feat: move all install path logic into __call

Also does this following:
* Properly types metatable return
* Runs tool after installation, previously the tool would not get
  executed post installation
* Further removal of manual alias handling

toolchainlib/src/init.luau

@@ -85,16 +85,8 @@ function runTool(tool: ToolId | pathfs.Path): number
 	}).code
 end
 
-function installTool(tool: ToolId)
+function installTool(tool: ToolId, installPath: pathfs.Path)
 	local toolAlias = toolAliasOrDefault(tool)
-	local toolId = string.gsub(tool.repo, "/", "+")
-	local toolInstallPath = TOOL_STORAGE_DIR:join(toolId)
-		:join(`{toolAlias}-` .. tostring(tool.version:map(tostring):unwrapOr("latest")))
-
-	if pathfs.isFile(toolInstallPath) then
-		runTool(toolInstallPath)
-		return
-	end
 
 	local client = Github.new(
 		tool.repo,
@@ -166,12 +158,12 @@ function installTool(tool: ToolId)
 
 	-- Maintain multiple versions of a tool, and avoid downloading
 	-- the binary for a version again if it's already there
-	local toolDir = Option.from(toolInstallPath:parent()):unwrap()
+	local toolDir = Option.from(installPath:parent()):unwrap()
 	if not pathfs.isFile(toolDir) then
 		pathfs.writeDir(toolDir)
 	end
 
-	pathfs.move(binaryPath, toolInstallPath)
+	pathfs.move(binaryPath, installPath)
 
 	-- In order to eliminate fs read overhead on startup and to disallow
 	-- the use of the tool binary when outside a package where it is installed,
@@ -193,13 +185,25 @@ function installTool(tool: ToolId)
 		-- Now we can use `path` to figure out the real tool to execute
 		-- ...
 	]]
+	runTool(installPath)
 end
 
-return setmetatable({
+type LibExports = {
+	runTool: (pathfs.Path | ToolId) -> number,
+	installTool: (ToolId, pathfs.Path) -> never,
+}
+type LibExportsImpl = typeof(setmetatable(
+	{} :: LibExports,
+	{ __call = function(lib: LibExportsImpl, tool: string, pesdeRoot: string?) end }
+))
+
+return setmetatable(
+	{
 		runTool = runTool,
 		installTool = installTool,
-}, {
+	} :: LibExports,
-	__call = function(lib, tool: string, pesdeRoot: string?)
+	{
+		__call = function(lib: LibExportsImpl, tool: string, pesdeRoot: string?)
 			-- TODO: Progress bar maybe? :D
 
 			local ERROR_PREFIX = `{stdio.color("red")}{stdio.style("bold")}error{stdio.color("reset")}:`
@@ -222,23 +226,36 @@ return setmetatable({
 				-- TODO: Create a pesde manifest type in toolchainlib, and use that here
 				local ok, manifest = pcall(serde.decode, "toml" :: "toml", manifestContents)
 				if not ok then
-				stdio.ewrite(`{ERROR_PREFIX} Failed to decode bundled manifest. This is probably a bug.\n\n{manifest}`)
+					stdio.ewrite(
+						`{ERROR_PREFIX} Failed to decode bundled manifest. This is probably a bug.\n\n{manifest}`
+					)
 					process.exit(1)
 				end
 
 				return manifest.version
 			end
 
+			local toolId = string.gsub(repo :: string, "/", "+")
+			local toolAlias = string.split(toolId, "+")[2]
+			local toolInstallPath = TOOL_STORAGE_DIR:join(toolId):join(
+				`{toolAlias}-` .. if version ~= "" then version :: string else manifestVersion()
+			)
+
+			print(toolInstallPath)
+			if pathfs.isFile(toolInstallPath) then
+				process.exit(lib.runTool(toolInstallPath))
+			end
+
 			local ok, err = pcall(
 				lib.installTool,
 				{
-				-- TODO: Use alias within pesde.toml in linker script
 					alias = Option.None,
 					repo = repo,
 					version = Option.Some(
 						Semver.parse(if version ~= "" then version :: string else manifestVersion()):unwrap()
 					) :: Option<Semver.SemverImpl>,
-			} :: ToolId
+				} :: ToolId,
+				toolInstallPath
 			)
 
 			if not ok then
@@ -246,4 +263,5 @@ return setmetatable({
 				stdio.ewrite(`	- {err}\n`)
 			end
 		end,
-})
+	}
+)