feat: Mason 2.0 migration Pt. 2: backward compatibility with Mason 1.x

nvim-java · s1n7ax · Aug 6, 2025 · Jul 23, 2025 · Aug 4, 2025 · Aug 5, 2025
commit cecd82a58afaa243f65c083adb7774687ddb9e1b
diff --git a/lua/java/startup/mason-dep.lua b/lua/java/startup/mason-dep.lua
@@ -6,14 +6,15 @@ local notify = require('java-core.utils.notify')
 local async = require('java-core.utils.async')
 local lazy = require('java.ui.lazy')
 local sync = async.sync
+local mason_v2 = require("mason.version").MAJOR_VERSION == 2
 
 local List = require('java-core.utils.list')
 
 local M = {}
 
----Add custom registries to mason
+---Add custom registries to Mason 1.x
 ---@param registries java.Config
-function M.add_custom_registries(registries)
+local function add_custom_registries_v1(registries)
 	local mason_default_config = require('mason.settings').current
 
 	local new_registries =
@@ -24,6 +25,20 @@ function M.add_custom_registries(registries)
 	})
 end
 
+---Add custom registries to Mason 2.x
+---@param registries java.Config
+local function add_custom_registries_v2(registries)
+	for _, reg in ipairs(registries) do
+		require("mason-registry").sources:prepend(reg)
+	end
+end
+
+if (mason_v2) then
+	M.add_custom_registries = add_custom_registries_v2
+else
+	M.add_custom_registries = add_custom_registries_v1
+end
+
 ---Install mason package dependencies for nvim-java
 ---@param config java.Config
 function M.install(config)

diff --git a/lua/java/startup/mason-registry-check.lua b/lua/java/startup/mason-registry-check.lua
@@ -1,26 +1,41 @@
-local mason_source = require('mason-registry.sources')
+local mason_v2 = require('mason.version').MAJOR_VERSION==2
 
-local M = {
-	JAVA_REG_ID = 'github:nvim-java/mason-registry',
-}
+local mason_sources
+
+if mason_v2 then
+	mason_sources = require('mason-registry').sources
+else
+	mason_sources = require('mason-registry.sources')
+end
+
+local M = {}
+if mason_v2 then
+	M.JAVA_REG_ID = 'nvim-java/mason-registry'
+else
+	M.JAVA_REG_ID = 'github:nvim-java/mason-registry'
+end
 
 function M.is_valid()
-	local has_reg = false
+	local iterator
 
-	for reg in mason_source:iterate() do
-		if reg.id == M.JAVA_REG_ID then
-			has_reg = true
-			goto continue
-		end
+	if mason_v2 then
+		-- the compiler will complain when Mason 1.x is in use
+		---@diagnostic disable-next-line: undefined-field
+		iterator = mason_sources.iterate
+	else
+		-- the compiler will complain when Mason 2.x is in use
+		---@diagnostic disable-next-line: undefined-field
+		iterator = mason_sources.iter
 	end
 
-	::continue::
 
-	if has_reg then
-		return {
-			success = true,
-			continue = true,
-		}
+	for reg in iterator(mason_sources) do
+		if reg.id == M.JAVA_REG_ID then
+			return {
+				success = true,
+				continue = true
+			}
+		end
 	end
 
 	return {

diff --git a/lua/java/utils/mason.lua b/lua/java/utils/mason.lua
@@ -2,31 +2,60 @@ local log = require('java.utils.log')
 local mason_reg = require('mason-registry')
 local async = require('java-core.utils.async')
 local await = async.wait_handle_ok
+local mason_v2 = require('mason.version').MAJOR_VERSION == 2
 
 local M = {}
 
 function M.is_available(package_name, package_version)
-	-- get_package errors if the package is not available in Mason 2.0
+	-- get_package errors if the package is not available in Mason 2.x
+	-- it works fine in Mason 1.x this way too.
 	local has_pkg, pkg = pcall(mason_reg.get_package, package_name)
 
 	if not has_pkg then
 		return false
 	end
 
-	local installed_version = pkg:get_installed_version()
+	local installed_version
+	if mason_v2 then
+		-- the compiler will complain when Mason 1.x is in use
+		---@diagnostic disable-next-line: missing-parameter
+		installed_version = pkg:get_installed_version()
+	else
+		-- the compiler will complain when mason 2.x is in use
+		---@diagnostic disable-next-line: param-type-mismatch
+		pkg:get_installed_version(function (success, version)
+			if success then
+				installed_version = version
+			end
+		end)
+	end
 
 	return installed_version == package_version
 end
 
 function M.is_installed(package_name, package_version)
-	-- get_package errors if the package is not available in Mason 2.0
+	-- get_package errors if the package is not available in Mason 2.x
+	-- it works fine in Mason 1.x this way too.
 	local found, pkg = pcall(mason_reg.get_package, package_name)
 
 	if not found or not pkg:is_installed() then
 		return false
 	end
 
-	local installed_version = pkg:get_installed_version()
+	local installed_version
+	if mason_v2 then
+		-- the compiler will complain when Mason 1.x is in use
+		---@diagnostic disable-next-line: missing-parameter
+		installed_version = pkg:get_installed_version()
+	else
+		-- the compiler will complain when Mason 2.x is in use
+		---@diagnostic disable-next-line: param-type-mismatch
+		pkg:get_installed_version(function (success, version)
+			if success then
+				installed_version = version
+			end
+		end)
+	end
 
 	return installed_version == package_version
 end
@@ -56,8 +85,17 @@ function M.install_pkgs(packages)
 		if not M.is_installed(dep.name, dep.version) then
 			local pkg = mason_reg.get_package(dep.name)
 
-			-- install errors if installation is already running in Mason 2.0
-			if not pkg:is_installing() then
+			-- install errors if installation is already running in Mason 2.x
+			local guard
+			if mason_v2 then
+				-- guard if the package is already installing in Mason 2.x
+				-- the compiler will complain about the following line with Mason 1.x
+				---@diagnostic disable-next-line: undefined-field
+				guard = pkg:is_installing()
+			else
+				guard = false
+			end
+			if not guard then
 				pkg:install({
 					version = dep.version,
 					force = true,