Add --print-location flag to swiftly list subcommand

Documentation/SwiftlyDocs.docc/swiftly-cli-reference.md

@@ -281,7 +281,7 @@ Finally, all installed toolchains can be uninstalled by specifying 'all':
 List installed toolchains.
 
 ```
-swiftly list [<toolchain-selector>] [--version] [--help]
+swiftly list [<toolchain-selector>] [--print-location] [--version] [--help]
 ```
 
 **toolchain-selector:**
@@ -307,6 +307,11 @@ The installed snapshots for a given devlopment branch can be listed by specifyin
     $ swiftly list 5.7-snapshot
 
 
+**--print-location:**
+
+*Print the location of the toolchains prefixed with the version <x.y.z> - <path/to/toolchain>.*
+
+
 **--version:**
 
 *Show the version.*

Sources/Swiftly/List.swift

@@ -33,6 +33,9 @@ struct List: SwiftlyCommand {
     ))
     var toolchainSelector: String?
 
+    @Flag(name: .shortAndLong, help: "Print the location of the toolchains prefixed with the version <x.y.z> - <path/to/toolchain>.")
+    var printLocation: Bool = false
+
     internal mutating func run() async throws {
         try validateSwiftly()
         let selector = try self.toolchainSelector.map { input in
@@ -42,6 +45,14 @@ struct List: SwiftlyCommand {
         var config = try Config.load()
 
         let toolchains = config.listInstalledToolchains(selector: selector).sorted { $0 > $1 }
+
+        guard !self.printLocation else {
+            for toolchain in toolchains {
+                SwiftlyCore.print("\(toolchain.name) - \(Swiftly.currentPlatform.findToolchainLocation(toolchain).path)")
+            }
+
+            return
+        }
         let (inUse, _) = try await selectToolchain(config: &config)
 
         let printToolchain = { (toolchain: ToolchainVersion) in

Tests/SwiftlyTests/ListTests.swift

@@ -43,7 +43,7 @@ final class ListTests: SwiftlyTests {
         }
 
         var list = try self.parseCommand(List.self, args)
-        let output = try await list.runWithMockedIO()
+        var output = try await list.runWithMockedIO()
 
         let parsedToolchains = output.compactMap { outputLine in
             Self.allToolchains.first {
@@ -56,6 +56,20 @@ final class ListTests: SwiftlyTests {
             throw SwiftlyTestError(message: "unexpected listed toolchains in \(output)")
         }
 
+        // Check that the print location flag runs as expected
+        list = try self.parseCommand(List.self, args + ["--print-location"])
+        output = try await list.runWithMockedIO()
+
+        let toolchainLocations = output.compactMap { outputLine in
+            Self.allToolchains.first {
+                outputLine.contains("\($0.name) - \(Swiftly.currentPlatform.findToolchainLocation($0).path)")
+            }
+        }
+
+        guard toolchainLocations.count == parsedToolchains.count else {
+            throw SwiftlyTestError(message: "list --print-location didn't yield the same toolchains as plain list")
+        }
+
         return parsedToolchains
     }