Remove Bootsnap cache priming support

The `--only-bootsnap-rbs-cache` flag and read-only cache path supported sharing a primed cache between CI jobs. That workflow is no longer used.

Keep the cache local and writable. Normal `tapioca dsl` runs populate it, and lockfile changes reset the cached iseq payload.

Author: KaanOzkan

README.md

@@ -52,7 +52,6 @@ Tapioca makes it easy to work with [Sorbet](https://sorbet.org) in your codebase
     * [Writing custom DSL extensions](#writing-custom-dsl-extensions)
   * [Rewriting RBS comments to Sorbet signatures](#rewriting-rbs-comments-to-sorbet-signatures)
     * [Caching rewrites with Bootsnap](#caching-rewrites-with-bootsnap)
-    * [Priming the cache from CI](#priming-the-cache-from-ci)
   * [RBI files for missing constants and methods](#rbi-files-for-missing-constants-and-methods)
   * [Configuration](#configuration)
 * [Editor Integration](#editor-integration)
@@ -492,37 +491,35 @@ Usage:
   tapioca dsl [constant...]
 
 Options:
-  --out, -o, [--outdir=directory]                                                                           # The output directory for generated DSL RBI files
-                                                                                                            # Default: sorbet/rbi/dsl
-             [--file-header], [--no-file-header], [--skip-file-header]                                      # Add a "This file is generated" header on top of each generated RBI file
-                                                                                                            # Default: true
-             [--only=compiler [compiler ...]]                                                               # Only run supplied DSL compiler(s)
-             [--exclude=compiler [compiler ...]]                                                            # Exclude supplied DSL compiler(s)
-             [--verify], [--no-verify], [--skip-verify]                                                     # Verifies RBIs are up-to-date
-                                                                                                            # Default: false
-             [--only-bootsnap-rbs-cache], [--no-only-bootsnap-rbs-cache], [--skip-only-bootsnap-rbs-cache]  # Only boot the application and load DSL extensions/compilers to populate the bootsnap iseq cache, then exit. Skips compiler execution and RBI generation. Mutually exclusive with --verify and --list-compilers.
-                                                                                                            # Default: false
-  -q,        [--quiet], [--no-quiet], [--skip-quiet]                                                        # Suppresses file creation output
-                                                                                                            # Default: false
-  -w,        [--workers=N]                                                                                  # Number of parallel workers to use when generating RBIs (default: auto)
-             [--rbi-max-line-length=N]                                                                      # Set the max line length of generated RBIs. Signatures longer than the max line length will be wrapped
-                                                                                                            # Default: 120
-             [--max-diff-lines=N]                                                                           # Max number of diff lines to include in the `dsl --verify` output
-                                                                                                            # Default: 250
-  -e,        [--environment=ENVIRONMENT]                                                                    # The Rack/Rails environment to use when generating RBIs
-                                                                                                            # Default: development
-  -l,        [--list-compilers], [--no-list-compilers], [--skip-list-compilers]                             # List all loaded compilers
-                                                                                                            # Default: false
-             [--app-root=APP_ROOT]                                                                          # The path to the Rails application
-                                                                                                            # Default: .
-             [--halt-upon-load-error], [--no-halt-upon-load-error], [--skip-halt-upon-load-error]           # Halt upon a load error while loading the Rails application
-                                                                                                            # Default: true
-             [--skip-constant=constant [constant ...]]                                                      # Do not generate RBI definitions for the given application constant(s)
-             [--compiler-options=key:value]                                                                 # Options to pass to the DSL compilers
-  -c,        [--config=<config file path>]                                                                  # Path to the Tapioca configuration file
-                                                                                                            # Default: sorbet/tapioca/config.yml
-  -V,        [--verbose], [--no-verbose], [--skip-verbose]                                                  # Verbose output for debugging purposes
-                                                                                                            # Default: false
+  --out, -o, [--outdir=directory]                                                                  # The output directory for generated DSL RBI files
+                                                                                                   # Default: sorbet/rbi/dsl
+             [--file-header], [--no-file-header], [--skip-file-header]                             # Add a "This file is generated" header on top of each generated RBI file
+                                                                                                   # Default: true
+             [--only=compiler [compiler ...]]                                                      # Only run supplied DSL compiler(s)
+             [--exclude=compiler [compiler ...]]                                                   # Exclude supplied DSL compiler(s)
+             [--verify], [--no-verify], [--skip-verify]                                            # Verifies RBIs are up-to-date
+                                                                                                   # Default: false
+  -q,        [--quiet], [--no-quiet], [--skip-quiet]                                               # Suppresses file creation output
+                                                                                                   # Default: false
+  -w,        [--workers=N]                                                                         # Number of parallel workers to use when generating RBIs (default: auto)
+             [--rbi-max-line-length=N]                                                             # Set the max line length of generated RBIs. Signatures longer than the max line length will be wrapped
+                                                                                                   # Default: 120
+             [--max-diff-lines=N]                                                                  # Max number of diff lines to include in the `dsl --verify` output
+                                                                                                   # Default: 250
+  -e,        [--environment=ENVIRONMENT]                                                           # The Rack/Rails environment to use when generating RBIs
+                                                                                                   # Default: development
+  -l,        [--list-compilers], [--no-list-compilers], [--skip-list-compilers]                    # List all loaded compilers
+                                                                                                   # Default: false
+             [--app-root=APP_ROOT]                                                                 # The path to the Rails application
+                                                                                                   # Default: .
+             [--halt-upon-load-error], [--no-halt-upon-load-error], [--skip-halt-upon-load-error]  # Halt upon a load error while loading the Rails application
+                                                                                                   # Default: true
+             [--skip-constant=constant [constant ...]]                                             # Do not generate RBI definitions for the given application constant(s)
+             [--compiler-options=key:value]                                                        # Options to pass to the DSL compilers
+  -c,        [--config=<config file path>]                                                         # Path to the Tapioca configuration file
+                                                                                                   # Default: sorbet/tapioca/config.yml
+  -V,        [--verbose], [--no-verbose], [--skip-verbose]                                         # Verbose output for debugging purposes
+                                                                                                   # Default: false
 
 Generate RBIs for dynamic methods
 ```
@@ -865,29 +862,13 @@ lockfile changes, Tapioca sees the digest mismatch and resets Bootsnap's cache p
 This lets gem bumps that affect rewriting, such as `tapioca`, start from a fresh cache without accumulating old cache
 directories.
 
-The first run is slower because every file is rewritten and the result is baked into the iseq cache; subsequent runs
-against the same lockfile skip the rewrite entirely.
-
 `Bootsnap.setup` mutates a process-wide singleton, and a second call would overwrite Tapioca's dedicated cache directory and start writing rewritten iseqs into the host's normal cache. Tapioca enforces this under `TAPIOCA_RBS_CACHE=1`: after its own setup runs, any subsequent `Bootsnap.setup` raises a clear error pointing at the fix. Gate your host's `Bootsnap.setup` on the same env var. Rails apps do this in `config/boot.rb`:
 
 ```ruby
 # e.g. config/boot.rb
 require "bootsnap/setup" unless ENV["TAPIOCA_RBS_CACHE"] == "1"
 ```
 
-#### Priming the cache from CI
-
-For CI pipelines that want to populate the cache once and have downstream jobs read from a warm copy, use `--only-bootsnap-rbs-cache`. This pattern lets you scope cache writes to a single job (the prime) so PR-side jobs read from it without uploading on every successful build:
-
-```shell
-# Prime: populate the cache.
-$ TAPIOCA_RBS_CACHE=1 bin/tapioca dsl --only-bootsnap-rbs-cache
-
-# Consumer: read from the populated cache.
-# BOOTSNAP_READONLY=1 prevents bootsnap from writing back to a read-only mount.
-$ TAPIOCA_RBS_CACHE=1 BOOTSNAP_READONLY=1 bin/tapioca dsl
-```
-
 ### RBI files for missing constants and methods
 
 Even after generating the RBIs, it is possible that some constants or methods are still undefined for Sorbet.
@@ -1009,7 +990,6 @@ dsl:
   only: []
   exclude: []
   verify: false
-  only_bootsnap_rbs_cache: false
   quiet: false
   workers: 1
   rbi_max_line_length: 120

lib/tapioca/cli.rb

@@ -103,10 +103,6 @@ def todo
       type: :boolean,
       default: false,
       desc: "Verifies RBIs are up-to-date"
-    option :only_bootsnap_rbs_cache,
-      type: :boolean,
-      default: false,
-      desc: "Only boot the application and load DSL extensions/compilers to populate the bootsnap iseq cache, then exit. Skips compiler execution and RBI generation. Mutually exclusive with --verify and --list-compilers."
     option :quiet,
       aliases: ["-q"],
       type: :boolean,
@@ -154,12 +150,6 @@ def todo
     def dsl(*constant_or_paths)
       set_environment(options)
 
-      if options[:only_bootsnap_rbs_cache] && (options[:verify] || options[:list_compilers])
-        conflicting = options[:verify] ? "--verify" : "--list-compilers"
-        raise MalformattedArgumentError,
-          "Options '--only-bootsnap-rbs-cache' and '#{conflicting}' are mutually exclusive"
-      end
-
       # Assume anything starting with a capital letter or colon is a class, otherwise a path
       constants, paths = constant_or_paths.partition { |c| c =~ /\A[A-Z:]/ }
 
@@ -192,7 +182,7 @@ def dsl(*constant_or_paths)
       elsif options[:list_compilers]
         Commands::DslCompilerList.new(**command_args)
       else
-        Commands::DslGenerate.new(**command_args, only_bootsnap_rbs_cache: options[:only_bootsnap_rbs_cache])
+        Commands::DslGenerate.new(**command_args)
       end
 
       command.run

lib/tapioca/commands/dsl_generate.rb

@@ -4,28 +4,13 @@
 module Tapioca
   module Commands
     class DslGenerate < AbstractDsl
-      #: (?only_bootsnap_rbs_cache: bool, **untyped) -> void
-      def initialize(only_bootsnap_rbs_cache: false, **kwargs)
-        @only_bootsnap_rbs_cache = only_bootsnap_rbs_cache
-        super(**T.unsafe(kwargs))
-      end
-
       private
 
       # @override
       #: -> void
       def execute
         load_application
 
-        if @only_bootsnap_rbs_cache
-          if ENV["TAPIOCA_RBS_CACHE"] == "1"
-            say("Bootsnap RBS cache populated, exiting before RBI generation.", :green)
-          else
-            say_error("Warning: --only-bootsnap-rbs-cache requires TAPIOCA_RBS_CACHE=1 to populate the cache", :yellow)
-          end
-          return
-        end
-
         say("Compiling DSL RBI files...")
         say("")
 

lib/tapioca/rbs/bootsnap_cache.rb

@@ -13,31 +13,20 @@ module RBS
     # source files are unchanged.
     # To account for this, we store the current Gemfile.lock SHA256 in a
     # `.gemfile-lock-digest` file.
-    # On writable runs, a digest mismatch deletes Bootsnap's cache payload and
-    # records the new digest, so this run rebuilds the cache from scratch. On
-    # read-only runs, a digest mismatch means the cache is stale and must not be
-    # used.
+    # A digest mismatch deletes Bootsnap's cache payload and records the new
+    # digest, so this run rebuilds the cache from scratch.
     module BootsnapCache
-      PrepareResult = Struct.new(:setup_bootsnap, keyword_init: true)
-
       DIGEST_FILE = ".gemfile-lock-digest" #: String
 
       class << self
-        #: (String, readonly: bool) -> PrepareResult
-        def prepare_for_setup(cache_dir, readonly:)
+        #: (String) -> void
+        def prepare_for_setup(cache_dir)
           digest = gemfile_lock_digest
+          return if digest_matches?(cache_dir, digest)
 
-          if readonly
-            return PrepareResult.new(setup_bootsnap: digest_matches?(cache_dir, digest))
-          end
-
-          unless digest_matches?(cache_dir, digest)
-            FileUtils.rm_rf(File.join(cache_dir, "bootsnap"))
-            FileUtils.mkdir_p(cache_dir)
-            File.write(digest_path(cache_dir), digest)
-          end
-
-          PrepareResult.new(setup_bootsnap: true)
+          FileUtils.rm_rf(File.join(cache_dir, "bootsnap"))
+          FileUtils.mkdir_p(cache_dir)
+          File.write(digest_path(cache_dir), digest)
         end
 
         private

lib/tapioca/rbs/rewriter.rb

@@ -32,49 +32,40 @@ def setup(**_kwargs)
       end
     end
 
-    module BootsnapSetup
+    module BootsnapIntegration
       class << self
         extend T::Sig
 
         sig { void }
         def setup
           require "bootsnap"
 
-          # Respect BOOTSNAP_READONLY for consumers reading a pre-populated cache
-          # (e.g. a CI prime step).
-          readonly = !["0", "false", false].include?(ENV.fetch("BOOTSNAP_READONLY") { false })
           cache_dir = ENV.fetch("TAPIOCA_BOOTSNAP_CACHE_DIR", File.join(Dir.pwd, "tmp/cache/bootsnap-tapioca-rbs"))
-          # A read-only cache with a mismatched lockfile digest may contain stale rewritten iseqs,
-          # and this process cannot reset it.
-          return unless Tapioca::RBS::BootsnapCache.prepare_for_setup(
-            cache_dir,
-            readonly: readonly,
-          ).setup_bootsnap
+          Tapioca::RBS::BootsnapCache.prepare_for_setup(cache_dir)
 
           Bootsnap.setup(
             cache_dir: cache_dir,
             development_mode: true,
             load_path_cache: true,
             compile_cache_iseq: true,
             compile_cache_yaml: true,
-            readonly: readonly,
+            readonly: false,
             revalidation: true,
           )
           Bootsnap.log_stats!
-        ensure
-          Bootsnap.singleton_class.prepend(Tapioca::RBS::BootsnapGuard) if defined?(Bootsnap)
+
+          Bootsnap.singleton_class.prepend(Tapioca::RBS::BootsnapGuard)
         end
       end
     end
   end
 end
 
 # When TAPIOCA_RBS_CACHE=1, use a dedicated Bootsnap cache directory for
-# RBS-rewritten iseqs. Stale read-only caches are skipped because this process
-# cannot reset them.
+# RBS-rewritten iseqs.
 if ENV["TAPIOCA_RBS_CACHE"] == "1"
   begin
-    Tapioca::RBS::BootsnapSetup.setup
+    Tapioca::RBS::BootsnapIntegration.setup
   rescue LoadError
     # Bootsnap is not in the bundle, skip iseq caching.
   end