Merge pull request #752 from ruby/andrykonchin-ruby-2-7-continue

[Ruby 2.7] Pattern matching (continuation)

Author: andrykonchin

core/struct/deconstruct_keys_spec.rb

@@ -10,8 +10,11 @@
     end
 
     it "requires one argument" do
+      struct = Struct.new(:x)
+      obj = struct.new(1)
+
       -> {
-        Struct.new(:x).new(1).deconstruct_keys
+        obj.deconstruct_keys
       }.should raise_error(ArgumentError, /wrong number of arguments \(given 0, expected 1\)/)
     end
 
@@ -46,5 +49,22 @@
 
       s.deconstruct_keys([:a, :b, :c]).should == {}
     end
+
+    it "accepts nil argument and return all the attributes" do
+      struct = Struct.new(:x, :y)
+      obj = struct.new(1, 2)
+
+      obj.deconstruct_keys(nil).should == {x: 1, y: 2}
+    end
+
+    it "raise TypeError if passed anything accept nil or array" do
+      struct = Struct.new(:x, :y)
+      s = struct.new(1, 2)
+
+      -> { s.deconstruct_keys('x') }.should raise_error(TypeError, /expected Array or nil/)
+      -> { s.deconstruct_keys(1)   }.should raise_error(TypeError, /expected Array or nil/)
+      -> { s.deconstruct_keys(:x)  }.should raise_error(TypeError, /expected Array or nil/)
+      -> { s.deconstruct_keys({})  }.should raise_error(TypeError, /expected Array or nil/)
+    end
   end
 end

language/pattern_matching_spec.rb

@@ -109,6 +109,17 @@
       }.should raise_error(NoMatchingPatternError, /\[0, 1\]/)
     end
 
+    it "does not allow calculation or method calls in a pattern" do
+      -> {
+        eval <<~RUBY
+          case 0
+            in 1 + 1
+              true
+          end
+        RUBY
+      }.should raise_error(SyntaxError, /unexpected/)
+    end
+
     describe "guards" do
       it "supports if guard" do
         eval(<<~RUBY).should == false
@@ -273,6 +284,18 @@
         RUBY
       end
 
+      it "create local variables even if a pattern doesn't match" do
+        eval(<<~RUBY).should == [0, nil, nil]
+          case 0
+            in a
+            in b
+            in c
+          end
+
+          [a, b, c]
+        RUBY
+      end
+
       it "allow using _ name to drop values" do
         eval(<<~RUBY).should == 0
           case [0, 1]
@@ -345,6 +368,19 @@
           end
         RUBY
       end
+
+      it "requires bound variable to be specified in a pattern before ^ operator when it relies on a bound variable" do
+        -> {
+          eval <<~RUBY
+            case [1, 2]
+              in [^n, n]
+                true
+            else
+              false
+            end
+          RUBY
+        }.should raise_error(SyntaxError, /n: no such local variable/)
+      end
     end
 
     describe "alternative pattern" do
@@ -569,6 +605,15 @@ def obj.deconstruct; [1] end
           end
         RUBY
       end
+
+      it "matches anything with *" do
+        eval(<<~RUBY).should == true
+          case [0, 1]
+            in *;
+              true
+          end
+        RUBY
+      end
     end
 
     describe "Hash pattern" do
@@ -663,7 +708,16 @@ def obj.deconstruct; [1] end
         RUBY
       end
 
-      it 'supports "str": key literal' do
+      it "can mix key (a:) and key-value (a: b) declarations" do
+        eval(<<~RUBY).should == [0, 1]
+          case {a: 0, b: 1}
+            in Hash(a:, b: x)
+              [a, x]
+          end
+        RUBY
+      end
+
+      it "supports 'string': key literal" do
         eval(<<~RUBY).should == true
           case {a: 0}
             in {"a": 0}
@@ -898,6 +952,15 @@ def obj.deconstruct_keys(*args)
           end
         RUBY
       end
+
+      it "matches anything with **" do
+        eval(<<~RUBY).should == true
+          case {a: 1}
+            in **;
+              true
+          end
+        RUBY
+      end
     end
   end
 end

language/range_spec.rb

@@ -16,4 +16,11 @@
       eval("(1...)").should == Range.new(1, nil, true)
     end
   end
+
+  ruby_version_is "2.7" do
+    it "creates beginless ranges" do
+      eval("(..1)").should == Range.new(nil, 1)
+      eval("(...1)").should == Range.new(nil, 1, true)
+    end
+  end
 end