1 files changed, 79 insertions, 9 deletions

diff --git a/lib/rubygems/errors.rb b/lib/rubygems/errors.rb
index fc9bfbc0dc..4bbc5217e0 100644
--- a/lib/rubygems/errors.rb
+++ b/lib/rubygems/errors.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 #--
 # This file contains all the various exceptions and other errors that are used
 # inside of RubyGems.
@@ -19,6 +21,80 @@ module Gem
     attr_accessor :requirement
   end
 
+  ##
+  # Raised when trying to activate a gem, and that gem does not exist on the
+  # system.  Instead of rescuing from this class, make sure to rescue from the
+  # superclass Gem::LoadError to catch all types of load errors.
+  class MissingSpecError < Gem::LoadError
+    def initialize(name, requirement, extra_message = nil)
+      @name        = name
+      @requirement = requirement
+      @extra_message = extra_message
+      super(message)
+    end
+
+    def message # :nodoc:
+      build_message +
+        "Checked in 'GEM_PATH=#{Gem.path.join(File::PATH_SEPARATOR)}' #{@extra_message}, execute `gem env` for more information"
+    end
+
+    private
+
+    def build_message
+      total = Gem::Specification.stubs.size
+      "Could not find '#{name}' (#{requirement}) among #{total} total gem(s)\n"
+    end
+  end
+
+  ##
+  # Raised when trying to activate a gem, and the gem exists on the system, but
+  # not the requested version. Instead of rescuing from this class, make sure to
+  # rescue from the superclass Gem::LoadError to catch all types of load errors.
+  class MissingSpecVersionError < MissingSpecError
+    attr_reader :specs
+
+    def initialize(name, requirement, specs)
+      @specs = specs
+      super(name, requirement)
+    end
+
+    private
+
+    def build_message
+      names = specs.map(&:full_name)
+      "Could not find '#{name}' (#{requirement}) - did find: [#{names.join ","}]\n"
+    end
+  end
+
+  # Raised when there are conflicting gem specs loaded
+
+  class ConflictError < LoadError
+    ##
+    # A Hash mapping conflicting specifications to the dependencies that
+    # caused the conflict
+
+    attr_reader :conflicts
+
+    ##
+    # The specification that had the conflict
+
+    attr_reader :target
+
+    def initialize(target, conflicts)
+      @target    = target
+      @conflicts = conflicts
+      @name      = target.name
+
+      reason = conflicts.map do |act, dependencies|
+        "#{act.full_name} conflicts with #{dependencies.join(", ")}"
+      end.join ", "
+
+      # TODO: improve message by saying who activated `con`
+
+      super("Unable to activate #{target.full_name}, because #{reason}")
+    end
+  end
+
   class ErrorReason; end
 
   # Generated when trying to lookup a gem to indicate that the gem
@@ -28,7 +104,6 @@ module Gem
   # in figuring out why a gem couldn't be installed.
   #
   class PlatformMismatch < ErrorReason
-
     ##
     # the name of the gem
     attr_reader :name
@@ -60,11 +135,7 @@ module Gem
     ##
     # A wordy description of the error.
     def wordy
-      "Found %s (%s), but was for platform%s %s" %
-        [@name,
-         @version,
-         @platforms.size == 1 ? '' : 's',
-         @platforms.join(' ,')]
+      format("Found %s (%s), but was for platform%s %s", @name, @version, @platforms.size == 1 ? "" : "s", @platforms.join(" ,"))
     end
   end
 
@@ -73,7 +144,6 @@ module Gem
   # data from a source
 
   class SourceFetchProblem < ErrorReason
-
     ##
     # Creates a new SourceFetchProblem for the given +source+ and +error+.
 
@@ -96,12 +166,12 @@ module Gem
     # An English description of the error.
 
     def wordy
-      "Unable to download data from #{@source.uri} - #{@error.message}"
+      "Unable to download data from #{Gem::Uri.redact(@source.uri)} - #{@error.message}"
     end
 
     ##
     # The "exception" alias allows you to call raise on a SourceFetchProblem.
 
-    alias exception error
+    alias_method :exception, :error
   end
 end