x\\\": 7}; unicode cents \\\"\\u0661\\u0662\\\" (Arabic digits) -> ValueError\\n7. cents validation: \\\"5\\\" ok, \\\"-5\\\" ok, \\\"\\\" ValueError, \\\"+5\\\" ValueError, \\\"5.0\\\" ValueError, \\\"x\\\" ValueError, \\\"5 \\\" ValueError\\n8. field count: \\\"a|b\\\" and \\\"a|b|c|d\\\" -> ValueError; malformed encoding line like \\\"a\\\\\\\\x|b|c\\\" -> ValueError (from decode)\\n9. exact retransmission: [\\\"e|x|10\\\",\\\"e|x|10\\\",\\\"e|x|010\\\"] -> {\\\"x\\\": 10}\\n10. conflicts: [\\\"e|x|10\\\",\\\"e|y|10\\\"] -> ValueError; [\\\"e|x|10\\\",\\\"e|x|-10\\\"] -> ValueError; [\\\"e|x|5\\\",\\\"e|x|05\\\"] -> OK {\\\"x\\\":5}\\n11. input immutability: pass a list, confirm after the call the list is unchanged.\\n12. iterable input: a generator expression works; trailing-newline variant \\\"e|x|10\\\\n\\\" and \\\"e|x|10\\\\r\\\\n\\\" equal \\\"e|x|10\\\".\\n\\nReport back concisely:\\n- The exact summary of your summarize implementation (structure, not full code).\\n- Each probe (input -> expected -> observed) and pass/fail, including the ValueError cases.\\n- Your assumptions (especially newline-stripping and the \\\"5\\\"/\\\"05\\\" decision).\\nKeep the report under ~700 words. Do not describe changes to any file other than reducer.py.\", \"security_risk\": \"MEDIUM\"}",
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  "summary": "task: {\"subagent_type\": \"reducer-specialist\", \"description\": \"Implement only reducer.py per README\", \"prompt\": \"Workspace: /private/tmp/odsc-workshop6-v2/ledger-team-t1\\n\\nREADME.md there is the complete acceptance contract. Your job: implement ONLY the file reducer.py (function `summarize(lines)`). It must use `codec.decode` from codec.py (the import is already at the top of the stub). Do NOT edit codec.py or test_ledger.py, and do NOT create any new files. Use `PYTHONDONTWRITEBYTECODE=1` in all shell commands. Do not run git commands, do not install anything, no network.\\n\\nContract (verbatim README clauses relevant to you):\\n\\\"summarize consumes iterable encoded records [event_id, account, signed_integer_cents]. Each record has exactly 3 fields, cents matches optional minus sign followed by one or more ASCII digits (leading zeros allowed, + disallowed). Account and ID may be empty or contain escaped delimiters. Exact retransmissions (same decoded ID/account/integer cents) count once. Conflicting duplicate IDs raise ValueError. Malformed encoding, field count or cents raises ValueError. Return dict account -> summed integer cents, retaining zero totals; empty input -> {}. Use codec.decode in reducer. Do not mutate input.\\\"\\n\\nThe team interface for codec (agreed, from README \\u2014 codec.py may still be a stub on disk while you work; DO NOT rely on its on-disk state):\\n- codec.decode(line: str) -> list[str]: inverse of encode; splits on unescaped '|'; preserves empty and Unicode fields; raises ValueError on trailing backslash or escape other than '\\\\\\\\' or '|'; decode(\\\"\\\") == [\\\"\\\"].\\nBehavior requirements for summarize(lines):\\n- lines is any iterable of encoded record strings (list, generator, or file-like). Handle a trailing single newline per line: if a line ends with '\\\\n', drop it; then if it ends with '\\\\r', drop it (so \\\"a|b|c\\\\n\\\" and \\\"a|b|c\\\" are equivalent). Do NOT mutate or consume the input iterable beyond iterating it.\\n- Decode each line with codec.decode; propagate any ValueError from decode unchanged.\\n- After decoding there must be exactly 3 fields: [event_id, account, cents_field]; otherwise raise ValueError.\\n- cents_field must fully match `-?[0-9]+` (ASCII digit regex, not \\\\d): optional ASCII minus then one or more ASCII digits. Leading zeros allowed, '+' disallowed, anything else (empty, spaces, '.', unicode digits, letters) -> ValueError. Convert cents_field to Python int.\\n- event_id and account may be empty and may contain escaped delimiters (they come back already unescaped from decode). Preserve them exactly as the decoded values.\\n- Exact retransmission = same decoded event_id AND same account AND same integer cents; count once (do not add twice).\\n- Conflicting duplicate ID: same decoded event_id appearing with a different account OR a different integer cents (including e.g. \\\"10\\\" vs \\\"-10\\\", \\\"10\\\" vs \\\"7\\\") -> raise ValueError. Note \\\"5\\\" and \\\"05\\\" both equal integer 5, so same id + same account + \\\"5\\\" then \\\"05\\\" is an exact retransmission, NOT a conflict.\\n- Result: dict mapping account -> summed integer cents across all unique records. Accounts that appear must remain in the dict even when their total is 0 (\\\"retaining zero totals\\\"). Empty input -> {}.\\n- Do not change any input structure/list; strings are immutable so just don't write to whatever you're given.\\n\\nIMPORTANT verification approach (you cannot rely on codec.py being implemented): verify your reducer with in-memory probes by injecting a reference `codec` module into sys.modules inside the python heredoc, e.g.:\\n\\n```\\nimport sys, types\\nref = types.ModuleType(\\\"codec\\\")\\ndef _enc(f): ...\\ndef decode(line): ...  # reference implementation matching the agreed interface above\\nref.decode = decode\\nsys.modules[\\\"codec\\\"] = ref\\nimport reducer\\n```\\n\\nDo NOT write this reference into any file and do NOT alter the on-disk codec.py. (If by the time you run, codec.py on disk already implements the interface, you may additionally run an integration probe against the real codec at the end for confidence, but your correctness must stand with the injected module.)\\n\\nCover at minimum these probes against summarize:\\n1. summarize([]) == {}\\n2. single record, e.g. [\\\"e1|acct|10\\\"] -> {\\\"acct\\\": 10}\\n3. multiple records summing: [\\\"a1|x|5\\\",\\\"a2|x|3\\\",\\\"a3|x|-8\\\"] -> {\\\"x\\\": 0} (zero retained)\\n4. empty account: [\\\"e0||5\\\",\\\"e1||7\\\"] -> {\\\"\\\": 12}; empty id: [\\\"|x|9\\\"] -> {\\\"x\\\": 9}\\n5. escaped delimiters: id \\\"a\\\\b\\\", account \\\"North|South\\\", cents \\\"-100\\\" encoded via the reference encoder -> decoded account key \\\"North|South\\\" with -100\\n6. leading zeros: [\\\"e|x|0007\\\"] -> {\\\"x\\\": 7}; unicode cents \\\"\\u0661\\u0662\\\" (Arabic digits) -> ValueError\\n7. cents validation: \\\"5\\\" ok, \\\"-5\\\" ok, \\\"\\\" ValueError, \\\"+5\\\" ValueError, \\\"5.0\\\" ValueError, \\\"x\\\" ValueError, \\\"5 \\\" ValueError\\n8. field count: \\\"a|b\\\" and \\\"a|b|c|d\\\" -> ValueError; malformed encoding line like \\\"a\\\\\\\\x|b|c\\\" -> ValueError (from decode)\\n9. exact retransmission: [\\\"e|x|10\\\",\\\"e|x|10\\\",\\\"e|x|010\\\"] -> {\\\"x\\\": 10}\\n10. conflicts: [\\\"e|x|10\\\",\\\"e|y|10\\\"] -> ValueError; [\\\"e|x|10\\\",\\\"e|x|-10\\\"] -> ValueError; [\\\"e|x|5\\\",\\\"e|x|05\\\"] -> OK {\\\"x\\\":5}\\n11. input immutability: pass a list, confirm after the call the list is unchanged.\\n12. iterable input: a generator expression works; trailing-newline variant \\\"e|x|10\\\\n\\\" and \\\"e|x|10\\\\r\\\\n\\\" equal \\\"e|x|10\\\".\\n\\nReport back concisely:\\n- The exact summary of your summarize implementation (structure, not full code).\\n- Each probe (input -> expected -> observed) and pass/fail, including the ValueError cases.\\n- Your assumptions (especially newline-stripping and the \\\"5\\\"/\\\"05\\\" decision).\\nKeep the report under ~700 words. 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