Support Rails 4+

jack-core/src/Dockerfile

@@ -0,0 +1,17 @@
+# Use an official Ruby runtime as a parent image
+FROM ruby:2.3.0
+
+# Set the working directory to /app
+WORKDIR /app
+
+# Copy the current directory contents into the container at /app
+COPY . /app
+
+RUN bundle install
+
+# The consumer is expected to provide two additional arguments:
+#   1. the path to the Jack config file
+#   2. the output directory
+#
+# example usage: docker run -w /app -v $(pwd):/app/temp --rm jack temp/jack_config.yml temp/jack
+ENTRYPOINT ["ruby", "./rb/jack.rb"]

jack-core/src/Gemfile

@@ -1,4 +1,4 @@
 source "http://rubygems.org"
-gem "activesupport", "~> 4.1"
-gem "i18n", "~> 0.9"
+gem "activesupport", ">= 4.1"
+gem "i18n", ">= 0.9"
 gem 'fattr'

jack-core/src/Gemfile.lock

@@ -1,29 +1,27 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    activesupport (4.2.5)
-      i18n (~> 0.7)
-      json (~> 1.7, >= 1.7.7)
+    activesupport (5.2.4.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
       minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    concurrent-ruby (1.0.5)
+    concurrent-ruby (1.1.6)
     fattr (2.4.0)
-    i18n (0.9.1)
+    i18n (1.8.2)
       concurrent-ruby (~> 1.0)
-    json (1.8.6)
-    minitest (5.10.3)
+    minitest (5.14.0)
     thread_safe (0.3.6)
-    tzinfo (1.2.4)
+    tzinfo (1.2.6)
       thread_safe (~> 0.1)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  activesupport (~> 4.1)
+  activesupport (>= 4.1)
   fattr
-  i18n (~> 0.9)
+  i18n (>= 0.9)
 
 BUNDLED WITH
-   1.16.1
+   1.17.2

jack-core/src/rb/rails_3_to_5_translator.rb

@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+# Jack is designed for a version of Rails 3, which was end-of-lifed
+# back in June of 2016. When Jack reads from the ActiveRecord
+# schema, it does not account for various changes in the schema
+# format that have been introduced subsequently:
+#   1. add_index(table, columns, opts={}) was replaced by
+#      t.index(columns, opts={}) within a create_table block
+#   2. t.integer(column, limit: 8) was replaced by t.bigint(column, opts={})
+#
+# Because there aren't very many schema changes and they are relatively
+# simple, it seemed to Jacob that the laziest way to offer compatibility
+# between Jack and newer versions of Rails is to programmatically
+# translate Rails 4+ schemas into Rails 3 schemas and then run Jack
+# as usual. He at least tried to update Jack to Rails 5, but it soon
+# became clear that doing so would be more of a struggle than the
+# aforementioned solution, and time happens to be of the essence right now.
+# Future maintainers of this project should not hesitate to update Jack
+# properly as time allows.
+class Rails3To5Translator
+  def initialize(schema_rb_path)
+    @schema_rb_path = schema_rb_path
+  end
+
+  def translate
+    new_contents = ''
+    index_calls_by_table_name = hash_with_empty_arrays_as_new_values
+    this_table_name = nil
+    nesting_degree = 0
+
+    File.readlines(@schema_rb_path).each do |line|
+      # comments and empty lines
+      next if line.strip.start_with?('#') || line.strip == ''
+
+      if line.strip.start_with?('create_table')
+        # remember which table we're operating on
+        match = /create_table \"(.*?)\"/.match(line)
+        this_table_name = match[1]
+        nesting_degree += 1
+
+      elsif line.end_with?("do\n") || /do \|.*\|/.match(line)
+        # remember how far nested we are in terms of do/end blocks
+        nesting_degree += 1
+
+      elsif line.strip.start_with?('end')
+        # check if we have reached the final "end" in the file
+        # and, if so, replace it with the add_index calls we need
+        nesting_degree -= 1
+
+        if nesting_degree.zero?
+          index_calls_by_table_name.each do |table_name, index_calls|
+            index_calls.each do |index_call|
+              new_contents += "  add_index [\"#{table_name}\"], #{index_call}\n"
+            end
+          end
+        end
+
+      elsif /\.bigint/.match(line)
+        # case 1 described in the top level comment
+        line.sub!('.bigint', '.integer')
+        line.sub!("\n", ", limit: 8\n")
+
+      elsif /\.index/.match(line)
+        # case 2 described in the top level comment
+        method_parameters = /\.index (.*?)\n/.match(line)[1]
+        index_calls_by_table_name[this_table_name].push(method_parameters)
+        next
+      end
+
+      new_contents += line
+    end
+
+    new_contents
+  end
+
+  private
+
+  def hash_with_empty_arrays_as_new_values
+    Hash.new do |hash, unrecognized_key|
+      hash[unrecognized_key] = []
+    end
+  end
+end

jack-core/src/rb/requires.rb

@@ -16,5 +16,6 @@
 require File.expand_path(File.dirname(__FILE__) + "/database_defn")
 require File.expand_path(File.dirname(__FILE__) + "/project_defn")
 require File.expand_path(File.dirname(__FILE__) + "/schema_rb_parser")
+require File.expand_path(File.dirname(__FILE__) + "/rails_3_to_5_translator")
 require File.expand_path(File.dirname(__FILE__) + "/models_dir_processor")
 require File.expand_path(File.dirname(__FILE__) + "/template_processor")

jack-core/src/rb/schema_rb_parser.rb

@@ -18,6 +18,7 @@
 
 module FromHash
   def from_hash(ops)
+    ops.delete(:options)
     ops.each do |k,v|
       send("#{k}=",v)
     end
@@ -124,9 +125,20 @@ def to_h
 
 class SchemaRbParser
   def self.parse(schema_rb, ignored_tables = [])
-    load schema_rb
+    translated_contents = Rails3To5Translator.new(schema_rb).translate
+    old_filename = schema_rb.split('/').last
+    new_schema_rb = schema_rb.sub(old_filename, 'TEMP_rails_3_compatible_schema.rb')
+    FileUtils.touch(new_schema_rb)
+    File.write(new_schema_rb, translated_contents)
+    load_new_schema(new_schema_rb, ignored_tables)
+  end
+
+  def self.load_new_schema(translated_schema_rb, ignored_tables)
+    load translated_schema_rb
     defns = $schema.tables.map(&:to_model_defn).compact.reject { |x| ignored_tables.include?(x.table_name) }
     [defns, $schema.version.to_s]
+  ensure
+    FileUtils.rm(translated_schema_rb)
   end
 end