dev-cmd/typecheck: Delete old files from sorbet/files.yaml

- I was going through the `sorbet/files.yaml` moving various things to
  `true`, playing around locally, and happened upon some files that it
  was tracking that had been deleted.
- We want to do some automation of new files, but I'm not sure we'd ever
  considered the possibility of code being removed. :-D
- This adds a `--prune-files-list` switch and updates the Tapioca GitHub
  Actions workflow to use it. Any changes to the `sorbet/files.yaml`
  file will be committed as part of the scheduled Tapioca update job.

.github/workflows/tapioca.yml

@@ -37,7 +37,7 @@ jobs:
             BRANCH_EXISTS="1"
           fi
 
-          if brew typecheck --update-definitions --fail-if-not-changed; then
+          if brew typecheck --prune-files-list --update-definitions --fail-if-not-changed; then
             git add "$GITHUB_WORKSPACE/Library/Homebrew/sorbet"
             git commit -m "sorbet: update RBI files using Tapioca." -m "Autogenerated by [a scheduled GitHub Action](https://github.com/Homebrew/brew/blob/master/.github/workflows/tapioca.yml)."
             echo "::set-output name=committed::true"

Library/Homebrew/dev-cmd/typecheck.rb

@@ -5,6 +5,8 @@ require "cli/parser"
 module Homebrew
   module_function
 
+  SORBET_FILES_YAML = "sorbet/files.yaml"
+
   def typecheck_args
     Homebrew::CLI::Parser.new do
       usage_banner <<~EOS
@@ -16,6 +18,8 @@ module Homebrew
              description: "Silence all non-critical errors."
       switch "--update-definitions",
              description: "Update Tapioca gem definitions of recently bumped gems"
+      switch "--prune-files-list",
+             description: "Remove deleted filepaths from #{SORBET_FILES_YAML}"
       switch "--fail-if-not-changed",
              description: "Return a failing status code if all gems are up to date " \
                           "and gem definitions do not need a tapioca update"
@@ -37,6 +41,22 @@ module Homebrew
     Homebrew.install_bundler_gems!
 
     HOMEBREW_LIBRARY_PATH.cd do
+      if args.prune_files_list?
+        lines_to_keep = []
+        sorbet_keywords = ["true:", "false:", "strict:", "strong:"]
+
+        File.readlines(SORBET_FILES_YAML).map(&:chomp).each do |line|
+          if sorbet_keywords.include?(line) || line.blank?
+            lines_to_keep << line
+          elsif line.end_with?(".rb")
+            filepath = line.split(" ").last
+            lines_to_keep << line if File.exist?(filepath)
+          end
+        end
+
+        File.write(SORBET_FILES_YAML, lines_to_keep.join("\n"))
+      end
+
       if args.update_definitions?
         system "bundle", "exec", "tapioca", "sync"
         system "bundle", "exec", "srb", "rbi", "hidden-definitions"
@@ -55,7 +75,7 @@ module Homebrew
         srb_exec += ["--file", "../#{args.file}"] if args.file
         srb_exec += ["--dir", "../#{args.dir}"] if args.dir
       else
-        srb_exec += ["--typed-override", "sorbet/files.yaml"]
+        srb_exec += ["--typed-override", SORBET_FILES_YAML]
       end
       Homebrew.failed = !system(*srb_exec)
     end

docs/Manpage.md

@@ -1236,6 +1236,8 @@ Check for typechecking errors using Sorbet.
   Silence all non-critical errors.
 * `--update-definitions`:
   Update Tapioca gem definitions of recently bumped gems
+* `--prune-files-list`:
+  Remove deleted filepaths from sorbet/files.yaml
 * `--fail-if-not-changed`:
   Return a failing status code if all gems are up to date and gem definitions do not need a tapioca update
 * `--dir`:

manpages/brew.1

@@ -1702,6 +1702,10 @@ Silence all non\-critical errors\.
 Update Tapioca gem definitions of recently bumped gems
 .
 .TP
+\fB\-\-prune\-files\-list\fR
+Remove deleted filepaths from sorbet/files\.yaml
+.
+.TP
 \fB\-\-fail\-if\-not\-changed\fR
 Return a failing status code if all gems are up to date and gem definitions do not need a tapioca update
 .