Allow leading hyphen in switch values when specified with =

lib/thor/parser/options.rb

@@ -45,6 +45,7 @@ def initialize(hash_options = {}, defaults = {}, stop_on_unknown = false, disabl
       @switches = {}
       @extra = []
       @stopped_parsing_after_extra_index = nil
+      @force_current_to_be_value = false
 
       options.each do |option|
         @switches[option.switch_name] = option
@@ -74,8 +75,19 @@ def peek
       end
     end
 
+    def shift
+      @force_current_to_be_value = false
+      super
+    end
+
+    def unshift(arg, force_value: false)
+      @force_current_to_be_value = force_value
+      super(arg)
+    end
+
     def parse(args) # rubocop:disable MethodLength
       @pile = args.dup
+      @force_current_to_be_value = false
       @parsing_options = true
 
       while peek
@@ -88,7 +100,10 @@ def parse(args) # rubocop:disable MethodLength
             when SHORT_SQ_RE
               unshift($1.split("").map { |f| "-#{f}" })
               next
-            when EQ_RE, SHORT_NUM
+            when EQ_RE
+              unshift($2, force_value: true)
+              switch = $1
+            when SHORT_NUM
               unshift($2)
               switch = $1
             when LONG_RE, SHORT_RE
@@ -148,6 +163,7 @@ def assign_result!(option, result)
     # Two booleans are returned.  The first is true if the current value
     # starts with a hyphen; the second is true if it is a registered switch.
     def current_is_switch?
+      return [false, false] if @force_current_to_be_value
       case peek
       when LONG_RE, SHORT_RE, EQ_RE, SHORT_NUM
         [true, switch?($1)]
@@ -159,6 +175,7 @@ def current_is_switch?
     end
 
     def current_is_switch_formatted?
+      return false if @force_current_to_be_value
       case peek
       when LONG_RE, SHORT_RE, EQ_RE, SHORT_NUM, SHORT_SQ_RE
         true
@@ -168,6 +185,7 @@ def current_is_switch_formatted?
     end
 
     def current_is_value?
+      return true if @force_current_to_be_value
       peek && (!parsing_options? || super)
     end
 

spec/parser/options_spec.rb

@@ -263,6 +263,8 @@ def remaining
         expect(parse("-f=12")["foo"]).to eq("12")
         expect(parse("--foo=12")["foo"]).to eq("12")
         expect(parse("--foo=bar=baz")["foo"]).to eq("bar=baz")
+        expect(parse("--foo=-bar")["foo"]).to eq("-bar")
+        expect(parse("--foo=-bar -baz")["foo"]).to eq("-bar -baz")
       end
 
       it "must accept underscores switch=value assignment" do
@@ -398,6 +400,7 @@ def remaining
 
       it "accepts a switch=<value> assignment" do
         expect(parse("--attributes=name:string", "age:integer")["attributes"]).to eq("name" => "string", "age" => "integer")
+        expect(parse("--attributes=-name:string", "age:integer", "--gender:string")["attributes"]).to eq("-name" => "string", "age" => "integer")
       end
 
       it "accepts a switch <value> assignment" do
@@ -425,6 +428,7 @@ def remaining
 
       it "accepts a switch=<value> assignment" do
         expect(parse("--attributes=a", "b", "c")["attributes"]).to eq(%w(a b c))
+        expect(parse("--attributes=-a", "b", "-c")["attributes"]).to eq(%w(-a b))
       end
 
       it "accepts a switch <value> assignment" do