ruby.h: fix rb_scan_args_trail_idx

* include/ruby/ruby.h (rb_scan_args_trail_idx): fix the case both
  of optional and rest arguments are defined.
  [ruby-core:82427] [Bug #13830]

* include/ruby/ruby.h (rb_scan_args_n_trail): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59624 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/-test-/scan_args/extconf.rb

@@ -0,0 +1 @@
+create_makefile("-test-/scan_args")

ext/-test-/scan_args/scan_args.c

@@ -0,0 +1,286 @@
+#include <ruby.h>
+
+#ifndef numberof
+#define numberof(array) (int)(sizeof(array) / sizeof((array)[0]))
+#endif
+
+static VALUE
+scan_args_lead(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[2];
+    int n = rb_scan_args(argc, argv, "1", args+1);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_opt(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[2];
+    int n = rb_scan_args(argc, argv, "01", args+1);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_opt(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n = rb_scan_args(argc, argv, "11", args+1, args+2);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+/* var */
+static VALUE
+scan_args_var(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[2];
+    int n = rb_scan_args(argc, argv, "*", args+1);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_var(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n = rb_scan_args(argc, argv, "1*", args+1, args+2);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_opt_var(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n = rb_scan_args(argc, argv, "01*", args+1, args+2);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_opt_var(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "11*", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+/* trail */
+static VALUE
+scan_args_opt_trail(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n = rb_scan_args(argc, argv, "011", args+1, args+2);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_opt_trail(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "111", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_var_trail(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n = rb_scan_args(argc, argv, "*1", args+1, args+2);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_var_trail(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "1*1", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_opt_var_trail(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "01*1", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_opt_var_trail(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[5];
+    int n = rb_scan_args(argc, argv, "11*1", args+1, args+2, args+3, args+4);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+/* hash */
+static VALUE
+scan_args_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[2];
+    int n = rb_scan_args(argc, argv, ":", args+1);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n = rb_scan_args(argc, argv, "1:", args+1, args+2);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_opt_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n = rb_scan_args(argc, argv, "01:", args+1, args+2);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_opt_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "11:", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_var_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n = rb_scan_args(argc, argv, "*:", args+1, args+2);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_var_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "1*:", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_opt_var_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "01*:", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_opt_var_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[5];
+    int n = rb_scan_args(argc, argv, "11*:", args+1, args+2, args+3, args+4);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_opt_trail_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "011:", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_opt_trail_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[5];
+    int n = rb_scan_args(argc, argv, "111:", args+1, args+2, args+3, args+4);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_var_trail_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[4];
+    int n = rb_scan_args(argc, argv, "*1:", args+1, args+2, args+3);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_var_trail_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[5];
+    int n = rb_scan_args(argc, argv, "1*1:", args+1, args+2, args+3, args+4);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_opt_var_trail_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[5];
+    int n = rb_scan_args(argc, argv, "01*1:", args+1, args+2, args+3, args+4);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+static VALUE
+scan_args_lead_opt_var_trail_hash(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[6];
+    int n = rb_scan_args(argc, argv, "11*1:", args+1, args+2, args+3, args+4, args+5);
+    args[0] = INT2NUM(n);
+    return rb_ary_new_from_values(numberof(args), args);
+}
+
+void
+Init_scan_args(void)
+{
+    VALUE module = rb_define_module("Bug");
+    module = rb_define_module_under(module, "ScanArgs");
+    rb_define_singleton_method(module, "lead", scan_args_lead, -1);
+    rb_define_singleton_method(module, "opt", scan_args_opt, -1);
+    rb_define_singleton_method(module, "lead_opt", scan_args_lead_opt, -1);
+    rb_define_singleton_method(module, "var", scan_args_var, -1);
+    rb_define_singleton_method(module, "lead_var", scan_args_lead_var, -1);
+    rb_define_singleton_method(module, "opt_var", scan_args_opt_var, -1);
+    rb_define_singleton_method(module, "lead_opt_var", scan_args_lead_opt_var, -1);
+    rb_define_singleton_method(module, "opt_trail", scan_args_opt_trail, -1);
+    rb_define_singleton_method(module, "lead_opt_trail", scan_args_lead_opt_trail, -1);
+    rb_define_singleton_method(module, "var_trail", scan_args_var_trail, -1);
+    rb_define_singleton_method(module, "lead_var_trail", scan_args_lead_var_trail, -1);
+    rb_define_singleton_method(module, "opt_var_trail", scan_args_opt_var_trail, -1);
+    rb_define_singleton_method(module, "lead_opt_var_trail", scan_args_lead_opt_var_trail, -1);
+    rb_define_singleton_method(module, "hash", scan_args_hash, -1);
+    rb_define_singleton_method(module, "lead_hash", scan_args_lead_hash, -1);
+    rb_define_singleton_method(module, "opt_hash", scan_args_opt_hash, -1);
+    rb_define_singleton_method(module, "lead_opt_hash", scan_args_lead_opt_hash, -1);
+    rb_define_singleton_method(module, "var_hash", scan_args_var_hash, -1);
+    rb_define_singleton_method(module, "lead_var_hash", scan_args_lead_var_hash, -1);
+    rb_define_singleton_method(module, "opt_var_hash", scan_args_opt_var_hash, -1);
+    rb_define_singleton_method(module, "lead_opt_var_hash", scan_args_lead_opt_var_hash, -1);
+    rb_define_singleton_method(module, "opt_trail_hash", scan_args_opt_trail_hash, -1);
+    rb_define_singleton_method(module, "lead_opt_trail_hash", scan_args_lead_opt_trail_hash, -1);
+    rb_define_singleton_method(module, "var_trail_hash", scan_args_var_trail_hash, -1);
+    rb_define_singleton_method(module, "lead_var_trail_hash", scan_args_lead_var_trail_hash, -1);
+    rb_define_singleton_method(module, "opt_var_trail_hash", scan_args_opt_var_trail_hash, -1);
+    rb_define_singleton_method(module, "lead_opt_var_trail_hash", scan_args_lead_opt_var_trail_hash, -1);
+}
+

include/ruby/ruby.h

@@ -2279,29 +2279,16 @@ ALWAYS_INLINE(static int rb_scan_args_trail_idx(const char *fmt));
 static inline int
 rb_scan_args_trail_idx(const char *fmt)
 {
-    return (rb_scan_args_lead_p(fmt) ?
+    const int idx = rb_scan_args_var_idx(fmt);
-	    (rb_scan_args_isdigit(fmt[1]) || fmt[1]=='*')+1 :
+    return idx+(fmt[idx]=='*');
-	    (fmt[0]=='*'));
-}
-
-ALWAYS_INLINE(static int rb_scan_args_trail_p(const char *fmt));
-static inline int
-rb_scan_args_trail_p(const char *fmt)
-{
-    return (rb_scan_args_lead_p(fmt) ?
-	    (rb_scan_args_isdigit(fmt[1]) || fmt[1]=='*') &&
-	    rb_scan_args_isdigit(fmt[2]) :
-	    fmt[0]=='*' && rb_scan_args_isdigit(fmt[1]));
 }
 
 ALWAYS_INLINE(static int rb_scan_args_n_trail(const char *fmt));
 static inline int
 rb_scan_args_n_trail(const char *fmt)
 {
-    return (rb_scan_args_lead_p(fmt) ?
+    const int idx = rb_scan_args_trail_idx(fmt);
-	    ((rb_scan_args_isdigit(fmt[1]) || fmt[1]=='*') &&
+    return (rb_scan_args_isdigit(fmt[idx]) ? fmt[idx]-'0' : 0);
-	     rb_scan_args_isdigit(fmt[2]) ? fmt[2]-'0' : 0) :
-	    (fmt[0]=='*' && rb_scan_args_isdigit(fmt[1]) ? fmt[1]-'0' : 0));
 }
 
 ALWAYS_INLINE(static int rb_scan_args_hash_idx(const char *fmt));

test/-ext-/test_scan_args.rb

@@ -0,0 +1,219 @@
+require 'test/unit'
+require '-test-/scan_args'
+
+class TestScanArgs < Test::Unit::TestCase
+  def test_lead
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead()}
+    assert_equal([1, "a"], Bug::ScanArgs.lead("a"))
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead("a", "b")}
+  end
+
+  def test_opt
+    assert_equal([0, nil], Bug::ScanArgs.opt())
+    assert_equal([1, "a"], Bug::ScanArgs.opt("a"))
+    assert_raise(ArgumentError) {Bug::ScanArgs.opt("a", "b")}
+  end
+
+  def test_lead_opt
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt()}
+    assert_equal([1, "a", nil], Bug::ScanArgs.lead_opt("a"))
+    assert_equal([2, "a", "b"], Bug::ScanArgs.lead_opt("a", "b"))
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt("a", "b", "c")}
+  end
+
+  def test_var
+    assert_equal([0, []], Bug::ScanArgs.var())
+    assert_equal([3, ["a", "b", "c"]], Bug::ScanArgs.var("a", "b", "c"))
+  end
+
+  def test_lead_var
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_var()}
+    assert_equal([3, "a", ["b", "c"]], Bug::ScanArgs.lead_var("a", "b", "c"))
+  end
+
+  def test_opt_var
+    assert_equal([0, nil, []], Bug::ScanArgs.opt_var())
+    assert_equal([3, "a", ["b", "c"]], Bug::ScanArgs.opt_var("a", "b", "c"))
+  end
+
+  def test_lead_opt_var
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_var()}
+    assert_equal([3, "a", "b", ["c"]], Bug::ScanArgs.lead_opt_var("a", "b", "c"))
+  end
+
+  def test_opt_trail
+    assert_raise(ArgumentError) {Bug::ScanArgs.opt_trail()}
+    assert_equal([2, "a", "b"], Bug::ScanArgs.opt_trail("a", "b"))
+    assert_equal([1, nil, "a"], Bug::ScanArgs.opt_trail("a"))
+    assert_raise(ArgumentError) {Bug::ScanArgs.opt_trail("a", "b", "c")}
+  end
+
+  def test_lead_opt_trail
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_trail()}
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_trail("a")}
+    assert_equal([2, "a", nil, "b"], Bug::ScanArgs.lead_opt_trail("a", "b"))
+    assert_equal([3, "a", "b", "c"], Bug::ScanArgs.lead_opt_trail("a", "b", "c"))
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_trail("a", "b", "c", "d")}
+  end
+
+  def test_var_trail
+    assert_raise(ArgumentError) {Bug::ScanArgs.var_trail()}
+    assert_equal([1, [], "a"], Bug::ScanArgs.var_trail("a"))
+    assert_equal([2, ["a"], "b"], Bug::ScanArgs.var_trail("a", "b"))
+  end
+
+  def test_lead_var_trail
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_var_trail("a")}
+    assert_equal([2, "a", [], "b"], Bug::ScanArgs.lead_var_trail("a", "b"))
+    assert_equal([3, "a", ["b"], "c"], Bug::ScanArgs.lead_var_trail("a", "b", "c"))
+  end
+
+  def test_opt_var_trail
+    assert_raise(ArgumentError) {Bug::ScanArgs.opt_var_trail()}
+    assert_equal([1, nil, [], "a"], Bug::ScanArgs.opt_var_trail("a"))
+    assert_equal([2, "a", [], "b"], Bug::ScanArgs.opt_var_trail("a", "b"))
+    assert_equal([3, "a", ["b"], "c"], Bug::ScanArgs.opt_var_trail("a", "b", "c"))
+  end
+
+  def test_lead_opt_var_trail
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_var_trail("a")}
+    assert_equal([2, "a", nil, [], "b"], Bug::ScanArgs.lead_opt_var_trail("a", "b"))
+    assert_equal([3, "a", "b", [], "c"], Bug::ScanArgs.lead_opt_var_trail("a", "b", "c"))
+    assert_equal([4, "a", "b", ["c"], "d"], Bug::ScanArgs.lead_opt_var_trail("a", "b", "c", "d"))
+  end
+
+  def test_hash
+    assert_equal([0, nil], Bug::ScanArgs.hash())
+    assert_raise(ArgumentError) {Bug::ScanArgs.hash("a")}
+    assert_equal([0, {a: 0}], Bug::ScanArgs.hash(a: 0))
+  end
+
+  def test_lead_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_hash()}
+    assert_equal([1, "a", nil], Bug::ScanArgs.lead_hash("a"))
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_hash("a", "b")}
+    assert_equal([1, "a", {b: 1}], Bug::ScanArgs.lead_hash("a", b: 1))
+    assert_equal([1, {b: 1}, nil], Bug::ScanArgs.lead_hash(b: 1))
+  end
+
+  def test_opt_hash
+    assert_equal([0, nil, nil], Bug::ScanArgs.opt_hash())
+    assert_equal([1, "a", nil], Bug::ScanArgs.opt_hash("a"))
+    assert_equal([0, nil, {b: 1}], Bug::ScanArgs.opt_hash(b: 1))
+    assert_equal([1, "a", {b: 1}], Bug::ScanArgs.opt_hash("a", b: 1))
+    assert_raise(ArgumentError) {Bug::ScanArgs.opt_hash("a", "b")}
+  end
+
+  def test_lead_opt_hash
+    assert_equal([1, "a", nil, nil], Bug::ScanArgs.lead_opt_hash("a"))
+    assert_equal([2, "a", "b", nil], Bug::ScanArgs.lead_opt_hash("a", "b"))
+    assert_equal([1, "a", nil, {c: 1}], Bug::ScanArgs.lead_opt_hash("a", c: 1))
+    assert_equal([2, "a", "b", {c: 1}], Bug::ScanArgs.lead_opt_hash("a", "b", c: 1))
+    assert_equal([1, {c: 1}, nil, nil], Bug::ScanArgs.lead_opt_hash(c: 1))
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_hash("a", "b", "c")}
+  end
+
+  def test_var_hash
+    assert_equal([0, [], nil], Bug::ScanArgs.var_hash())
+    assert_equal([1, ["a"], nil], Bug::ScanArgs.var_hash("a"))
+    assert_equal([1, ["a"], {b: 1}], Bug::ScanArgs.var_hash("a", b: 1))
+    assert_equal([0, [], {b: 1}], Bug::ScanArgs.var_hash(b: 1))
+  end
+
+  def test_lead_var_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_var_hash()}
+    assert_equal([1, "a", [], nil], Bug::ScanArgs.lead_var_hash("a"))
+    assert_equal([2, "a", ["b"], nil], Bug::ScanArgs.lead_var_hash("a", "b"))
+    assert_equal([2, "a", ["b"], {c: 1}], Bug::ScanArgs.lead_var_hash("a", "b", c: 1))
+    assert_equal([1, "a", [], {c: 1}], Bug::ScanArgs.lead_var_hash("a", c: 1))
+    assert_equal([1, {c: 1}, [], nil], Bug::ScanArgs.lead_var_hash(c: 1))
+    assert_equal([3, "a", ["b", "c"], nil], Bug::ScanArgs.lead_var_hash("a", "b", "c"))
+  end
+
+  def test_opt_var_hash
+    assert_equal([0, nil, [], nil], Bug::ScanArgs.opt_var_hash())
+    assert_equal([1, "a", [], nil], Bug::ScanArgs.opt_var_hash("a"))
+    assert_equal([2, "a", ["b"], nil], Bug::ScanArgs.opt_var_hash("a", "b"))
+    assert_equal([2, "a", ["b"], {c: 1}], Bug::ScanArgs.opt_var_hash("a", "b", c: 1))
+    assert_equal([1, "a", [], {c: 1}], Bug::ScanArgs.opt_var_hash("a", c: 1))
+    assert_equal([0, nil, [], {c: 1}], Bug::ScanArgs.opt_var_hash(c: 1))
+    assert_equal([3, "a", ["b", "c"], nil], Bug::ScanArgs.opt_var_hash("a", "b", "c"))
+  end
+
+  def test_lead_opt_var_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_var_hash()}
+    assert_equal([1, "a", nil, [], nil], Bug::ScanArgs.lead_opt_var_hash("a"))
+    assert_equal([2, "a", "b", [], nil], Bug::ScanArgs.lead_opt_var_hash("a", "b"))
+    assert_equal([2, "a", "b", [], {c: 1}], Bug::ScanArgs.lead_opt_var_hash("a", "b", c: 1))
+    assert_equal([1, "a", nil, [], {c: 1}], Bug::ScanArgs.lead_opt_var_hash("a", c: 1))
+    assert_equal([1, {c: 1}, nil, [], nil], Bug::ScanArgs.lead_opt_var_hash(c: 1))
+    assert_equal([3, "a", "b", ["c"], nil], Bug::ScanArgs.lead_opt_var_hash("a", "b", "c"))
+    assert_equal([3, "a", "b", ["c"], {d: 1}], Bug::ScanArgs.lead_opt_var_hash("a", "b", "c", d: 1))
+  end
+
+  def test_opt_trail_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.opt_trail_hash()}
+    assert_equal([1, nil, "a", nil], Bug::ScanArgs.opt_trail_hash("a"))
+    assert_equal([2, "a", "b", nil], Bug::ScanArgs.opt_trail_hash("a", "b"))
+    assert_equal([1, nil, "a", {c: 1}], Bug::ScanArgs.opt_trail_hash("a", c: 1))
+    assert_equal([2, "a", "b", {c: 1}], Bug::ScanArgs.opt_trail_hash("a", "b", c: 1))
+    assert_equal([1, nil, {c: 1}, nil], Bug::ScanArgs.opt_trail_hash(c: 1))
+    assert_raise(ArgumentError) {Bug::ScanArgs.opt_trail_hash("a", "b", "c")}
+  end
+
+  def test_lead_opt_trail_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_trail_hash()}
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_trail_hash("a")}
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_trail_hash(c: 1)}
+    assert_equal([2, "a", nil, "b", nil], Bug::ScanArgs.lead_opt_trail_hash("a", "b"))
+    assert_equal([2, "a", nil, {c: 1}, nil], Bug::ScanArgs.lead_opt_trail_hash("a", c: 1))
+    assert_equal([2, "a", nil, "b", {c: 1}], Bug::ScanArgs.lead_opt_trail_hash("a", "b", c: 1))
+    assert_equal([3, "a", "b", "c", nil], Bug::ScanArgs.lead_opt_trail_hash("a", "b", "c"))
+    assert_equal([3, "a", "b", "c", {c: 1}], Bug::ScanArgs.lead_opt_trail_hash("a", "b", "c", c: 1))
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_trail_hash("a", "b", "c", "d")}
+  end
+
+  def test_var_trail_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.var_trail_hash()}
+    assert_equal([1, [], "a", nil], Bug::ScanArgs.var_trail_hash("a"))
+    assert_equal([2, ["a"], "b", nil], Bug::ScanArgs.var_trail_hash("a", "b"))
+    assert_equal([1, [], "a", {c: 1}], Bug::ScanArgs.var_trail_hash("a", c: 1))
+    assert_equal([2, ["a"], "b", {c: 1}], Bug::ScanArgs.var_trail_hash("a", "b", c: 1))
+    assert_equal([1, [], {c: 1}, nil], Bug::ScanArgs.var_trail_hash(c: 1))
+    assert_equal([3, ["a", "b"], "c", nil], Bug::ScanArgs.var_trail_hash("a", "b", "c"))
+    assert_equal([3, ["a", "b"], "c", {c: 1}], Bug::ScanArgs.var_trail_hash("a", "b", "c", c: 1))
+  end
+
+  def test_lead_var_trail_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_var_trail_hash()}
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_var_trail_hash("a")}
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_var_trail_hash(c: 1)}
+    assert_equal([2, "a", [], {c: 1}, nil], Bug::ScanArgs.lead_var_trail_hash("a", c: 1))
+    assert_equal([2, "a", [], "b", nil], Bug::ScanArgs.lead_var_trail_hash("a", "b"))
+    assert_equal([2, "a", [], "b", {c: 1}], Bug::ScanArgs.lead_var_trail_hash("a", "b", c: 1))
+    assert_equal([3, "a", ["b"], "c", nil], Bug::ScanArgs.lead_var_trail_hash("a", "b", "c"))
+    assert_equal([3, "a", ["b"], "c", {c: 1}], Bug::ScanArgs.lead_var_trail_hash("a", "b", "c", c: 1))
+  end
+
+  def test_opt_var_trail_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.opt_var_trail_hash()}
+    assert_equal([1, nil, [], "a", nil], Bug::ScanArgs.opt_var_trail_hash("a"))
+    assert_equal([1, nil, [], {c: 1}, nil], Bug::ScanArgs.opt_var_trail_hash(c: 1))
+    assert_equal([1, nil, [], "a", {c: 1}], Bug::ScanArgs.opt_var_trail_hash("a", c: 1))
+    assert_equal([2, "a", [], "b", nil], Bug::ScanArgs.opt_var_trail_hash("a", "b"))
+    assert_equal([2, "a", [], "b", {c: 1}], Bug::ScanArgs.opt_var_trail_hash("a", "b", c: 1))
+    assert_equal([3, "a", ["b"], "c", nil], Bug::ScanArgs.opt_var_trail_hash("a", "b", "c"))
+    assert_equal([3, "a", ["b"], "c", {c: 1}], Bug::ScanArgs.opt_var_trail_hash("a", "b", "c", c: 1))
+  end
+
+  def test_lead_opt_var_trail_hash
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_var_trail_hash()}
+    assert_raise(ArgumentError) {Bug::ScanArgs.lead_opt_var_trail_hash("a")}
+    assert_equal([2, "a", nil, [], {b: 1}, nil], Bug::ScanArgs.lead_opt_var_trail_hash("a", b: 1))
+    assert_equal([2, "a", nil, [], "b", nil], Bug::ScanArgs.lead_opt_var_trail_hash("a", "b"))
+    assert_equal([2, "a", nil, [], "b", {c: 1}], Bug::ScanArgs.lead_opt_var_trail_hash("a", "b", c: 1))
+    assert_equal([3, "a", "b", [], "c", nil], Bug::ScanArgs.lead_opt_var_trail_hash("a", "b", "c"))
+    assert_equal([3, "a", "b", [], "c", {c: 1}], Bug::ScanArgs.lead_opt_var_trail_hash("a", "b", "c", c: 1))
+    assert_equal([4, "a", "b", ["c"], "d", nil], Bug::ScanArgs.lead_opt_var_trail_hash("a", "b", "c", "d"))
+  end
+end