feat(registry): add has_package() method (#847)

3 files changed, 37 insertions, 0 deletions

diff --git a/doc/mason.txt b/doc/mason.txt
index 5a5c9bda..604b16ac 100644
--- a/doc/mason.txt
+++ b/doc/mason.txt
@@ -411,6 +411,16 @@ get_package({package_name})
     Returns:
         Package
 
+                                                *mason-registry.has_package()*
+has_package({package_name})
+    Returns true if the provided package_name can be found in the registry.
+
+    Parameters:
+        {package_name} - string
+
+    Returns:
+        boolean
+
                                      *mason-registry.get_installed_packages()*
 get_installed_packages()
     Returns all installed package instances. This is a slower function that
diff --git a/lua/mason-registry/init.lua b/lua/mason-registry/init.lua
index dc64cc47..164e9c02 100644
--- a/lua/mason-registry/init.lua
+++ b/lua/mason-registry/init.lua
@@ -70,6 +70,13 @@ function M.get_package(package_name)
     return pkg
 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)
+    return index[package_name] ~= nil
+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.
diff --git a/tests/mason-registry/registry_spec.lua b/tests/mason-registry/registry_spec.lua
new file mode 100644
index 00000000..5931ca35
--- /dev/null
+++ b/tests/mason-registry/registry_spec.lua
@@ -0,0 +1,20 @@
+local Pkg = require "mason-core.package"
+local registry = require "mason-registry"
+
+describe("mason-registry", function()
+    it("should return package", function()
+        assert.is_true(getmetatable(registry.get_package "dummy").__index == Pkg)
+    end)
+
+    it("should error when getting non-existent package", function()
+        local err = assert.has_error(function()
+            registry.get_package "non-existent"
+        end)
+        assert.equals([[Cannot find package "non-existent".]], err)
+    end)
+
+    it("should check whether package exists", function()
+        assert.is_true(registry.has_package "dummy")
+        assert.is_false(registry.has_package "non-existent")
+    end)
+end)