feat!: Rework globals mechanism to better support shared resources (#70)

Author: dazuma

.github/workflows/unit.yml

@@ -13,9 +13,6 @@ jobs:
     strategy:
       matrix:
         include:
-          - os: ubuntu-latest
-            ruby: "2.4"
-            flags: "--only --test-unit"
           - os: ubuntu-latest
             ruby: "2.5"
             flags: "--only --test-unit"

.rubocop.yml

@@ -2,6 +2,7 @@ inherit_gem:
   google-style: google-style.yml
 
 AllCops:
+  TargetRubyVersion: 2.5
   Include:
     - "examples/**/.toys.rb"
     - "**/*.rb"

README.md

@@ -42,11 +42,11 @@ requiring an HTTP server or complicated request handling logic.
 
 ## Supported Ruby versions
 
-This library is supported on Ruby 2.4+.
+This library is supported on Ruby 2.5+.
 
 Google provides official support for Ruby versions that are actively supported
 by Ruby Core—that is, Ruby versions that are either in normal maintenance or
-in security maintenance, and not end of life. Currently, this means Ruby 2.4
+in security maintenance, and not end of life. Currently, this means Ruby 2.5
 and later. Older versions of Ruby _may_ still work, but are unsupported and not
 recommended. See https://www.ruby-lang.org/en/downloads/branches/ for details
 about the Ruby support schedule.

docs/overview.md

@@ -46,11 +46,11 @@ requiring an HTTP server or complicated request handling logic.
 
 ## Supported Ruby versions
 
-This library is supported on Ruby 2.4+.
+This library is supported on Ruby 2.5+.
 
 Google provides official support for Ruby versions that are actively supported
 by Ruby Core—that is, Ruby versions that are either in normal maintenance or
-in security maintenance, and not end of life. Currently, this means Ruby 2.4
+in security maintenance, and not end of life. Currently, this means Ruby 2.5
 and later. Older versions of Ruby _may_ still work, but are unsupported and not
 recommended. See https://www.ruby-lang.org/en/downloads/branches/ for details
 about the Ruby support schedule.
@@ -64,7 +64,7 @@ Create a `Gemfile` listing the Functions Framework as a dependency:
 ```ruby
 # Gemfile
 source "https://rubygems.org"
-gem "functions_framework", "~> 0.5"
+gem "functions_framework", "~> 0.7"
 ```
 
 Create a file called `app.rb` and include the following code. This defines a

docs/testing-functions.md

@@ -165,3 +165,53 @@ class MyTest < Minitest::Test
   end
 end
 ```
+
+## Testing startup tasks
+
+When a functions server is starting up, it calls startup tasks automatically.
+In the testing environment, when you call a function using the
+{FunctionsFramework::Testing#call_http} or
+{FunctionsFramework::Testing#call_event} methods, the testing environment will
+also automatically execute any startup tasks for you.
+
+You can also call startup tasks explicitly to test them in isolation, using the
+{FunctionsFramework::Testing#run_startup_tasks} method. Pass the name of a
+function, and the testing module will execute all defined startup blocks, in
+order, as if the server were preparing that function for execution.
+{FunctionsFramework::Testing#run_startup_tasks} returns the resulting globals
+as a hash, so you can assert against its contents.
+
+If you use {FunctionsFramework::Testing#run_startup_tasks} to run the startup
+tasks explicitly, they will not be run again when you call the function itself
+using {FunctionsFramework::Testing#call_http} or
+{FunctionsFramework::Testing#call_event}. However, if startup tasks have
+already been run implicitly by {FunctionsFramework::Testing#call_http} or
+{FunctionsFramework::Testing#call_event}, then attempting to run them again
+explicitly by calling {FunctionsFramework::Testing#run_startup_tasks} will
+result in an exception.
+
+There is currently no way to run a single startup block in isolation. If you
+have multiple startup blocks defined, they are always executed together.
+
+Following is an example test that runs startup tasks explicitly and asserts
+against the effect on the globals.
+
+```ruby
+require "minitest/autorun"
+require "functions_framework/testing"
+
+class MyTest < Minitest::Test
+  include FunctionsFramework::Testing
+
+  def test_startup_tasks
+    load_temporary "app.rb" do
+      globals = run_startup_tasks "my_function"
+      assert_equal "foo", globals[:my_global]
+
+      request = make_get_request "https://example.com/foo"
+      response = call_http "my_function", request
+      assert_equal 200, response.status
+    end
+  end
+end
+```