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+require_relative '../spec_helper'
+
+describe "The 'case'-construct" do
+ it "evaluates the body of the when clause matching the case target expression" do
+ case 1
+ when 2; false
+ when 1; true
+ end.should == true
+ end
+
+ it "evaluates the body of the when clause whose array expression includes the case target expression" do
+ case 2
+ when 3, 4; false
+ when 1, 2; true
+ end.should == true
+ end
+
+ it "evaluates the body of the when clause in left-to-right order if it's an array expression" do
+ @calls = []
+ def foo; @calls << :foo; end
+ def bar; @calls << :bar; end
+
+ case true
+ when foo, bar;
+ end
+
+ @calls.should == [:foo, :bar]
+ end
+
+ it "evaluates the body of the when clause whose range expression includes the case target expression" do
+ case 5
+ when 21..30; false
+ when 1..20; true
+ end.should == true
+ end
+
+ it "returns nil when no 'then'-bodies are given" do
+ case "a"
+ when "a"
+ when "b"
+ end.should == nil
+ end
+
+ it "evaluates the 'else'-body when no other expression matches" do
+ case "c"
+ when "a"; 'foo'
+ when "b"; 'bar'
+ else 'zzz'
+ end.should == 'zzz'
+ end
+
+ it "returns nil when no expression matches and 'else'-body is empty" do
+ case "c"
+ when "a"; "a"
+ when "b"; "b"
+ else
+ end.should == nil
+ end
+
+ it "returns 2 when a then body is empty" do
+ case Object.new
+ when Numeric then
+ 1
+ when String then
+ # ok
+ else
+ 2
+ end.should == 2
+ end
+
+ it "returns the statement following 'then'" do
+ case "a"
+ when "a" then 'foo'
+ when "b" then 'bar'
+ end.should == 'foo'
+ end
+
+ it "tests classes with case equality" do
+ case "a"
+ when String
+ 'foo'
+ when Symbol
+ 'bar'
+ end.should == 'foo'
+ end
+
+ it "tests with matching regexps" do
+ case "hello"
+ when /abc/; false
+ when /^hell/; true
+ end.should == true
+ end
+
+ it "tests with matching regexps and sets $~ and captures" do
+ case "foo42"
+ when /oo(\d+)/
+ $~.should be_kind_of(MatchData)
+ $1.should == "42"
+ else
+ flunk
+ end
+ $~.should be_kind_of(MatchData)
+ $1.should == "42"
+ end
+
+ it "tests with a string interpolated in a regexp" do
+ digits = '\d+'
+ case "foo44"
+ when /oo(#{digits})/
+ $~.should be_kind_of(MatchData)
+ $1.should == "44"
+ else
+ flunk
+ end
+ $~.should be_kind_of(MatchData)
+ $1.should == "44"
+ end
+
+ it "tests with a regexp interpolated within another regexp" do
+ digits_regexp = /\d+/
+ case "foo43"
+ when /oo(#{digits_regexp})/
+ $~.should be_kind_of(MatchData)
+ $1.should == "43"
+ else
+ flunk
+ end
+ $~.should be_kind_of(MatchData)
+ $1.should == "43"
+ end
+
+ it "does not test with equality when given classes" do
+ case :symbol.class
+ when Symbol
+ "bar"
+ when String
+ "bar"
+ else
+ "foo"
+ end.should == "foo"
+ end
+
+ it "takes lists of values" do
+ case 'z'
+ when 'a', 'b', 'c', 'd'
+ "foo"
+ when 'x', 'y', 'z'
+ "bar"
+ end.should == "bar"
+
+ case 'b'
+ when 'a', 'b', 'c', 'd'
+ "foo"
+ when 'x', 'y', 'z'
+ "bar"
+ end.should == "foo"
+ end
+
+ it "tests an empty array" do
+ case []
+ when []
+ 'foo'
+ else
+ 'bar'
+ end.should == 'foo'
+ end
+
+ it "expands arrays to lists of values" do
+ case 'z'
+ when *['a', 'b', 'c', 'd']
+ "foo"
+ when *['x', 'y', 'z']
+ "bar"
+ end.should == "bar"
+ end
+
+ it "takes an expanded array in addition to a list of values" do
+ case 'f'
+ when 'f', *['a', 'b', 'c', 'd']
+ "foo"
+ when *['x', 'y', 'z']
+ "bar"
+ end.should == "foo"
+
+ case 'b'
+ when 'f', *['a', 'b', 'c', 'd']
+ "foo"
+ when *['x', 'y', 'z']
+ "bar"
+ end.should == "foo"
+ end
+
+ it "takes an expanded array before additional listed values" do
+ case 'f'
+ when *['a', 'b', 'c', 'd'], 'f'
+ "foo"
+ when *['x', 'y', 'z']
+ "bar"
+ end.should == 'foo'
+ end
+
+ it "expands arrays from variables before additional listed values" do
+ a = ['a', 'b', 'c']
+ case 'a'
+ when *a, 'd', 'e'
+ "foo"
+ when 'x'
+ "bar"
+ end.should == "foo"
+ end
+
+ it "expands arrays from variables before a single additional listed value" do
+ a = ['a', 'b', 'c']
+ case 'a'
+ when *a, 'd'
+ "foo"
+ when 'x'
+ "bar"
+ end.should == "foo"
+ end
+
+ it "expands multiple arrays from variables before additional listed values" do
+ a = ['a', 'b', 'c']
+ b = ['d', 'e', 'f']
+
+ case 'f'
+ when *a, *b, 'g', 'h'
+ "foo"
+ when 'x'
+ "bar"
+ end.should == "foo"
+ end
+
+ # MR: critical
+ it "concats arrays before expanding them" do
+ a = ['a', 'b', 'c', 'd']
+ b = ['f']
+
+ case 'f'
+ when 'f', *a|b
+ "foo"
+ when *['x', 'y', 'z']
+ "bar"
+ end.should == "foo"
+ end
+
+ it "never matches when clauses with no values" do
+ case nil
+ when *[]
+ "foo"
+ end.should == nil
+ end
+
+ it "lets you define a method after the case statement" do
+ case (def foo; 'foo'; end; 'f')
+ when 'a'
+ 'foo'
+ when 'f'
+ 'bar'
+ end.should == 'bar'
+ end
+
+ it "raises a SyntaxError when 'else' is used when no 'when' is given" do
+ -> {
+ eval <<-CODE
+ case 4
+ else
+ true
+ end
+ CODE
+ }.should raise_error(SyntaxError)
+ end
+
+ it "raises a SyntaxError when 'else' is used before a 'when' was given" do
+ -> {
+ eval <<-CODE
+ case 4
+ else
+ true
+ when 4; false
+ end
+ CODE
+ }.should raise_error(SyntaxError)
+ end
+
+ it "supports nested case statements" do
+ result = false
+ case :x
+ when Symbol
+ case :y
+ when Symbol
+ result = true
+ end
+ end
+ result.should == true
+ end
+
+ it "supports nested case statements followed by a when with a splatted array" do
+ result = false
+ case :x
+ when Symbol
+ case :y
+ when Symbol
+ result = true
+ end
+ when *[Symbol]
+ result = false
+ end
+ result.should == true
+ end
+
+ it "supports nested case statements followed by a when with a splatted non-array" do
+ result = false
+ case :x
+ when Symbol
+ case :y
+ when Symbol
+ result = true
+ end
+ when *Symbol
+ result = false
+ end
+ result.should == true
+ end
+
+ it "works even if there's only one when statement" do
+ case 1
+ when 1
+ 100
+ end.should == 100
+ end
+
+ it "evaluates true as only 'true' when true is the first clause" do
+ case 1
+ when true; "bad"
+ when Integer; "good"
+ end.should == "good"
+ end
+
+ it "evaluates false as only 'false' when false is the first clause" do
+ case nil
+ when false; "bad"
+ when nil; "good"
+ end.should == "good"
+ end
+
+ it "treats a literal array as its own when argument, rather than a list of arguments" do
+ case 'foo'
+ when ['foo', 'foo']; 'bad'
+ when 'foo'; 'good'
+ end.should == 'good'
+ end
+
+ it "takes multiple expanded arrays" do
+ a1 = ['f', 'o', 'o']
+ a2 = ['b', 'a', 'r']
+
+ case 'f'
+ when *a1, *['x', 'y', 'z']
+ "foo"
+ when *a2, *['x', 'y', 'z']
+ "bar"
+ end.should == "foo"
+
+ case 'b'
+ when *a1, *['x', 'y', 'z']
+ "foo"
+ when *a2, *['x', 'y', 'z']
+ "bar"
+ end.should == "bar"
+ end
+
+ it "calls === even when private" do
+ klass = Class.new do
+ def ===(o)
+ true
+ end
+ private :===
+ end
+
+ case 1
+ when klass.new
+ :called
+ end.should == :called
+ end
+
+ it "accepts complex expressions within ()" do
+ case 'a'
+ when (raise if 2+2 == 3; /a/)
+ :called
+ end.should == :called
+ end
+
+ it "only matches last value in complex expressions within ()" do
+ case 'a'
+ when ('a'; 'b')
+ :wrong_called
+ when ('b'; 'a')
+ :called
+ end.should == :called
+ end
+
+ it "supports declaring variables in the case target expression" do
+ def test(v)
+ case new_variable_in_expression = v
+ when true
+ # This extra block is a test that `new_variable_in_expression` is declared outside of it and not inside
+ self.then { new_variable_in_expression }
+ else
+ # Same
+ self.then { new_variable_in_expression.casecmp?("foo") }
+ end
+ end
+
+ self.test("bar").should == false
+ self.test(true).should == true
+ end
+
+ ruby_version_is ""..."3.4" do
+ it "warns if there are identical when clauses" do
+ -> {
+ eval <<~RUBY
+ case 1
+ when 2
+ :foo
+ when 2
+ :bar
+ end
+ RUBY
+ }.should complain(/warning: (duplicated .when' clause with line \d+ is ignored|'when' clause on line \d+ duplicates 'when' clause on line \d+ and is ignored)/, verbose: true)
+ end
+ end
+
+ ruby_version_is "3.4" do
+ it "warns if there are identical when clauses" do
+ -> {
+ eval <<~RUBY
+ case 1
+ when 2
+ :foo
+ when 2
+ :bar
+ end
+ RUBY
+ }.should complain(/warning: 'when' clause on line \d+ duplicates 'when' clause on line \d+ and is ignored/, verbose: true)
+ end
+ end
+end
+
+describe "The 'case'-construct with no target expression" do
+ it "evaluates the body of the first clause when at least one of its condition expressions is true" do
+ case
+ when true, false; 'foo'
+ end.should == 'foo'
+ end
+
+ it "evaluates the body of the first when clause that is not false/nil" do
+ case
+ when false; 'foo'
+ when 2; 'bar'
+ when 1 == 1; 'baz'
+ end.should == 'bar'
+
+ case
+ when false; 'foo'
+ when nil; 'foo'
+ when 1 == 1; 'bar'
+ end.should == 'bar'
+ end
+
+ it "evaluates the body of the else clause if all when clauses are false/nil" do
+ case
+ when false; 'foo'
+ when nil; 'foo'
+ when 1 == 2; 'bar'
+ else 'baz'
+ end.should == 'baz'
+ end
+
+ it "evaluates multiple conditional expressions as a boolean disjunction" do
+ case
+ when true, false; 'foo'
+ else 'bar'
+ end.should == 'foo'
+
+ case
+ when false, true; 'foo'
+ else 'bar'
+ end.should == 'foo'
+ end
+
+ # Homogeneous cases are often optimized to avoid === using a jump table, and should be tested separately.
+ # See https://github.com/jruby/jruby/issues/6440
+ it "handles homogeneous cases" do
+ case
+ when 1; 'foo'
+ when 2; 'bar'
+ end.should == 'foo'
+ end
+
+ it "expands arrays to lists of values" do
+ case
+ when *[false]
+ "foo"
+ when *[true]
+ "bar"
+ end.should == "bar"
+ end
+end
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