schema_catalog/
lib.rs

1#![doc = include_str!("../README.md")]
2#![no_std]
3
4extern crate alloc;
5
6use alloc::borrow::ToOwned;
7use alloc::collections::BTreeMap;
8use alloc::string::String;
9use alloc::vec;
10use alloc::vec::Vec;
11
12use schemars::{JsonSchema, schema_for};
13use serde::{Deserialize, Serialize};
14use serde_json::Value;
15
16mod compiled;
17pub use compiled::{CompiledCatalog, SchemaMatch};
18
19/// The default `$schema` URL for Lintel catalogs.
20pub const DEFAULT_SCHEMA_URL: &str =
21    "https://catalog.lintel.tools/schemas/lintel/catalog/latest.json";
22
23/// Schema catalog index that maps file patterns to JSON Schema URLs.
24///
25/// A catalog is a collection of schema entries used by editors and tools to
26/// automatically associate files with the correct schema for validation and
27/// completion. Follows the `SchemaStore` catalog format.
28///
29/// See: <https://json.schemastore.org/schema-catalog.json>
30#[derive(Debug, Clone, Default, Deserialize, JsonSchema)]
31#[schemars(title = "Schema Catalog")]
32pub struct Catalog {
33    /// The `$schema` URL for this catalog. Defaults to the Lintel catalog schema.
34    #[serde(default, rename = "$schema")]
35    pub schema: Option<String>,
36    /// The catalog format version.
37    #[serde(default = "default_version")]
38    pub version: u32,
39    /// An optional human-readable title for the catalog.
40    #[serde(default)]
41    pub title: Option<String>,
42    /// The list of schema entries in this catalog.
43    pub schemas: Vec<SchemaEntry>,
44    /// Optional grouping of related schemas for catalog consumers that
45    /// support richer organization. Consumers that don't understand
46    /// `groups` simply ignore this field.
47    #[serde(default)]
48    pub groups: Vec<CatalogGroup>,
49}
50
51impl Serialize for Catalog {
52    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
53        use serde::ser::SerializeMap;
54
55        let mut len = 3; // $schema, version, schemas
56        if self.title.is_some() {
57            len += 1;
58        }
59        if !self.groups.is_empty() {
60            len += 1;
61        }
62
63        let mut map = serializer.serialize_map(Some(len))?;
64        map.serialize_entry(
65            "$schema",
66            self.schema.as_deref().unwrap_or(DEFAULT_SCHEMA_URL),
67        )?;
68        map.serialize_entry("version", &self.version)?;
69        if let Some(ref title) = self.title {
70            map.serialize_entry("title", title)?;
71        }
72        map.serialize_entry("schemas", &self.schemas)?;
73        if !self.groups.is_empty() {
74            map.serialize_entry("groups", &self.groups)?;
75        }
76        map.end()
77    }
78}
79
80/// A group of related schemas in the catalog.
81///
82/// Groups provide richer metadata for catalog consumers that support them.
83/// Consumers that don't understand `groups` simply ignore the field.
84#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
85#[schemars(title = "Schema Group")]
86pub struct CatalogGroup {
87    /// The display name for this group.
88    pub name: String,
89    /// A short description of the schemas in this group.
90    pub description: String,
91    /// Schema names that belong to this group.
92    pub schemas: Vec<String>,
93}
94
95/// A single schema entry in the catalog.
96///
97/// Each entry maps a schema to its URL and the file patterns it applies to.
98#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
99#[serde(rename_all = "camelCase")]
100#[schemars(title = "Schema Entry")]
101pub struct SchemaEntry {
102    /// The display name of the schema.
103    #[schemars(example = example_schema_name())]
104    pub name: String,
105    /// A short description of what the schema validates.
106    #[serde(default)]
107    pub description: String,
108    /// The URL where the schema can be fetched.
109    #[schemars(example = example_schema_url())]
110    pub url: String,
111    /// An optional URL pointing to the upstream or canonical source of
112    /// the schema (e.g. a GitHub raw URL).
113    #[serde(default, skip_serializing_if = "Option::is_none")]
114    pub source_url: Option<String>,
115    /// Glob patterns for files this schema should be applied to.
116    ///
117    /// Editors and tools use these patterns to automatically associate
118    /// matching files with this schema.
119    #[serde(default, skip_serializing_if = "Vec::is_empty")]
120    #[schemars(title = "File Match")]
121    #[schemars(example = example_file_match())]
122    pub file_match: Vec<String>,
123    /// Alternate versions of this schema, keyed by version identifier.
124    /// Values are URLs to the versioned schema.
125    #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
126    pub versions: BTreeMap<String, String>,
127}
128
129fn default_version() -> u32 {
130    1
131}
132
133fn example_schema_name() -> String {
134    "My Config".to_owned()
135}
136
137fn example_schema_url() -> String {
138    "https://example.com/schemas/my-config.json".to_owned()
139}
140
141fn example_file_match() -> Vec<String> {
142    vec!["*.config.json".to_owned(), "**/.config.json".to_owned()]
143}
144
145/// Supported file formats for parsing and validation.
146#[derive(
147    Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize, JsonSchema,
148)]
149#[serde(rename_all = "lowercase")]
150pub enum FileFormat {
151    Json,
152    Json5,
153    Jsonc,
154    Toml,
155    Yaml,
156    Markdown,
157}
158
159/// Generate the JSON Schema for the [`Catalog`] type.
160///
161/// # Panics
162///
163/// Panics if the schema cannot be serialized to JSON (should never happen).
164pub fn schema() -> Value {
165    serde_json::to_value(schema_for!(Catalog)).expect("schema serialization cannot fail")
166}
167
168/// Parse a catalog from a JSON string.
169///
170/// # Errors
171///
172/// Returns an error if the string is not valid JSON or does not match the catalog schema.
173pub fn parse_catalog(json: &str) -> Result<Catalog, serde_json::Error> {
174    serde_json::from_str(json)
175}
176
177/// Parse a catalog from a `serde_json::Value`.
178///
179/// # Errors
180///
181/// Returns an error if the value does not match the expected catalog schema.
182pub fn parse_catalog_value(value: serde_json::Value) -> Result<Catalog, serde_json::Error> {
183    serde_json::from_value(value)
184}
185
186#[cfg(test)]
187mod tests {
188    use alloc::string::ToString;
189
190    use super::*;
191
192    #[test]
193    fn round_trip_catalog() {
194        let catalog = Catalog {
195            version: 1,
196            schemas: vec![SchemaEntry {
197                name: "Test Schema".into(),
198                description: "A test schema".into(),
199                url: "https://example.com/test.json".into(),
200                source_url: None,
201                file_match: vec!["*.test.json".into()],
202                versions: BTreeMap::new(),
203            }],
204            ..Catalog::default()
205        };
206        let json = serde_json::to_string_pretty(&catalog).expect("serialize");
207        let parsed: Catalog = serde_json::from_str(&json).expect("deserialize");
208        assert_eq!(parsed.version, 1);
209        assert_eq!(parsed.schemas.len(), 1);
210        assert_eq!(parsed.schemas[0].name, "Test Schema");
211        assert_eq!(parsed.schemas[0].file_match, vec!["*.test.json"]);
212    }
213
214    #[test]
215    fn parse_catalog_from_json_string() {
216        let json = r#"{"version":1,"schemas":[{"name":"test","description":"desc","url":"https://example.com/s.json","fileMatch":["*.json"]}]}"#;
217        let catalog = parse_catalog(json).expect("parse");
218        assert_eq!(catalog.schemas.len(), 1);
219        assert_eq!(catalog.schemas[0].name, "test");
220        assert_eq!(catalog.schemas[0].file_match, vec!["*.json"]);
221    }
222
223    #[test]
224    fn empty_file_match_omitted_in_serialization() {
225        let entry = SchemaEntry {
226            name: "No Match".into(),
227            description: "desc".into(),
228            url: "https://example.com/no.json".into(),
229            source_url: None,
230            file_match: vec![],
231            versions: BTreeMap::new(),
232        };
233        let json = serde_json::to_string(&entry).expect("serialize");
234        assert!(!json.contains("fileMatch"));
235        assert!(!json.contains("sourceUrl"));
236        assert!(!json.contains("versions"));
237    }
238
239    #[test]
240    fn source_url_serialized_as_camel_case() {
241        let entry = SchemaEntry {
242            name: "Test".into(),
243            description: "desc".into(),
244            url: "https://catalog.example.com/test.json".into(),
245            source_url: Some("https://upstream.example.com/test.json".into()),
246            file_match: vec![],
247            versions: BTreeMap::new(),
248        };
249        let json = serde_json::to_string(&entry).expect("serialize");
250        assert!(json.contains("\"sourceUrl\""));
251        assert!(json.contains("https://upstream.example.com/test.json"));
252
253        // Round-trip
254        let parsed: SchemaEntry = serde_json::from_str(&json).expect("deserialize");
255        assert_eq!(
256            parsed.source_url.as_deref(),
257            Some("https://upstream.example.com/test.json")
258        );
259    }
260
261    #[test]
262    fn deserialize_with_versions() {
263        let json = r#"{
264            "version": 1,
265            "schemas": [{
266                "name": "test",
267                "description": "desc",
268                "url": "https://example.com/s.json",
269                "versions": {"draft-07": "https://example.com/draft07.json"}
270            }]
271        }"#;
272        let catalog = parse_catalog(json).expect("parse");
273        assert_eq!(
274            catalog.schemas[0].versions.get("draft-07"),
275            Some(&"https://example.com/draft07.json".to_string())
276        );
277    }
278
279    #[test]
280    fn schema_has_camel_case_properties() {
281        let schema = schema();
282        let schema_str = serde_json::to_string(&schema).expect("serialize");
283        assert!(
284            schema_str.contains("fileMatch"),
285            "schema should contain fileMatch"
286        );
287        assert!(
288            schema_str.contains("sourceUrl"),
289            "schema should contain sourceUrl"
290        );
291    }
292}
schema_catalog/lib.rs

schema_catalog/
lib.rs
