working setenv/unsetenv + tests

need to be implemented for Windows too

t/CMDTEST_setenv.rb

@@ -0,0 +1,83 @@
+require "selftest_utils"
+
+class CMDTEST_setenv < Cmdtest::Testcase
+
+  include SelftestUtils
+
+  #-----------------------------------
+
+  def test_setenv
+    #----------
+    create_CMDTEST_foo [
+      'cmd "env | grep TESTVAR1" do',
+      '  exit_nonzero', # no match in grep
+      'end',
+    ]
+    cmd_cmdtest do
+      comment "TESTVAR1 not set"
+      stdout_equal [
+        "### env | grep TESTVAR1",
+      ]
+    end
+
+    #----------
+    create_CMDTEST_foo [
+      'setenv "TESTVAR1", "123456"',
+      'cmd "env | grep TESTVAR1" do',
+      '  stdout_equal "TESTVAR1=123456\\n"',
+      'end',
+    ]
+    cmd_cmdtest do
+      comment "TESTVAR1 set by setenv"
+      stdout_equal [
+        "### env | grep TESTVAR1",
+      ]
+    end
+
+    cmd("env | grep TESTVAR1") do
+      comment "TESTVAR1 still unset on level1"
+      exit_nonzero # no match in grep
+    end
+  end
+
+  #-----------------------------------
+
+  def test_unsetenv
+    ENV['TESTVAR2'] = '987654'
+    #----------
+    create_CMDTEST_foo [
+      'cmd "env | grep TESTVAR2" do',
+      '  stdout_equal "TESTVAR2=987654\\n"',
+      'end',
+    ]
+    cmd_cmdtest do
+      comment "TESTVAR2 set from start"
+      stdout_equal [
+        "### env | grep TESTVAR2",
+      ]
+    end
+
+    #----------
+    create_CMDTEST_foo [
+      'unsetenv "TESTVAR2"',
+      'cmd "env | grep TESTVAR2" do',
+      '  exit_nonzero', # no match in grep
+      'end',
+    ]
+    cmd_cmdtest do
+      comment "TESTVAR2 unset by unsetenv"
+      stdout_equal [
+        "### env | grep TESTVAR2",
+      ]
+    end
+
+    cmd("env | grep TESTVAR2") do
+      comment "TESTVAR2 still set on level1"
+      stdout_equal [
+        "TESTVAR2=987654",
+      ]
+    end
+  end
+
+end
+