Regex start of string and end of string; lstrip/rstrip

rubys · rubys · commit 05c8897466c9 · 2019-09-05T13:34:17.000-04:00
diff --git a/README.md b/README.md
@@ -236,6 +236,7 @@ the script.
     * `.keys` becomes `Object.keys()`
     * `.last` becomes `[*.length-1]`
     * `.last(n)` becomes `.slice(*.length-1, *.length)`
+    * `.lstrip` becomes `.replace(/^\s+/, "")`
     * `.max` becomes `Math.max.apply(Math)`
     * `.merge` becomes `Object.assign({}, ...)`
     * `.merge!` becomes `Object.assign()`
@@ -245,6 +246,7 @@ the script.
     * `puts` becomes `console.log`
     * `.replace` becomes `.length = 0; ...push.apply(*)`
     * `.respond_to?` becomes `right in left`
+    * `.rstrip` becomes `.replace(/s+$/, "")`
     * `.scan` becomes `.match(//g)`
     * `.start_with?` becomes `.substring(0, arg.length) == arg`
     * `.upto(lim)` becomes `for (var i=num; i<=lim; i+=1)`
diff --git a/lib/ruby2js/converter/regexp.rb b/lib/ruby2js/converter/regexp.rb
@@ -27,12 +27,23 @@ class Converter
         end
       end
 
+      # in Ruby regular expressions, ^ and $ apply to each line
       if parts.first.type == :str and parts.first.children[0].start_with?('^')
         opts = opts + [:m] unless opts.include? :m or opts.include? 'm'
       elsif parts.last.type == :str and parts.last.children[0].end_with?('$')
         opts = opts + [:m] unless opts.include? :m or opts.include? 'm'
       end
 
+      if parts.first.type == :str and parts.first.children[0].start_with?('\A')
+        parts = [s(:str, parts.first.children[0].sub('\A', '^'))] +
+          parts[1..-1]
+      end
+
+      if parts.last.type == :str and parts.last.children[0].end_with?('\z')
+        parts = parts[0..-2] +
+          [s(:str, parts.first.children[0].sub(/\\z\z/, '$'))]
+      end
+
       # use slash syntax if there are few embedded slashes in the regexp
       if parts.all? {|part| part.type == :str}
         str = parts.map {|part| part.children.first}.join
diff --git a/lib/ruby2js/filter/functions.rb b/lib/ruby2js/filter/functions.rb
@@ -417,11 +417,21 @@ def on_send(node)
           process node.updated(nil, [s(:const, nil, :Object), :fromEntries,
             target])
 
-        elsif es2019 and method==:rstrip
-          process node.updated(nil, [target, :trimStart, *args])
+        elsif method==:rstrip
+          if es2019
+            process node.updated(nil, [target, :trimEnd, *args])
+          else
+            node.updated(nil, [process(target), :replace,
+              s(:regexp, s(:str, '\s+\z') , s(:regopt)), s(:str, '')])
+          end
 
-        elsif es2019 and method==:lstrip
-          process node.updated(nil, [target, :trimEnd, *args])
+        elsif method==:lstrip and args.length == 0
+          if es2019
+            process s(:send, target, :trimStart)
+          else
+            node.updated(nil, [process(target), :replace,
+              s(:regexp, s(:str, '\A\s+') , s(:regopt)), s(:str, '')])
+          end
 
         elsif method == :class and args.length==0 and not node.is_method?
           process node.updated(:attr, [target, :constructor])
diff --git a/spec/es2019_spec.rb b/spec/es2019_spec.rb
@@ -33,11 +33,11 @@ def to_js_fn(string)
 
   describe :String do
     it "should handle lstrip" do
-      to_js_fn( 'a.lstrip()' ).must_equal 'a.trimEnd()'
+      to_js_fn( 'a.lstrip()' ).must_equal 'a.trimStart()'
     end
 
     it "should handle rstrip" do
-      to_js_fn( 'a.rstrip()' ).must_equal 'a.trimStart()'
+      to_js_fn( 'a.rstrip()' ).must_equal 'a.trimEnd()'
     end
   end
 end
diff --git a/spec/functions_spec.rb b/spec/functions_spec.rb
@@ -145,9 +145,11 @@ def to_js(string)
       to_js( 'x.end_with?("z")' ).must_equal 'x.slice(-1) == "z"'
     end
 
-    it 'should handle strip' do
+    it 'should handle strip/lstrip/rstrip' do
       to_js( 'x.strip()' ).must_equal 'x.trim()'
       to_js( 'x.strip' ).must_equal 'x.trim()'
+      to_js( 'a.lstrip()' ).must_equal 'a.replace(/^\s+/, "")'
+      to_js( 'a.rstrip()' ).must_equal 'a.replace(/\s+$/, "")'
     end
 
     it 'should handle string multiply' do
diff --git a/spec/transliteration_spec.rb b/spec/transliteration_spec.rb
@@ -963,6 +963,12 @@ def to_js( string, opts={} )
       to_js( "/^./m" ).must_equal '/^./m'
       to_js( "Regexp.new('^$', 'm')" ).must_equal '/^$/m'
     end
+
+    it "should treat \A and \z as singleline" do
+      to_js( '/\A./' ).must_equal '/^./'
+      to_js( '/.\z/' ).must_equal '/.$/'
+      to_js( "Regexp.new(#{'\A\z'.inspect})" ).must_equal '/^$/'
+    end
   end
 
   describe "exceptions" do
