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#[schemars(title = "Schema Entry")]
100pub struct SchemaEntry {
101    /// The display name of the schema.
102    #[schemars(example = example_schema_name())]
103    pub name: String,
104    /// A short description of what the schema validates.
105    #[serde(default)]
106    pub description: String,
107    /// The URL where the schema can be fetched.
108    #[schemars(example = example_schema_url())]
109    pub url: String,
110    /// An optional URL pointing to the upstream or canonical source of
111    /// the schema (e.g. a GitHub raw URL).
112    #[serde(default, rename = "sourceUrl", skip_serializing_if = "Option::is_none")]
113    pub source_url: Option<String>,
114    /// Glob patterns for files this schema should be applied to.
115    ///
116    /// Editors and tools use these patterns to automatically associate
117    /// matching files with this schema.
118    #[serde(default, rename = "fileMatch", skip_serializing_if = "Vec::is_empty")]
119    #[schemars(title = "File Match")]
120    #[schemars(example = example_file_match())]
121    pub file_match: Vec<String>,
122    /// Alternate versions of this schema, keyed by version identifier.
123    /// Values are URLs to the versioned schema.
124    #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
125    pub versions: BTreeMap<String, String>,
126}
127
128fn default_version() -> u32 {
129    1
130}
131
132fn example_schema_name() -> String {
133    "My Config".to_owned()
134}
135
136fn example_schema_url() -> String {
137    "https://example.com/schemas/my-config.json".to_owned()
138}
139
140fn example_file_match() -> Vec<String> {
141    vec!["*.config.json".to_owned(), "**/.config.json".to_owned()]
142}
143
144/// Generate the JSON Schema for the [`Catalog`] type.
145///
146/// # Panics
147///
148/// Panics if the schema cannot be serialized to JSON (should never happen).
149pub fn schema() -> Value {
150    serde_json::to_value(schema_for!(Catalog)).expect("schema serialization cannot fail")
151}
152
153/// Parse a catalog from a JSON string.
154///
155/// # Errors
156///
157/// Returns an error if the string is not valid JSON or does not match the catalog schema.
158pub fn parse_catalog(json: &str) -> Result<Catalog, serde_json::Error> {
159    serde_json::from_str(json)
160}
161
162/// Parse a catalog from a `serde_json::Value`.
163///
164/// # Errors
165///
166/// Returns an error if the value does not match the expected catalog schema.
167pub fn parse_catalog_value(value: serde_json::Value) -> Result<Catalog, serde_json::Error> {
168    serde_json::from_value(value)
169}
170
171#[cfg(test)]
172mod tests {
173    use alloc::string::ToString;
174
175    use super::*;
176
177    #[test]
178    fn round_trip_catalog() {
179        let catalog = Catalog {
180            version: 1,
181            schemas: vec![SchemaEntry {
182                name: "Test Schema".into(),
183                description: "A test schema".into(),
184                url: "https://example.com/test.json".into(),
185                source_url: None,
186                file_match: vec!["*.test.json".into()],
187                versions: BTreeMap::new(),
188            }],
189            ..Catalog::default()
190        };
191        let json = serde_json::to_string_pretty(&catalog).expect("serialize");
192        let parsed: Catalog = serde_json::from_str(&json).expect("deserialize");
193        assert_eq!(parsed.version, 1);
194        assert_eq!(parsed.schemas.len(), 1);
195        assert_eq!(parsed.schemas[0].name, "Test Schema");
196        assert_eq!(parsed.schemas[0].file_match, vec!["*.test.json"]);
197    }
198
199    #[test]
200    fn parse_catalog_from_json_string() {
201        let json = r#"{"version":1,"schemas":[{"name":"test","description":"desc","url":"https://example.com/s.json","fileMatch":["*.json"]}]}"#;
202        let catalog = parse_catalog(json).expect("parse");
203        assert_eq!(catalog.schemas.len(), 1);
204        assert_eq!(catalog.schemas[0].name, "test");
205        assert_eq!(catalog.schemas[0].file_match, vec!["*.json"]);
206    }
207
208    #[test]
209    fn empty_file_match_omitted_in_serialization() {
210        let entry = SchemaEntry {
211            name: "No Match".into(),
212            description: "desc".into(),
213            url: "https://example.com/no.json".into(),
214            source_url: None,
215            file_match: vec![],
216            versions: BTreeMap::new(),
217        };
218        let json = serde_json::to_string(&entry).expect("serialize");
219        assert!(!json.contains("fileMatch"));
220        assert!(!json.contains("sourceUrl"));
221        assert!(!json.contains("versions"));
222    }
223
224    #[test]
225    fn source_url_serialized_as_camel_case() {
226        let entry = SchemaEntry {
227            name: "Test".into(),
228            description: "desc".into(),
229            url: "https://catalog.example.com/test.json".into(),
230            source_url: Some("https://upstream.example.com/test.json".into()),
231            file_match: vec![],
232            versions: BTreeMap::new(),
233        };
234        let json = serde_json::to_string(&entry).expect("serialize");
235        assert!(json.contains("\"sourceUrl\""));
236        assert!(json.contains("https://upstream.example.com/test.json"));
237
238        // Round-trip
239        let parsed: SchemaEntry = serde_json::from_str(&json).expect("deserialize");
240        assert_eq!(
241            parsed.source_url.as_deref(),
242            Some("https://upstream.example.com/test.json")
243        );
244    }
245
246    #[test]
247    fn deserialize_with_versions() {
248        let json = r#"{
249            "version": 1,
250            "schemas": [{
251                "name": "test",
252                "description": "desc",
253                "url": "https://example.com/s.json",
254                "versions": {"draft-07": "https://example.com/draft07.json"}
255            }]
256        }"#;
257        let catalog = parse_catalog(json).expect("parse");
258        assert_eq!(
259            catalog.schemas[0].versions.get("draft-07"),
260            Some(&"https://example.com/draft07.json".to_string())
261        );
262    }
263
264    #[test]
265    fn schema_has_camel_case_properties() {
266        let schema = schema();
267        let schema_str = serde_json::to_string(&schema).expect("serialize");
268        assert!(
269            schema_str.contains("fileMatch"),
270            "schema should contain fileMatch"
271        );
272        assert!(
273            schema_str.contains("sourceUrl"),
274            "schema should contain sourceUrl"
275        );
276    }
277}
schema_catalog/lib.rs

schema_catalog/
lib.rs
