Merge pull request #1241 from bovi/add-gem-dependency-check

[mrbgems] GEM Dependency Check

tasks/mrbgem_spec.rake

@@ -89,7 +89,7 @@ module MRuby
       def add_dependency(name, *requirements)
         requirements = ['> 0.0.0'] if requirements.empty?
         requirements.flatten!
-        @dependencies << [:gem => name, :requirements => requirements]
+        @dependencies << {:gem => name, :requirements => requirements}
       end
 
       def self.bin=(bin)
@@ -168,8 +168,82 @@ module MRuby
         f.puts %Q[#include "mruby/hash.h"]
       end
 
+      def version_ok?(req_versions)
+        req_versions.map do |req|
+          cmp, ver = req.split
+          cmp_result = Version.new(version) <=> Version.new(ver)
+          case cmp
+          when '=' then cmp_result == 0
+          when '!=' then cmp_result != 0
+          when '>' then cmp_result == 1
+          when '<' then cmp_result == -1
+          when '>=' then cmp_result >= 0
+          when '<=' then cmp_result <= 0
+          when '~>'
+            Version.new(version).twiddle_wakka_ok?(Version.new(ver))
+          else
+            fail "Comparison not possible with '#{cmp}'"
+          end
+        end.all?
+      end
     end # Specification
 
+    class Version
+      include Comparable
+      include Enumerable
+
+      def <=>(other)
+        ret = 0
+        own = to_enum
+
+        other.each do |oth|
+          begin
+            ret = own.next <=> oth
+          rescue StopIteration
+            ret = 0 <=> oth
+          end
+
+          break unless ret == 0
+        end
+
+        ret
+      end
+
+      # ~> compare alghorithm
+      # 
+      # Example:
+      #    ~> 2.2   means >= 2.2.0 and < 3.0.0
+      #    ~> 2.2.0 means >= 2.2.0 and < 2.3.0
+      def twiddle_wakka_ok?(other)
+        gr_or_eql = (self <=> other) >= 0
+        still_minor = (self <=> other.skip_minor) < 0
+        gr_or_eql and still_minor
+      end
+
+      def skip_minor
+        a = @ary.dup
+        a.slice!(-1)
+        a[-1] = a[-1].succ
+        a
+      end
+
+      def initialize(str)
+        @str = str
+        @ary = @str.split('.').map(&:to_i)
+      end
+
+      def each(&block); @ary.each(&block); end
+      def [](index); @ary[index]; end
+      def []=(index, value)
+        @ary[index] = value
+        @str = @ary.join('.')
+      end
+      def slice!(index)
+        @ary.slice!(index)
+        @str = @ary.join('.')
+      end
+    end # Version
+
     class List
       include Enumerable
 
@@ -192,6 +266,24 @@ module MRuby
       def empty?
         @ary.empty?
       end
+
+      def check
+        each do |g|
+          g.dependencies.each do |dep|
+            name = dep[:gem]
+            req_versions = dep[:requirements]
+
+            # check each GEM dependency against all available GEMs
+            each do |dep_g|
+              if name == dep_g.name
+                unless dep_g.version_ok?(req_versions)
+                  fail "#{name} version should be #{req_versions.join(' and ')} but was '#{dep_g.version}'"
+                end
+              end
+            end
+          end
+        end
+      end
     end # List
   end # Gem
 

tasks/mrbgems.rake

@@ -5,6 +5,7 @@ MRuby.each_target do
   if enable_gems?
     # set up all gems
     gems.each(&:setup)
+    gems.check
     
     # loader all gems
     self.libmruby << objfile("#{build_dir}/mrbgems/gem_init")