Support selector for String#strip family.

Author: ksss

core/string.rbs

@@ -3665,7 +3665,7 @@ class String
   # Related: see [Converting to New
   # String](rdoc-ref:String@Converting+to+New+String).
   #
-  def lstrip: () -> String
+  def lstrip: (*selector) -> String
 
   # <!--
   #   rdoc-file=string.c
@@ -3678,7 +3678,7 @@ class String
   #
   # Related: see [Modifying](rdoc-ref:String@Modifying).
   #
-  def lstrip!: () -> self?
+  def lstrip!: (*selector) -> self?
 
   # <!--
   #   rdoc-file=string.c
@@ -4191,7 +4191,7 @@ class String
   # Related: see [Converting to New
   # String](rdoc-ref:String@Converting+to+New+String).
   #
-  def rstrip: () -> String
+  def rstrip: (*selector) -> String
 
   # <!--
   #   rdoc-file=string.c
@@ -4204,7 +4204,7 @@ class String
   #
   # Related: see [Modifying](rdoc-ref:String@Modifying).
   #
-  def rstrip!: () -> self?
+  def rstrip!: (*selector) -> self?
 
   # <!--
   #   rdoc-file=string.c
@@ -4677,7 +4677,7 @@ class String
   # Related: see [Converting to New
   # String](rdoc-ref:String@Converting+to+New+String).
   #
-  def strip: () -> String
+  def strip: (*selector) -> String
 
   # <!--
   #   rdoc-file=string.c
@@ -4690,7 +4690,7 @@ class String
   #
   # Related: see [Modifying](rdoc-ref:String@Modifying).
   #
-  def strip!: () -> self?
+  def strip!: (*selector) -> self?
 
   # <!--
   #   rdoc-file=string.c

test/stdlib/String_test.rb

@@ -1099,13 +1099,27 @@ def test_lstrip
                       ' hello', :lstrip
     assert_send_type  '() -> String',
                       'hello', :lstrip
+
+    if_ruby("4.0"...) do
+      with_string "0-9" do |selector|
+        assert_send_type  '(String::selector) -> String',
+                          "01234abc56789", :lstrip, selector
+      end
+    end
   end
 
   def test_lstrip!
     assert_send_type  '() -> String',
                       +' hello', :lstrip!
     assert_send_type  '() -> nil',
                       +'hello', :lstrip!
+
+    if_ruby("4.0"...) do
+      with_string "0-9" do |selector|
+        assert_send_type  '(String::selector) -> String',
+                          "01234abc56789", :lstrip!, selector
+      end
+    end
   end
 
   def test_match
@@ -1252,13 +1266,27 @@ def test_rstrip
                       'hello ', :rstrip
     assert_send_type  '() -> String',
                       'hello', :rstrip
+
+    if_ruby("4.0"...) do
+      with_string "0-9" do |selector|
+        assert_send_type '(String::selector) -> String',
+                         "01234abc56789", :rstrip, selector
+      end
+    end
   end
 
   def test_rstrip!
     assert_send_type  '() -> String',
                       +'hello ', :rstrip!
     assert_send_type  '() -> nil',
                       +'hello', :rstrip!
+
+    if_ruby("4.0"...) do
+      with_string "0-9" do |selector|
+        assert_send_type '(String::selector) -> String',
+                         "01234abc56789", :rstrip!, selector
+      end
+    end
   end
 
   def test_scan
@@ -1491,13 +1519,27 @@ def test_strip
                       ' hello ', :strip
     assert_send_type  '() -> String',
                       'hello', :strip
+
+    if_ruby("4.0"...) do
+      with_string "0-9" do |selector|
+        assert_send_type '(String::selector) -> String',
+                         "01234abc56789", :strip, selector
+      end
+    end
   end
 
   def test_strip!
     assert_send_type  '() -> String',
                       ' hello ', :strip!
     assert_send_type  '() -> nil',
                       'hello', :strip!
+
+    if_ruby("4.0"...) do
+      with_string "0-9" do |selector|
+        assert_send_type '(String::selector) -> String',
+                         "01234abc56789", :strip!, selector
+      end
+    end
   end
 
   def test_sub