[fix] allow loading files (#3517)

I messed up the schema validator for loading files.

### Change Type

<!-- ❗ Please select a 'Scope' label ❗️ -->

- [x] `sdk` — Changes the tldraw SDK
- [ ] `dotcom` — Changes the tldraw.com web app
- [ ] `docs` — Changes to the documentation, examples, or templates.
- [ ] `vs code` — Changes to the vscode plugin
- [ ] `internal` — Does not affect user-facing stuff

<!-- ❗ Please select a 'Type' label ❗️ -->

- [x] `bugfix` — Bug fix
- [ ] `feature` — New feature
- [ ] `improvement` — Improving existing features
- [ ] `chore` — Updating dependencies, other boring stuff
- [ ] `galaxy brain` — Architectural changes
- [ ] `tests` — Changes to any test code
- [ ] `tools` — Changes to infrastructure, CI, internal scripts,
debugging tools, etc.
- [ ] `dunno` — I don't know

packages/tldraw/src/lib/utils/tldr/file.ts

@@ -62,7 +62,7 @@ const schemaV2 = T.object<SerializedSchemaV2>({
 
 const tldrawFileValidator: T.Validator<TldrawFile> = T.object({
 	tldrawFileFormatVersion: T.nonZeroInteger,
-	schema: T.union('schemaVersion', {
+	schema: T.numberUnion('schemaVersion', {
 		1: schemaV1,
 		2: schemaV2,
 	}),

packages/validate/api-report.md

@@ -83,6 +83,9 @@ function nullable<T>(validator: Validatable<T>): Validator<null | T>;
 // @public
 const number: Validator<number>;
 
+// @internal (undocumented)
+function numberUnion<Key extends string, Config extends UnionValidatorConfig<Key, Config>>(key: Key, config: Config): UnionValidator<Key, Config>;
+
 // @public
 function object<Shape extends object>(config: {
     readonly [K in keyof Shape]: Validatable<Shape[K]>;
@@ -134,6 +137,7 @@ declare namespace T {
         jsonDict,
         dict,
         union,
+        numberUnion,
         model,
         setEnum,
         optional,
@@ -178,7 +182,7 @@ function union<Key extends string, Config extends UnionValidatorConfig<Key, Conf
 
 // @public (undocumented)
 export class UnionValidator<Key extends string, Config extends UnionValidatorConfig<Key, Config>, UnknownValue = never> extends Validator<TypeOf<Config[keyof Config]> | UnknownValue> {
-    constructor(key: Key, config: Config, unknownValueValidation: (value: object, variant: string) => UnknownValue);
+    constructor(key: Key, config: Config, unknownValueValidation: (value: object, variant: string) => UnknownValue, useNumberKeys: boolean);
     // (undocumented)
     validateUnknownVariants<Unknown>(unknownValueValidation: (value: object, variant: string) => Unknown): UnionValidator<Key, Config, Unknown>;
 }

packages/validate/api/api.json

@@ -3027,6 +3027,14 @@
                       "kind": "Content",
                       "text": "(value: object, variant: string) => UnknownValue"
                     },
+                    {
+                      "kind": "Content",
+                      "text": ", useNumberKeys: "
+                    },
+                    {
+                      "kind": "Content",
+                      "text": "boolean"
+                    },
                     {
                       "kind": "Content",
                       "text": ");"
@@ -3059,6 +3067,14 @@
                         "endIndex": 6
                       },
                       "isOptional": false
+                    },
+                    {
+                      "parameterName": "useNumberKeys",
+                      "parameterTypeTokenRange": {
+                        "startIndex": 7,
+                        "endIndex": 8
+                      },
+                      "isOptional": false
                     }
                   ]
                 },
@@ -4260,6 +4276,14 @@
                   "kind": "Content",
                   "text": "(value: object, variant: string) => UnknownValue"
                 },
+                {
+                  "kind": "Content",
+                  "text": ", useNumberKeys: "
+                },
+                {
+                  "kind": "Content",
+                  "text": "boolean"
+                },
                 {
                   "kind": "Content",
                   "text": ");"
@@ -4292,6 +4316,14 @@
                     "endIndex": 6
                   },
                   "isOptional": false
+                },
+                {
+                  "parameterName": "useNumberKeys",
+                  "parameterTypeTokenRange": {
+                    "startIndex": 7,
+                    "endIndex": 8
+                  },
+                  "isOptional": false
                 }
               ]
             },

packages/validate/src/lib/validation.ts

@@ -394,7 +394,8 @@ export class UnionValidator<
 	constructor(
 		private readonly key: Key,
 		private readonly config: Config,
-		private readonly unknownValueValidation: (value: object, variant: string) => UnknownValue
+		private readonly unknownValueValidation: (value: object, variant: string) => UnknownValue,
+		private readonly useNumberKeys: boolean
 	) {
 		super(
 			(input) => {
@@ -442,11 +443,13 @@ export class UnionValidator<
 		matchingSchema: Validatable<any> | undefined
 		variant: string
 	} {
-		const variant = getOwnProperty(object, this.key) as keyof Config | undefined
+		const variant = getOwnProperty(object, this.key) as string & keyof Config
-		if (typeof variant !== 'string') {
+		if (!this.useNumberKeys && typeof variant !== 'string') {
 			throw new ValidationError(
 				`Expected a string for key "${this.key}", got ${typeToString(variant)}`
 			)
+		} else if (this.useNumberKeys && !Number.isFinite(Number(variant))) {
+			throw new ValidationError(`Expected a number for key "${this.key}", got "${variant as any}"`)
 		}
 
 		const matchingSchema = hasOwnProperty(this.config, variant) ? this.config[variant] : undefined
@@ -456,7 +459,7 @@ export class UnionValidator<
 	validateUnknownVariants<Unknown>(
 		unknownValueValidation: (value: object, variant: string) => Unknown
 	): UnionValidator<Key, Config, Unknown> {
-		return new UnionValidator(this.key, this.config, unknownValueValidation)
+		return new UnionValidator(this.key, this.config, unknownValueValidation, this.useNumberKeys)
 	}
 }
 
@@ -829,14 +832,41 @@ export function union<Key extends string, Config extends UnionValidatorConfig<Ke
 	key: Key,
 	config: Config
 ): UnionValidator<Key, Config> {
-	return new UnionValidator(key, config, (unknownValue, unknownVariant) => {
+	return new UnionValidator(
+		key,
+		config,
+		(unknownValue, unknownVariant) => {
 			throw new ValidationError(
 				`Expected one of ${Object.keys(config)
 					.map((key) => JSON.stringify(key))
 					.join(' or ')}, got ${JSON.stringify(unknownVariant)}`,
 				[key]
 			)
-	})
+		},
+		false
+	)
+}
+
+/**
+ * @internal
+ */
+export function numberUnion<Key extends string, Config extends UnionValidatorConfig<Key, Config>>(
+	key: Key,
+	config: Config
+): UnionValidator<Key, Config> {
+	return new UnionValidator(
+		key,
+		config,
+		(unknownValue, unknownVariant) => {
+			throw new ValidationError(
+				`Expected one of ${Object.keys(config)
+					.map((key) => JSON.stringify(key))
+					.join(' or ')}, got ${JSON.stringify(unknownVariant)}`,
+				[key]
+			)
+		},
+		true
+	)
 }
 
 /**