stack: docs verify prueft § Commands und § Error contracts in tools/CONTRACT.md getrennt, 10 fehlende Fehlerkontrakt-Zeilen nachgetragen (schliesst #91)

Files changed:
- CHANGES.md
- VERSION
- tools/CONTRACT.md
- tools/chemenu/commands/docs_verify.py
- tools/chemenu/tests/test_docs_verify.py

tools/chemenu/tests/test_docs_verify.py

@@ -42,13 +42,136 @@ def test_invented_subcommand_under_a_real_group_is_caught(tmp_path, monkeypatch)
     group. The reverse check must match the full registered path, not just
     the top-level word."""
     fake = tmp_path / "README.md"
-    fake.write_text("| `xref frobnicate --a X --b Y` | does not exist |\n", encoding="utf-8")
+    fake.write_text(
+        "## Commands\n\n"
+        "| `xref frobnicate --a X --b Y` | does not exist |\n\n"
+        "## Error contracts\n\n"
+        "| `xref frobnicate --a X --b Y` | does not exist |\n",
+        encoding="utf-8",
+    )
     monkeypatch.setattr(docs_verify, "CLI_README", fake)
     monkeypatch.setattr(docs_verify, "registered_commands", lambda: {"xref add", "xref remove"})
     issues = docs_verify.check_cli_readme()
     assert any("xref frobnicate" in issue for issue in issues)
 
 
+# --- section-scoped § Commands vs. § Error contracts (Gitea #91) ------------
+
+
+def test_section_text_extracts_between_headings():
+    text = "# T\n\n## A\n\nfoo\n\n## B\n\nbar\n"
+    assert docs_verify.section_text(text, "## A").strip() == "foo"
+
+
+def test_section_text_extends_to_end_of_file_when_last():
+    text = "# T\n\n## A\n\nfoo\nbar\n"
+    assert docs_verify.section_text(text, "## A").strip() == "foo\nbar"
+
+
+def test_section_text_raises_on_missing_heading():
+    with pytest.raises(ValueError):
+        docs_verify.section_text("# T\n\nno headings here\n", "## Commands")
+
+
+def _fake_contract(tmp_path, commands_rows: str, error_rows: str):
+    fake = tmp_path / "CONTRACT.md"
+    fake.write_text(
+        f"## Commands\n\n{commands_rows}\n## Error contracts\n\n{error_rows}\n",
+        encoding="utf-8",
+    )
+    return fake
+
+
+def test_a_row_deleted_from_commands_is_caught_even_if_error_contracts_still_has_it(
+    tmp_path, monkeypatch
+):
+    """Regression for the bug the section split fixes: before, a name
+    surviving in either table hid its own deletion from the other, so
+    § Commands losing a row was invisible as long as § Error contracts still
+    named it."""
+    fake = _fake_contract(
+        tmp_path,
+        commands_rows="| Command | Purpose |\n",  # `frobnicate`'s row was deleted here
+        error_rows="| `frobnicate` | never | yes | retry |\n",
+    )
+    monkeypatch.setattr(docs_verify, "CLI_README", fake)
+    monkeypatch.setattr(docs_verify, "registered_commands", lambda: {"frobnicate"})
+    issues = docs_verify.check_cli_readme()
+    assert any(
+        "frobnicate" in issue and "§ Commands" in issue and "not documented" in issue
+        for issue in issues
+    )
+
+
+def test_error_contracts_is_enforced_against_registered_commands(tmp_path, monkeypatch):
+    """Before the split, § Error contracts was never itself compared against
+    the registered commands - a row missing there was invisible."""
+    fake = _fake_contract(
+        tmp_path,
+        commands_rows="| `frobnicate` | does things |\n",
+        error_rows="| Command | Exit 1 means | Atomic? | Retry policy |\n",
+    )
+    monkeypatch.setattr(docs_verify, "CLI_README", fake)
+    monkeypatch.setattr(docs_verify, "registered_commands", lambda: {"frobnicate"})
+    issues = docs_verify.check_cli_readme()
+    assert any(
+        "frobnicate" in issue and "§ Error contracts" in issue and "not documented" in issue
+        for issue in issues
+    )
+
+
+def test_a_phantom_error_contract_row_is_reported(tmp_path, monkeypatch):
+    """The reverse direction inside § Error contracts: a row for a command
+    that does not exist must be reported there too, not only in § Commands."""
+    fake = _fake_contract(
+        tmp_path,
+        commands_rows="| `frobnicate` | does things |\n",
+        error_rows="| `frobnicate` | never | yes | retry |\n| `ghost command` | never happened | no | n/a |\n",
+    )
+    monkeypatch.setattr(docs_verify, "CLI_README", fake)
+    monkeypatch.setattr(docs_verify, "registered_commands", lambda: {"frobnicate"})
+    issues = docs_verify.check_cli_readme()
+    assert any(
+        "ghost command" in issue and "§ Error contracts" in issue and "not a wikitool command" in issue
+        for issue in issues
+    )
+
+
+def test_a_renamed_commands_heading_is_reported_not_silently_scanned(tmp_path, monkeypatch):
+    """A renamed or removed `## Commands` heading must fail loudly - falling
+    back to scanning the whole file would make the two tables indistinguishable
+    again, which is the exact bug this check exists to prevent."""
+    fake = tmp_path / "CONTRACT.md"
+    fake.write_text(
+        "## Kommandos\n\n"
+        "| `frobnicate` | does things |\n\n"
+        "## Error contracts\n\n"
+        "| `frobnicate` | never | yes | retry |\n",
+        encoding="utf-8",
+    )
+    monkeypatch.setattr(docs_verify, "CLI_README", fake)
+    monkeypatch.setattr(docs_verify, "registered_commands", lambda: {"frobnicate"})
+    issues = docs_verify.check_cli_readme()
+    assert any("no '## Commands' heading found" in issue for issue in issues)
+    assert not any("§ Commands" in issue and "not documented" in issue for issue in issues)
+
+
+def test_a_renamed_error_contracts_heading_is_reported_not_silently_scanned(tmp_path, monkeypatch):
+    fake = tmp_path / "CONTRACT.md"
+    fake.write_text(
+        "## Commands\n\n"
+        "| `frobnicate` | does things |\n\n"
+        "## Fehlerkontrakte\n\n"
+        "| `frobnicate` | never | yes | retry |\n",
+        encoding="utf-8",
+    )
+    monkeypatch.setattr(docs_verify, "CLI_README", fake)
+    monkeypatch.setattr(docs_verify, "registered_commands", lambda: {"frobnicate"})
+    issues = docs_verify.check_cli_readme()
+    assert any("no '## Error contracts' heading found" in issue for issue in issues)
+    assert not any("§ Error contracts" in issue and "not documented" in issue for issue in issues)
+
+
 def test_collection_contracts_exist():
     assert docs_verify.check_collection_contracts() == []