[gguf & st] parse shard filenames in typed function (#631)

follow up to
#627 (review)

> why not a typed function fn(filename) that returns all the data in a
typed manner instead of the regex 🙈 .
> Currently in the next version of HF.js we can change the regex to
something else, removing or renaming the groups, and on moon's side we'd
have no clue. No compiler warning or anything.

packages/gguf/src/gguf.spec.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { GGMLQuantizationType, RE_GGUF_SHARD_FILE, gguf } from "./gguf";
+import { GGMLQuantizationType, gguf, parseGgufShardFile } from "./gguf";
 
 const URL_LLAMA = "https://huggingface.co/TheBloke/Llama-2-7B-Chat-GGUF/resolve/191239b/llama-2-7b-chat.Q2_K.gguf";
 const URL_MISTRAL_7B =
@@ -223,11 +223,10 @@ describe("gguf", () => {
 
 	it("should detect sharded gguf filename", async () => {
 		const ggufPath = "grok-1/grok-1-q4_0-00003-of-00009.gguf"; // https://huggingface.co/ggml-org/models/blob/fcf344adb9686474c70e74dd5e55465e9e6176ef/grok-1/grok-1-q4_0-00003-of-00009.gguf
-		const match = ggufPath.match(RE_GGUF_SHARD_FILE);
+		const ggufShardFileInfo = parseGgufShardFile(ggufPath);
 
-		expect(RE_GGUF_SHARD_FILE.test(ggufPath)).toEqual(true);
-		expect(match?.groups?.prefix).toEqual("grok-1/grok-1-q4_0");
-		expect(match?.groups?.shard).toEqual("00003");
-		expect(match?.groups?.total).toEqual("00009");
+		expect(ggufShardFileInfo?.prefix).toEqual("grok-1/grok-1-q4_0");
+		expect(ggufShardFileInfo?.shard).toEqual("00003");
+		expect(ggufShardFileInfo?.total).toEqual("00009");
 	});
 });

packages/gguf/src/gguf.ts

@@ -8,6 +8,24 @@ export { GGUF_QUANT_DESCRIPTIONS } from "./quant-descriptions";
 export const RE_GGUF_FILE = /\.gguf$/;
 export const RE_GGUF_SHARD_FILE = /^(?<prefix>.*?)-(?<shard>\d{5})-of-(?<total>\d{5})\.gguf$/;
 
+export interface GgufShardFileInfo {
+	prefix: string;
+	shard: string;
+	total: string;
+}
+
+export function parseGgufShardFile(filename: string): GgufShardFileInfo | null {
+	const match = RE_GGUF_SHARD_FILE.exec(filename);
+	if (match && match.groups) {
+		return {
+			prefix: match.groups["prefix"],
+			shard: match.groups["shard"],
+			total: match.groups["total"],
+		};
+	}
+	return null;
+}
+
 const isVersion = (version: number): version is Version => version === 1 || version === 2 || version === 3;
 
 /**

packages/hub/src/lib/parse-safetensors-metadata.spec.ts

@@ -1,5 +1,5 @@
 import { assert, it, describe } from "vitest";
-import { RE_SAFETENSORS_SHARD_FILE, parseSafetensorsMetadata } from "./parse-safetensors-metadata";
+import { parseSafetensorsMetadata, parseSafetensorsShardFile } from "./parse-safetensors-metadata";
 import { sum } from "../utils/sum";
 
 describe("parseSafetensorsMetadata", () => {
@@ -112,12 +112,11 @@ describe("parseSafetensorsMetadata", () => {
 
 	it("should detect sharded safetensors filename", async () => {
 		const safetensorsFilename = "model_00005-of-00072.safetensors"; // https://huggingface.co/bigscience/bloom/blob/4d8e28c67403974b0f17a4ac5992e4ba0b0dbb6f/model_00005-of-00072.safetensors
-		const match = safetensorsFilename.match(RE_SAFETENSORS_SHARD_FILE);
+		const safetensorsShardFileInfo = parseSafetensorsShardFile(safetensorsFilename);
 
-		assert.strictEqual(RE_SAFETENSORS_SHARD_FILE.test(safetensorsFilename), true);
-		assert.strictEqual(match?.groups?.prefix, "model_");
-		assert.strictEqual(match?.groups?.basePrefix, "model");
-		assert.strictEqual(match?.groups?.shard, "00005");
-		assert.strictEqual(match?.groups?.total, "00072");
+		assert.strictEqual(safetensorsShardFileInfo?.prefix, "model_");
+		assert.strictEqual(safetensorsShardFileInfo?.basePrefix, "model");
+		assert.strictEqual(safetensorsShardFileInfo?.shard, "00005");
+		assert.strictEqual(safetensorsShardFileInfo?.total, "00072");
 	});
 });

packages/hub/src/lib/parse-safetensors-metadata.ts

@@ -16,6 +16,25 @@ export const RE_SAFETENSORS_FILE = /\.safetensors$/;
 export const RE_SAFETENSORS_INDEX_FILE = /\.safetensors\.index\.json$/;
 export const RE_SAFETENSORS_SHARD_FILE =
 	/^(?<prefix>(?<basePrefix>.*?)[_-])(?<shard>\d{5})-of-(?<total>\d{5})\.safetensors$/;
+export interface SafetensorsShardFileInfo {
+	prefix: string;
+	basePrefix: string;
+	shard: string;
+	total: string;
+}
+export function parseSafetensorsShardFile(filename: string): SafetensorsShardFileInfo | null {
+	const match = RE_SAFETENSORS_SHARD_FILE.exec(filename);
+	if (match && match.groups) {
+		return {
+			prefix: match.groups["prefix"],
+			basePrefix: match.groups["basePrefix"],
+			shard: match.groups["shard"],
+			total: match.groups["total"],
+		};
+	}
+	return null;
+}
+
 const PARALLEL_DOWNLOADS = 20;
 const MAX_HEADER_LENGTH = 25_000_000;