seriesof: the series a book belongs to, and which volume this is

parity/tests/seriesof.rs

@@ -0,0 +1,124 @@
+//! Every series and volume read off a title must match the Python exactly.
+//!
+//! The cost of getting it wrong is a shelf that looks right and is not: a
+//! volume filed under the wrong series disappears from the work it belongs
+//! to, and a title reconstructed from the wrong template renames a book to
+//! something nobody published.
+
+use serde_json::Value;
+
+fn records(text: &str) -> Vec<Value> {
+    text.lines()
+        .filter(|line| !line.trim().is_empty())
+        .map(|line| serde_json::from_str(line).expect("valid JSON"))
+        .collect()
+}
+
+fn cases() -> Vec<Value> {
+    let text = std::fs::read_to_string(parity::dir().join("cases/seriesof/cases.ndjson"))
+        .expect("a readable case file");
+    records(&text)
+}
+
+/// A string field, where `null` and absent mean the same thing.
+fn text(value: &Value) -> Option<&str> {
+    value.as_str()
+}
+
+#[test]
+fn every_series_matches_python() {
+    let golden = records(&parity::read_golden_text("seriesof/cases.ndjson"));
+    let cases = cases();
+    assert_eq!(cases.len(), golden.len(), "case count moved — regenerate");
+
+    let mut wrong: Vec<String> = Vec::new();
+    for (case, theirs) in cases.iter().zip(&golden) {
+        let name = case["name"].as_str().expect("a name");
+        let kind = case["kind"].as_str().expect("a kind");
+        assert_eq!(theirs["name"].as_str(), Some(name), "cases out of order");
+
+        let mut note = |field: &str, ours: String, theirs: &Value| {
+            wrong.push(format!("{name}.{field}: python {theirs}, rust {ours}"));
+        };
+
+        match kind {
+            "number" => {
+                let ours = seriesof::roman_or_int(case["text"].as_str().expect("text"));
+                let theirs_number = theirs["number"].as_u64().map(|n| n as u32);
+                if ours != theirs_number {
+                    note("number", format!("{ours:?}"), &theirs["number"]);
+                }
+            }
+            "volume" => {
+                let found = seriesof::parse_volume(case["title"].as_str().expect("a title"));
+                let (series, volume) = match &found {
+                    Some((series, volume)) => (Some(series.as_str()), Some(*volume)),
+                    None => (None, None),
+                };
+                if series != text(&theirs["series"]) {
+                    note("series", format!("{series:?}"), &theirs["series"]);
+                }
+                let theirs_volume = theirs["volume"].as_u64().map(|n| n as u32);
+                if volume != theirs_volume {
+                    note("volume", format!("{volume:?}"), &theirs["volume"]);
+                }
+            }
+            "publisher" => {
+                let author = case["author"].as_str();
+                let found = author.and_then(|author| {
+                    seriesof::publisher_series(case["title"].as_str().expect("a title"), author)
+                });
+                let (proposed, series) = match &found {
+                    Some((proposed, series)) => (proposed.as_deref(), Some(series.as_str())),
+                    None => (None, None),
+                };
+                if proposed != text(&theirs["proposed_title"]) {
+                    note(
+                        "proposed_title",
+                        format!("{proposed:?}"),
+                        &theirs["proposed_title"],
+                    );
+                }
+                if series != text(&theirs["series"]) {
+                    note("series", format!("{series:?}"), &theirs["series"]);
+                }
+            }
+            other => panic!("nothing answers a {other} case"),
+        }
+    }
+
+    assert!(
+        wrong.is_empty(),
+        "{} answers differ:\n{}",
+        wrong.len(),
+        wrong
+            .iter()
+            .take(20)
+            .map(|line| line.chars().take(200).collect::<String>())
+            .collect::<Vec<_>>()
+            .join("\n")
+    );
+}
+
+/// All three questions have to be asked, or the file proves less than it
+/// looks like it does.
+#[test]
+fn every_kind_of_case_is_present() {
+    let cases = cases();
+    for kind in ["number", "volume", "publisher"] {
+        assert!(
+            cases.iter().any(|case| case["kind"] == kind),
+            "no {kind} case"
+        );
+    }
+}
+
+/// Catches a golden file drifting away from a Python that has moved on.
+#[test]
+#[cfg(feature = "python")]
+fn the_golden_file_still_matches_live_python() {
+    let cases = std::fs::read_to_string(parity::dir().join("cases/seriesof/cases.ndjson"))
+        .expect("a readable case file");
+    let live = parity::run_oracle("series.py", &cases).expect("the oracle runs");
+    assert_eq!(live, parity::read_golden_text("seriesof/cases.ndjson"));
+}