4 files changed, 125 insertions, 2 deletions

diff --git a/spec/03-environment_spec.lua b/spec/03-environment_spec.lua
index 842ed6f..96f4a78 100644
--- a/spec/03-environment_spec.lua
+++ b/spec/03-environment_spec.lua
@@ -1,5 +1,6 @@
 -- Import the library that contains the environment-related functions
 local system = require("system")
+require("spec.helpers")
 
 describe("Environment Variables:", function()
 
@@ -11,9 +12,8 @@ describe("Environment Variables:", function()
     end)
 
 
-    local func = system.windows and pending or it --pending on Windows
     -- Windows will unset a variable if set as an empty string
-    func("should set an empty environment variable value", function()
+    nix_it("should set an empty environment variable value", function()
       assert.is_true(system.setenv("TEST_VAR", ""))
       assert.is_equal("", system.getenv("TEST_VAR"))
     end)
diff --git a/spec/04-term_helper.lua b/spec/04-term_helper.lua
new file mode 100644
index 0000000..7fd39d2
--- /dev/null
+++ b/spec/04-term_helper.lua
@@ -0,0 +1,13 @@
+-- sub-script executed for isatty test
+local writefile = require("pl.utils").writefile
+local isatty = require("system").isatty
+assert(arg[1] == "--", "missing -- argument")
+local tempfile = assert(arg[2], "missing tempfile argument")
+
+-- print("my temp file: ", tempfile)
+
+assert(writefile(tempfile, [[{
+  stdin = ]]..tostring(isatty(io.stdin))..[[,
+  stdout = ]]..tostring(isatty(io.stdout))..[[,
+  stderr = ]]..tostring(isatty(io.stderr))..[[,
+}]]))
diff --git a/spec/04-term_spec.lua b/spec/04-term_spec.lua
new file mode 100644
index 0000000..a2034aa
--- /dev/null
+++ b/spec/04-term_spec.lua
@@ -0,0 +1,94 @@
+-- Import the library that contains the environment-related functions
+local system = require("system")
+require("spec.helpers")
+
+describe("Terminal:", function()
+
+  describe("isatty()", function()
+
+    local newtmpfile = require("pl.path").tmpname
+
+    -- set each param to true to make it a tty, to false for a stream
+    local function getttyresults(sin, sout, serr)
+      assert(type(sin) == "boolean", "sin must be a boolean")
+      assert(type(sout) == "boolean", "sout must be a boolean")
+      assert(type(serr) == "boolean", "serr must be a boolean")
+
+      local tmpfile = "./spec/04-term_helper.output"
+      local execcmd = "lua ./spec/04-term_helper.lua -- " .. tmpfile
+
+      sin = sin and "" or 'echo "hello" | '
+      if system.windows then
+        sout = sout and "" or (" > " .. newtmpfile())
+        serr = serr and "" or (" 2> " .. newtmpfile())
+      else
+        sout = sout and "" or (" > " .. newtmpfile())
+        serr = serr and "" or (" 2> " .. newtmpfile())
+      end
+
+      local cmd = sin .. execcmd .. sout .. serr
+
+      -- print("cmd: ", cmd)
+
+      os.remove(tmpfile)
+      assert(os.execute(cmd))
+      local result = assert(require("pl.utils").readfile(tmpfile))
+      os.remove(tmpfile)
+
+      -- print("result: ", result)
+
+      return assert(require("pl.compat").load("return " .. result))()
+    end
+
+
+
+    it("returns true for all if a terminal #manual", function()
+      assert.are.same(
+        {
+          stdin = true,
+          stdout = true,
+          stderr = true,
+        },
+        getttyresults(true, true, true)
+      )
+    end)
+
+
+    it("returns false for stdin if not a terminal #manual", function()
+      assert.are.same(
+        {
+          stdin = false,
+          stdout = true,
+          stderr = true,
+        },
+        getttyresults(false, true, true)
+      )
+    end)
+
+
+    it("returns false for stdout if not a terminal #manual", function()
+      assert.are.same(
+        {
+          stdin = true,
+          stdout = false,
+          stderr = true,
+        },
+        getttyresults(true, false, true)
+      )
+    end)
+
+
+    it("returns false for stderr if not a terminal #manual", function()
+      assert.are.same(
+        {
+          stdin = true,
+          stdout = true,
+          stderr = false,
+        },
+        getttyresults(true, true, false)
+      )
+    end)
+
+  end)
+
+end)
diff --git a/spec/helpers.lua b/spec/helpers.lua
new file mode 100644
index 0000000..8f766e7
--- /dev/null
+++ b/spec/helpers.lua
@@ -0,0 +1,16 @@
+local busted = require("busted")
+
+local function is_windows()
+  return package.config:sub(1,1) == "\\"
+end
+
+local function postfixer(postfix)
+  return function(description, ...)
+    return busted.pending(description.." ["..postfix.."]", ...)
+  end
+end
+
+-- win_it only executes on Windows, and is "pending" otherwise
+win_it = is_windows() and busted.it or postfixer("Windows only")
+-- nix_it only executes on Unix/Mac, and is "pending" otherwise
+nix_it = is_windows() and postfixer("Unix/Mac only") or busted.it