Allow creating casks with brew create --cask.

Library/Homebrew/cask/exceptions.rb

@@ -111,7 +111,7 @@ module Cask
 
     sig { returns(String) }
     def to_s
-      %Q(Cask '#{token}' already exists. Run #{Formatter.identifier("brew cask edit #{token}")} to edit it.)
+      %Q(Cask '#{token}' already exists. Run #{Formatter.identifier("brew edit --cask #{token}")} to edit it.)
     end
   end
 

Library/Homebrew/dev-cmd/create.rb

@@ -6,6 +6,7 @@ require "formula_creator"
 require "missing_formula"
 require "cli/parser"
 require "utils/pypi"
+require "cask/cask_loader"
 
 module Homebrew
   extend T::Sig
@@ -18,14 +19,16 @@ module Homebrew
       usage_banner <<~EOS
         `create` [<options>] <URL>
 
-        Generate a formula for the downloadable file at <URL> and open it in the editor.
+        Generate a formula or, with `--cask`, a cask for the downloadable file at <URL>
-        Homebrew will attempt to automatically derive the formula name and version, but
+        and open it in the editor. Homebrew will attempt to automatically derive the
-        if it fails, you'll have to make your own template. The `wget` formula serves as
+        formula name and version, but if it fails, you'll have to make your own template.
-        a simple example. For the complete API, see:
+        The `wget` formula serves as a simple example. For the complete API, see:
         <https://rubydoc.brew.sh/Formula>
       EOS
       switch "--autotools",
              description: "Create a basic template for an Autotools-style build."
+      switch "--cask",
+             description: "Create a basic template for a cask."
       switch "--cmake",
              description: "Create a basic template for a CMake-style build."
       switch "--crystal",
@@ -51,9 +54,10 @@ module Homebrew
       switch "--HEAD",
              description: "Indicate that <URL> points to the package's repository rather than a file."
       flag   "--set-name=",
-             description: "Explicitly set the <name> of the new formula."
+             description:  "Explicitly set the <name> of the new formula or cask.",
+             required_for: "--cask"
       flag   "--set-version=",
-             description: "Explicitly set the <version> of the new formula."
+             description: "Explicitly set the <version> of the new formula or cask."
       flag   "--set-license=",
              description: "Explicitly set the <license> of the new formula."
       flag   "--tap=",
@@ -61,7 +65,12 @@ module Homebrew
       switch "-f", "--force",
              description: "Ignore errors for disallowed formula names and names that shadow aliases."
 
-      conflicts "--autotools", "--cmake", "--crystal", "--go", "--meson", "--node", "--perl", "--python", "--rust"
+      conflicts "--autotools", "--cmake", "--crystal", "--go", "--meson", "--node",
+                "--perl", "--python", "--ruby", "--rust", "--cask"
+      conflicts "--cask", "--HEAD"
+      conflicts "--cask", "--set-license"
+      conflicts "--cask", "--tap"
+
       named 1
     end
   end
@@ -70,24 +79,73 @@ module Homebrew
   def create
     args = create_args.parse
 
-    # Ensure that the cache exists so we can fetch the tarball
+    path = if args.cask?
-    HOMEBREW_CACHE.mkpath
+      create_cask(args: args)
+    else
+      create_formula(args: args)
+    end
 
-    url = args.named.first # Pull the first (and only) url from ARGV
+    exec_editor path
+  end
 
-    version = args.set_version
+  def create_cask(args:)
-    name = args.set_name
+    url = args.named.first
-    license = args.set_license
-    tap = args.tap
 
+    if (token = args.set_name).nil?
+      raise UsageError, "The `--set-name` flag is required for creating casks."
+    end
+
+    cask_path = Cask::CaskLoader.path(token)
+    raise Cask::CaskAlreadyCreatedError, token if cask_path.exist?
+
+    version = if args.set_version
+      Version.create(args.set_version)
+    else
+      Version.detect(url.gsub(token, ""))
+    end
+
+    interpolated_url, sha256 = if version.null?
+      [url, ""]
+    else
+      sha256 = if args.no_fetch?
+        ""
+      else
+        strategy = DownloadStrategyDetector.detect(url)
+        downloader = strategy.new(url, token, version.to_s, cache: Cask::Cache.path)
+        downloader.fetch
+        downloader.cached_location.sha256
+      end
+
+      [url.gsub(version.to_s, "\#{version}"), sha256]
+    end
+
+    cask_path.atomic_write <<~RUBY
+      cask "#{token}" do
+        version "#{version}"
+        sha256 "#{sha256}"
+
+        url "#{interpolated_url}"
+        name ""
+        desc ""
+        homepage ""
+
+        app ""
+      end
+    RUBY
+
+    puts "Please run `brew audit --cask --new #{token}` before submitting, thanks."
+    cask_path
+  end
+
+  def create_formula(args:)
     fc = FormulaCreator.new(args)
-    fc.name = name
+    fc.name = args.name
-    fc.version = version
+    fc.version = args.version
-    fc.license = license
+    fc.license = args.license
-    fc.tap = Tap.fetch(tap || "homebrew/core")
+    fc.tap = Tap.fetch(args.tap || "homebrew/core")
     raise TapUnavailableError, tap unless fc.tap.installed?
 
-    fc.url = url
+    fc.url = args.named.first # Pull the first (and only) url from ARGV
 
     fc.mode = if args.cmake?
       :cmake
@@ -143,8 +201,8 @@ module Homebrew
 
     PyPI.update_python_resources! Formula[fc.name], ignore_non_pypi_packages: true if args.python?
 
-    puts "Please run `brew audit --new-formula #{fc.name}` before submitting, thanks."
+    puts "Please run `brew audit --new #{fc.name}` before submitting, thanks."
-    exec_editor fc.path
+    fc.path
   end
 
   def __gets

docs/Manpage.md

@@ -946,14 +946,16 @@ Display the path to the file being used when invoking `brew` *`cmd`*.
 
 ### `create` [*`options`*] *`URL`*
 
-Generate a formula for the downloadable file at *`URL`* and open it in the editor.
+Generate a formula or, with `--cask`, a cask for the downloadable file at *`URL`*
-Homebrew will attempt to automatically derive the formula name and version, but
+and open it in the editor. Homebrew will attempt to automatically derive the
-if it fails, you'll have to make your own template. The `wget` formula serves as
+formula name and version, but if it fails, you'll have to make your own template.
-a simple example. For the complete API, see:
+The `wget` formula serves as a simple example. For the complete API, see:
 <https://rubydoc.brew.sh/Formula>
 
 * `--autotools`:
   Create a basic template for an Autotools-style build.
+* `--cask`:
+  Create a basic template for a cask.
 * `--cmake`:
   Create a basic template for a CMake-style build.
 * `--crystal`:
@@ -977,9 +979,9 @@ a simple example. For the complete API, see:
 * `--HEAD`:
   Indicate that *`URL`* points to the package's repository rather than a file.
 * `--set-name`:
-  Explicitly set the *`name`* of the new formula.
+  Explicitly set the *`name`* of the new formula or cask.
 * `--set-version`:
-  Explicitly set the *`version`* of the new formula.
+  Explicitly set the *`version`* of the new formula or cask.
 * `--set-license`:
   Explicitly set the *`license`* of the new formula.
 * `--tap`:

manpages/brew.1

@@ -1316,13 +1316,17 @@ Treat all named arguments as casks\.
 Display the path to the file being used when invoking \fBbrew\fR \fIcmd\fR\.
 .
 .SS "\fBcreate\fR [\fIoptions\fR] \fIURL\fR"
-Generate a formula for the downloadable file at \fIURL\fR and open it in the editor\. Homebrew will attempt to automatically derive the formula name and version, but if it fails, you\'ll have to make your own template\. The \fBwget\fR formula serves as a simple example\. For the complete API, see: \fIhttps://rubydoc\.brew\.sh/Formula\fR
+Generate a formula or, with \fB\-\-cask\fR, a cask for the downloadable file at \fIURL\fR and open it in the editor\. Homebrew will attempt to automatically derive the formula name and version, but if it fails, you\'ll have to make your own template\. The \fBwget\fR formula serves as a simple example\. For the complete API, see: \fIhttps://rubydoc\.brew\.sh/Formula\fR
 .
 .TP
 \fB\-\-autotools\fR
 Create a basic template for an Autotools\-style build\.
 .
 .TP
+\fB\-\-cask\fR
+Create a basic template for a cask\.
+.
+.TP
 \fB\-\-cmake\fR
 Create a basic template for a CMake\-style build\.
 .
@@ -1368,11 +1372,11 @@ Indicate that \fIURL\fR points to the package\'s repository rather than a file\.
 .
 .TP
 \fB\-\-set\-name\fR
-Explicitly set the \fIname\fR of the new formula\.
+Explicitly set the \fIname\fR of the new formula or cask\.
 .
 .TP
 \fB\-\-set\-version\fR
-Explicitly set the \fIversion\fR of the new formula\.
+Explicitly set the \fIversion\fR of the new formula or cask\.
 .
 .TP
 \fB\-\-set\-license\fR