Factor shared Sejm API helpers into sejm_api_common.py

fetch_sejm_api_2011_2022.py kept byte-identical copies of sha256_file,
canonical_sha256, write_json and near-identical legal_evidence / stable_id
(differing only in signatures). The shared logic now lives once in
src/sejm_api_common.py; both fetchers import it (review item 4 on #18).

src/fetch_sejm_api.py

@@ -41,26 +41,12 @@ class ContributionError(ValueError):
     """Raised when the contribution cannot meet its declared contract."""
 
 
-def canonical_sha256(value: Any) -> str:
-    payload = json.dumps(
-        value, ensure_ascii=False, sort_keys=True, separators=(",", ":")
-    ).encode("utf-8")
-    return hashlib.sha256(payload).hexdigest()
-
-
-def sha256_file(path: pathlib.Path) -> str:
-    digest = hashlib.sha256()
-    with path.open("rb") as stream:
-        for chunk in iter(lambda: stream.read(1024 * 1024), b""):
-            digest.update(chunk)
-    return digest.hexdigest()
+import sejm_api_common as common
+from sejm_api_common import canonical_sha256, sha256_file, write_json
 
 
 def stable_document_id(row: dict[str, Any]) -> str:
-    material = "\x1f".join(
-        str(row.get(field, "")).strip() for field in ("date", "term", "speaker", "text")
-    )
-    return f"{SOURCE_NAME}_{hashlib.sha256(material.encode('utf-8')).hexdigest()}"
+    return common.stable_document_id(row, SOURCE_NAME)
 
 
 def text_fingerprint(text: str) -> str:
@@ -181,40 +167,17 @@ def insert_source_registry_entry(registry: str, *, end_date: str) -> str:
 
 
 def legal_evidence(*, source_revision: str, target_revision: str) -> dict[str, Any]:
-    return {
-        "status": "reviewed-open-official-materials",
-        "source": SOURCE_NAME,
-        "dataset_record_license": SOURCE_LICENSE,
-        "hf_source_license_name": "polish-public-sector-open-statutory-reuse",
-        "provider": "Kancelaria Sejmu RP",
-        "official_source": SEJM_API,
-        "official_source_documentation": SEJM_API_DOCUMENTATION,
-        "copyright_basis": {
-            "act": "Polish Copyright and Related Rights Act",
-            "article": "4(2)",
-            "finding": "official documents and materials are excluded from copyright",
-            "url": COPYRIGHT_ACT,
-        },
-        "reuse_basis": {
-            "act": "Polish Open Data and Reuse of Public Sector Information Act",
-            "articles": ["2(12)", "5", "6", "14(1)", "15", "17"],
-            "url": OPEN_DATA_ACT,
-        },
-        "limitations": [
-            "privacy and personal-data exceptions",
-            "third-party rights and provider-specific conditions",
-            "no upstream Creative Commons grant is asserted",
-        ],
-        "pinned_source": f"hf://datasets/{SOURCE_REPOSITORY}@{source_revision}",
-        "pinned_target_base": f"hf://datasets/{TARGET_REPOSITORY}@{target_revision}",
-    }
+    return common.legal_evidence(
+        source_revision,
+        target_revision,
+        source_name=SOURCE_NAME,
+        source_license=SOURCE_LICENSE,
+        source_repository=SOURCE_REPOSITORY,
+        target_repository=TARGET_REPOSITORY,
+    )
+
 
 
-def write_json(path: pathlib.Path, payload: Any) -> None:
-    path.write_text(
-        json.dumps(payload, ensure_ascii=False, indent=2, sort_keys=True) + "\n",
-        encoding="utf-8",
-    )
 
 
 def source_datasheet(

src/fetch_sejm_api_2011_2022.py

@@ -41,33 +41,15 @@ class BuildError(ValueError):
     pass
 
 
-def sha256_file(path: pathlib.Path) -> str:
-    digest = hashlib.sha256()
-    with path.open("rb") as stream:
-        for chunk in iter(lambda: stream.read(1024 * 1024), b""):
-            digest.update(chunk)
-    return digest.hexdigest()
-
+import sejm_api_common as common
+from sejm_api_common import canonical_sha256, sha256_file, write_json
 
-def canonical_sha256(value: Any) -> str:
-    payload = json.dumps(
-        value, ensure_ascii=False, sort_keys=True, separators=(",", ":")
-    ).encode("utf-8")
-    return hashlib.sha256(payload).hexdigest()
 
 
-def write_json(path: pathlib.Path, payload: Any) -> None:
-    path.write_text(
-        json.dumps(payload, ensure_ascii=False, indent=2, sort_keys=True) + "\n",
-        encoding="utf-8",
-    )
 
 
 def stable_id(row: dict[str, Any]) -> str:
-    material = "\x1f".join(
-        str(row.get(field, "")).strip() for field in ("date", "term", "speaker", "text")
-    )
-    return f"{SOURCE_NAME}_{hashlib.sha256(material.encode('utf-8')).hexdigest()}"
+    return common.stable_document_id(row, SOURCE_NAME)
 
 
 def registry_entry() -> str:
@@ -108,33 +90,14 @@ def update_registry(registry: str) -> str:
 
 
 def legal_evidence(source_revision: str, target_revision: str) -> dict[str, Any]:
-    return {
-        "status": "reviewed-open-official-materials",
-        "source": SOURCE_NAME,
-        "dataset_record_license": SOURCE_LICENSE,
-        "hf_source_license_name": "polish-public-sector-open-statutory-reuse",
-        "provider": "Kancelaria Sejmu RP",
-        "official_source": SEJM_API,
-        "official_source_documentation": SEJM_API_DOCUMENTATION,
-        "copyright_basis": {
-            "act": "Polish Copyright and Related Rights Act",
-            "article": "4(2)",
-            "finding": "official documents and materials are excluded from copyright",
-            "url": COPYRIGHT_ACT,
-        },
-        "reuse_basis": {
-            "act": "Polish Open Data and Reuse of Public Sector Information Act",
-            "articles": ["2(12)", "5", "6", "14(1)", "15", "17"],
-            "url": OPEN_DATA_ACT,
-        },
-        "limitations": [
-            "privacy and personal-data exceptions",
-            "third-party rights and provider-specific conditions",
-            "no upstream Creative Commons grant is asserted",
-        ],
-        "pinned_source": f"hf://datasets/{SOURCE_REPOSITORY}@{source_revision}",
-        "pinned_target_base": f"hf://datasets/{TARGET_REPOSITORY}@{target_revision}",
-    }
+    return common.legal_evidence(
+        source_revision,
+        target_revision,
+        source_name=SOURCE_NAME,
+        source_license=SOURCE_LICENSE,
+        source_repository=SOURCE_REPOSITORY,
+        target_repository=TARGET_REPOSITORY,
+    )
 
 
 def datasheet(stats: dict[str, Any], source_revision: str, target_revision: str) -> str:

src/sejm_api_common.py

@@ -0,0 +1,90 @@
+"""Shared helpers for the Sejm API speech fetchers.
+
+Extracted from `fetch_sejm_api.py` and `fetch_sejm_api_2011_2022.py`, which kept
+byte-identical copies of these utilities (and of `legal_evidence` /
+`stable_document_id`, differing only in function signatures). Both fetchers now
+wrap these; behavior is unchanged.
+"""
+
+from __future__ import annotations
+
+import hashlib
+import json
+import pathlib
+from typing import Any
+
+COPYRIGHT_ACT = "https://eli.gov.pl/api/acts/DU/2025/24/text/O/D20250024.pdf"
+OPEN_DATA_ACT = "https://eli.gov.pl/api/acts/DU/2023/1524/text.html"
+SEJM_API = "https://api.sejm.gov.pl/"
+SEJM_API_DOCUMENTATION = "https://api.sejm.gov.pl/sejm.html"
+
+EXPECTED_FIELDS = (
+    "id", "text", "source", "added", "created", "token_count", "license", "author"
+)
+
+
+def sha256_file(path: pathlib.Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as stream:
+        for chunk in iter(lambda: stream.read(1024 * 1024), b""):
+            digest.update(chunk)
+    return digest.hexdigest()
+
+
+def canonical_sha256(value: Any) -> str:
+    payload = json.dumps(
+        value, ensure_ascii=False, sort_keys=True, separators=(",", ":")
+    ).encode("utf-8")
+    return hashlib.sha256(payload).hexdigest()
+
+
+def write_json(path: pathlib.Path, payload: Any) -> None:
+    path.write_text(
+        json.dumps(payload, ensure_ascii=False, indent=2, sort_keys=True) + "\n",
+        encoding="utf-8",
+    )
+
+
+def stable_document_id(row: dict[str, Any], source_name: str) -> str:
+    material = "\x1f".join(
+        str(row.get(field, "")).strip() for field in ("date", "term", "speaker", "text")
+    )
+    return f"{source_name}_{hashlib.sha256(material.encode('utf-8')).hexdigest()}"
+
+
+def legal_evidence(
+    source_revision: str,
+    target_revision: str,
+    *,
+    source_name: str,
+    source_license: str,
+    source_repository: str,
+    target_repository: str,
+) -> dict[str, Any]:
+    return {
+        "status": "reviewed-open-official-materials",
+        "source": source_name,
+        "dataset_record_license": source_license,
+        "hf_source_license_name": "polish-public-sector-open-statutory-reuse",
+        "provider": "Kancelaria Sejmu RP",
+        "official_source": SEJM_API,
+        "official_source_documentation": SEJM_API_DOCUMENTATION,
+        "copyright_basis": {
+            "act": "Polish Copyright and Related Rights Act",
+            "article": "4(2)",
+            "finding": "official documents and materials are excluded from copyright",
+            "url": COPYRIGHT_ACT,
+        },
+        "reuse_basis": {
+            "act": "Polish Act on Open Data and Reuse of Public Sector Information Act",
+            "articles": ["2(12)", "5", "6", "14(1)", "15", "17"],
+            "url": OPEN_DATA_ACT,
+        },
+        "limitations": [
+            "privacy and personal-data exceptions",
+            "third-party rights and provider-specific conditions",
+            "no upstream Creative Commons grant is asserted",
+        ],
+        "pinned_source": f"hf://datasets/{source_repository}@{source_revision}",
+        "pinned_target_base": f"hf://datasets/{target_repository}@{target_revision}",
+    }