diff options
| -rw-r--r-- | railties/CHANGELOG.md | 4 | ||||
| -rw-r--r-- | railties/lib/rails/generators.rb | 60 | ||||
| -rw-r--r-- | railties/test/generators_test.rb | 8 |
3 files changed, 63 insertions, 9 deletions
diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md index b328619646..3350b1a4b2 100644 --- a/railties/CHANGELOG.md +++ b/railties/CHANGELOG.md @@ -1,3 +1,7 @@ +* Invalid `bin/rails generate` commands will now show spelling suggestions. + + *Richard Schneeman* + * Add `bin/setup` script to bootstrap an application. *Yves Senn* diff --git a/railties/lib/rails/generators.rb b/railties/lib/rails/generators.rb index 2a0148fe9d..bf2390cb7e 100644 --- a/railties/lib/rails/generators.rb +++ b/railties/lib/rails/generators.rb @@ -156,8 +156,12 @@ module Rails args << "--help" if args.empty? && klass.arguments.any? { |a| a.required? } klass.start(args, config) else - puts "Could not find generator '#{namespace}'. Please choose a generator below." - print_generators + options = sorted_groups.map(&:last).flatten + suggestions = options.sort_by {|suggested| levenshtein_distance(namespace.to_s, suggested) }.first(3) + msg = "Could not find generator '#{namespace}'. " + msg << "Maybe you meant #{ suggestions.map {|s| "'#{s}'"}.join(" or ") }\n" + msg << "Run `rails generate --help` for more options." + puts msg end end @@ -220,31 +224,71 @@ module Rails print_generators end - def self.print_generators + def self.public_namespaces lookup! + subclasses.map { |k| k.namespace } + end - namespaces = subclasses.map{ |k| k.namespace } - namespaces.sort! + def self.print_generators + sorted_groups.each { |b, n| print_list(b, n) } + end + def self.sorted_groups + namespaces = public_namespaces + namespaces.sort! groups = Hash.new { |h,k| h[k] = [] } namespaces.each do |namespace| base = namespace.split(':').first groups[base] << namespace end - # Print Rails defaults first. rails = groups.delete("rails") rails.map! { |n| n.sub(/^rails:/, '') } rails.delete("app") rails.delete("plugin") - print_list("rails", rails) hidden_namespaces.each { |n| groups.delete(n.to_s) } - groups.sort.each { |b, n| print_list(b, n) } + [["rails", rails]] + groups.sort.to_a end protected + # This code is based directly on the Text gem implementation + # Returns a value representing the "cost" of transforming str1 into str2 + def self.levenshtein_distance str1, str2 + s = str1 + t = str2 + n = s.length + m = t.length + max = n/2 + + return m if (0 == n) + return n if (0 == m) + return n if (n - m).abs > max + + d = (0..m).to_a + x = nil + + str1.each_char.each_with_index do |char1,i| + e = i+1 + + str2.each_char.each_with_index do |char2,j| + cost = (char1 == char2) ? 0 : 1 + x = [ + d[j+1] + 1, # insertion + e + 1, # deletion + d[j] + cost # substitution + ].min + d[j] = e + e = x + end + + d[m] = x + end + + return x + end + # Prints a list of generators. def self.print_list(base, namespaces) #:nodoc: namespaces = namespaces.reject do |n| diff --git a/railties/test/generators_test.rb b/railties/test/generators_test.rb index 8d6dbf80c2..0b4edafaca 100644 --- a/railties/test/generators_test.rb +++ b/railties/test/generators_test.rb @@ -24,7 +24,13 @@ class GeneratorsTest < Rails::Generators::TestCase name = :unknown output = capture(:stdout){ Rails::Generators.invoke name } assert_match "Could not find generator '#{name}'", output - assert_match "scaffold", output + assert_match "`rails generate --help`", output + end + + def test_generator_suggestions + name = :migrationz + output = capture(:stdout){ Rails::Generators.invoke name } + assert_match "Maybe you meant 'migration'", output end def test_help_when_a_generator_with_required_arguments_is_invoked_without_arguments |