fix: Allow for custom schemas in TS types (#325)

Author: eemeli

src/options.ts

@@ -5,7 +5,6 @@ import type { ParsedNode } from './nodes/Node.js'
 import type { Pair } from './nodes/Pair.js'
 import type { Scalar } from './nodes/Scalar.js'
 import type { LineCounter } from './parse/line-counter.js'
-import type { SchemaName } from './schema/Schema.js'
 import type { Tags } from './schema/tags.js'
 import type { CollectionTag, ScalarTag } from './schema/types.js'
 
@@ -112,9 +111,18 @@ export type SchemaOptions = {
   /**
    * The base schema to use.
    *
-   * Default: `"core"` for YAML 1.2, `"yaml-1.1"` for earlier versions
+   * The core library has built-in support for the following:
+   * - `'failsafe'`: A minimal schema that parses all scalars as strings
+   * - `'core'`: The YAML 1.2 core schema
+   * - `'json'`: The YAML 1.2 JSON schema, with minimal rules for JSON compatibility
+   * - `'yaml-1.1'`: The YAML 1.1 schema
+   *
+   * If using another (custom) schema, the `customTags` array needs to
+   * fully define the schema's tags.
+   *
+   * Default: `'core'` for YAML 1.2, `'yaml-1.1'` for earlier versions
    */
-  schema?: SchemaName
+  schema?: string
 
   /**
    * When adding to or stringifying a map, sort the entries.

src/schema/Schema.ts

@@ -7,15 +7,13 @@ import { string } from './common/string.js'
 import { coreKnownTags, getTags } from './tags.js'
 import type { CollectionTag, ScalarTag } from './types.js'
 
-export type SchemaName = 'core' | 'failsafe' | 'json' | 'yaml-1.1'
-
 const sortMapEntriesByKey = (a: Pair<any>, b: Pair<any>) =>
   a.key < b.key ? -1 : a.key > b.key ? 1 : 0
 
 export class Schema {
   knownTags: Record<string, CollectionTag | ScalarTag>
   merge: boolean
-  name: SchemaName
+  name: string
   sortMapEntries: ((a: Pair, b: Pair) => number) | null
   tags: Array<CollectionTag | ScalarTag>;
 

src/schema/tags.ts

@@ -14,16 +14,15 @@ import { pairs } from './yaml-1.1/pairs.js'
 import { schema as yaml11 } from './yaml-1.1/schema.js'
 import { set } from './yaml-1.1/set.js'
 import { floatTime, intTime, timestamp } from './yaml-1.1/timestamp.js'
-import type { SchemaName } from './Schema.js'
 import type { CollectionTag, ScalarTag } from './types.js'
 
-const schemas = {
-  core,
-  failsafe: [map, seq, string],
-  json,
-  yaml11,
-  'yaml-1.1': yaml11
-}
+const schemas = new Map<string, Array<CollectionTag | ScalarTag>>([
+  ['core', core],
+  ['failsafe', [map, seq, string]],
+  ['json', json],
+  ['yaml11', yaml11],
+  ['yaml-1.1', yaml11]
+])
 
 const tagsByName = {
   binary,
@@ -59,13 +58,13 @@ export const coreKnownTags = {
 
 export function getTags(
   customTags: SchemaOptions['customTags'] | undefined,
-  schemaName: SchemaName
+  schemaName: string
 ) {
-  let tags: Tags = schemas[schemaName]
+  let tags: Tags | undefined = schemas.get(schemaName)
   if (!tags) {
     if (Array.isArray(customTags)) tags = []
     else {
-      const keys = Object.keys(schemas)
+      const keys = Array.from(schemas.keys())
         .filter(key => key !== 'yaml11')
         .map(key => JSON.stringify(key))
         .join(', ')