Fix Hub API URL construction

Author: DePasqualeOrg

Sources/Hub/HubApi.swift

@@ -258,7 +258,12 @@ public extension HubApi {
     /// - Throws: HubClientError if the repository cannot be accessed or parsed
     func getFilenames(from repo: Repo, revision: String = "main", matching globs: [String] = []) async throws -> [String] {
         // Read repo info and only parse "siblings"
-        let url = URL(string: "\(endpoint)/api/\(repo.type)/\(repo.id)/revision/\(revision)")!
+        let url = URL(string: endpoint)!
+            .appendingPathComponent("api")
+            .appendingPathComponent(repo.type.rawValue)
+            .appendingPathComponent(repo.id)
+            .appendingPathComponent("revision")
+            .appending(component: revision) // Use appending(component:) to encode slashes (e.g., "pr/1" -> "pr%2F1")
         let (data, _) = try await httpGet(for: url)
         let response = try JSONDecoder().decode(SiblingsResponse.self, from: data)
         let filenames = response.siblings.map { $0.rfilename }
@@ -333,7 +338,9 @@ public extension HubApi {
     func whoami() async throws -> Config {
         guard hfToken != nil else { throw Hub.HubClientError.authorizationRequired }
 
-        let url = URL(string: "\(endpoint)/api/whoami-v2")!
+        let url = URL(string: endpoint)!
+            .appendingPathComponent("api")
+            .appendingPathComponent("whoami-v2")
         let (data, _) = try await httpGet(for: url)
 
         let parsed = try JSONSerialization.jsonObject(with: data, options: [])
@@ -462,11 +469,12 @@ public extension HubApi {
             // https://huggingface.co/coreml-projects/Llama-2-7b-chat-coreml/resolve/main/tokenizer.json?download=true
             var url = URL(string: endpoint ?? "https://huggingface.co")!
             if repo.type != .models {
-                url = url.appending(component: repo.type.rawValue)
+                url = url.appendingPathComponent(repo.type.rawValue)
             }
-            url = url.appending(path: repo.id)
-            url = url.appending(path: "resolve/\(revision)")
-            url = url.appending(path: relativeFilename)
+            url = url.appendingPathComponent(repo.id)
+            url = url.appendingPathComponent("resolve")
+            url = url.appending(component: revision) // Use appending(component:) to encode slashes (e.g., "pr/1" -> "pr%2F1")
+            url = url.appendingPathComponent(relativeFilename)
             return url
         }
 
@@ -792,7 +800,10 @@ public extension HubApi {
 
     func getFileMetadata(from repo: Repo, revision: String = "main", matching globs: [String] = []) async throws -> [FileMetadata] {
         let files = try await getFilenames(from: repo, matching: globs)
-        let url = URL(string: "\(endpoint)/\(repo.id)/resolve/\(revision)")!
+        let url = URL(string: endpoint)!
+            .appendingPathComponent(repo.id)
+            .appendingPathComponent("resolve")
+            .appending(component: revision) // Use appending(component:) to encode slashes (e.g., "pr/1" -> "pr%2F1")
         var selectedMetadata: [FileMetadata] = []
         for file in files {
             let fileURL = url.appending(path: file)

Tests/HubTests/HubApiTests.swift

@@ -11,6 +11,20 @@ import XCTest
 class HubApiTests: XCTestCase {
     // TODO: use a specific revision for these tests
 
+    /// Test that revision values containing slashes (like "pr/1") are properly URL encoded.
+    /// The Hub API requires "pr/1" to be encoded as "pr%2F1" - otherwise it returns 404.
+    func testFilenameRetrievalWithPRRevision() async throws {
+        // This repo has a PR #1 that we can use to test the pr/N revision format
+        // If URL encoding is broken, this will fail with a 404 error
+        let hubApi = HubApi()
+        let filenames = try await hubApi.getFilenames(
+            from: Hub.Repo(id: "coreml-projects/sam-2-studio"),
+            revision: "pr/1",
+            matching: ["*.md"]
+        )
+        XCTAssertFalse(filenames.isEmpty, "Should retrieve filenames from PR revision")
+    }
+
     func testFilenameRetrieval() async {
         do {
             let filenames = try await Hub.getFilenames(from: "coreml-projects/Llama-2-7b-chat-coreml")