Add install step rebuild actions

Library/Homebrew/install_steps.rb

@@ -168,6 +168,36 @@ def ln_sf(source, target, source_base: nil, target_base: nil, source_formula: ni
         symlink(source, target, source_base:, target_base:, source_formula:, target_formula:, force: true, uninstall:)
       end
 
+      sig { void }
+      def compile_gsettings_schemas
+        add_rebuild_action("compile_gsettings_schemas", "share/glib-2.0/schemas")
+      end
+
+      sig { void }
+      def gio_querymodules
+        add_rebuild_action("gio_querymodules", "lib/gio/modules")
+      end
+
+      sig { void }
+      def gdk_pixbuf_query_loaders
+        add_step("gdk_pixbuf_query_loaders")
+      end
+
+      sig { void }
+      def gtk_update_icon_cache
+        add_rebuild_action("gtk_update_icon_cache", "share/icons/hicolor")
+      end
+
+      sig { void }
+      def update_mime_database
+        add_rebuild_action("update_mime_database", "share/mime")
+      end
+
+      sig { void }
+      def update_desktop_database
+        add_rebuild_action("update_desktop_database", "share/applications")
+      end
+
       private
 
       sig { params(type: ::String, fields: ::T.untyped).void }
@@ -177,6 +207,11 @@ def add_step(type, **fields)
         @steps << ::T.cast(::Utils.deep_compact_blank(step), Step)
       end
 
+      sig { params(type: ::String, path: ::String).void }
+      def add_rebuild_action(type, path)
+        add_step(type, "path" => path_spec(path, base: :homebrew_prefix))
+      end
+
       sig {
         params(
           path:         ::T.any(::String, ::Pathname),
@@ -255,6 +290,18 @@ def run_install_step(step)
           target.dirname.mkpath
           FileUtils.rm_f target if step["force"] == true
           File.symlink link_source(step.fetch("source")), target
+        when "compile_gsettings_schemas"
+          run_formula_tool("glib", "glib-compile-schemas", resolve_path(step.fetch("path")))
+        when "gio_querymodules"
+          run_formula_tool("glib", "gio-querymodules", resolve_path(step.fetch("path")))
+        when "gdk_pixbuf_query_loaders"
+          run_formula_tool("gdk-pixbuf", "gdk-pixbuf-query-loaders", "--update-cache")
+        when "gtk_update_icon_cache"
+          run_formula_tool("gtk+3", "gtk3-update-icon-cache", "-q", "-t", "-f", resolve_path(step.fetch("path")))
+        when "update_mime_database"
+          run_formula_tool("shared-mime-info", "update-mime-database", resolve_path(step.fetch("path")))
+        when "update_desktop_database"
+          run_formula_tool("desktop-file-utils", "update-desktop-database", resolve_path(step.fetch("path")))
         else
           raise ArgumentError, "unknown install step: #{step.fetch("type")}"
         end
@@ -299,6 +346,11 @@ def normalise_path_spec(spec)
         end
       end
 
+      sig { params(formula: String, executable: String, args: T.untyped).void }
+      def run_formula_tool(formula, executable, *args)
+        @context.send(:safe_system, Formula[formula].opt_bin/executable, *args)
+      end
+
       sig { params(base: String, formula: T.nilable(String)).returns(Pathname) }
       def root_path(base, formula)
         case base

Library/Homebrew/json_api_postinstall_preflight_postflight_plan.md

@@ -29,12 +29,20 @@ future step types that invoke non-Homebrew code.
 Future cask work should sandbox all `*flight` run scripts from non-Homebrew and
 non-system sources, for example scripts shipped by upstream artifacts.
 
+For each future operation type, check `homebrew/core` and `homebrew/cask`
+separately and add formula support only when needed by `homebrew/core` or cask
+support only when needed by `homebrew/cask`.
+
 RuboCop autocorrection converts the simplest existing `post_install` and
 `*flight` Ruby blocks to steps blocks when every statement is a supported file
 preparation operation with literal paths and known bases. Future post-install
 and `*flight` DSLs should include the same style of conservative autocorrection
 from the matching legacy Ruby pattern where possible.
 
+Before opening follow-up PRs, run `bundle exec rake lint` from `docs/` to catch
+markdown lint issues and run `brew style homebrew/core homebrew/cask` to catch
+tap-wide formula or cask opportunities exposed by the new DSLs.
+
 ## Formula Patterns
 
 Local scan source: `homebrew/core` at `fb0ca6682b4`.
@@ -161,15 +169,19 @@ be resolved before the download can be enqueued.
   `uninstall: true` symlink cleanup available for install-phase steps. Keep
   the tap-wide autocorrect audit in a follow-up commit so the implementation
   can land before converted casks.
-- [ ] PR 4, desktop and cache rebuild actions.
+- [x] PR 4, desktop and cache rebuild actions.
   Estimated existing formulae/casks affected: about `35` formulae run rebuild
   tools such as `glib-compile-schemas`, `gtk*-update-icon-cache`,
   `gio-querymodules`, `gdk-pixbuf-query-loaders`, `update-mime-database` and
   `update-desktop-database`; no cask count was identified in the initial scan.
+  Scope: shared named action types for GSettings schemas, GIO modules,
+  GDK Pixbuf loaders, GTK icon caches, MIME databases and desktop databases,
+  runner dispatch through Homebrew-owned tools and docs.
   Notes for implementation: add named action types rather than raw commands;
-  define idempotence and failure handling; include RuboCop autocorrection for
-  exact known command patterns only; decide whether any action invokes
-  non-Homebrew code and should be ready for future sandboxing.
+  define idempotence and failure handling; decide whether any action invokes
+  non-Homebrew code and should be ready for future sandboxing. Land RuboCop
+  autocorrection and tap-wide conversions in a separate follow-up after the
+  new DSL methods are available in a stable Homebrew release.
 - [ ] PR 5, default config and template writes.
   Estimated existing formulae/casks affected: about `71` formulae write or
   patch default configuration/data files, and a subset of the `78` file-prep

Library/Homebrew/test/install_steps_spec.rb

@@ -96,6 +96,37 @@
     )
   end
 
+  specify "runs named desktop and cache rebuild actions" do
+    steps = Homebrew::InstallSteps::DSL.build do
+      compile_gsettings_schemas
+      gio_querymodules
+      gdk_pixbuf_query_loaders
+      gtk_update_icon_cache
+      update_mime_database
+      update_desktop_database
+    end
+
+    formula = instance_double(Formula, opt_bin: root/"opt/bin")
+    allow(Formula).to receive(:[]).with("glib").and_return(formula)
+    allow(Formula).to receive(:[]).with("gdk-pixbuf").and_return(formula)
+    allow(Formula).to receive(:[]).with("gtk+3").and_return(formula)
+    allow(Formula).to receive(:[]).with("shared-mime-info").and_return(formula)
+    allow(Formula).to receive(:[]).with("desktop-file-utils").and_return(formula)
+    expect(context).to receive(:safe_system).with(root/"opt/bin/glib-compile-schemas",
+                                                  HOMEBREW_PREFIX/"share/glib-2.0/schemas").ordered
+    expect(context).to receive(:safe_system).with(root/"opt/bin/gio-querymodules",
+                                                  HOMEBREW_PREFIX/"lib/gio/modules").ordered
+    expect(context).to receive(:safe_system).with(root/"opt/bin/gdk-pixbuf-query-loaders", "--update-cache").ordered
+    expect(context).to receive(:safe_system).with(root/"opt/bin/gtk3-update-icon-cache", "-q", "-t", "-f",
+                                                  HOMEBREW_PREFIX/"share/icons/hicolor").ordered
+    expect(context).to receive(:safe_system).with(root/"opt/bin/update-mime-database",
+                                                  HOMEBREW_PREFIX/"share/mime").ordered
+    expect(context).to receive(:safe_system).with(root/"opt/bin/update-desktop-database",
+                                                  HOMEBREW_PREFIX/"share/applications").ordered
+
+    Homebrew::InstallSteps::Runner.new(context:).run(steps)
+  end
+
   specify "does not add the default base to home paths" do
     steps = Homebrew::InstallSteps::DSL.build(default_base: :var) do
       mkdir_p "~/example"

docs/Cask-Cookbook.md

@@ -577,7 +577,21 @@ postflight_steps do
 end
 ```
 
-`mkdir`, `mkdir_p`, `touch`, `move`, `mv`, `move_children`, `symlink`, `ln_s` and `ln_sf` are available in steps blocks. Relative paths default to `staged_path` for `base:`, `source_base:` and `target_base:`. Symlink steps can use `uninstall: true` to remove the symlink during uninstall. A steps block may only contain those step calls with literal arguments; it cannot call the wider cask DSL or arbitrary Ruby code. Each phase may define either its Ruby flight block or its matching steps block, not both.
+A steps block may only contain supported step calls with literal arguments; it cannot call the wider cask DSL or arbitrary Ruby code. Each phase may define either its Ruby flight block or its matching steps block, not both.
+
+#### File preparation steps
+
+Relative paths default to `staged_path` for `base:`, `source_base:` and `target_base:`. Symlink steps can use `uninstall: true` to remove the symlink during uninstall.
+
+* `mkdir`: create one directory; example: `mkdir "Shared"`.
+* `mkdir_p`: create a directory and any missing parents; example: `mkdir_p "Shared"`.
+* `touch`: create or update a file timestamp; example: `touch "Shared/state"`.
+* `move`: move one file or directory; example: `move "payload", "Shared/payload"`.
+* `mv`: alias for `move`; example: `mv "payload", "Shared/payload"`.
+* `move_children`: move the contents of one directory into another; example: `move_children "payload", "Shared/payload"`.
+* `symlink`: create a symlink; example: `symlink "Shared/payload", "Payload", source_base: :relative`.
+* `ln_s`: alias for `symlink`; example: `ln_s "Shared/payload", "Payload", source_base: :relative`.
+* `ln_sf`: create or replace a symlink; example: `ln_sf "Shared/payload", "Payload", source_base: :relative, uninstall: true`.
 
 Flight blocks are not currently run in the cask sandbox. They should be written as though they may be sandboxed in the future: prefer the mini-DSL helpers below and keep filesystem writes limited to paths owned by the cask.
 

docs/Formula-Cookbook.md

@@ -1116,7 +1116,32 @@ class Foo < Formula
 end
 ```
 
-`mkdir`, `mkdir_p` and `touch` default to paths relative to `var`. `move`, `mv`, `move_children`, `symlink`, `ln_s` and `ln_sf` default their source and target paths to `prefix`. Use `base:`, `source_base:` or `target_base:` when a step needs another formula path such as `pkgetc`; use `source_base: :relative` for relative symlink sources. A formula may define either `post_install_steps` or `post_install`, not both.
+A formula may define either `post_install_steps` or `post_install`, not both.
+
+#### File preparation steps
+
+`mkdir`, `mkdir_p` and `touch` default to paths relative to `var`. `move`, `mv`, `move_children`, `symlink`, `ln_s` and `ln_sf` default their source and target paths to `prefix`. Use `base:`, `source_base:` or `target_base:` when a step needs another formula path such as `pkgetc`; use `source_base: :relative` for relative symlink sources.
+
+* `mkdir`: create one directory; example: `mkdir "log/foo"`.
+* `mkdir_p`: create a directory and any missing parents; example: `mkdir_p "log/foo"`.
+* `touch`: create or update a file timestamp; example: `touch "foo/state"`.
+* `move`: move one file or directory; example: `move "default.conf", "foo/default.conf"`.
+* `mv`: alias for `move`; example: `mv "default.conf", "foo/default.conf"`.
+* `move_children`: move the contents of one directory into another; example: `move_children "defaults", "foo/defaults"`.
+* `symlink`: create a symlink; example: `symlink "cert.pem", "foo/cert.pem", source_base: :relative`.
+* `ln_s`: alias for `symlink`; example: `ln_s "cert.pem", "foo/cert.pem", source_base: :relative`.
+* `ln_sf`: create or replace a symlink; example: `ln_sf "cert.pem", "foo/cert.pem", source_base: :relative`.
+
+#### Desktop and cache rebuild steps
+
+These steps rebuild shared desktop and cache state using Homebrew-owned tools.
+
+* `compile_gsettings_schemas`: compile GSettings schemas in `share/glib-2.0/schemas`.
+* `gio_querymodules`: rebuild the GIO module cache in `lib/gio/modules`.
+* `gdk_pixbuf_query_loaders`: update the GDK Pixbuf loader cache.
+* `gtk_update_icon_cache`: refresh the `hicolor` GTK icon cache.
+* `update_mime_database`: rebuild the shared MIME database in `share/mime`.
+* `update_desktop_database`: rebuild the desktop entry database in `share/applications`.
 
 ```ruby
 class Foo < Formula