feat: add github registry source capabilities (#1091)

4 files changed, 252 insertions, 5 deletions

diff --git a/lua/mason-registry/init.lua b/lua/mason-registry/init.lua
index 01f18c90..a87b3b07 100644
--- a/lua/mason-registry/init.lua
+++ b/lua/mason-registry/init.lua
@@ -11,7 +11,7 @@ local sources = require "mason-registry.sources"
 ---@field get_all_package_names fun(self: RegistrySource): string[]
 ---@field get_display_name fun(self: RegistrySource): string
 ---@field is_installed fun(self: RegistrySource): boolean
----@field install async fun(self: RegistrySource): Result
+---@field get_installer fun(self: RegistrySource): Optional # Optional<async fun (): Result>
 
 ---@class MasonRegistry : EventEmitter
 ---@diagnostic disable-next-line: assign-type-mismatch
@@ -118,4 +118,40 @@ function M.get_all_packages()
     return get_packages(M.get_all_package_names())
 end
 
+---@param cb fun(success: boolean, err: any?)
+function M.update(cb)
+    local a = require "mason-core.async"
+    local Result = require "mason-core.result"
+
+    a.run(function()
+        return 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)
+    end, function(success, sources_or_err)
+        if not success then
+            cb(success, sources_or_err)
+            return
+        end
+        sources_or_err
+            :on_success(function(updated_sources)
+                if #updated_sources > 0 then
+                    M:emit("update", updated_sources)
+                end
+                cb(true, updated_sources)
+            end)
+            :on_failure(function(err)
+                cb(false, err)
+            end)
+    end)
+end
+
 return M
diff --git a/lua/mason-registry/sources/github.lua b/lua/mason-registry/sources/github.lua
new file mode 100644
index 00000000..0cddff21
--- /dev/null
+++ b/lua/mason-registry/sources/github.lua
@@ -0,0 +1,195 @@
+local log = require "mason-core.log"
+local fs = require "mason-core.fs"
+local providers = require "mason-core.providers"
+local _ = require "mason-core.functional"
+local path = require "mason-core.path"
+local Result = require "mason-core.result"
+local Optional = require "mason-core.optional"
+local fetch = require "mason-core.fetch"
+local settings = require "mason.settings"
+local platform = require "mason-core.platform"
+local spawn = require "mason-core.spawn"
+local Pkg = require "mason-core.package"
+local registry_installer = require "mason-core.installer.registry"
+
+-- Parse sha256sum text output to a table<filename: string, sha256sum: string> structure
+local parse_checksums = _.compose(_.from_pairs, _.map(_.compose(_.reverse, _.split "  ")), _.split "\n", _.trim)
+
+---@class GitHubRegistrySourceSpec
+---@field id string
+---@field repo string
+---@field namespace string
+---@field name string
+---@field version string?
+
+---@class GitHubRegistrySource : RegistrySource
+---@field spec GitHubRegistrySourceSpec
+---@field repo string
+---@field root_dir string
+---@field private data_file string
+---@field private info_file string
+---@field buffer table<string, Package>?
+local GitHubRegistrySource = {}
+GitHubRegistrySource.__index = GitHubRegistrySource
+
+---@param spec GitHubRegistrySourceSpec
+function GitHubRegistrySource.new(spec)
+    local root_dir = path.concat { path.registry_prefix(), "github", spec.namespace, spec.name }
+    return setmetatable({
+        spec = spec,
+        root_dir = root_dir,
+        data_file = path.concat { root_dir, "registry.json" },
+        info_file = path.concat { root_dir, "info.json" },
+    }, GitHubRegistrySource)
+end
+
+function GitHubRegistrySource:is_installed()
+    return fs.sync.file_exists(self.data_file)
+end
+
+function GitHubRegistrySource:reload()
+    if not self:is_installed() then
+        return
+    end
+    local data = vim.json.decode(fs.sync.read_file(self.data_file))
+    self.buffer = _.compose(
+        _.index_by(_.prop "name"),
+        _.filter_map(
+            ---@param spec RegistryPackageSpec
+            function(spec)
+                -- registry+v1 specifications doesn't include a schema property, so infer it
+                spec.schema = spec.schema or "registry+v1"
+
+                if not registry_installer.SCHEMA_CAP[spec.schema] then
+                    log.fmt_debug("Excluding package=%s with unsupported schema_version=%s", spec.name, spec.schema)
+                    return Optional.empty()
+                end
+
+                -- hydrate Pkg.Lang index
+                _.each(function(lang)
+                    local _ = Pkg.Lang[lang]
+                end, spec.languages)
+
+                local pkg = self.buffer and self.buffer[spec.name]
+                if pkg then
+                    -- Apply spec to the existing Package instance. This is important as to not have lingering package
+                    -- instances.
+                    pkg.spec = spec
+                    return Optional.of(pkg)
+                end
+                return Optional.of(Pkg.new(spec))
+            end
+        )
+    )(data)
+    return self.buffer
+end
+
+function GitHubRegistrySource:get_buffer()
+    return self.buffer or self:reload() or {}
+end
+
+---@param pkg string
+---@return Package?
+function GitHubRegistrySource:get_package(pkg)
+    return self:get_buffer()[pkg]
+end
+
+function GitHubRegistrySource:get_all_package_names()
+    return _.keys(self:get_buffer())
+end
+
+function GitHubRegistrySource:get_installer()
+    return Optional.of(_.partial(self.install, self))
+end
+
+---@async
+function GitHubRegistrySource:install()
+    return Result.try(function(try)
+        if not fs.async.dir_exists(self.root_dir) then
+            log.debug("Creating registry directory", self)
+            try(Result.pcall(fs.async.mkdirp, self.root_dir))
+        end
+
+        local version = self.spec.version
+        if version == nil or version == "latest" then
+            log.trace("Resolving latest version for registry", self)
+            ---@type GitHubRelease
+            local release = try(providers.github.get_latest_release(self.spec.repo))
+            version = release.tag_name
+            log.trace("Resolved latest registry version", self, version)
+        end
+
+        try(fetch(settings.current.github.download_url_template:format(self.spec.repo, version, "registry.json.zip"), {
+            out_file = path.concat { self.root_dir, "registry.json.zip" },
+        }):map_err(_.always "Failed to download registry.json.zip."))
+
+        local checksums = try(
+            fetch(settings.current.github.download_url_template:format(self.spec.repo, version, "checksums.txt")):map_err(
+                _.always "Failed to download checksums.txt."
+            )
+        )
+        local parsed_checksums = parse_checksums(checksums)
+
+        platform.when {
+            unix = function()
+                try(spawn.unzip({ "-o", "registry.json.zip", cwd = self.root_dir }):map_err(function(err)
+                    return ("Failed to unpack registry contents: %s"):format(err.stderr)
+                end))
+            end,
+            win = function()
+                local powershell = require "mason-core.managers.powershell"
+                powershell
+                    .command(
+                        ("Microsoft.PowerShell.Archive\\Expand-Archive -Force -Path %q -DestinationPath ."):format "registry.json.zip",
+                        {
+                            cwd = self.root_dir,
+                        }
+                    )
+                    :map_err(function(err)
+                        return ("Failed to unpack registry contents: %s"):format(err.stderr)
+                    end)
+            end,
+        }
+        pcall(fs.async.unlink, path.concat { self.root_dir, "registry.json.zip" })
+
+        try(Result.pcall(
+            fs.async.write_file,
+            self.info_file,
+            vim.json.encode {
+                checksums = parsed_checksums,
+                version = version,
+                download_timestamp = os.time(),
+            }
+        ))
+    end)
+        :on_success(function()
+            self:reload()
+        end)
+        :on_failure(function(err)
+            log.fmt_error("Failed to install registry %s. %s", self, err)
+        end)
+end
+
+---@return { checksums: table<string, string>, version: string, download_timestamp: integer }
+function GitHubRegistrySource:get_info()
+    return vim.json.decode(fs.sync.read_file(self.info_file))
+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)
+    else
+        return ("github.com/%s [uninstalled]"):format(self.spec.repo)
+    end
+end
+
+function GitHubRegistrySource:__tostring()
+    if self.spec.version then
+        return ("GitHubRegistrySource(repo=%s, version=%s)"):format(self.spec.repo, self.spec.version)
+    else
+        return ("GitHubRegistrySource(repo=%s)"):format(self.spec.repo)
+    end
+end
+
+return GitHubRegistrySource
diff --git a/lua/mason-registry/sources/init.lua b/lua/mason-registry/sources/init.lua
index e4abe062..5a332326 100644
--- a/lua/mason-registry/sources/init.lua
+++ b/lua/mason-registry/sources/init.lua
@@ -4,7 +4,23 @@ local M = {}
 ---@return fun(): RegistrySource # Thunk to instantiate provider.
 local function parse(registry_id)
     local type, id = registry_id:match "^(.+):(.+)$"
-    if type == "lua" then
+    if type == "github" then
+        local namespace, name = id:match "^(.+)/(.+)$"
+        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 or "latest",
+            }
+        end
+    elseif type == "lua" then
         return function()
             local LuaRegistrySource = require "mason-registry.sources.lua"
             return LuaRegistrySource.new {
diff --git a/lua/mason-registry/sources/lua.lua b/lua/mason-registry/sources/lua.lua
index 7af4feee..ac41c03c 100644
--- a/lua/mason-registry/sources/lua.lua
+++ b/lua/mason-registry/sources/lua.lua
@@ -34,9 +34,9 @@ function LuaRegistrySource:is_installed()
     return ok
 end
 
-function LuaRegistrySource:install()
-    local Result = require "mason-core.result"
-    return Result.success()
+function LuaRegistrySource:get_installer()
+    local Optional = require "mason-core.optional"
+    return Optional.empty()
 end
 
 function LuaRegistrySource:get_display_name()