refactor(registry): refactor registry initialization

11 files changed, 301 insertions, 307 deletions

diff --git a/lua/mason-core/installer/InstallLocation.lua b/lua/mason-core/installer/InstallLocation.lua
index 00b517b9..77252761 100644
--- a/lua/mason-core/installer/InstallLocation.lua
+++ b/lua/mason-core/installer/InstallLocation.lua
@@ -24,7 +24,6 @@ function InstallLocation:get_dir()
     return self.dir
 end
 
----@async
 function InstallLocation:initialize()
     local Result = require "mason-core.result"
     local fs = require "mason-core.fs"
@@ -37,8 +36,8 @@ function InstallLocation:initialize()
             self:package(),
             self:staging(),
         } do
-            if not fs.async.dir_exists(p) then
-                try(Result.pcall(fs.async.mkdirp, p))
+            if not fs.sync.dir_exists(p) then
+                try(Result.pcall(fs.sync.mkdirp, p))
             end
         end
     end)
diff --git a/lua/mason-registry/init.lua b/lua/mason-registry/init.lua
index 746e487b..5e4d124f 100644
--- a/lua/mason-registry/init.lua
+++ b/lua/mason-registry/init.lua
@@ -1,230 +1,158 @@
 local EventEmitter = require "mason-core.EventEmitter"
 local InstallLocation = require "mason-core.installer.InstallLocation"
-local Optional = require "mason-core.optional"
-local _ = require "mason-core.functional"
-local fs = require "mason-core.fs"
 local log = require "mason-core.log"
-local path = require "mason-core.path"
-local sources = require "mason-registry.sources"
+local uv = vim.loop
+local LazySourceCollection = require "mason-registry.sources"
 
----@class RegistrySource
----@field id string
----@field get_package fun(self: RegistrySource, pkg_name: string): Package?
----@field get_all_package_names fun(self: RegistrySource): string[]
----@field get_all_package_specs fun(self: RegistrySource): PackageSpec[] | RegistryPackageSpec[]
----@field get_display_name fun(self: RegistrySource): string
----@field is_installed fun(self: RegistrySource): boolean
----@field get_installer fun(self: RegistrySource): Optional # Optional<async fun (): Result>
+-- singleton
+local Registry = EventEmitter:new()
 
----@class MasonRegistry : EventEmitter
----@diagnostic disable-next-line: assign-type-mismatch
-local M = setmetatable({}, { __index = EventEmitter })
-EventEmitter.init(M)
-
----@type fun(location: InstallLocation): table<string, true>
-local scan_install_root
-
-do
-    ---@type table<string, true>?
-    local cached_dirs
-
-    local get_directories = _.compose(
-        _.set_of,
-        _.filter_map(function(entry)
-            if entry.type == "directory" then
-                return Optional.of(entry.name)
-            else
-                return Optional.empty()
-            end
-        end)
-    )
-
-    ---@param location InstallLocation
-    ---@return table<string, true>
-    scan_install_root = function(location)
-        if cached_dirs then
-            return cached_dirs
-        end
-        log.trace "Scanning installation root dir"
-        local ok, entries = pcall(fs.sync.readdir, location:package())
-        if not ok then
-            log.debug("Failed to scan installation root dir", entries)
-            -- presume installation root dir has not been created yet (i.e., no packages installed)
-            return {}
-        end
-        cached_dirs = get_directories(entries)
-        vim.schedule(function()
-            cached_dirs = nil
-        end)
-        log.trace("Resolved installation root dirs", cached_dirs)
-        return cached_dirs
-    end
-end
+Registry.sources = LazySourceCollection:new()
+---@type table<string, string[]>
+Registry.aliases = {}
 
----Checks whether the provided package name is installed.
----In many situations, this is a more efficient option than the Package:is_installed() method due to a smaller amount of
----modules required to load.
----@param package_name string
-function M.is_installed(package_name)
-    return scan_install_root(InstallLocation.global())[package_name] == true
+---@param pkg_name string
+function Registry.is_installed(pkg_name)
+    local ok, stat = pcall(uv.fs_stat, InstallLocation.global():package(pkg_name), "r", 438)
+    return ok and stat.type == "directory"
 end
 
----Returns an instance of the Package class if the provided package name exists. This function errors if a package cannot be found.
----@param package_name string
+---Returns an instance of the Package class if the provided package name exists. This function errors if a package
+---cannot be found.
+---@param pkg_name string
 ---@return Package
-function M.get_package(package_name)
-    for source in sources.iter() do
-        local pkg = source:get_package(package_name)
+function Registry.get_package(pkg_name)
+    for source in Registry.sources:iterate() do
+        local pkg = source:get_package(pkg_name)
         if pkg then
             return pkg
         end
     end
-    log.fmt_error("Cannot find package %q.", package_name)
-    error(("Cannot find package %q."):format(package_name))
+    log.fmt_error("Cannot find package %q.", pkg_name)
+    error(("Cannot find package %q."):format(pkg_name))
 end
 
----Returns true if the provided package_name can be found in the registry.
----@param package_name string
----@return boolean
-function M.has_package(package_name)
-    local ok = pcall(M.get_package, package_name)
+function Registry.has_package(pkg_name)
+    local ok = pcall(Registry.get_package, pkg_name)
     return ok
 end
 
-local get_packages = _.map(M.get_package)
-
----Returns all installed package names. This is a fast function that doesn't load any extra modules.
----@return string[]
-function M.get_installed_package_names()
-    return _.keys(scan_install_root(InstallLocation.global()))
+function Registry.get_installed_package_names()
+    local fs = require "mason-core.fs"
+    if not fs.sync.dir_exists(InstallLocation.global():package()) then
+        return {}
+    end
+    local entries = fs.sync.readdir(InstallLocation:global():package())
+    local directories = {}
+    for _, entry in ipairs(entries) do
+        if entry.type == "directory" then
+            directories[#directories + 1] = entry.name
+        end
+    end
+    -- TODO: validate that entry is a mason package
+    return directories
 end
 
----Returns all installed package instances. This is a slower function that loads more modules.
----@return Package[]
-function M.get_installed_packages()
-    return get_packages(M.get_installed_package_names())
+function Registry.get_installed_packages()
+    return vim.tbl_map(Registry.get_package, Registry.get_installed_package_names())
 end
 
----Returns all package names. This is a fast function that doesn't load any extra modules.
----@return string[]
-function M.get_all_package_names()
+function Registry.get_all_package_names()
     local pkgs = {}
-    for source in sources.iter() do
+    for source in Registry.sources:iterate() do
         for _, name in ipairs(source:get_all_package_names()) do
             pkgs[name] = true
         end
     end
-    return _.keys(pkgs)
+    return vim.tbl_keys(pkgs)
 end
 
----Returns all package instances. This is a slower function that loads more modules.
----@return Package[]
-function M.get_all_packages()
-    return get_packages(M.get_all_package_names())
+function Registry.get_all_packages()
+    return vim.tbl_map(Registry.get_package, Registry.get_all_package_names())
 end
 
----@return RegistryPackageSpec[]
-function M.get_all_package_specs()
+function Registry.get_all_package_specs()
     local specs = {}
-    for source in sources.iter() do
-        vim.list_extend(specs, source:get_all_package_specs())
+    for source in Registry.sources:iterate() do
+        for _, spec in ipairs(source:get_all_package_specs()) do
+            if not specs[spec.name] then
+                specs[spec.name] = spec
+            end
+        end
     end
-    return _.uniq_by(_.prop "name", specs)
+    return vim.tbl_values(specs)
 end
 
-local STATE_FILE = path.concat {
-    vim.fn.stdpath((vim.fn.has "nvim-0.8.0" == 1) and "state" or "cache"),
-    "mason-registry-update",
-}
-
----@param time integer
-local function get_store_age(time)
-    local checksum = sources.checksum()
-    if fs.sync.file_exists(STATE_FILE) then
-        local parse_state_file =
-            _.compose(_.evolve { timestamp = tonumber }, _.zip_table { "checksum", "timestamp" }, _.split "\n")
-        local state = parse_state_file(fs.sync.read_file(STATE_FILE))
-        if checksum == state.checksum then
-            return math.abs(time - state.timestamp)
+---Register aliases for the specified packages
+---@param new_aliases table<string, string[]>
+function Registry.register_package_aliases(new_aliases)
+    for pkg_name, pkg_aliases in pairs(new_aliases) do
+        Registry.aliases[pkg_name] = Registry.aliases[pkg_name] or {}
+        for _, alias in pairs(pkg_aliases) do
+            if alias ~= pkg_name then
+                table.insert(Registry.aliases[pkg_name], alias)
+            end
         end
     end
-    return time
 end
 
----@param time integer
-local function update_store_timestamp(time)
-    local dir = vim.fn.fnamemodify(STATE_FILE, ":h")
-    if not fs.sync.dir_exists(dir) then
-        fs.sync.mkdirp(dir)
-    end
-    fs.sync.write_file(STATE_FILE, _.join("\n", { sources.checksum(), tostring(time) }))
+---@param name string
+function Registry.get_package_aliases(name)
+    return Registry.aliases[name] or {}
 end
 
 ---@param callback? fun(success: boolean, updated_registries: RegistrySource[])
-function M.update(callback)
+function Registry.update(callback)
+    log.debug "Updating the registry."
     local a = require "mason-core.async"
+    local installer = require "mason-registry.installer"
+    local noop = function() end
 
-    return a.run(require("mason-registry.installer").run, function(success, result)
-        if not callback then
-            return
+    a.run(function()
+        if installer.channel then
+            log.trace "Registry update already in progress."
+            return installer.channel:receive():get_or_throw()
+        else
+            return installer
+                .install(Registry.sources)
+                :on_success(function(updated_registries)
+                    Registry:emit("update", updated_registries)
+                end)
+                :get_or_throw()
         end
-        if not success then
-            return callback(false, result)
-        end
-        result
-            :on_success(function(value)
-                callback(true, value)
-            end)
-            :on_failure(function(err)
-                callback(false, err)
-            end)
-    end)
+    end, callback or noop)
 end
 
 local REGISTRY_STORE_TTL = 86400 -- 24 hrs
 
----@param cb? fun()
-function M.refresh(cb)
+---@param callback? fun(success: boolean, updated_registries: RegistrySource[])
+function Registry.refresh(callback)
+    log.debug "Refreshing the registry."
     local a = require "mason-core.async"
+    local installer = require "mason-registry.installer"
 
-    ---@async
-    local function refresh()
-        a.scheduler()
-        local is_outdated = get_store_age(os.time()) > REGISTRY_STORE_TTL
-        if is_outdated or not sources.is_installed() then
-            if a.wait(M.update) then
-                a.scheduler()
-                update_store_timestamp(os.time())
-            end
+    local state = installer.get_registry_state()
+    local is_state_ok = state
+        and (os.time() - state.timestamp) <= REGISTRY_STORE_TTL
+        and state.checksum == Registry.sources:checksum()
+
+    if is_state_ok and Registry.sources:is_all_installed() then
+        log.debug "Registry refresh not necessary."
+        if callback then
+            callback(true, {})
         end
+        return
     end
 
-    if not cb then
-        a.run_blocking(refresh)
+    if not callback then
+        return a.run_blocking(function()
+            return a.wait(Registry.update)
+        end)
     else
-        a.run(refresh, cb)
+        a.run(function()
+            return a.wait(Registry.update)
+        end, callback)
     end
 end
 
----@type table<string, string[]>
-local aliases = {}
-
----Register aliases for the specified packages
----@param new_aliases table<string, string[]>
-function M.register_package_aliases(new_aliases)
-    for pkg_name, pkg_aliases in pairs(new_aliases) do
-        aliases[pkg_name] = aliases[pkg_name] or {}
-        for _, alias in pairs(pkg_aliases) do
-            if alias ~= pkg_name then
-                table.insert(aliases[pkg_name], alias)
-            end
-        end
-    end
-end
-
----@param name string
-function M.get_package_aliases(name)
-    return aliases[name] or {}
-end
-
-return M
+return Registry
diff --git a/lua/mason-registry/installer.lua b/lua/mason-registry/installer.lua
index 3fc4fb31..a1984921 100644
--- a/lua/mason-registry/installer.lua
+++ b/lua/mason-registry/installer.lua
@@ -1,38 +1,58 @@
 local a = require "mason-core.async"
+local log = require "mason-core.log"
 local OneShotChannel = require("mason-core.async.control").OneShotChannel
 local Result = require "mason-core.result"
-local sources = require "mason-registry.sources"
+local _ = require "mason-core.functional"
+local fs = require "mason-core.fs"
+local path = require "mason-core.path"
 
 local M = {}
 
----@type OneShotChannel?
-local update_channel
+local STATE_FILE = path.concat { vim.fn.stdpath "cache", "mason-registry-update" }
 
----@async
-function M.run()
-    if not update_channel or update_channel:is_closed() then
-        update_channel = OneShotChannel:new()
-        a.run(function()
-            update_channel:send(Result.try(function(try)
-                local updated_sources = {}
-                for source in sources.iter { include_uninstalled = true } do
-                    source:get_installer():if_present(function(installer)
-                        try(installer():map_err(function(err)
-                            return ("%s failed to install: %s"):format(source, err)
-                        end))
-                        table.insert(updated_sources, source)
-                    end)
-                end
-                return updated_sources
-            end):on_success(function(updated_sources)
-                if #updated_sources > 0 then
-                    require("mason-registry"):emit("update", updated_sources)
-                end
-            end))
-        end, function() end)
+---@param sources LazySourceCollection
+---@param time integer
+local function update_registry_state(sources, time)
+    log.trace("Updating registry state", sources, time)
+    local dir = vim.fn.fnamemodify(STATE_FILE, ":h")
+    if not fs.sync.dir_exists(dir) then
+        fs.sync.mkdirp(dir)
+    end
+    fs.sync.write_file(STATE_FILE, _.join("\n", { sources:checksum(), tostring(time) }))
+end
+
+---@return { checksum: string, timestamp: integer }?
+function M.get_registry_state()
+    if fs.sync.file_exists(STATE_FILE) then
+        local parse_state_file =
+            _.compose(_.evolve { timestamp = tonumber }, _.zip_table { "checksum", "timestamp" }, _.split "\n")
+        return parse_state_file(fs.sync.read_file(STATE_FILE))
     end
+end
 
-    return update_channel:receive()
+---@async
+---@param sources LazySourceCollection
+---@return Result # Result<RegistrySource[]>
+function M.install(sources)
+    log.debug("Installing registries.", sources)
+    assert(not M.channel, "Cannot install when channel is active.")
+    M.channel = OneShotChannel:new()
+    local result = Result.try(function(try)
+        local updated_sources = {}
+        for source in sources:iterate { include_uninstalled = true } do
+            log.trace("Installing registry.", source)
+            try(source:install():map_err(function(err)
+                return ("%s failed to install: %s"):format(source, err)
+            end))
+            table.insert(updated_sources, source)
+        end
+        a.scheduler()
+        update_registry_state(sources, os.time())
+        return updated_sources
+    end)
+    M.channel:send(result)
+    M.channel = nil
+    return result
 end
 
 return M
diff --git a/lua/mason-registry/sources/file.lua b/lua/mason-registry/sources/file.lua
index 62e7d7a4..84566479 100644
--- a/lua/mason-registry/sources/file.lua
+++ b/lua/mason-registry/sources/file.lua
@@ -14,6 +14,7 @@ local util = require "mason-registry.sources.util"
 local Channel = async_control.Channel
 
 ---@class FileRegistrySourceSpec
+---@field id string
 ---@field path string
 
 ---@class FileRegistrySource : RegistrySource
@@ -28,6 +29,7 @@ function FileRegistrySource:new(spec)
     ---@type FileRegistrySource
     local instance = {}
     setmetatable(instance, self)
+    instance.id = spec.id
     instance.spec = spec
     return instance
 end
@@ -68,10 +70,6 @@ function FileRegistrySource:get_all_package_names()
     return _.map(_.prop "name", self:get_all_package_specs())
 end
 
-function FileRegistrySource:get_installer()
-    return Optional.of(_.partial(self.install, self))
-end
-
 ---@async
 function FileRegistrySource:install()
     return Result.try(function(try)
diff --git a/lua/mason-registry/sources/github.lua b/lua/mason-registry/sources/github.lua
index b314d690..ceb503dc 100644
--- a/lua/mason-registry/sources/github.lua
+++ b/lua/mason-registry/sources/github.lua
@@ -15,7 +15,6 @@ local parse_checksums = _.compose(_.from_pairs, _.map(_.compose(_.reverse, _.spl
 
 ---@class GitHubRegistrySourceSpec
 ---@field id string
----@field repo string
 ---@field namespace string
 ---@field name string
 ---@field version string?
@@ -38,6 +37,7 @@ function GitHubRegistrySource:new(spec)
     local root_dir = InstallLocation.global():registry(path.concat { "github", spec.namespace, spec.name })
     instance.id = spec.id
     instance.spec = spec
+    instance.repo = ("%s/%s"):format(spec.namespace, spec.name)
     instance.root_dir = root_dir
     instance.data_file = path.concat { root_dir, "registry.json" }
     instance.info_file = path.concat { root_dir, "info.json" }
@@ -81,10 +81,6 @@ function GitHubRegistrySource:get_all_package_names()
     return _.map(_.prop "name", self:get_all_package_specs())
 end
 
-function GitHubRegistrySource:get_installer()
-    return Optional.of(_.partial(self.install, self))
-end
-
 ---@async
 function GitHubRegistrySource:install()
     local zzlib = require "mason-vendor.zzlib"
@@ -106,7 +102,7 @@ function GitHubRegistrySource:install()
             ---@type GitHubRelease
             local release = try(
                 providers.github
-                    .get_latest_release(self.spec.repo)
+                    .get_latest_release(self.repo)
                     :map_err(_.always "Failed to fetch latest registry version from GitHub API.")
             )
             version = release.tag_name
@@ -114,7 +110,7 @@ function GitHubRegistrySource:install()
         end
 
         local zip_file = path.concat { self.root_dir, "registry.json.zip" }
-        try(fetch(settings.current.github.download_url_template:format(self.spec.repo, version, "registry.json.zip"), {
+        try(fetch(settings.current.github.download_url_template:format(self.repo, version, "registry.json.zip"), {
             out_file = zip_file,
         }):map_err(_.always "Failed to download registry archive."))
         local zip_buffer = fs.async.read_file(zip_file)
@@ -126,7 +122,7 @@ function GitHubRegistrySource:install()
         pcall(fs.async.unlink, zip_file)
 
         local checksums = try(
-            fetch(settings.current.github.download_url_template:format(self.spec.repo, version, "checksums.txt")):map_err(
+            fetch(settings.current.github.download_url_template:format(self.repo, version, "checksums.txt")):map_err(
                 _.always "Failed to download checksums.txt."
             )
         )
@@ -158,17 +154,17 @@ end
 function GitHubRegistrySource:get_display_name()
     if self:is_installed() then
         local info = self:get_info()
-        return ("github.com/%s version: %s"):format(self.spec.repo, info.version)
+        return ("github.com/%s version: %s"):format(self.repo, info.version)
     else
-        return ("github.com/%s [uninstalled]"):format(self.spec.repo)
+        return ("github.com/%s [uninstalled]"):format(self.repo)
     end
 end
 
 function GitHubRegistrySource:__tostring()
     if self.spec.version then
-        return ("GitHubRegistrySource(repo=%s, version=%s)"):format(self.spec.repo, self.spec.version)
+        return ("GitHubRegistrySource(repo=%s, version=%s)"):format(self.repo, self.spec.version)
     else
-        return ("GitHubRegistrySource(repo=%s)"):format(self.spec.repo)
+        return ("GitHubRegistrySource(repo=%s)"):format(self.repo)
     end
 end
 
diff --git a/lua/mason-registry/sources/init.lua b/lua/mason-registry/sources/init.lua
index af1b9f6a..fd9cc573 100644
--- a/lua/mason-registry/sources/init.lua
+++ b/lua/mason-registry/sources/init.lua
@@ -1,6 +1,76 @@
-local _ = require "mason-core.functional"
+---@class RegistrySource
+---@field id string
+---@field get_package fun(self: RegistrySource, pkg_name: string): Package?
+---@field get_all_package_names fun(self: RegistrySource): string[]
+---@field get_all_package_specs fun(self: RegistrySource): RegistryPackageSpec[]
+---@field get_display_name fun(self: RegistrySource): string
+---@field is_installed fun(self: RegistrySource): boolean
+---@field install fun(self: RegistrySource): Result
 
-local M = {}
+---@alias RegistrySourceType '"github"' | '"lua"' | '"file"'
+
+---@class LazySource
+---@field type RegistrySourceType
+---@field id string
+---@field init fun(id: string): RegistrySource
+local LazySource = {}
+LazySource.__index = LazySource
+
+---@param id string
+function LazySource.GitHub(id)
+    local namespace, name = id:match "^(.+)/(.+)$"
+    if not namespace or not name then
+        error(("Failed to parse repository from GitHub registry: %q"):format(id), 0)
+    end
+    local name, version = unpack(vim.split(name, "@"))
+    local GitHubRegistrySource = require "mason-registry.sources.github"
+    return GitHubRegistrySource:new {
+        id = id,
+        namespace = namespace,
+        name = name,
+        version = version,
+    }
+end
+
+---@param id string
+function LazySource.Lua(id)
+    local LuaRegistrySource = require "mason-registry.sources.lua"
+    return LuaRegistrySource:new {
+        id = id,
+        mod = id,
+    }
+end
+
+---@param id string
+function LazySource.File(id)
+    local FileRegistrySource = require "mason-registry.sources.file"
+    return FileRegistrySource:new {
+        id = id,
+        path = id,
+    }
+end
+
+---@param type RegistrySourceType
+---@param id string
+---@param init fun(id: string): RegistrySource
+function LazySource:new(type, id, init)
+    local instance = setmetatable({}, self)
+    instance.type = type
+    instance.id = id
+    instance.init = init
+    return instance
+end
+
+function LazySource:get()
+    if not self.instance then
+        self.instance = self.init(self.id)
+    end
+    return self.instance
+end
+
+function LazySource:__tostring()
+    return ("LazySource(type=%s, id=%s)"):format(self.type, self.id)
+end
 
 ---@param str string
 local function split_once_left(str, char)
@@ -14,88 +84,46 @@ local function split_once_left(str, char)
 end
 
 ---@param registry_id string
----@return fun(): RegistrySource # Thunk to instantiate provider.
 local function parse(registry_id)
     local type, id = split_once_left(registry_id, ":")
+    assert(id, ("Malformed registry %q"):format(registry_id))
     if type == "github" then
-        local namespace, name = id:match "^(.+)/(.+)$"
-        if not namespace or not name then
-            error(("Failed to parse repository from GitHub registry: %q."):format(registry_id), 0)
-        end
-        local name, version = unpack(vim.split(name, "@"))
-        return function()
-            local GitHubRegistrySource = require "mason-registry.sources.github"
-            return GitHubRegistrySource:new {
-                id = registry_id,
-                repo = ("%s/%s"):format(namespace, name),
-                namespace = namespace,
-                name = name,
-                version = version,
-            }
-        end
+        return LazySource:new(type, id, LazySource.GitHub)
     elseif type == "lua" then
-        return function()
-            local LuaRegistrySource = require "mason-registry.sources.lua"
-            return LuaRegistrySource:new {
-                id = registry_id,
-                mod = id,
-            }
-        end
+        return LazySource:new(type, id, LazySource.Lua)
     elseif type == "file" then
-        return function()
-            local FileRegistrySource = require "mason-registry.sources.file"
-            return FileRegistrySource:new {
-                path = id,
-            }
-        end
-    elseif type ~= nil then
-        error(("Unknown registry type %q: %q."):format(type, registry_id), 0)
+        return LazySource:new(type, id, LazySource.File)
     end
-    error(("Malformed registry id: %q."):format(registry_id), 0)
+    error(("Unknown registry type: %s"):format(type))
 end
 
----@type ((fun(): RegistrySource) | RegistrySource)[]
-local registries = {}
+---@class LazySourceCollection
+---@field list LazySource[]
+local LazySourceCollection = {}
+LazySourceCollection.__index = LazySourceCollection
 
----@param registry_ids string[]
-function M.set_registries(registry_ids)
-    registries = {}
-    for _, registry in ipairs(registry_ids) do
-        local ok, err = pcall(function()
-            table.insert(registries, parse(registry))
-        end)
-        if not ok then
-            local log = require "mason-core.log"
-            local notify = require "mason-core.notify"
-            log.fmt_error("Failed to parse registry %q: %s", registry, err)
-            notify(err, vim.log.levels.ERROR)
-        end
-    end
+---@return LazySourceCollection
+function LazySourceCollection:new()
+    local instance = {}
+    setmetatable(instance, self)
+    instance.list = {}
+    return instance
 end
 
----@param opts? { include_uninstalled?: boolean }
-function M.iter(opts)
-    opts = opts or {}
-    local i = 1
-    return function()
-        while i <= #registries do
-            local registry = registries[i]
-            if type(registry) == "function" then
-                -- unwrap thunk
-                registry = registry()
-                registries[i] = registry
-            end
-            i = i + 1
-            if opts.include_uninstalled or registry:is_installed() then
-                return registry
-            end
-        end
-    end
+---@param registry string
+function LazySourceCollection:append(registry)
+    table.insert(self.list, parse(registry))
+    return self
+end
+
+---@param registry string
+function LazySourceCollection:prepend(registry)
+    table.insert(self.list, 1, parse(registry))
+    return self
 end
 
----@return boolean #Returns true if all sources are installed.
-function M.is_installed()
-    for source in M.iter { include_uninstalled = true } do
+function LazySourceCollection:is_all_installed()
+    for source in self:iterate { include_uninstalled = true } do
         if not source:is_installed() then
             return false
         end
@@ -103,15 +131,37 @@ function M.is_installed()
     return true
 end
 
----@return string # The sha256 checksum of the currently registered sources.
-function M.checksum()
+function LazySourceCollection:checksum()
     ---@type string[]
-    local registry_ids = {}
-    for source in M.iter { include_uninstalled = true } do
-        table.insert(registry_ids, source.id)
+    local registry_ids = vim.tbl_map(
+        ---@param source LazySource
+        function(source)
+            return source.id
+        end,
+        self.list
+    )
+    table.sort(registry_ids)
+    return vim.fn.sha256(table.concat(registry_ids, ""))
+end
+
+---@param opts? { include_uninstalled?: boolean }
+function LazySourceCollection:iterate(opts)
+    opts = opts or {}
+
+    local idx = 1
+    return function()
+        while idx <= #self.list do
+            local source = self.list[idx]:get()
+            idx = idx + 1
+            if opts.include_uninstalled or source:is_installed() then
+                return source
+            end
+        end
     end
-    local checksum = _.compose(vim.fn.sha256, _.join "", _.sort_by(_.identity))
-    return checksum(registry_ids)
 end
 
-return M
+function LazySourceCollection:__tostring()
+    return ("LazySourceCollection(list={%s})"):format(table.concat(vim.tbl_map(tostring, self.list), ", "))
+end
+
+return LazySourceCollection
diff --git a/lua/mason-registry/sources/lua.lua b/lua/mason-registry/sources/lua.lua
index fd88a49d..7fae54fe 100644
--- a/lua/mason-registry/sources/lua.lua
+++ b/lua/mason-registry/sources/lua.lua
@@ -1,4 +1,5 @@
 local Optional = require "mason-core.optional"
+local Result = require "mason-core.result"
 local _ = require "mason-core.functional"
 local log = require "mason-core.log"
 
@@ -35,6 +36,10 @@ function LuaRegistrySource:get_package(pkg_name)
     end
 end
 
+function LuaRegistrySource:install()
+    return Result.pcall(require, self.spec.mod)
+end
+
 ---@return string[]
 function LuaRegistrySource:get_all_package_names()
     local index = require(self.spec.mod)
@@ -53,11 +58,6 @@ function LuaRegistrySource:is_installed()
     return ok
 end
 
-function LuaRegistrySource:get_installer()
-    local Optional = require "mason-core.optional"
-    return Optional.empty()
-end
-
 function LuaRegistrySource:get_display_name()
     if self:is_installed() then
         return ("require(%q)"):format(self.spec.mod)
diff --git a/lua/mason/health.lua b/lua/mason/health.lua
index 5c54b1b3..5ac2cd1b 100644
--- a/lua/mason/health.lua
+++ b/lua/mason/health.lua
@@ -6,7 +6,6 @@ local control = require "mason-core.async.control"
 local platform = require "mason-core.platform"
 local providers = require "mason-core.providers"
 local registry = require "mason-registry"
-local registry_sources = require "mason-registry.sources"
 local settings = require "mason.settings"
 local spawn = require "mason-core.spawn"
 local version = require "mason.version"
@@ -68,7 +67,7 @@ end
 local function check_registries()
     report_start "mason.nvim [Registries]"
     a.wait(registry.refresh)
-    for source in registry_sources.iter { include_uninstalled = true } do
+    for source in registry.sources:iterate { include_uninstalled = true } do
         if source:is_installed() then
             report_ok(("Registry `%s` is installed."):format(source:get_display_name()))
         else
diff --git a/lua/mason/init.lua b/lua/mason/init.lua
index ff26cc8d..9c507f5c 100644
--- a/lua/mason/init.lua
+++ b/lua/mason/init.lua
@@ -1,4 +1,5 @@
 local InstallLocation = require "mason-core.installer.InstallLocation"
+local Registry = require "mason-registry"
 local settings = require "mason.settings"
 
 local M = {}
@@ -20,11 +21,14 @@ function M.setup(config)
         settings.set(config)
     end
 
-    InstallLocation.global():set_env { PATH = settings.current.PATH }
+    local global_location = InstallLocation.global()
+    global_location:set_env { PATH = settings.current.PATH }
+    for _, registry in ipairs(settings.current.registries) do
+        Registry.sources:append(registry)
+    end
 
     require "mason.api.command"
     setup_autocmds()
-    require("mason-registry.sources").set_registries(settings.current.registries)
     M.has_setup = true
 end
 
diff --git a/lua/mason/ui/instance.lua b/lua/mason/ui/instance.lua
index 8a82bc64..70c85858 100644
--- a/lua/mason/ui/instance.lua
+++ b/lua/mason/ui/instance.lua
@@ -684,7 +684,7 @@ end
 
 local function update_registry_info()
     local registries = {}
-    for source in require("mason-registry.sources").iter { include_uninstalled = true } do
+    for source in registry.sources:iterate { include_uninstalled = true } do
         table.insert(registries, {
             name = source:get_display_name(),
             is_installed = source:is_installed(),
diff --git a/tests/mason/setup_spec.lua b/tests/mason/setup_spec.lua
index f3193a27..a4320bb3 100644
--- a/tests/mason/setup_spec.lua
+++ b/tests/mason/setup_spec.lua
@@ -10,7 +10,7 @@ describe("mason setup", function()
         settings.set(settings._DEFAULT_SETTINGS)
     end)
 
-    it("should enhance the PATH environment", function()
+    it("should modify the PATH environment", function()
         mason.setup()
         local global_location = InstallLocation.global()
         assert.equals(("%s:/usr/local/bin:/usr/bin"):format(global_location:bin()), vim.env.PATH)