Few explanations how the game works

README.md

@@ -2,8 +2,15 @@
 
 A text dungeon game that teaches you YAML.
 
+The game uses actual YAML parsing libraries and generates semi-random levels
+by describing a secret YAML file that the user has to recreate in the editor.
+
+There are 11 levels in the game, so if you're on level 12, you won the game!
+
 ![screenshot](screenshot.png)
 
 ## How to start:
 
-    cargo run
+    cargo run
+
+## Dependencies

src/levels/l07_complex.rs

@@ -112,14 +112,16 @@ impl Level for Complex {
             serde_yaml::to_string(&Value::Mapping(top)).expect("serialise mapping");
 
         let mut d = Describer::new();
+        // No tab characters: ratatui's Paragraph renders tabs unevenly,
+        // which combined with the typewriter's progressive reveal can
+        // produce overlapping characters. Use plain spaces for indents.
         d.register(
             "l07",
-            "Floor {{ floor }}.\n\
-             {% for r in rooms %}\n\
-             {{ r.name }} — a {{ r.kind }} (locked: {{ r.locked }})\n\
-             \texits:    {% for e in r.exits %}{{ e }}{% if not loop.last %}, {% endif %}{% endfor %}\n\
-             \tcontents: {% for c in r.contents %}{{ c }}{% if not loop.last %}, {% endif %}{% endfor %}\n\
-             {% endfor %}\n\
+            "Floor {{ floor }}.\n\n\
+             {% for r in rooms %}{{ r.name }} — a {{ r.kind }} (locked: {{ r.locked }})\n\
+               exits:    {% for e in r.exits %}{{ e }}{% if not loop.last %}, {% endif %}{% endfor %}\n\
+               contents: {% for c in r.contents %}{{ c }}{% if not loop.last %}, {% endif %}{% endfor %}\n\n\
+             {% endfor %}\
              💡 Combine maps, lists, and scalars — `floor:` is an int, each room is a dict with two lists.",
         )
         .expect("register template");

src/levels/mod.rs

@@ -93,5 +93,11 @@ pub fn registry() -> Vec<Box<dyn Level>> {
         Box::new(l03_dict::Dict),
         Box::new(l04_list::List),
         Box::new(l05_dict_list::DictList),
+        Box::new(l06_anchors::Anchors),
+        Box::new(l07_complex::Complex),
+        Box::new(l08_tags::Tags),
+        Box::new(l09_operators::Operators),
+        Box::new(l10_dynamic::Dynamic),
+        Box::new(l11_adv_anchors::AdvAnchors),
     ]
 }

src/lib.rs

@@ -81,50 +81,246 @@ mod smoke {
         assert_eq!(loaded.current_seed, p.current_seed);
     }
 
-    #[test]
-    fn levels_generate_canonical_yaml() {
-        let registry = levels::registry();
-        assert_eq!(registry.len(), 3);
+    // ---- Per-level tests --------------------------------------------
+    //
+    // One test per level. `checked_level` runs the invariants every
+    // level must satisfy (correct id, valid & deterministic canonical
+    // YAML, self-similarity 1.0); each test then pins the *shape* its
+    // design note promises and, where it is the whole lesson, the
+    // semantic forgiveness.
 
-        // Level 1: any null-equivalent passes via the semantic short-circuit.
-        let g1 = registry[0].generate(0);
-        let parsed: serde_yaml::Value = serde_yaml::from_str(&g1.target_yaml).unwrap();
-        assert!(parsed.is_null());
+    /// Look up a string key in a YAML mapping, panicking with a clear
+    /// message if it is missing — keeps the per-level assertions terse.
+    fn field<'a>(v: &'a Value, key: &str) -> &'a Value {
+        v.get(key)
+            .unwrap_or_else(|| panic!("expected key `{key}` in {v:?}"))
+    }
+
+    /// Parse a target YAML string, asserting it is well-formed.
+    fn parse(yaml: &str) -> Value {
+        serde_yaml::from_str(yaml).expect("target is valid YAML")
+    }
+
+    /// Generate level `index` (0-based) with `seed`, assert the invariants
+    /// every level must satisfy, and return its output for shape checks:
+    /// - the level reports `id == index + 1`,
+    /// - the target is valid YAML,
+    /// - generation is deterministic for a given seed,
+    /// - the canonical target scores 1.0 against itself.
+    fn checked_level(index: usize, seed: u64) -> levels::Generated {
+        let registry = levels::registry();
+        let level = &registry[index];
+        let want_id = index as u8 + 1;
         assert_eq!(
-            similarity::semantic_or_textual(&g1.target_yaml, "---"),
+            level.id(),
+            want_id,
+            "registry index {index} must hold level {want_id}"
+        );
+
+        let g = level.generate(seed);
+        serde_yaml::from_str::<Value>(&g.target_yaml)
+            .unwrap_or_else(|e| panic!("level {want_id} target is not valid YAML: {e}"));
+
+        let again = level.generate(seed);
+        assert_eq!(
+            g.target_yaml, again.target_yaml,
+            "level {want_id} must be deterministic for a given seed"
+        );
+
+        assert_eq!(
+            similarity::semantic_or_textual(&g.target_yaml, &g.target_yaml),
+            1.0,
+            "level {want_id} target must score 1.0 against itself"
+        );
+        g
+    }
+
+    #[test]
+    fn registry_lists_all_eleven_levels() {
+        assert_eq!(
+            levels::registry().len(),
+            11,
+            "all 11 levels must be registered"
+        );
+    }
+
+    #[test]
+    fn level_01_minimum_is_a_null_document() {
+        // Any null-equivalent passes via the semantic short-circuit.
+        let g = checked_level(0, 0);
+        assert!(parse(&g.target_yaml).is_null(), "the minimum YAML is null");
+        assert_eq!(
+            similarity::semantic_or_textual(&g.target_yaml, "---"),
             1.0,
             "`---` should be accepted as the minimum YAML"
         );
         assert_eq!(
-            similarity::semantic_or_textual(&g1.target_yaml, "null"),
-            1.0
+            similarity::semantic_or_textual(&g.target_yaml, "null"),
+            1.0,
+            "`null` should be accepted as the minimum YAML"
         );
+    }
 
-        // Level 2: deterministic per seed, non-empty mapping.
-        let g2 = registry[1].generate(42);
-        let v2: serde_yaml::Value = serde_yaml::from_str(&g2.target_yaml).unwrap();
-        let m = v2.as_mapping().expect("level 2 produces a mapping");
-        assert!(!m.is_empty());
-        let g2_again = registry[1].generate(42);
-        assert_eq!(
-            g2.target_yaml, g2_again.target_yaml,
-            "same seed should produce the same target"
+    #[test]
+    fn level_02_key_value_is_a_non_empty_mapping() {
+        let g = checked_level(1, 42);
+        let v = parse(&g.target_yaml);
+        assert!(
+            !v.as_mapping()
+                .expect("level 2 produces a mapping")
+                .is_empty(),
+            "level 2 yields a non-empty mapping"
         );
+    }
 
-        // Level 3: deterministic per seed; produces a mapping of mappings,
-        // each inner mapping has a `type` key.
-        let g3 = registry[2].generate(123);
-        let v3: serde_yaml::Value = serde_yaml::from_str(&g3.target_yaml).unwrap();
-        let m3 = v3.as_mapping().expect("level 3 produces a mapping");
-        assert!(!m3.is_empty());
-        for (_dir, feature) in m3 {
-            let inner = feature.as_mapping().expect("level 3 inner is a mapping");
+    #[test]
+    fn level_03_dict_nests_typed_mappings() {
+        // A mapping of mappings; each inner mapping carries a `type` key.
+        let g = checked_level(2, 123);
+        let v = parse(&g.target_yaml);
+        let m = v.as_mapping().expect("level 3 produces a mapping");
+        assert!(!m.is_empty(), "at least one direction");
+        for (_dir, feature) in m {
+            feature.as_mapping().expect("level 3 inner is a mapping");
             assert!(
-                inner.get(serde_yaml::Value::String("type".into())).is_some(),
+                feature.get("type").is_some(),
                 "each direction must carry a `type` key"
             );
         }
-        let g3_again = registry[2].generate(123);
-        assert_eq!(g3.target_yaml, g3_again.target_yaml);
+    }
+
+    #[test]
+    fn level_04_chest_is_a_list() {
+        // `chest:` is a list of 3–5 item strings.
+        let v = parse(&checked_level(3, 4).target_yaml);
+        let chest = field(&v, "chest").as_sequence().expect("chest is a list");
+        assert!((3..=5).contains(&chest.len()), "chest holds 3–5 items");
+        assert!(chest.iter().all(Value::is_string), "every item is a string");
+    }
+
+    #[test]
+    fn level_05_chambers_is_a_dict_of_lists() {
+        // `chambers:` is a dict of 2–3 lists, 2–3 items each.
+        let v = parse(&checked_level(4, 5).target_yaml);
+        let chambers = field(&v, "chambers")
+            .as_mapping()
+            .expect("chambers is a dict");
+        assert!((2..=3).contains(&chambers.len()), "2–3 chambers");
+        for (_name, items) in chambers {
+            let items = items.as_sequence().expect("each chamber holds a list");
+            assert!((2..=3).contains(&items.len()), "2–3 items per chamber");
+        }
+    }
+
+    #[test]
+    fn level_06_trap_repeats_in_every_room() {
+        // `trap:` is defined once; every room repeats it verbatim, so a
+        // player using `&anchor`/`*alias` parses to the same Value.
+        let v = parse(&checked_level(5, 6).target_yaml);
+        let trap = field(&v, "trap");
+        for key in ["type", "depth", "spikes"] {
+            assert!(trap.get(key).is_some(), "trap carries `{key}`");
+        }
+        let rooms = field(&v, "rooms").as_mapping().expect("rooms is a dict");
+        assert!(!rooms.is_empty(), "at least one room");
+        for (_room, payload) in rooms {
+            assert_eq!(payload, trap, "every room repeats the trap definition");
+        }
+    }
+
+    #[test]
+    fn level_07_floor_map_nests_maps_and_lists() {
+        // `floor:` int + `rooms:` dict; each room nests two lists.
+        let v = parse(&checked_level(6, 7).target_yaml);
+        assert!(field(&v, "floor").is_i64(), "floor is an integer");
+        let rooms = field(&v, "rooms").as_mapping().expect("rooms is a dict");
+        assert!(!rooms.is_empty(), "at least one room");
+        for (_name, room) in rooms {
+            assert!(field(room, "type").is_string(), "room.type is a string");
+            assert!(field(room, "locked").is_bool(), "room.locked is a bool");
+            assert!(field(room, "exits").is_sequence(), "room.exits is a list");
+            assert!(
+                field(room, "contents").is_sequence(),
+                "room.contents is a list"
+            );
+        }
+    }
+
+    #[test]
+    fn level_08_scroll_keeps_explicit_types() {
+        // Explicit types: a multi-line string, a float, and a digit-only
+        // string that must NOT collapse to an integer.
+        let v = parse(&checked_level(7, 8).target_yaml);
+        let scroll = field(&v, "scroll").as_str().expect("scroll is a string");
+        assert!(scroll.contains('\n'), "scroll preserves its newlines");
+        assert!(field(&v, "weight").is_f64(), "weight is a float");
+        let title = field(&v, "title");
+        assert!(title.is_string(), "title stays a string, not an int");
+        assert!(
+            title.as_str().unwrap().chars().all(|c| c.is_ascii_digit()),
+            "title is digit-only — the point of the `!!str` lesson"
+        );
+    }
+
+    #[test]
+    fn level_09_doors_merge_shared_defaults() {
+        // Merge keys: each door carries a literal `<<` whose value is the
+        // shared defaults dict, plus its own override.
+        let v = parse(&checked_level(8, 9).target_yaml);
+        let defaults = field(&v, "door_defaults");
+        for door in ["north_door", "south_door"] {
+            assert_eq!(
+                field(field(&v, door), "<<"),
+                defaults,
+                "{door} merges the shared defaults via `<<`"
+            );
+        }
+        assert!(field(field(&v, "north_door"), "locked").is_bool());
+        assert!(field(field(&v, "south_door"), "material").is_string());
+    }
+
+    #[test]
+    fn level_10_ledger_forgives_numeric_forms() {
+        // The ledger: int gold/silver, float experience, ISO date. The
+        // lesson is numeric forgiveness, so hex must score a perfect match.
+        let g = checked_level(9, 10);
+        let v = parse(&g.target_yaml);
+        let vault = field(&v, "vault");
+        let gold = field(vault, "gold").as_i64().expect("gold is an integer");
+        assert!(field(vault, "silver").is_i64(), "silver is an integer");
+        assert!(field(vault, "experience").is_f64(), "experience is a float");
+        assert!(field(vault, "date").is_string(), "date is an ISO string");
+        let hex_candidate = g
+            .target_yaml
+            .replace(&format!("gold: {gold}"), &format!("gold: 0x{gold:X}"));
+        assert_ne!(hex_candidate, g.target_yaml, "hex rewrite must apply");
+        assert_eq!(
+            similarity::semantic_or_textual(&g.target_yaml, &hex_candidate),
+            1.0,
+            "writing gold in hex must still score a perfect match"
+        );
+    }
+
+    #[test]
+    fn level_11_copies_alias_defined_shapes() {
+        // `shapes:` defines polygons; `copies:` reuses them, so each copy
+        // is structurally identical to one of the definitions.
+        let v = parse(&checked_level(10, 11).target_yaml);
+        let shapes = field(&v, "shapes").as_sequence().expect("shapes is a list");
+        assert!((2..=3).contains(&shapes.len()), "2–3 defined shapes");
+        for s in shapes {
+            assert!(field(s, "name").is_string(), "shape.name is a string");
+            let sides = field(s, "sides").as_i64().expect("shape.sides is an int");
+            assert_eq!(
+                field(s, "interior").as_i64().expect("shape.interior is an int"),
+                (sides - 2) * 180,
+                "interior angle sum follows (n-2)·180"
+            );
+        }
+        let copies = field(&v, "copies").as_sequence().expect("copies is a list");
+        assert!((3..=4).contains(&copies.len()), "3–4 copies");
+        for c in copies {
+            assert!(shapes.contains(c), "every copy aliases a defined shape");
+        }
     }
 }