Support numbers in Join type

readme.md

@@ -143,7 +143,7 @@ Click the type names for complete docs.
 - [`DelimiterCase`](source/delimiter-case.d.ts) – Convert a string literal to a custom string delimiter casing.
 - [`DelimiterCasedProperties`](source/delimiter-cased-properties.d.ts) – Convert object properties to a custom string delimiter casing.
 - [`DelimiterCasedPropertiesDeep`](source/delimiter-cased-properties-deep.d.ts) – Convert object properties to a custom string delimiter casing recursively.
-- [`Join`](source/join.d.ts) - Join an array of strings using the given string as delimiter.
+- [`Join`](source/join.d.ts) - Join an array of strings and/or numbers using the given string as a delimiter.
 - [`Split`](source/split.d.ts) - Represents an array of strings split using a given character or character set.
 - [`Trim`](source/trim.d.ts) - Remove leading and trailing spaces from a string.
 - [`Get`](source/get.d.ts) - Get a deeply-nested property from an object using a key path, like [Lodash's `.get()`](https://lodash.com/docs/latest#get) function.

source/join.d.ts

@@ -1,22 +1,22 @@
 /**
-Join an array of strings using the given string as delimiter.
+Join an array of strings and/or numbers using the given string as delimiter.
 
 Use-case: Defining key paths in a nested object. For example, for dot-notation fields in MongoDB queries.
 
 @example
 ```
 import {Join} from 'type-fest';
 
-const path: Join<['foo', 'bar', 'baz'], '.'> = ['foo', 'bar', 'baz'].join('.');
+const path: Join<['foo', '0', 'baz'], '.'> = ['foo', '0', 'baz'].join('.');
 ```
 
 @category Template Literals
 */
 export type Join<
-	Strings extends string[],
+	Strings extends (string | number)[],
 	Delimiter extends string,
 > = Strings extends [] ? '' :
-	Strings extends [string] ? `${Strings[0]}` :
+	Strings extends [string | number] ? `${Strings[0]}` :
 	// @ts-expect-error `Rest` is inferred as `unknown` here: https://github.com/microsoft/TypeScript/issues/45281
-	Strings extends [string, ...infer Rest] ? `${Strings[0]}${Delimiter}${Join<Rest, Delimiter>}` :
-	string;
+	Strings extends [string | number, ...infer Rest] ? `${Strings[0]}${Delimiter}${Join<Rest, Delimiter>}` :
+	string | number;

test-d/join.ts

@@ -3,7 +3,9 @@ import {Join} from '../index';
 
 // General use.
 const generalTest: Join<['foo', 'bar', 'baz'], '.'> = 'foo.bar.baz';
+const generalTestVariantWithNumbers: Join<['foo', 0, 'baz'], '.'> = 'foo.0.baz';
 expectType<'foo.bar.baz'>(generalTest);
+expectType<'foo.0.baz'>(generalTestVariantWithNumbers);
 expectError<'foo'>(generalTest);
 expectError<'foo.bar'>(generalTest);
 expectError<'foo.bar.ham'>(generalTest);