Schema: Fix handling of arrays (#887)

sindresorhus · Jun 15, 2024 · c570ec2 · c570ec2
1 parent 7d4e875
commit c570ec2
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Showing 2 changed files with 33 additions and 28 deletions.
diff --git a/source/schema.d.ts b/source/schema.d.ts
@@ -47,25 +47,25 @@ export type Schema<ObjectType, ValueType> = ObjectType extends string
 				? ValueType
 				: ObjectType extends ReadonlySet<unknown>
 					? ValueType
-					: ObjectType extends readonly unknown[]
-						? ValueType
-						: ObjectType extends unknown[]
+					: ObjectType extends Array<infer U>
+						? Array<Schema<U, ValueType>>
+						: ObjectType extends (...arguments_: unknown[]) => unknown
 							? ValueType
-							: ObjectType extends (...arguments_: unknown[]) => unknown
+							: ObjectType extends Date
 								? ValueType
-								: ObjectType extends Date
+								: ObjectType extends Function
 									? ValueType
-									: ObjectType extends Function
+									: ObjectType extends RegExp
 										? ValueType
-										: ObjectType extends RegExp
-											? ValueType
-											: ObjectType extends object
-												? SchemaObject<ObjectType, ValueType>
-												: ValueType;
+										: ObjectType extends object
+											? SchemaObject<ObjectType, ValueType>
+											: ValueType;
 
 /**
 Same as `Schema`, but accepts only `object`s as inputs. Internal helper for `Schema`.
 */
 type SchemaObject<ObjectType extends object, K> = {
-	[KeyType in keyof ObjectType]: Schema<ObjectType[KeyType], K> | K;
+	[KeyType in keyof ObjectType]: ObjectType[KeyType] extends readonly unknown[] | unknown[]
+		? Schema<ObjectType[KeyType], K>
+		: Schema<ObjectType[KeyType], K> | K;
 };
diff --git a/test-d/schema.ts b/test-d/schema.ts
@@ -14,6 +14,7 @@ const foo = {
 		set: new Set<string>(),
 		array: ['foo'],
 		tuple: ['foo'] as ['foo'],
+		objectArray: [{key: 'value'}],
 		readonlyMap: new Map<string, string>() as ReadonlyMap<string, string>,
 		readonlySet: new Set<string>() as ReadonlySet<string>,
 		readonlyArray: ['foo'] as readonly string[],
@@ -36,12 +37,13 @@ const fooSchema: FooSchema = {
 		symbol: 'A',
 		map: 'A',
 		set: 'A',
-		array: 'A',
-		tuple: 'A',
+		array: ['A'],
+		tuple: ['A'],
+		objectArray: [{key: 'A'}],
 		readonlyMap: 'A',
 		readonlySet: 'A',
-		readonlyArray: 'A',
-		readonlyTuple: 'A',
+		readonlyArray: ['A'] as const,
+		readonlyTuple: ['A'] as const,
 		regExp: 'A',
 	},
 };
@@ -60,12 +62,13 @@ expectType<FooOption>(barSchema.boolean);
 expectType<FooOption>(barSchema.symbol);
 expectType<FooOption>(barSchema.map);
 expectType<FooOption>(barSchema.set);
-expectType<FooOption>(barSchema.array);
-expectType<FooOption>(barSchema.tuple);
+expectType<FooOption[]>(barSchema.array);
+expectType<FooOption[]>(barSchema.tuple);
+expectType<Array<{key: FooOption}>>(barSchema.objectArray);
 expectType<FooOption>(barSchema.readonlyMap);
 expectType<FooOption>(barSchema.readonlySet);
-expectType<FooOption>(barSchema.readonlyArray);
-expectType<FooOption>(barSchema.readonlyTuple);
+expectType<readonly FooOption[]>(barSchema.readonlyArray);
+expectType<readonly [FooOption]>(barSchema.readonlyTuple);
 expectType<FooOption>(barSchema.regExp);
 
 type ComplexOption = {
@@ -92,12 +95,13 @@ const complexFoo: ComplexSchema = {
 		symbol: createComplexOption('readonly'),
 		map: createComplexOption('readonly'),
 		set: createComplexOption('readonly'),
-		array: createComplexOption('readonly'),
-		tuple: createComplexOption('readonly'),
+		array: [createComplexOption('readonly')],
+		tuple: [createComplexOption('readonly')],
+		objectArray: [{key: createComplexOption('readonly')}],
 		readonlyMap: createComplexOption('readonly'),
 		readonlySet: createComplexOption('readonly'),
-		readonlyArray: createComplexOption('readonly'),
-		readonlyTuple: createComplexOption('readonly'),
+		readonlyArray: [createComplexOption('readonly')] as const,
+		readonlyTuple: [createComplexOption('readonly')] as const,
 		regExp: createComplexOption('readonly'),
 	},
 };
@@ -114,10 +118,11 @@ expectType<ComplexOption>(complexBarSchema.boolean);
 expectType<ComplexOption>(complexBarSchema.symbol);
 expectType<ComplexOption>(complexBarSchema.map);
 expectType<ComplexOption>(complexBarSchema.set);
-expectType<ComplexOption>(complexBarSchema.array);
-expectType<ComplexOption>(complexBarSchema.tuple);
+expectType<ComplexOption[]>(complexBarSchema.array);
+expectType<ComplexOption[]>(complexBarSchema.tuple);
+expectType<Array<{key: ComplexOption}>>(complexBarSchema.objectArray);
 expectType<ComplexOption>(complexBarSchema.readonlyMap);
 expectType<ComplexOption>(complexBarSchema.readonlySet);
-expectType<ComplexOption>(complexBarSchema.readonlyArray);
-expectType<ComplexOption>(complexBarSchema.readonlyTuple);
+expectType<readonly ComplexOption[]>(complexBarSchema.readonlyArray);
+expectType<readonly [ComplexOption]>(complexBarSchema.readonlyTuple);
 expectType<ComplexOption>(complexBarSchema.regExp);