Fix a bug where `Pry::Config.new(nil) == nil` would return true. (#1903)

lib/pry/config/behavior.rb

@@ -215,6 +215,8 @@ class Pry
       #   True if self and `other` are considered `eql?`, otherwise false.
       #
       def ==(other)
+        return false if !other
+
         @lookup == __try_convert_to_hash(other)
       end
       alias_method :eql?, :==

spec/config_spec.rb

@@ -1,4 +1,24 @@
-describe Pry::Config do
+RSpec.describe Pry::Config do
+  describe ".from_hash" do
+    it "returns an object without a default" do
+      local = described_class.from_hash({})
+      expect(local.default).to eq(nil)
+    end
+
+    it "returns an object with a default" do
+      default = described_class.new(nil)
+      local = described_class.from_hash({}, default)
+      expect(local.default).to eq(local)
+    end
+
+    it "recursively creates Pry::Config objects from a Hash" do
+      h = {'foo1' => {'foo2' => {'foo3' => 'foobar'}}}
+      default = described_class.from_hash(h)
+      expect(default.foo1).to be_instance_of(described_class)
+      expect(default.foo1.foo2).to be_instance_of(described_class)
+    end
+  end
+
   describe "bug #1552" do
     specify "a local key has precendence over its default when the stored value is false" do
       local = described_class.from_hash({}, described_class.from_hash('color' => true))
@@ -53,26 +73,6 @@ describe Pry::Config do
     end
   end
 
-  describe ".from_hash" do
-    it "returns an object without a default" do
-      local = described_class.from_hash({})
-      expect(local.default).to eq(nil)
-    end
-
-    it "returns an object with a default" do
-      default = described_class.new(nil)
-      local = described_class.from_hash({}, default)
-      expect(local.default).to eq(local)
-    end
-
-    it "recursively creates Pry::Config objects from a Hash" do
-      h = {'foo1' => {'foo2' => {'foo3' => 'foobar'}}}
-      default = described_class.from_hash(h)
-      expect(default.foo1).to be_instance_of(described_class)
-      expect(default.foo1.foo2).to be_instance_of(described_class)
-    end
-  end
-
   describe "#respond_to_missing?" do
     before do
       @config = described_class.new(nil)
@@ -140,6 +140,12 @@ describe Pry::Config do
       local1 = described_class.new(nil)
       expect(local1).not_to eq(Object.new)
     end
+
+    it "returns false when compared against nil" do
+      # rubocop:disable Style/NilComparison
+      expect(described_class.new(nil) == nil).to eq(false)
+      # rubocop:enable Style/NilComparison
+    end
   end
 
   describe "#forget" do