refactor!: refactor installer internals and add new Package class methods (#1523)

This contains the following changes:
1) `Package:install()` now accepts a second, optional, callback argument which is called when installation finishes
   (successfully or not).
2) Adds a `Package:is_installing()` method.

This contains the following breaking changes:
1) `Package:install()` will now error when called while an installation is already ongoing. Use the new
   `Package:is_installing()` method to check whether an installation is already running.

This also refactors large portions of the tests by removing test globals, removing async_test, and adding the
`mason-test` Lua module instead. Test helpers via globals are problematic to work with due to not being detected through
tools like the Lua language server without additional configuration. This has been replaced with a Lua module
`mason-test`. `async_test` has also been removed in favour of explicitly making use of the `mason-core.async` API. These
changes stands for a significant portion of the diff.

1 files changed, 20 insertions, 20 deletions

diff --git a/tests/mason-core/result_spec.lua b/tests/mason-core/result_spec.lua
index 46f4d35c..227e53ae 100644
--- a/tests/mason-core/result_spec.lua
+++ b/tests/mason-core/result_spec.lua
@@ -250,27 +250,28 @@ describe("Result.try", function()
         assert.equals("42", failure:err_or_nil())
     end)
 
-    it(
-        "should allow calling async functions inside try blocks",
-        async_test(function()
-            assert.same(
-                Result.success "Hello, world!",
-                Result.try(function(try)
+    it("should allow calling async functions inside try blocks", function()
+        assert.same(
+            Result.success "Hello, world!",
+            a.run_blocking(function()
+                return Result.try(function(try)
                     a.sleep(10)
                     local hello = try(Result.success "Hello, ")
                     local world = try(Result.success "world!")
                     return hello .. world
                 end)
-            )
-            local failure = Result.try(function(try)
+            end)
+        )
+        local failure = a.run_blocking(function()
+            return Result.try(function(try)
                 a.sleep(10)
                 local err = try(Result.success "42")
                 error(err)
             end)
-            assert.is_true(failure:is_failure())
-            assert.is_true(match.matches ": 42$"(failure:err_or_nil()))
         end)
-    )
+        assert.is_true(failure:is_failure())
+        assert.is_true(match.matches ": 42$"(failure:err_or_nil()))
+    end)
 
     it("should not unwrap result values in try blocks", function()
         assert.same(
@@ -300,12 +301,11 @@ describe("Result.try", function()
         )
     end)
 
-    it(
-        "should allow nesting try blocks in async scope",
-        async_test(function()
-            assert.same(
-                Result.success "Hello from the underworld!",
-                Result.try(function(try)
+    it("should allow nesting try blocks in async scope", function()
+        assert.same(
+            Result.success "Hello from the underworld!",
+            a.run_blocking(function()
+                return Result.try(function(try)
                     a.sleep(10)
                     local greeting = try(Result.success "Hello from the %s!")
                     a.sleep(10)
@@ -316,7 +316,7 @@ describe("Result.try", function()
                         return value
                     end)))
                 end)
-            )
-        end)
-    )
+            end)
+        )
+    end)
 end)