linter: expand to 21 rules covering all 8 source types (v0.3.0)

Close the defense-in-depth gap flagged after iter 6: chapter, magazine,
newspaper, social_media, podcast, and video exemplars had ZERO applicable
linter rules, so their 100% linter pass rate was trivially true. Every
exemplar now has 3-6 structural rules firing.

Bump LINTER_VERSION to v0.3.0. Per harness discipline, this invalidates
prior run logs' scores for cross-version comparison (they stay in the
log as history). The re-baseline run still scores scalar 1.000, canary
1.000 on all 14 exemplars — formatter was already producing output that
matches the new structural conventions, so tightening the linter didn't
surface any regressions.

New rules (12):
 - chapter_book_title_italicized
 - chapter_in_book_marker
 - magazine_name_italicized
 - newspaper_name_italicized
 - periodical_comma_before_date  (magazine + newspaper; not journal)
 - social_media_post_quoted
 - social_media_platform_comma_date
 - podcast_series_italicized
 - podcast_episode_quoted
 - podcast_format_label
 - video_title_quoted             (in quotes, NOT italicized)
 - video_format_label

Extended:
 - article_title_quoted           now covers journal, magazine, newspaper,
                                  and accepts ?/! as terminal punctuation

Each rule has a positive + negative unit test with the CMOS/Purdue source
cited in the docstring. Tests: 48 → 78 (30 new).

Per-exemplar applicable-rule counts after this change:
 book    4    journal  5-6  web        3
 chapter 4    magazine 5    social     4
 podcast 5    video    4    newspaper  5

src/cmos/linter.py

@@ -24,7 +24,7 @@ from typing import Callable
 
 from harness.score import Exemplar
 
-LINTER_VERSION = "v0.2.0"
+LINTER_VERSION = "v0.3.0"
 
 
 @dataclass
@@ -153,20 +153,30 @@ def rule_journal_title_italicized(candidate: str, exemplar: Exemplar) -> RuleRes
     )
 
 
+_PERIODICAL_TYPES = ("journal", "magazine", "newspaper")
+
+
 def rule_article_title_quoted(candidate: str, exemplar: Exemplar) -> RuleResult:
     """Article titles are wrapped in double quotes, with the trailing period inside the quotes.
 
     Source: Purdue OWL CMOS 18 NB poster page 3 "Bibliography: Basics" —
     "titles of articles, chapters, poems, etc. are placed in quotation marks."
     CMOS also places the terminating period inside the closing quote
-    (American style).
+    (American style). Applies to journal, magazine, and newspaper articles.
     """
-    if exemplar.type != "journal":
+    if exemplar.type not in _PERIODICAL_TYPES:
         return RuleResult(name="article_title_quoted", applicable=False, passed=True)
     article_title = exemplar.canonical.get("article_title")
     if not article_title:
         return RuleResult(name="article_title_quoted", applicable=False, passed=True)
-    passed = f'"{article_title}."' in candidate
+    # Period OR question mark OR exclamation point closing — CMOS preserves
+    # terminal punctuation that's part of the title (e.g., "Are Flax Seeds All
+    # That?").
+    variants = (
+        f'"{article_title}."',
+        f'"{article_title}"' if article_title[-1] in "?!" else None,
+    )
+    passed = any(v is not None and v in candidate for v in variants)
     return RuleResult(
         name="article_title_quoted",
         applicable=True,
@@ -243,6 +253,284 @@ def rule_web_page_title_quoted(candidate: str, exemplar: Exemplar) -> RuleResult
     )
 
 
+# --- Chapter rules ------------------------------------------------------------
+
+
+def rule_chapter_book_title_italicized(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """For a chapter in an edited volume, the enclosing book's title is italicized.
+
+    Source: Purdue OWL CMOS 18 NB page 3, "Article, Chapter, Essay, etc., in
+    a Book or Edited Collection" — the book title is italicized like any
+    other book title.
+    """
+    if exemplar.type != "chapter":
+        return RuleResult(name="chapter_book_title_italicized", applicable=False, passed=True)
+    book_title = exemplar.canonical.get("book_title")
+    if not book_title:
+        return RuleResult(name="chapter_book_title_italicized", applicable=False, passed=True)
+    passed = f"*{book_title}*" in candidate
+    return RuleResult(
+        name="chapter_book_title_italicized",
+        applicable=True,
+        passed=passed,
+        message="" if passed else f"enclosing book title '{book_title}' must be wrapped in *...*",
+    )
+
+
+def rule_chapter_in_book_marker(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Chapter entries include the keyword "In" before the italicized book title.
+
+    Source: Purdue OWL CMOS 18 NB page 3 example: "Chilson, Peter. 'The
+    Border.' In *The Best American Travel Writing 2008*, ..." The "In"
+    keyword distinguishes a chapter from a standalone book.
+    """
+    if exemplar.type != "chapter":
+        return RuleResult(name="chapter_in_book_marker", applicable=False, passed=True)
+    # "In *" — capital I, capital N, space, asterisk marking the start of the
+    # italicized book title. Strict; catches "in *" (lowercase) as a failure.
+    passed = " In *" in candidate or candidate.startswith("In *")
+    return RuleResult(
+        name="chapter_in_book_marker",
+        applicable=True,
+        passed=passed,
+        message="" if passed else "chapter entry must contain 'In *BookTitle*'",
+    )
+
+
+# --- Magazine / newspaper rules -----------------------------------------------
+
+
+def rule_magazine_name_italicized(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Magazine titles are italicized.
+
+    Source: CMOS 18 quick guide example (e.g., *New Yorker*, December 18,
+    2023).
+    """
+    if exemplar.type != "magazine":
+        return RuleResult(name="magazine_name_italicized", applicable=False, passed=True)
+    magazine = exemplar.canonical.get("magazine")
+    if not magazine:
+        return RuleResult(name="magazine_name_italicized", applicable=False, passed=True)
+    passed = f"*{magazine}*" in candidate
+    return RuleResult(
+        name="magazine_name_italicized",
+        applicable=True,
+        passed=passed,
+        message="" if passed else f"magazine title '{magazine}' must be wrapped in *...*",
+    )
+
+
+def rule_newspaper_name_italicized(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Newspaper titles are italicized.
+
+    Source: CMOS 18 quick guide example (e.g., *New York Times*, December
+    13, 2023).
+    """
+    if exemplar.type != "newspaper":
+        return RuleResult(name="newspaper_name_italicized", applicable=False, passed=True)
+    newspaper = exemplar.canonical.get("newspaper")
+    if not newspaper:
+        return RuleResult(name="newspaper_name_italicized", applicable=False, passed=True)
+    passed = f"*{newspaper}*" in candidate
+    return RuleResult(
+        name="newspaper_name_italicized",
+        applicable=True,
+        passed=passed,
+        message="" if passed else f"newspaper title '{newspaper}' must be wrapped in *...*",
+    )
+
+
+def rule_periodical_comma_before_date(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Magazine and newspaper entries use a comma between the italic name and the date.
+
+    Journals use a different structure (volume, issue, year in parens), so
+    this rule only applies to magazines and newspapers.
+
+    Source: CMOS 18 quick guide examples — "*New Yorker*, December 18,
+    2023."; "*New York Times*, December 13, 2023."
+    """
+    if exemplar.type not in ("magazine", "newspaper"):
+        return RuleResult(name="periodical_comma_before_date", applicable=False, passed=True)
+    name = exemplar.canonical.get("magazine") or exemplar.canonical.get("newspaper")
+    if not name:
+        return RuleResult(name="periodical_comma_before_date", applicable=False, passed=True)
+    passed = f"*{name}*, " in candidate
+    return RuleResult(
+        name="periodical_comma_before_date",
+        applicable=True,
+        passed=passed,
+        message=(
+            ""
+            if passed
+            else f"'*{name}*' must be followed by a comma-space, not a period or nothing"
+        ),
+    )
+
+
+# --- Social media rules -------------------------------------------------------
+
+
+def rule_social_media_post_quoted(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Social media post content is wrapped in straight double quotes.
+
+    Source: CMOS 18 quick guide example: 'Chicago Manual of Style. "Is the
+    world ready for singular they? ..." Facebook, April 17, 2015. URL.'
+    Original post casing must be preserved (this rule checks for the
+    canonical form literally — if the formatter title-cases the post, the
+    match fails).
+    """
+    if exemplar.type != "social_media":
+        return RuleResult(name="social_media_post_quoted", applicable=False, passed=True)
+    post_text = exemplar.canonical.get("post_text")
+    if not post_text:
+        return RuleResult(name="social_media_post_quoted", applicable=False, passed=True)
+    passed = f'"{post_text}"' in candidate
+    return RuleResult(
+        name="social_media_post_quoted",
+        applicable=True,
+        passed=passed,
+        message="" if passed else "post content must appear verbatim inside double quotes",
+    )
+
+
+def rule_social_media_platform_comma_date(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Social media entries use a comma between the platform name and the date.
+
+    Source: CMOS 18 quick guide: '... Facebook, April 17, 2015. URL.'
+    """
+    if exemplar.type != "social_media":
+        return RuleResult(
+            name="social_media_platform_comma_date", applicable=False, passed=True
+        )
+    platform = exemplar.canonical.get("platform")
+    if not platform:
+        return RuleResult(
+            name="social_media_platform_comma_date", applicable=False, passed=True
+        )
+    passed = f"{platform}, " in candidate
+    return RuleResult(
+        name="social_media_platform_comma_date",
+        applicable=True,
+        passed=passed,
+        message=(
+            ""
+            if passed
+            else f"'{platform}' must be followed by a comma-space before the date"
+        ),
+    )
+
+
+# --- Podcast rules ------------------------------------------------------------
+
+
+def rule_podcast_series_italicized(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Podcast series titles are italicized like book titles.
+
+    Source: CMOS 18 quick guide example: 'Ober, Lauren, host. *The Loudest
+    Girl in the World*. Season 1, episode 2, ...'
+    """
+    if exemplar.type != "podcast":
+        return RuleResult(name="podcast_series_italicized", applicable=False, passed=True)
+    podcast = exemplar.canonical.get("podcast")
+    if not podcast:
+        return RuleResult(name="podcast_series_italicized", applicable=False, passed=True)
+    passed = f"*{podcast}*" in candidate
+    return RuleResult(
+        name="podcast_series_italicized",
+        applicable=True,
+        passed=passed,
+        message="" if passed else f"podcast series '{podcast}' must be wrapped in *...*",
+    )
+
+
+def rule_podcast_episode_quoted(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Podcast episode titles are in straight double quotes.
+
+    Source: CMOS 18 quick guide example (Ober). Terminal punctuation (! ?
+    .) that's part of the title must also be inside the closing quote.
+    """
+    if exemplar.type != "podcast":
+        return RuleResult(name="podcast_episode_quoted", applicable=False, passed=True)
+    episode = exemplar.canonical.get("episode_title")
+    if not episode:
+        return RuleResult(name="podcast_episode_quoted", applicable=False, passed=True)
+    # Accept the episode with its source-provided trailing punctuation OR
+    # with an added period (CMOS American-style period inside quote).
+    variants = [f'"{episode}"', f'"{episode}."']
+    passed = any(v in candidate for v in variants)
+    return RuleResult(
+        name="podcast_episode_quoted",
+        applicable=True,
+        passed=passed,
+        message="" if passed else f'episode title must appear in "{episode}"',
+    )
+
+
+def rule_podcast_format_label(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Podcast entries include a 'Podcast,' format label before the duration.
+
+    Source: CMOS 18 quick guide example: '... Pushkin Industries,
+    September 13, 2022. Podcast, 41 min., 37 sec. URL.'
+    """
+    if exemplar.type != "podcast":
+        return RuleResult(name="podcast_format_label", applicable=False, passed=True)
+    passed = "Podcast, " in candidate
+    return RuleResult(
+        name="podcast_format_label",
+        applicable=True,
+        passed=passed,
+        message="" if passed else "podcast entry must contain the 'Podcast, ' format label",
+    )
+
+
+# --- Video rules --------------------------------------------------------------
+
+
+def rule_video_title_quoted(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Video titles are in straight double quotes (not italicized).
+
+    Unlike books/journals/podcasts, video/TED-talk titles are treated as
+    shorter works and put in quotes.
+
+    Source: CMOS 18 quick guide example: 'Cowan, Vaitea. "How Green
+    Hydrogen Could End the Fossil Fuel Era." TED Talk, ...'
+    """
+    if exemplar.type != "video":
+        return RuleResult(name="video_title_quoted", applicable=False, passed=True)
+    title = exemplar.canonical.get("title")
+    if not title:
+        return RuleResult(name="video_title_quoted", applicable=False, passed=True)
+    # Must be in quotes, not in italic markers.
+    passed = f'"{title}."' in candidate and f"*{title}*" not in candidate
+    return RuleResult(
+        name="video_title_quoted",
+        applicable=True,
+        passed=passed,
+        message=(
+            ""
+            if passed
+            else f'video title must appear as "{title}." (in quotes, not italicized)'
+        ),
+    )
+
+
+def rule_video_format_label(candidate: str, exemplar: Exemplar) -> RuleResult:
+    """Video entries include a 'Video,' format label before the duration.
+
+    Source: CMOS 18 quick guide example: '... April 2022. Video, 9 min.,
+    15 sec. URL.'
+    """
+    if exemplar.type != "video":
+        return RuleResult(name="video_format_label", applicable=False, passed=True)
+    passed = "Video, " in candidate
+    return RuleResult(
+        name="video_format_label",
+        applicable=True,
+        passed=passed,
+        message="" if passed else "video entry must contain the 'Video, ' format label",
+    )
+
+
 RULES: list[RuleFn] = [
     rule_ends_with_period,
     rule_no_place_of_publication_for_books,
@@ -253,6 +541,18 @@ RULES: list[RuleFn] = [
     rule_page_range_uses_en_dash,
     rule_doi_is_https_url,
     rule_web_page_title_quoted,
+    rule_chapter_book_title_italicized,
+    rule_chapter_in_book_marker,
+    rule_magazine_name_italicized,
+    rule_newspaper_name_italicized,
+    rule_periodical_comma_before_date,
+    rule_social_media_post_quoted,
+    rule_social_media_platform_comma_date,
+    rule_podcast_series_italicized,
+    rule_podcast_episode_quoted,
+    rule_podcast_format_label,
+    rule_video_title_quoted,
+    rule_video_format_label,
 ]
 
 

tests/test_linter.py

@@ -15,12 +15,24 @@ from cmos.linter import (
     lint,
     rule_article_title_quoted,
     rule_book_title_italicized,
+    rule_chapter_book_title_italicized,
+    rule_chapter_in_book_marker,
     rule_doi_is_https_url,
     rule_ends_with_period,
     rule_journal_title_italicized,
+    rule_magazine_name_italicized,
+    rule_newspaper_name_italicized,
     rule_no_ibid,
     rule_no_place_of_publication_for_books,
     rule_page_range_uses_en_dash,
+    rule_periodical_comma_before_date,
+    rule_podcast_episode_quoted,
+    rule_podcast_format_label,
+    rule_podcast_series_italicized,
+    rule_social_media_platform_comma_date,
+    rule_social_media_post_quoted,
+    rule_video_format_label,
+    rule_video_title_quoted,
     rule_web_page_title_quoted,
 )
 from harness.score import Exemplar
@@ -81,6 +93,114 @@ WEB = Exemplar(
     expected_bibliography='Google. "Privacy Policy." Privacy & Terms. Effective November 15, 2023. https://policies.google.com/privacy.',
 )
 
+CHAPTER = Exemplar(
+    name="chapter",
+    source="test",
+    type="chapter",
+    tags=["chapter"],
+    canary=False,
+    messy_input="",
+    canonical={
+        "author": "Doyle, Kathleen",
+        "chapter_title": "The Queen Mary Psalter",
+        "book_title": "The Book by Design: The Remarkable Story of the World's Greatest Invention",
+        "editors": "edited by P. J. M. Marks and Stephen Parkin",
+        "publisher": "University of Chicago Press",
+        "year": 2023,
+    },
+    expected_bibliography='Doyle, Kathleen. "The Queen Mary Psalter." In *The Book by Design: The Remarkable Story of the World\'s Greatest Invention*, edited by P. J. M. Marks and Stephen Parkin. University of Chicago Press, 2023.',
+)
+
+MAGAZINE = Exemplar(
+    name="magazine",
+    source="test",
+    type="magazine",
+    tags=["magazine"],
+    canary=False,
+    messy_input="",
+    canonical={
+        "author": "Mead, Rebecca",
+        "article_title": "Terms of Aggrievement",
+        "magazine": "New Yorker",
+        "date": "December 18, 2023",
+    },
+    expected_bibliography='Mead, Rebecca. "Terms of Aggrievement." *New Yorker*, December 18, 2023.',
+)
+
+NEWSPAPER = Exemplar(
+    name="newspaper",
+    source="test",
+    type="newspaper",
+    tags=["newspaper"],
+    canary=False,
+    messy_input="",
+    canonical={
+        "author": "Blum, Dani",
+        "article_title": "Are Flax Seeds All That?",
+        "newspaper": "New York Times",
+        "date": "December 13, 2023",
+        "url": "https://www.nytimes.com/2023/12/13/well/eat/flax-seeds-benefits.html",
+    },
+    expected_bibliography='Blum, Dani. "Are Flax Seeds All That?" *New York Times*, December 13, 2023. https://www.nytimes.com/2023/12/13/well/eat/flax-seeds-benefits.html.',
+)
+
+SOCIAL = Exemplar(
+    name="social_media",
+    source="test",
+    type="social_media",
+    tags=["social_media"],
+    canary=False,
+    messy_input="",
+    canonical={
+        "author": "Chicago Manual of Style",
+        "post_text": "Is the world ready for singular they? We thought so in 1993.",
+        "platform": "Facebook",
+        "date": "April 17, 2015",
+        "url": "https://www.facebook.com/ChicagoManual/posts/10152906193679151",
+    },
+    expected_bibliography='Chicago Manual of Style. "Is the world ready for singular they? We thought so in 1993." Facebook, April 17, 2015. https://www.facebook.com/ChicagoManual/posts/10152906193679151.',
+)
+
+PODCAST = Exemplar(
+    name="podcast",
+    source="test",
+    type="podcast",
+    tags=["podcast"],
+    canary=False,
+    messy_input="",
+    canonical={
+        "host": "Ober, Lauren, host",
+        "podcast": "The Loudest Girl in the World",
+        "season_episode": "Season 1, episode 2",
+        "episode_title": "Goodbye, Routine; Hello, Meltdown!",
+        "publisher": "Pushkin Industries",
+        "date": "September 13, 2022",
+        "format": "Podcast",
+        "duration": "41 min., 37 sec.",
+        "url": "https://www.pushkin.fm/podcasts/loudest-girl-in-the-world",
+    },
+    expected_bibliography='Ober, Lauren, host. *The Loudest Girl in the World*. Season 1, episode 2, "Goodbye, Routine; Hello, Meltdown!" Pushkin Industries, September 13, 2022. Podcast, 41 min., 37 sec. https://www.pushkin.fm/podcasts/loudest-girl-in-the-world.',
+)
+
+VIDEO = Exemplar(
+    name="video",
+    source="test",
+    type="video",
+    tags=["video"],
+    canary=False,
+    messy_input="",
+    canonical={
+        "author": "Cowan, Vaitea",
+        "title": "How Green Hydrogen Could End the Fossil Fuel Era",
+        "venue": "TED Talk, Vancouver, BC",
+        "date": "April 2022",
+        "format": "Video",
+        "duration": "9 min., 15 sec.",
+        "url": "https://www.ted.com/talks/vaitea_cowan_how_green_hydrogen_could_end_the_fossil_fuel_era",
+    },
+    expected_bibliography='Cowan, Vaitea. "How Green Hydrogen Could End the Fossil Fuel Era." TED Talk, Vancouver, BC, April 2022. Video, 9 min., 15 sec. https://www.ted.com/talks/vaitea_cowan_how_green_hydrogen_could_end_the_fossil_fuel_era.',
+)
+
 
 def test_linter_version_is_set():
     assert LINTER_VERSION
@@ -254,13 +374,229 @@ def test_web_page_title_quoted_fails_when_unquoted():
     assert result.passed is False
 
 
+# --- Article title rule extended to magazines and newspapers -----------------
+
+
+def test_article_title_quoted_passes_on_magazine():
+    # Magazines follow the same article-title convention as journals.
+    result = rule_article_title_quoted(MAGAZINE.expected_bibliography, MAGAZINE)
+    assert result.applicable is True
+    assert result.passed is True
+
+
+def test_article_title_quoted_passes_on_newspaper():
+    result = rule_article_title_quoted(NEWSPAPER.expected_bibliography, NEWSPAPER)
+    assert result.applicable is True
+    assert result.passed is True
+
+
+def test_article_title_quoted_not_applicable_to_book():
+    result = rule_article_title_quoted(BOOK.expected_bibliography, BOOK)
+    assert result.applicable is False
+
+
+# --- Chapter rules ------------------------------------------------------------
+
+
+def test_chapter_book_title_italicized_passes():
+    # Chapters have their enclosing book's title italicized (CMOS 18,
+    # "Article, Chapter, Essay, etc., in a Book" model).
+    result = rule_chapter_book_title_italicized(CHAPTER.expected_bibliography, CHAPTER)
+    assert result.applicable is True
+    assert result.passed is True
+
+
+def test_chapter_book_title_italicized_fails_when_plain():
+    bad = CHAPTER.expected_bibliography.replace(
+        "*The Book by Design: The Remarkable Story of the World's Greatest Invention*",
+        "The Book by Design: The Remarkable Story of the World's Greatest Invention",
+    )
+    result = rule_chapter_book_title_italicized(bad, CHAPTER)
+    assert result.passed is False
+
+
+def test_chapter_book_title_italicized_not_applicable_to_book():
+    result = rule_chapter_book_title_italicized(BOOK.expected_bibliography, BOOK)
+    assert result.applicable is False
+
+
+def test_chapter_in_book_marker_passes():
+    # Chapter entries include the keyword "In" before the italicized book
+    # title to distinguish them from standalone books.
+    result = rule_chapter_in_book_marker(CHAPTER.expected_bibliography, CHAPTER)
+    assert result.passed is True
+
+
+def test_chapter_in_book_marker_fails_without_in():
+    bad = CHAPTER.expected_bibliography.replace(" In *", " *")
+    result = rule_chapter_in_book_marker(bad, CHAPTER)
+    assert result.passed is False
+
+
+# --- Magazine and newspaper name italicized ----------------------------------
+
+
+def test_magazine_name_italicized_passes():
+    # CMOS 18: magazine titles are italicized.
+    result = rule_magazine_name_italicized(MAGAZINE.expected_bibliography, MAGAZINE)
+    assert result.passed is True
+
+
+def test_magazine_name_italicized_fails_when_plain():
+    bad = MAGAZINE.expected_bibliography.replace("*New Yorker*", "New Yorker")
+    result = rule_magazine_name_italicized(bad, MAGAZINE)
+    assert result.passed is False
+
+
+def test_newspaper_name_italicized_passes():
+    result = rule_newspaper_name_italicized(NEWSPAPER.expected_bibliography, NEWSPAPER)
+    assert result.passed is True
+
+
+def test_newspaper_name_italicized_fails_when_plain():
+    bad = NEWSPAPER.expected_bibliography.replace("*New York Times*", "New York Times")
+    result = rule_newspaper_name_italicized(bad, NEWSPAPER)
+    assert result.passed is False
+
+
+# --- Periodical comma before date (magazine/newspaper only) -------------------
+
+
+def test_periodical_comma_before_date_passes_on_magazine():
+    # Magazines and newspapers use a COMMA between the italicized name and
+    # the date, not a period: *New Yorker*, December 18, 2023.
+    result = rule_periodical_comma_before_date(MAGAZINE.expected_bibliography, MAGAZINE)
+    assert result.passed is True
+
+
+def test_periodical_comma_before_date_fails_when_period_used():
+    bad = MAGAZINE.expected_bibliography.replace("*New Yorker*,", "*New Yorker*.")
+    result = rule_periodical_comma_before_date(bad, MAGAZINE)
+    assert result.passed is False
+
+
+def test_periodical_comma_before_date_passes_on_newspaper():
+    result = rule_periodical_comma_before_date(NEWSPAPER.expected_bibliography, NEWSPAPER)
+    assert result.passed is True
+
+
+def test_periodical_comma_before_date_not_applicable_to_journal():
+    # Journals use volume/issue/year in parens, no comma-after-italic pattern.
+    result = rule_periodical_comma_before_date(JOURNAL.expected_bibliography, JOURNAL)
+    assert result.applicable is False
+
+
+# --- Social media rules -------------------------------------------------------
+
+
+def test_social_media_post_quoted_passes():
+    # The post content is wrapped in straight double quotes.
+    result = rule_social_media_post_quoted(SOCIAL.expected_bibliography, SOCIAL)
+    assert result.passed is True
+
+
+def test_social_media_post_quoted_fails_when_title_cased():
+    # Title-casing is a common LLM error on social media content.
+    bad = SOCIAL.expected_bibliography.replace(
+        "Is the world ready for singular they? We thought so in 1993.",
+        "Is the World Ready for Singular They? We Thought So in 1993.",
+    )
+    result = rule_social_media_post_quoted(bad, SOCIAL)
+    assert result.passed is False
+
+
+def test_social_media_platform_comma_date_passes():
+    # The platform name is followed by a comma (not a period) before the date.
+    result = rule_social_media_platform_comma_date(SOCIAL.expected_bibliography, SOCIAL)
+    assert result.passed is True
+
+
+def test_social_media_platform_comma_date_fails_when_period_used():
+    bad = SOCIAL.expected_bibliography.replace("Facebook, April", "Facebook. April")
+    result = rule_social_media_platform_comma_date(bad, SOCIAL)
+    assert result.passed is False
+
+
+# --- Podcast rules ------------------------------------------------------------
+
+
+def test_podcast_series_italicized_passes():
+    # Podcast series titles are italicized like book titles.
+    result = rule_podcast_series_italicized(PODCAST.expected_bibliography, PODCAST)
+    assert result.passed is True
+
+
+def test_podcast_series_italicized_fails_when_plain():
+    bad = PODCAST.expected_bibliography.replace(
+        "*The Loudest Girl in the World*", "The Loudest Girl in the World"
+    )
+    result = rule_podcast_series_italicized(bad, PODCAST)
+    assert result.passed is False
+
+
+def test_podcast_episode_quoted_passes():
+    # Episode titles are in quotes (including terminal punctuation like !).
+    result = rule_podcast_episode_quoted(PODCAST.expected_bibliography, PODCAST)
+    assert result.passed is True
+
+
+def test_podcast_episode_quoted_fails_when_unquoted():
+    bad = PODCAST.expected_bibliography.replace(
+        '"Goodbye, Routine; Hello, Meltdown!"',
+        "Goodbye, Routine; Hello, Meltdown!",
+    )
+    result = rule_podcast_episode_quoted(bad, PODCAST)
+    assert result.passed is False
+
+
+def test_podcast_format_label_passes():
+    # CMOS includes a "Podcast," format label before duration.
+    result = rule_podcast_format_label(PODCAST.expected_bibliography, PODCAST)
+    assert result.passed is True
+
+
+def test_podcast_format_label_fails_when_missing():
+    bad = PODCAST.expected_bibliography.replace("Podcast, ", "")
+    result = rule_podcast_format_label(bad, PODCAST)
+    assert result.passed is False
+
+
+# --- Video rules --------------------------------------------------------------
+
+
+def test_video_title_quoted_passes():
+    # Video/TED Talk titles are in quotes (not italicized).
+    result = rule_video_title_quoted(VIDEO.expected_bibliography, VIDEO)
+    assert result.passed is True
+
+
+def test_video_title_quoted_fails_when_italicized():
+    bad = VIDEO.expected_bibliography.replace(
+        '"How Green Hydrogen Could End the Fossil Fuel Era."',
+        "*How Green Hydrogen Could End the Fossil Fuel Era.*",
+    )
+    result = rule_video_title_quoted(bad, VIDEO)
+    assert result.passed is False
+
+
+def test_video_format_label_passes():
+    # CMOS includes a "Video," format label before duration.
+    result = rule_video_format_label(VIDEO.expected_bibliography, VIDEO)
+    assert result.passed is True
+
+
+def test_video_format_label_fails_when_missing():
+    bad = VIDEO.expected_bibliography.replace("Video, ", "")
+    result = rule_video_format_label(bad, VIDEO)
+    assert result.passed is False
+
+
 # --- Aggregate check_passes ---------------------------------------------------
 
 
 def test_check_passes_on_canonical_outputs():
-    # All three seed exemplars' expected_bibliography strings must lint clean.
+    # Every in-test exemplar's expected_bibliography must lint clean.
-    # If any of them fail, either the linter is too strict or the exemplar is
+    # If any fail, either the linter is too strict or the exemplar is wrong —
-    # wrong — either way, we want to know immediately.
+    # either way, we want to know immediately.
-    assert check_passes(BOOK.expected_bibliography, BOOK)
+    for ex in (BOOK, JOURNAL, WEB, CHAPTER, MAGAZINE, NEWSPAPER, SOCIAL, PODCAST, VIDEO):
-    assert check_passes(JOURNAL.expected_bibliography, JOURNAL)
+        assert check_passes(ex.expected_bibliography, ex), f"linter rejected {ex.name}"
-    assert check_passes(WEB.expected_bibliography, WEB)