Mock out test interactions with swift.org and github.com

Package.swift

@@ -2,6 +2,8 @@
 
 import PackageDescription
 
+let ghApiCacheResources = (1...16).map { Resource.embedInCode("gh-api-cache/swift-tags-page\($0).json") }
+
 let package = Package(
     name: "swiftly",
     platforms: [
@@ -62,7 +64,11 @@ let package = Package(
         ),
         .testTarget(
             name: "SwiftlyTests",
-            dependencies: ["Swiftly"]
+            dependencies: ["Swiftly"],
+            resources: ghApiCacheResources + [
+                .embedInCode("gh-api-cache/swift-releases-page1.json"),
+                .embedInCode("mock-signing-key-private.pgp"),
+            ]
         ),
     ]
 )

Sources/LinuxPlatform/Linux.swift

@@ -1,6 +1,8 @@
 import Foundation
 import SwiftlyCore
 
+var swiftGPGKeysRefreshed = false
+
 /// `Platform` implementation for Linux systems.
 /// This implementation can be reused for any supported Linux platform.
 /// TODO: replace dummy implementations
@@ -65,18 +67,22 @@ public struct Linux: Platform {
                 Self.skipVerificationMessage)
         }
 
-        SwiftlyCore.print("Refreshing Swift PGP keys...")
-        do {
-            try self.runProgram(
-                "gpg",
-                "--quiet",
-                "--keyserver",
-                "hkp://keyserver.ubuntu.com",
-                "--refresh-keys",
-                "Swift"
-            )
-        } catch {
-            throw Error(message: "Failed to refresh PGP keys: \(error)")
+        // We only need to refresh the keys once per session, which will help with performance in tests
+        if !swiftGPGKeysRefreshed {
+            SwiftlyCore.print("Refreshing Swift PGP keys...")
+            do {
+                try self.runProgram(
+                    "gpg",
+                    "--quiet",
+                    "--keyserver",
+                    "hkp://keyserver.ubuntu.com",
+                    "--refresh-keys",
+                    "Swift"
+                )
+            } catch {
+                throw Error(message: "Failed to refresh PGP keys: \(error)")
+            }
+            swiftGPGKeysRefreshed = true
         }
     }
 
@@ -116,6 +122,10 @@ public struct Linux: Platform {
             .appendingPathComponent("usr", isDirectory: true)
             .appendingPathComponent("bin", isDirectory: true)
 
+        if !FileManager.default.fileExists(atPath: toolchainBinURL.path) {
+            return false
+        }
+
         // Delete existing symlinks from previously in-use toolchain.
         if let currentToolchain {
             try self.unUse(currentToolchain: currentToolchain)

Sources/MacOSPlatform/MacOS.swift

@@ -102,6 +102,10 @@ public struct MacOS: Platform {
             .appendingPathComponent("usr", isDirectory: true)
             .appendingPathComponent("bin", isDirectory: true)
 
+        if !FileManager.default.fileExists(atPath: toolchainBinURL.path) {
+            return false
+        }
+
         // Delete existing symlinks from previously in-use toolchain.
         if let currentToolchain {
             try self.unUse(currentToolchain: currentToolchain)

Sources/SwiftlyCore/HTTPClient+GitHubAPI.swift

@@ -62,7 +62,7 @@ extension SwiftlyHTTPClient {
     /// page number.
     ///
     /// The results are returned in lexicographic order.
-    internal func getReleases(page: Int, perPage: Int = 100) async throws -> [GitHubTag] {
+    public func getReleases(page: Int, perPage: Int = 100) async throws -> [GitHubTag] {
         let url = "https://api.github.com/repos/apple/swift/releases?per_page=\(perPage)&page=\(page)"
         let releases: [GitHubRelease] = try await self.getFromGitHub(url: url)
         return releases.filter { !$0.prerelease }.map { $0.toGitHubTag() }
@@ -72,15 +72,15 @@ extension SwiftlyHTTPClient {
     /// The tags are returned in pages of 100. The page argument specifies the page number.
     ///
     /// The results are returned in lexicographic order.
-    internal func getTags(page: Int) async throws -> [GitHubTag] {
+    public func getTags(page: Int) async throws -> [GitHubTag] {
         let url = "https://api.github.com/repos/apple/swift/tags?per_page=100&page=\(page)"
         return try await self.getFromGitHub(url: url)
     }
 }
 
 /// Model of a GitHub REST API release object.
 /// See: https://docs.github.com/en/rest/releases/releases?apiVersion=2022-11-28#list-releases
-private struct GitHubRelease: Decodable {
+public struct GitHubRelease: Decodable {
     fileprivate let name: String
     fileprivate let prerelease: Bool
 
@@ -90,7 +90,7 @@ private struct GitHubRelease: Decodable {
 }
 
 /// Model of a GitHub REST API tag/release object.
-internal struct GitHubTag: Decodable {
+public struct GitHubTag: Decodable {
     internal struct Commit: Decodable {
         internal let sha: String
     }

Sources/SwiftlyCore/Platform.swift

@@ -21,7 +21,7 @@ public protocol Platform {
     var toolchainFileExtension: String { get }
 
     /// Checks whether a given system dependency has been installed yet or not.
-    /// This will only really be used on Linux.
+    /// This will only really used on Linux.
     func isSystemDependencyPresent(_ dependency: SystemDependency) -> Bool
 
     /// Installs a toolchain from a file on disk pointed to by the given URL.

Tests/SwiftlyTests/E2ETests.swift

@@ -0,0 +1,35 @@
+import Foundation
+@testable import Swiftly
+@testable import SwiftlyCore
+import XCTest
+
+final class E2ETests: SwiftlyTests {
+    /// Tests that `swiftly install latest` successfully installs the latest stable release of Swift end-to-end.
+    ///
+    /// This will modify the user's system, but will undo those changes afterwards.
+    func testInstallLatest() async throws {
+        try await self.rollbackLocalChanges {
+            var cmd = try self.parseCommand(Install.self, ["install", "latest"])
+            try await cmd.run()
+
+            let config = try Config.load()
+
+            guard !config.installedToolchains.isEmpty else {
+                XCTFail("expected to install latest main snapshot toolchain but installed toolchains is empty in the config")
+                return
+            }
+
+            let installedToolchain = config.installedToolchains.first!
+
+            guard case let .stable(release) = installedToolchain else {
+                XCTFail("expected swiftly install latest to insall release toolchain but got \(installedToolchain)")
+                return
+            }
+
+            // As of writing this, 5.8.0 is the latest stable release. Assert it is at least that new.
+            XCTAssertTrue(release >= ToolchainVersion.StableRelease(major: 5, minor: 8, patch: 0))
+
+            try await validateInstalledToolchains([installedToolchain], description: "install latest")
+        }
+    }
+}

Tests/SwiftlyTests/HTTPClientTests.swift

@@ -0,0 +1,79 @@
+@testable import Swiftly
+@testable import SwiftlyCore
+import XCTest
+
+final class HTTPClientTests: SwiftlyTests {
+    func testGet() async throws {
+        // GIVEN: we have a swiftly http client
+        // WHEN: we make get request for a particular type of JSON
+        var releases: [GitHubRelease] = try await SwiftlyCore.httpClient.getFromJSON(
+            url: "https://api.github.com/repos/apple/swift/releases?per_page=100&page=1",
+            type: [GitHubRelease].self,
+            headers: [:]
+        )
+        // THEN: we get a decoded JSON response
+        XCTAssertTrue(releases.count > 0)
+
+        // GIVEN: we have a swiftly http client
+        // WHEN: we make a request to an invalid URL path
+        var exceptionThrown = false
+        do {
+            releases = try await SwiftlyCore.httpClient.getFromJSON(
+                url: "https://api.github.com/repos/apple/swift/releases2",
+                type: [GitHubRelease].self,
+                headers: [:]
+            )
+        } catch {
+            exceptionThrown = true
+        }
+        // THEN: we receive an exception
+        XCTAssertTrue(exceptionThrown)
+
+        // GIVEN: we have a swiftly http client
+        // WHEN: we make a request to an invalid host path
+        exceptionThrown = false
+        do {
+            releases = try await SwiftlyCore.httpClient.getFromJSON(
+                url: "https://inavlid.github.com/repos/apple/swift/releases",
+                type: [GitHubRelease].self,
+                headers: [:]
+            )
+        } catch {
+            exceptionThrown = true
+        }
+        // THEN: we receive an exception
+        XCTAssertTrue(exceptionThrown)
+    }
+
+    func testGetFromGitHub() async throws {
+        // GIVEN: we have a swiftly http client with github capability
+        // WHEN: we ask for the first page of releases with page size 5
+        var releases = try await SwiftlyCore.httpClient.getReleases(page: 1, perPage: 5)
+        // THEN: we get five releases
+        XCTAssertEqual(5, releases.count)
+
+        let firstRelease = releases[0]
+
+        // GIVEN: we have a swiftly http client with github capability
+        // WHEN: we ask for the second page of releases with page size 5
+        releases = try await SwiftlyCore.httpClient.getReleases(page: 2, perPage: 5)
+        // THEN: we get five different releases
+        XCTAssertEqual(5, releases.count)
+        XCTAssertTrue(releases[0].name != firstRelease.name)
+
+        // GIVEN: we have a swiftly http client with github capability
+        // WHEN: we ask for the first page of tags
+        var tags = try await SwiftlyCore.httpClient.getTags(page: 1)
+        // THEN: we get a collection of tags
+        XCTAssertTrue(tags.count > 0)
+
+        let firstTag = tags[0]
+
+        // GIVEN: we have a swiftly http client with github capability
+        // WHEN: we ask for the second page of tags
+        tags = try await SwiftlyCore.httpClient.getTags(page: 2)
+        // THEN: we get a different collection of tags
+        XCTAssertTrue(tags.count > 0)
+        XCTAssertTrue(tags[0].name != firstTag.name)
+    }
+}