- Add support for reading config from stdin and writing to stdout

Author: DannyBen

lib/completely/commands/base.rb

@@ -35,15 +35,25 @@ def script
       end
 
       def completions
-        @completions ||= Completions.load(config_path, function_name: args['--function'])
+        @completions ||= if config_path == '-'
+          raise Error, "Nothing is piped on stdin" if $stdin.tty?
+
+          Completions.read $stdin, function_name: args['--function']
+        else
+          Completions.load config_path, function_name: args['--function']
+        end
       end
 
       def config_path
         @config_path ||= args['CONFIG_PATH'] || ENV['COMPLETELY_CONFIG_PATH'] || 'completely.yaml'
       end
 
       def output_path
-        @output_path ||= args['OUTPUT_PATH'] || ENV['COMPLETELY_OUTPUT_PATH'] || "#{config_basename}.bash"
+        @output_path ||= args['OUTPUT_PATH'] || ENV['COMPLETELY_OUTPUT_PATH'] || stdout || "#{config_basename}.bash"
+      end
+
+      def stdout
+        @stdout ||= config_path == '-' ? '-' : nil
       end
 
       def config_basename

lib/completely/commands/generate.rb

@@ -3,7 +3,7 @@
 module Completely
   module Commands
     class Generate < Base
-      help 'Generate the bash completion script to a file'
+      help 'Generate the bash completion script'
 
       usage 'completely generate [CONFIG_PATH OUTPUT_PATH --function NAME --wrap NAME]'
       usage 'completely generate (-h|--help)'
@@ -12,10 +12,19 @@ class Generate < Base
       option '-w --wrap NAME', 'Wrap the completion script inside a function that echos the ' \
         'script. This is useful if you wish to embed it directly in your script.'
 
-      param_config_path
+      param 'CONFIG_PATH', <<~USAGE
+        Path to the YAML configuration file [default: completely.yaml].
+        Use '-' to read from stdin.
+        
+        Can also be set by an environment variable.
+      USAGE
+
       param 'OUTPUT_PATH', <<~USAGE
         Path to the output bash script.
-        When not provided, the name of the input file will be used with a .bash extension.
+        Use '-' for stdout.
+        
+        When not provided, the name of the input file will be used with a .bash extension, unless the input is stdin - in this case the default will be to output to stdout.
+        
         Can also be set by an environment variable.
       USAGE
 
@@ -26,8 +35,12 @@ class Generate < Base
       def run
         wrap = args['--wrap']
         output = wrap ? wrapper_function(wrap) : script
-        File.write output_path, output
-        say "Saved m`#{output_path}`"
+        if output_path == '-'
+          puts output
+        else
+          File.write output_path, output
+          say "Saved m`#{output_path}`"
+        end
         syntax_warning unless completions.valid?
       end
 

lib/completely/completions.rb

@@ -6,9 +6,12 @@ class Completions
     attr_reader :config
 
     class << self
-      def load(config_path, function_name: nil)
-        config = Config.load config_path
-        new config, function_name: function_name
+      def load(path, function_name: nil)
+        new Config.load(path), function_name: function_name
+      end
+
+      def read(io, function_name: nil)
+        new Config.read(io), function_name: function_name
       end
     end
 

lib/completely/config.rb

@@ -3,17 +3,14 @@ class Config
     attr_reader :config, :options
 
     class << self
-      def load(config_path)
-        begin
-          config = YAML.load_file config_path, aliases: true
-        rescue ArgumentError
-          # :nocov:
-          config = YAML.load_file config_path
-          # :nocov:
-        end
-
-        new config
+      def parse(str)
+        new YAML.load(str, aliases: true)
+      rescue Psych::Exception => e
+        raise ParseError, "Invalid YAML: #{e.message}"
       end
+
+      def load(path) = parse(File.read(path))
+      def read(io) = parse(io.read)
     end
 
     def initialize(config)

lib/completely/exceptions.rb

@@ -1,4 +1,5 @@
 module Completely
   class Error < StandardError; end
   class InstallError < Error; end
+  class ParseError < Error; end
 end

spec/approvals/cli/commands

@@ -3,7 +3,7 @@ Completely - Bash Completions Generator
 Commands:
   init       Create a new sample YAML configuration file
   preview    Generate the bash completion script to STDOUT
-  generate   Generate the bash completion script to a file
+  generate   Generate the bash completion script
   test       Test completions
   install    Install a bash completion script
   uninstall  Uninstall a bash completion script

spec/approvals/cli/generate/help

@@ -1,4 +1,4 @@
-Generate the bash completion script to a file
+Generate the bash completion script
 
 Usage:
   completely generate [CONFIG_PATH OUTPUT_PATH --function NAME --wrap NAME]
@@ -18,12 +18,18 @@ Options:
 Parameters:
   CONFIG_PATH
     Path to the YAML configuration file [default: completely.yaml].
+    Use '-' to read from stdin.
+    
     Can also be set by an environment variable.
 
   OUTPUT_PATH
     Path to the output bash script.
+    Use '-' for stdout.
+    
     When not provided, the name of the input file will be used with a .bash
-    extension.
+    extension, unless the input is stdin - in this case the default will be to
+    output to stdout.
+    
     Can also be set by an environment variable.
 
 Environment Variables: