Split internal.d.ts into multiple files

script/test/source-files-extension.js

@@ -4,10 +4,14 @@ const process = require('node:process');
 
 const checkSourceFilesExtension = async () => {
 	try {
-		const files = await fs.promises.readdir('source');
+		const files = await fs.promises.readdir('source', {recursive: true});
 
 		let hasIncorrectFileExtension = false;
 		for (const file of files) {
+			if (!file.includes('.')) {
+				continue;
+			}
+
 			if (!file.endsWith('.d.ts')) {
 				hasIncorrectFileExtension = true;
 				console.error(`source/${file} extension should be \`.d.ts\`.`);

source/array-slice.d.ts

@@ -3,7 +3,7 @@ import type {LessThanOrEqual} from './less-than-or-equal';
 import type {GreaterThanOrEqual} from './greater-than-or-equal';
 import type {GreaterThan} from './greater-than';
 import type {IsNegative} from './numeric';
-import type {Not, ArrayMin} from './internal';
+import type {Not, TupleMin} from './internal';
 import type {IsEqual} from './is-equal';
 import type {And} from './and';
 import type {ArraySplice} from './array-splice';
@@ -95,7 +95,7 @@ type ArraySliceHelper<
 	PositiveE extends number = IsNegative<End> extends true ? Sum<ArrayLength, End> : End,
 > = true extends [IsNegative<PositiveS>, LessThanOrEqual<PositiveE, PositiveS>, GreaterThanOrEqual<PositiveS, ArrayLength>][number]
 	? []
-	: ArraySliceByPositiveIndex<Array_, ArrayMin<[PositiveS, ArrayLength]>, ArrayMin<[PositiveE, ArrayLength]>>;
+	: ArraySliceByPositiveIndex<Array_, TupleMin<[PositiveS, ArrayLength]>, TupleMin<[PositiveE, ArrayLength]>>;
 
 type ArraySliceByPositiveIndex<
 	Array_ extends readonly unknown[],

source/delimiter-case.d.ts

@@ -1,4 +1,4 @@
-import type {UpperCaseCharacters, WordSeparators} from '../source/internal';
+import type {UpperCaseCharacters, WordSeparators} from './internal';
 
 // Transforms a string that is fully uppercase into a fully lowercase version. Needed to add support for SCREAMING_SNAKE_CASE, see https://github.com/sindresorhus/type-fest/issues/385
 type UpperCaseToLowerCase<T extends string> = T extends Uppercase<T> ? Lowercase<T> : T;

source/get.d.ts

@@ -1,4 +1,4 @@
-import type {StringDigit} from '../source/internal';
+import type {StringDigit} from './internal';
 import type {Split} from './split';
 import type {StringKeyOf} from './string-key-of';