Update developement guide

docs/DevelopmentGuide.md

@@ -24,8 +24,8 @@ To start a development environment, choose a target Ruby version then run the fo
 # In the root directory of the project...
 cd ~/dd-trace-rb
 
-# Create and start a Ruby 3.0 test environment with its dependencies
-docker-compose run --rm tracer-3.0 /bin/bash
+# Create and start a Ruby 3.3 test environment with its dependencies
+docker compose run --rm tracer-3.3 /bin/bash
 
 # Then inside the container (e.g. `root@2a73c6d8673e:/app`)...
 # Install the library dependencies
@@ -64,18 +64,17 @@ All tests should run in CI. When adding new `_spec.rb` files, you may need to ad
 ```ruby
   {
     'foo' => {
-      # Without any appraisal group dependencies
+      # With default dependencies for each Ruby runtime
       ''    => '✅ 2.1 / ✅ 2.2 / ✅ 2.3 / ✅ 2.4 / ✅ 2.5 / ✅ 2.6 / ✅ 2.7 / ✅ 3.0 / ✅ 3.1 / ✅ 3.2 / ✅ 3.3 / ✅ jruby',
-
-      # or with appraisal group definition `foo-on-rails`, that includes additional gems
+      # or with dependency group definition `foo-on-rails`, that includes additional gems
       'foo-on-rails' => '✅ 2.1 / ✅ 2.2 / ✅ 2.3 / ✅ 2.4 / ✅ 2.5 / ✅ 2.6 / ✅ 2.7 / ✅ 3.0 / ✅ 3.1 / ✅ 3.2 / ✅ 3.3 / ✅ jruby'
     },
   }
 ```
 
 ### Running tests
 
-Simplest way to run tests is to run `bundle exec rake ci`, which will run the entire test suite, just as CI does.
+Run `bundle exec rake ci` will run the entire test suite with any given Ruby runtime, just as CI does. However, this is not recommended because it is going take a long time.
 
 **For the core library**
 
@@ -89,14 +88,15 @@ $ bundle exec rake test:main
 
 Integrations which interact with dependencies not listed in the `datadog` gemspec will need to load these dependencies to run their tests. Each test task could consist of multiple spec tasks which are executed with different groups of dependencies (likely against different versions or variations).
 
-To get a list of the test tasks, run `bundle exec rake -T test`
+To get a list of the test tasks, run `bundle exec rake -T test:`
 
 To run test, run `bundle exec rake test:<spec_name>`
 
-Take `bundle exec rake test:redis` as example, multiple versions of `redis` from different groups are tested.
+Take `bundle exec rake test:redis` as example, multiple versions of `redis` from different dependency definitions are being tested (from `Matrixfile`).
+
 
 ```ruby
-TEST_METADATA = {
+{
   'redis' => {
     'redis-3' => '✅ 2.1 / ✅ 2.2 / ✅ 2.3 / ✅ 2.4 / ✅ 2.5 / ✅ 2.6 / ✅ 2.7 / ✅ 3.0 / ✅ 3.1 / ✅ 3.2 / ✅ 3.3 / ✅ jruby',
     'redis-4' => '❌ 2.1 / ❌ 2.2 / ❌ 2.3 / ✅ 2.4 / ✅ 2.5 / ✅ 2.6 / ✅ 2.7 / ✅ 3.0 / ✅ 3.1 / ✅ 3.2 / ✅ 3.3 / ✅ jruby',
@@ -105,41 +105,75 @@ TEST_METADATA = {
 }
 ```
 
-**Using appraisal**
+If the dependency groups are prepared (with up-to-date gemfile and lockfile), the test task would install them before running the test.
+
+**Working with different dependencies**
 
-`appraisal` command should only be used to update gemfiles in `gemfiles/`
-and install dependencies. It should not be used to run tests, since it does not
-work in all configurations. To run the tests, use:
+We are actively developing tools to make it easier to manage dependencies. Currently, we are using rake tasks defined in `tasks/dependency.rake`.
+
+You can find them by running the following command:
 
 ```sh
-env BUNDLE_GEMFILE=gemfiles/#{ruby_runtime}_#{appraisal_group}.gemfile rake #{spec_task}
+bundle exec rake -T dependency:
 ```
 
-Note that the file names use underscores while appraisal group and
-configuration definitions use dashes. The conversion could be performed as
-follows:
+Dependency group definitions are located under `appraisal/` directory using the same DSL provided by [Appraisal](https://github.com/thoughtbot/appraisal). These definitions are used to generate `*.gemfile` and `*.gemfile.lock` under `gemfiles/` directory.
+
+> [!NOTE]
+> All the files are underscored and prefixed with Ruby runtime
+
+To find out existing gemfiles in your environment, run
 
 ```sh
-env BUNDLE_GEMFILE=gemfiles/#{ruby_runtime.tr('-', '_')}_#{appraisal_group.tr('-', '_')}.gemfile rake #{spec_task}
+bundle exec rake dependency:list
 ```
 
-**Working with appraisal groups**
+> [!IMPORTANT]
+> Do NOT manually edit `*.gemfile` and `*.gemfile.lock` under `gemfiles/` directory. Instead, make changes to `appraisal/*.rb` and propagates your changes programmatically.
 
-Checkout [Apppraisal](https://github.com/thoughtbot/appraisal) to learn the basics.
+After introducing a new dependency group or changing existing one, run `bundle exec rake dependency:generate` to propagate the changes to the gemfile.
 
-Groups are defined under `appraisal/` directory and their names are prefixed with Ruby runtime based on the environment. `*.gemfile` and `*.gemfile.lock` from `gemfiles/` directory are generated from those definitions.
+> [!NOTE]
+> `dependency:generate` is idempotent and only changes gemfiles (but not lockfiles)
 
-To find out existing groups in your environment, run `bundle exec appraisal list`
+To keep lockfile up-to-date with the gemfile, run `bundle exec rake dependency:lock`.
 
-After introducing a new group definition or changing existing one, run `bundle exec appraisal generate` to propagate the changes.
+To install dependencies, run `bundle exec rake dependency:install`.
 
-To install dependencies, run `bundle exec appraisal install`.
+Both `dependency:lock` and `dependency:install` can be provided with a specific gemfile path (from `bundle exec rake dependency:list`) or pattern to target specific groups.
 
-In addition, if you already know which appraisal group definition to work with, you can target a specific group operation with environment variable `APPRAISAL_GROUP`, instead of all the groups from your environment. For example:
+For example:
 
+```sh
+# Only generate lockfile for `stripe_latest` group
+bundle exec rake dependency:lock['/app/gemfiles/ruby_3.3_stripe_latest.gemfile']
+```
+
+or
+
+```sh
+# Only generate lockfiles for all the stripe groups with `stripe_*` pattern
+bundle exec rake dependency:lock['/app/gemfiles/ruby_3.3_stripe_*.gemfile']
 ```
-# This would only install dependencies for `aws` group definition
-APPRAISAL_GROUP=aws bundle exec appraisal install
+
+In addition, if you already know which dependency group to work with, you can provide a specific gemfile path (from `bundle exec rake dependency:list`) with environment variable `BUNDLE_GEMFILE`.
+
+For example:
+
+```sh
+env BUNDLE_GEMFILE=/app/gemfiles/ruby_3.3_stripe_latest.gemfile bundle lock --update=stripe
+```
+
+Another example: to run the tests, use:
+
+```sh
+env BUNDLE_GEMFILE=gemfiles/#{ruby_runtime}_#{group}.gemfile rake #{spec_task}
+```
+
+Note that the file names use underscores while appraisal group and configuration definitions use dashes. The conversion could be performed as follows:
+
+```sh
+env BUNDLE_GEMFILE=gemfiles/#{ruby_runtime.tr('-', '_')}_#{group.tr('-', '_')}.gemfile rake #{spec_task}
 ```
 
 **Passing arguments to tests**